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Cataract Management Guideline Panel. Cataract in Adults: Management of Functional Impairment. Rockville (MD): Agency for Health Care Policy and Research (AHCPR); 1993 Feb. (AHCPR Clinical Practice Guidelines, No. 4.)

  • This publication is provided for historical reference only and the information may be out of date.

This publication is provided for historical reference only and the information may be out of date.

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Cataract in Adults: Management of Functional Impairment.

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Attachment 1. Algorithm

Algorithm Figure, part 1

Algorithm Figure, part 2

Annotation

[Algorithm, node [1]

Cataract evaluation and management should begin only when patients complain of a visual problem or impairment. Screening of asymptomatic patients for the presence of cataract is not appropriate. However, identifying an impairment in visual function during patient history and physical examination constitutes sound medical practice. Patients manifesting such an impairment should be referred for further evaluation and management, as appropriate.

[Algorithm, node [2]

Most elderly patients presenting with visual problems do not have a cataract that causes functional impairment. Refractive error, macular degeneration, and glaucoma are common alternative etiologies for visual impairment. For this reason, patients who present with new or recent visual impairment should receive a comprehensive eye examination. The management of patients with visual problems due to causes other than cataract is not addressed in this guideline.

Patients with decreasing vision who have had cataract surgery commonly are found to have posterior capsular opacification (PCO). Decisionmaking concerning the management of this condition parallels that for patients with cataract. Therefore, these two conditions are considered together in this algorithm.

[Algorithm, node [3]

Once cataract or PCO has been identified as the cause of visual disability, patients should be counseled concerning the nature of the problem, its natural history, and the existence of both surgical and nonsurgical approaches to management. Patients should be advised that the principal factor that should guide decisionmaking with regard to surgery is the extent to which the cataract or PCO impairs their ability to function in their daily lives. The ophthalmologist should discuss with patients whether and how their visual problem affects their ability to work, care for themselves (or others), drive a car, read, or engage in hobbies and favorite activities.

The degree of functional impairment reported by patients should be placed in the context of Snellen visual acuity, as obtained during the complete eye examination. As a general rule, the better the Snellen acuity is, the greater is the need for verification and documentation of functional disability. When best corrected visual acuity is 20/40 or better, the risk of surgery relative to its potential benefit becomes significant. Cataract surgery is often considered successful when acuity is restored to 20/40. Furthermore, this is the acuity required to obtain a driver's license in most States. For these reasons, patients with corrected visual acuity of 20/40 or better ordinarily should not be considered for surgery unless they report quite substantial functional impairment. These issues are discussed in Chapter 5.

Formal or objective tests other than visual acuity are discussed in Chapter 4. The panel did not find evidence in the literature to support the use of any of these tests for deciding on the appropriateness of surgery.

[Algorithm, nodes [4-5]

Patients who report little or no functional impairment should generally be reassured that the cataract or PCO is not serious. Patients who complain of mild to moderate limitation in activities due to a visual problem, those whose corrected acuities are near 20/40, and those who do not yet wish to undergo surgery may be offered nonsurgical measures for improving visual function. Such measures include the use of strong bifocals or magnifying glasses and pupillary dilatation. At times, reassurance is all that is needed.

[Algorithm, node [6]

Patients who complain of visual functional disability and whose best corrected visual acuity is 20/50 or worse can be considered for surgery unless visual and medical contraindications exist. Patients with contraindications to surgery should be managed using nonsurgical measures. This management may consist of counseling and reassurance because, in patients with medical contraindications to surgery, there may be no nonsurgical measures that can change the patient's visual status.

[Algorithm, node [7]

Patients with significant functional and visual impairment due to cataract or PCO who have no contraindications to surgery should be counseled concerning the expected risks and benefits of surgery and alternatives to surgery. These outcomes are discussed in Chapter 5 for cataract surgery and Chapter 8 for YAG capsulotomy for PCO. Patients with a cataract should be informed of the likelihood of developing PCO following surgery and the possible need for an additional surgical procedure to correct this problem. PCO is discussed in detail in Chapter 8.

The most significant determinant of the potential outcome of surgery is the presence or absence of concomitant eye disease. Patients with preexisting glaucoma or corneal disease or with a history of previous eye surgery are at substantially greater risk for adverse outcomes than are patients without these factors. These issues are discussed in Chapter 5. In situations where concomitant eye disease could complicate the cataract procedure, patients might, after counseling, prefer to postpone surgery and should be managed using nonsurgical measures.

[Algorithm, node [8]

Technical considerations concerning the surgical removal of cataracts, including setting, choice of procedure, choice of anesthetic, monitoring, and arrangements for postoperative care, are discussed in Chapters 3 and 5. Correction of functionally significant PCO is generally performed using a YAG laser. This surgical procedure and appropriate followup activities are discussed in Chapter 8.

[Algorithm, node [9]

Following surgery, the ophthalmologist must assess whether any complications have arisen that would preclude safe discharge of the patient. These complications, which include hyphema, uncontrolled elevated intraocular pressure, unstable vital signs, nausea, and significant pain, are discussed in Chapter 6. Patients manifesting complications should be managed appropriately and should not be discharged until the complications have been resolved.

[Algorithm, nodes [10-11]

The ophthalmologist who performs the surgery has an obligation to educate the patient in the important areas of postoperative care prior to discharge, as discussed in Chapter 6. These areas include signs or symptoms of possible complications, eye protection, activity level permitted, medications, required visits, and details of access to emergency care. The patient should receive written followup instructions prior to discharge. In addition, the availability of an escort and of a suitable supportive environment should be assured prior to discharge.

[Algorithm, node [12]

The operating ophthalmologist should evaluate the patient the day following surgery. The content of this examination and the recommended schedule for additional followup visits are listed in Chapters 3 and 6. The findings on this first-day postoperative visit will in part determine the level of followup intensity required.

[Algorithm, node [13]

The ophthalmologist determines during the first-day postoperative visit whether complications have occurred. Complications, which are discussed in Chapter 5, include hyphema, infection, wound dehiscence, endophthalmitis, and severe pain. At this visit the ophthalmologist initiates postoperative treatment.

[Algorithm, node [14]

Patients who do not have complications and who are at low risk for developing complications should receive high-quality standard followup care, as discussed in Chapter 5. The ophthalmologist who performed the surgery is at all times responsible for the postoperative followup of his or her patient. In order to fulfill these responsibilities, the surgeon must examine the patient periodically until confident that the patient has fully recovered from surgery. The surgeon may, however, choose to delegate or involve other providers in some portion of the followup care. Use of this team approach to followup care is appropriate, provided that the patient is fully informed about the followup arrangements and understands how postoperative care is to be provided (including what to do in an emergency) and all those involved in followup care have demonstrated their ability to provide high-quality care.

Patients who are at high risk for complications and patients who develop complications either immediately postoperatively or during the course of standard followup care should receive more intensive followup care tailored to the particular problem or condition identified. In addition, high-risk patients should be counseled concerning the various rehabilitation modalities available, as described in Chapter 7.

[Algorithm, nodes [17-19]

Patients who have undergone cataract surgery are at relatively high risk for developing PCO. Patients who develop PCO should be counseled concerning the nature of this condition and available management options. The decisionmaking process described in this algorithm should again be followed, beginning at node #3.

Attachment 2. Literature Review Evidence: Contrast Sensitivity Testing

  • Reference:
  • Hess and Woo, 1978.
  • Study Design:
  • Case series.
  • Patients:
  • 10 patients with uniocular senile cataract.
  • Type of Contrast Sensitivity Test:
  • Vertical sine wave gratings of variable frequency and contrast.
  • Severity and Type of Cataract:
  • Severity: not given.Type: cortical, nuclear cataracts included.
  • Type of Comorbid Ocular Pathology:
  • None present.
  • Preoperative Visual Acuity:
  • Not given; ratio of cataract to normal eye VA given.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: ratio of cataract to normal eye VA.
  • Findings:
  • A single family of visual loss functions could not describe results. Correlation between ratio of cataract to normal eye VA and ratio of cataract to normal eye low spatial frequency abnormality was 0.1 (p>0.2).
  • Comments:
  • Ratios may not be meaningful. Too few patients to adequately assess results.
  • Reference:
  • Elliott, Gilchrist, and Whitaker, 1989.
  • Study Design:
  • Case series.
  • Patients:
  • 18 patients, 39 eyes with cataracts;16 patients, 16 normal eyes.
  • Type of Contrast Sensitivity Test:
  • Contrast sensitivity described, not named.Glare described, not named.
  • Severity and Type of Cataract:
  • Severity: graded 1 to 5 (Oxford cataract classification and grading system).Type: nuclear, cortical, and subcapsular.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • LogMar VA -- 0.12 to 0.50.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: LogMar VA.
  • Findings:
  • For each type of cataract, as severity grade increased, CS significantly decreased for spatial frequencies >=2 c/deg.Moderate to high (r=0.44 to 1.0) correlations between CS and LogMar VA at >=2 c/deg.
  • Comments:
  • Confidence interval around correlation coefficients is wide because of small numbers in each subgroup. Subjects all had VA better than 20/200.
  • Reference:
  • Maudgal, Stout, and vanBalen, 1988.
  • Study Design:
  • Case series.
  • Patients:
  • 211 patients with ocular complaints; 24 of these had cataract.30 normals.
  • Type of Contrast Sensitivity Test:
  • VCTS.
  • Severity and Type of Cataract:
  • Not stated.
  • Type of Comorbid Ocular Pathology:
  • Glaucoma (other, not specified)).
  • Preoperative Visual Acuity:
  • Not given.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: clinical exam.
  • Findings:
  • Clinical Exam

    VCTSCataractNoneTotal
    Cataract193655
    None5151156
    Total24187211
    Sensitivity =19/24 = 79%
    Specificity =151/187 = 81%
    Prevalence = 24/211 =11%
  • Comments:
  • VCTS evaluated in patients with ocular complaints.
  • Reference:
  • Howes, Caelli, and Mitchell, 1982.
  • Study Design:
  • Case series.
  • Patients:
  • 55 patients: 42 diabetic; 3 macular disease; 10 normal.
  • Type of Contrast Sensitivity Test:
  • CS described; not named.
  • Severity and Type of Cataract:
  • Severity grades: none (37 eyes), mild (35), and moderate((5).Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Diabetic retinopathy.
  • Preoperative Visual Acuity:
  • 20/20 or better.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: N/A.
  • Findings:
  • CS appeared graphically to decrease with increasing severity of cataract and retinopathy.
  • Comments:
  • No statistical tests done to determine if the lines graphed are significantly different from each other.
  • Reference:
  • Koch, 1989.
  • Study Design:
  • Case series.
  • Patients:
  • 41 cataract patients with VA 20/60 or better and complained of glare.10 patients without glare.
  • Type of Contrast Sensitivity Test:
  • Miller-Nadler glare tester. Baylor visual function tester.Stereo Optical glare tester.VCTS.
  • Severity and Type of Cataract:
  • Severity: VA 20/60 or better.Type: posterior subcapsular, nuclear.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • 20/60 or better.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: glare complaint.
  • Findings:
  • Correlation between contrast test results and glare complaints similar to contrast and Snellen VA. False negative and false positives for contrast test were similar to those from Snellen VA when compared with patient complaints (gold standard).
  • Comments:
  • Selection of patients (only those able to compare their glare complaints with the glare testing formats) might have inflated the correlations and decreased the false negative rate. Overall, Snellen performs similarly to, and is easier and less expensive than, contrast testing.
  • Reference:
  • Lempert, Hopcroft, and Lempert, 1987.
  • Study Design:
  • Case series.
  • Patients:
  • 68 eyes with PSC and VA 20/60 or better146 eyes normal.
  • Type of Contrast Sensitivity Test:
  • Computer controlled CS instrument, author's device.
  • Severity and Type of Cataract:
  • Severity: VA 20/60 or better.Type: PSC.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • 20/60 or better.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: N/A.
  • Findings:
  • Mean Snellen fraction denominators for the 146 normal eyes increased slightly (23 to 42) as contrast level decreased (95% to 3%). For the 68 PSC eyes, the denominator increased significantly (37 to 163) as contrast level decreased. VA decreased significantly for PSC but not for normals.
  • Comments:
  • Comparison of CS between normals and PSC eyes. Not directly applicable to decisions about cataract surgery.
  • Reference:
  • Singh, Cooper, Alder et al., 1981.
  • Study Design:
  • Case series.
  • Patients:
  • 90 normal patients.27 cataract (48 eyes).25 glaucoma (45 eyes).
  • Type of Contrast Sensitivity Test:
  • Arden gratings (plates 6 and 7).
  • Severity and Type of Cataract:
  • Severity: minimal.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • Not given.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: N/A.
  • Findings:
  • For cataract eyes, mean score was 14/5 +/- 3 (all 48 eyes saw grating) on plate 6 and 13.7 +/- 3 (33 eyes saw grating) on plate 7.
  • Comments:
  • Study describes findings in normal, mild cataract, and glaucoma eyes. Not directly applicable to decisions about cataract surgery.
  • Reference:
  • Skalka, 1981a.
  • Study Design:
  • Case series.
  • Patients:
  • 88 patients (122 eyes).
  • Type of Contrast Sensitivity Test:
  • Arden Grating.
  • Severity and Type of Cataract:
  • Severity: early (VA 20/40 or better).Type: PSC.
  • Type of Comorbid Ocular Pathology:
  • None.
  • Preoperative Visual Acuity:
  • 20/40 or better.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: N/A.
  • Findings:
  • Tables give the ranges of Arden grating scores by age for patients with mild PSC and normals. Mean scores increase with increasing age (98.5 for 3d decade to 110.8 for 9th decade).
  • Comments:
  • Although abstract claims that Arden scores correlate better than Snellen acuity with patients' subjective complaints, no data are present in the paper regarding patients' complaints.
  • Reference:
  • Morris, Klett, Gieser et al., 1991.
  • Study Design:
  • Case series.
  • Patients:
  • 15 patients, 15 eyes.
  • Type of Contrast Sensitivity Test:
  • Interferometric laser contrast sensitivity function.
  • Severity and Type of Cataract:
  • Severity: 20/70 to 20/200, N=11; worse than 20/200, N=4.Type: mixed.
  • Type of Comorbid Ocular Pathology:
  • Varied with patient.
  • Preoperative Visual Acuity:
  • Isolated retina contrast sensitivity function.
  • Postoperative Visual Acuity or "Gold Standard":
  • Postop optical plus retinal contrast sensitivity function.
  • Findings:
  • In 10 of 15 patients, postop CSF was predicted accurately. 4 of 5 inaccurate predictions were in patients with VA <20/200. Comments: 25% of cases lost to followup.
  • Reference:
  • Elliott, Hurst, and Weatherill, 1990.
  • Study Design:
  • Case series (cross-sectional).
  • Patients:
  • 33 patients with cataract in at least 1 eye who were also about to enter an anticataract drug trial or to undergo surgery.
  • Type of Contrast Sensitivity Test:
  • Pelli-Robson letter chart (both sides).
  • Severity and Type of Cataract:
  • VA range = 6/4 to 6/36.
  • Type of Comorbid Ocular Pathology:
  • Exclude patients with high intraocular pressure, retinal disease, diabetes, refractive error <+/-6DS, amblyopia, monophakia, abnormal neural function, poor general health.
  • Preoperative Visual Acuity:
  • N/A.
  • Postoperative Visual Acuity or "Gold Standard":
  • N/A.
  • Findings:
  • Patients also completed questionnaire on vision-related functional disability.Correlation (r) -0.65 between binocular CS score and patient responses on questions regarding mobility; mobility decreases as CS score increases.r = -0.60 between binocular CS and near-vision responses. r = -0.49 between binocular CS and discrimination responses.
  • Comments:
  • Moderately strong association between CS scores and patient perception of vision-related disability.No statistical test performed to determine whether the difference in magnitude of correlations between CS and functional disability compared with those between VA and functional disability are statistically significant. Cannot determine if differences in the correlation coefficients are clinically significant even if they are statistically significant.There are no postop data.
  • Note:
  • CS = Contrast sensitivity. CSF = Contrast sensitivity function. PSC = Posterior subcapsular. VA = Visual acuity. VCTS = Vistech vision contrast test system.

Attachment 3. Literature Review Evidence: Glare Testing

  • Reference:
  • Holladay, Prager, Trujillo et al., 1987.
  • Study Design:
  • Case series.
  • Patients:
  • 64 patients (14 normal, 50 cataract).
  • Type of Glare Test:
  • Brightness acuity tester.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Visual Acuity Without Glare:
  • Not given.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: outdoor VA (5,358 to 13,198 ft. candles).
  • Findings:
  • No decrease in VA with the BAT or outdoor testing in normals. For cataract subjects, correlation between BAT and outdoor VA was r=0.84. Cataract patients had a 1- to 10-line reduction in VA.
  • Comments:
  • No information regarding type/severity of cataract, complaints of glare, or sensitivity/specificity. No test-retest data given although abstract claims BAT reliable.
  • Reference:
  • Hirsch, Nadler, and Miller, 1984a.
  • Study Design:
  • Consecutive case series.
  • Patients:
  • 52 cataract patients (84 eyes), 48 normal patients (81 eyes).
  • Type of Glare Test:
  • Author's device.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Visual Acuity Without Glare:
  • Mean = 20/48; range = 20/20 to 20/60.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: outdoor VA (>=2,000 ft. candles).
  • Findings:
  • For cataract patients, correlation between glare scores and outdoor VA better for individuals facing sun (r**2=0.64) than those not facing sun (r**2=0.36). For normals, glare scores were "highly predictive" of outdoor acuity (r**2 not given).
  • Comments:
  • Data difficult to decipher. Methods not standardized. Sun glare not standardized for glare test measurement.
  • Reference:
  • Hirsch, Nadler, and Miller, 1984b.
  • Study Design:
  • Case series.
  • Patients:
  • 3 studies: N=46 (test-retest)); N=5 (effect of refractive error on glare); N=126 (effect of contrast on glare).
  • Type of Glare Test:
  • Described.
  • Severity and Type of Cataract:
  • N=46 (13 normal eyes, 23 cataract eyes, 27 aphakic eyes). N=126 (35 normal; 94 cataract; 57 aphakic eyes).
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Visual Acuity Without Glare:
  • N/A.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: N/A.
  • Findings:
  • Test-retest reliability varies with eye status: r=0.06, normal; r=0.95, cataract; r=0.54, aphakic. Glare scores change up to 5% with refractive error, and contrast sensitivity accounts for 10% of the variance in glare scores.
  • Comments:
  • Reliability is highest in patients with cataract.
  • Reference:
  • Hard, Abrahamsson, and Sjostrand, 1990.
  • Study Design:
  • Case series.
  • Patients:
  • N=16; 10 cataract patients who had glare problems, 3 normal, 3 others.
  • Type of Glare Test:
  • Described.
  • Severity and Type of Cataract:
  • Severity: not given.Type: nuclear, cortical, and PSC.
  • Type of Comorbid Ocular Pathology:
  • None in cataract subjects.
  • Visual Acuity Without Glare:
  • Better than 20/70.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: letter CS (without glare).
  • Findings:
  • Test-retest reliability for: letter CS r=0.83, letter CS with glare r=0.92, VA r=0.89. With glare, cataract patients had a decreased letter CS independent of VA.
  • Comments:
  • Tables and graphs difficult to interpret. Test-retest reliability good under conditions specified. However, study design would be stronger if individuals performing the test were not masked.
  • Reference:
  • Elliott, Gilchrist, and Whitaker, 1989.
  • Study Design:
  • Case series.
  • Patients:
  • 18 subjects (39 eyes) with cataracts, 16 subjects (16 eyes) normal.
  • Type of Glare Test:
  • Contrast sensitivity described, not named.Glare described, not named.
  • Severity and Type of Cataract:
  • Severity: graded 1-5 scale (Oxford cataract classification and grading system). Type: nuclear, cortical, subcapsular.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Visual Acuity Without Glare:
  • LogMar VA: 0.12 to 0.50.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: LogMar VA.
  • Findings:
  • High correlations between glare sensitivity and LogMar VA for cortical (r=1.0) and nuclear (r=0.77), but not PSC (r=0.12) cataracts.Moderate to high (r=0.44 to 1.0) correlations between CS and LogMar VA at >=2 c/deg (r=0.44 to 1.0).
  • Comments:
  • Correlation coefficients may not be precise because of small numbers in each subgroup. Study results vary considerably with the type of cataract.
  • Reference:
  • Abrahamsson and Sjostrand, 1986.
  • Case series.
  • Patients:
  • 18 normals, 34 subjects with PSC.
  • Type of Glare Test:
  • Described.
  • Severity and Type of Cataract:
  • Severity: 0 to 100% opacification.Type: PSC only.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Visual Acuity Without Glare:
  • 20/20 to 20/200 (by figure).
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: visual acuity.
  • Findings:
  • Weak correlation between glare score and visual acuity, with a trend of increasing glare relating to decreasing VA (r not given).
  • Comments:
  • 2 methods used to calculate glare scores gave different results. The average discrepancy in threshold contrast was used because of a "high reproducibility" of results, but no test-retest data were given.
  • Reference:
  • Maltzman, Horan, and Rengel, 1988.
  • Study Design:
  • Case series.
  • Patients:
  • 114 eyes cataract, 20 eyes normal.
  • Type of Glare Test:
  • Penlight.
  • Severity and Type of Cataract:
  • Severity: VA better than 20/200.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • None.
  • Visual Acuity Without Glare:
  • Better than 20/200.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: Snellen acuity.
  • Findings:
  • Out of 40 eyes with VA 20/40 or better, 22 (55%) did not change with penlight and 2 (5%) had VA of 20/200. 16 out of 22 eyes with VA of 20/50 had VA of 20/200 or worse with penlight.
  • Comments:
  • No mention was made of patients with glare complaints. Unclear whether patients with VA of 20/200 with the penlight complained of glare. Without an assessment of patients' functional disability and/or postop outcomes, these data do not directly address the ability of the penlight test to predict who will benefit from surgery.
  • Reference:
  • Neumann, McCarty, Locke et al., 1988.
  • Study Design:
  • Case series.
  • Patients:
  • 48 cataract eyes.
  • Type of Glare Test:
  • Miller-Nadler.Brightness acuity tester. InnoMed true vision analyzer. VisTech VCT8000.Eye-Con 5.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • None.
  • Visual Acuity Without Glare:
  • Not given.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: outdoor Snellen acuity.
  • Findings:
  • The tests predicted outdoor acuity to within 1-line accuracy in 73% for BAT, 69% for TVA, 56% for VisTech, 47% for Miller-Nadler, and 15% for EyeCon. False positive and negative rates provided in the article.
  • Comments:
  • Study highlights the problem of variability in glare tester's ability to predict outdoor acuity.
  • Reference:
  • Koch, 1989.
  • Study Design:
  • Case series.
  • Patients:
  • 41 cataract subjects with VA 20/60 or better and complained of glare. 10 patients without glare.
  • Type of Glare Test:
  • Miller-Nadler glare tester;Baylor visual function tester;Stereo Optical glare tester;Vistech vision contrast test system.
  • Severity and Type of Cataract:
  • Severity: acuity 20/60 or better.Type: PSC, nuclear.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Visual Acuity Without Glare:
  • 20/60 or better.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: glare complaint;severity and type of cataract.
  • Findings:
  • Correlation between the 3 glare testers and patients' complaints ranged from r=0.39 to r=0.68. False positive rates (1-Sp) were 20% to 50% and false negative rates (1-Se) were 2% to 15%.
  • Comments:
  • Selection of patients (only those able to compare their complaints with the glare testing formats) may bias the results and make the tests look better than they are (especially the correlations and false negative rates). With only moderate correlations with patients' complaints and a high false positive rate, these tests have questionable clinical utility.
  • Reference:
  • Neumann, McCarty, Steedle et al., 1988b.
  • Study Design:
  • Case series.
  • Patients:
  • 78 patients (92 eyes with cataract and glare scores between 10% and 80%).
  • Type of Glare Test:
  • Miller-Nadler glare tester.
  • Severity and Type of Cataract:
  • Severity: VA 20/20 to 20/300.Type: pure nuclear, nuclear PSC, and other.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Visual Acuity Without Glare:
  • 20/20 to 20/300 (81 eyes had VA 20/20 to 20/40 indoors and 33 had VA 20/20 to 20/40 outdoors).
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: outdoor VA (8,000 to 11,900 ft. candles).
  • Findings:
  • The Miller-Nadler predicted outdoor acuity was within 1 Snellen line of actual outdoor acuity for 47% of the eyes overall. For the 3 categories of cataract type, this percent ranged from 50% (nuclear), to 40% (nuclear and PSC), to 52% (other).
  • Comments:
  • Predictions of outdoor acuity (within 1 line) are poor for all 3 types of cataract. No assessments of patients' complaints of glare and/or postoperative outcomes. As a result, this study does not directly address value of the test for preoperative decisionmaking.
  • Reference:
  • Neumann, McCarty, Steedle et al., 1988a.
  • Study Design:
  • Case series.
  • Patients:
  • 78 subjects (106 cataractous eyes).
  • Type of Glare Test:
  • Indoor Snellen acuity.
  • Severity and Type of Cataract:
  • Severity: VA 20/20 to 20/300.Type: nuclear, nuclear and PSC, other.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Visual Acuity Without Glare:
  • 20/20 to 20/300 (81 eyes had VA 20/20 to 20/40 indoors and 33 had VA 20/20 to 20/40 outdoors).
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: outdoor VA (8,000 to 11,900 ft. candles).
  • Findings:
  • 74 (70%) of eyes had outdoor VA >= 2 Snellen lines worse than indoor VA and 23 (22%) had outdoor VA >= 5 lines worse.
  • Comments:
  • Authors compared indoor and outdoor Snellen acuity. There was no assessment of subjects' complaints of visual impairment or glare. Many of the eyes had VA of 20/40 or better indoors (76%) and outdoors (31%).
  • Reference:
  • Prager, Urso, Holladay et al., 1989.
  • Study Design:
  • Case series.
  • Patients:
  • 51 normal subjects/eyes; 47 cataractous subjects/eyes.
  • Type of Glare Test:
  • Miller-Nadler glare tester;brightness acuity tester.
  • Severity and Type of Cataract:
  • Severity: "minimal."Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Postoperative Visual Acuity or "Gold Standard":
  • Gold standard: outdoor VA.
  • Visual Acuity Without Glare:
  • Mean for controls 20/20 (+/-2.11 SD); cataracts 20/43 (+/-18 SD).
  • Findings:
  • Normal eyes had a mean VA of 20/20 indoors, outdoors, and with BAT. Miller-Nadler gave a VA mean of 20/24. For cataract eyes, mean outdoor acuity was 20/45 (+/-17 SD). BAT overpredicted glare disability in 81% at high and 42% at medium settings. Miller-Nadler underpredicted in 62%
  • Comments:
  • Randomization of indoor vs. outdoor testing and order of each instrument makes this a strong study design. It decreases the bias of a "carryover" or "training" effect from one test or setting to the other.Use of only one eye from each patient is also a strength of this study. Study demonstrates significant variability among glare testers.
  • Reference:
  • Weiss, 1990.
  • Study Design:
  • Case series.
  • Patients:
  • 74 patients (118 eyes).
  • Type of Glare Test:
  • Glare situation described.Mesopic vision situation described.
  • Severity and Type of Cataract:
  • Severity: VA 20/46 to 20/154.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Visual Acuity Without Glare:
  • 20/46 to 20/154.
  • Postoperative Visual Acuity or "Gold Standard":
  • Postop vision: 20/22 to 20/42.
  • Findings:
  • Statistically significant improvements occurred for all 3 acuity measures postop: standard landolt (0.28 preop vs. 0.69 postop), glare (0.06 vs 0.22), and mesopic (0.11 vs 0.34).
  • Comments:
  • Comparisons were not made between preop glare (or mesopic vision) and postop Snellen acuity. Patients' complaints of glare were not given for preop and postop periods.
  • Reference:
  • Masket, 1989.
  • Study Design:
  • Case series.
  • Patients:
  • 26 patients (30 eyes) with uncomplicated cataract surgery and postop acuity 20/20.
  • Type of Glare Test:
  • Miller-Nadler.
  • Severity and Type of Cataract:
  • Severity: VA 20/30 to HM. Type: nuclear, PSC, cortical.
  • Type of Comorbid Ocular Pathology:
  • None.
  • Visual Acuity Without Glare:
  • 20/30 to HM (mean 20/122).
  • Postoperative Visual Acuity or "Gold Standard":
  • Postoperative VA: 20/20.
  • Findings:
  • Mean glare score preop (55.2%, range 25 to 80%) was significantly different from postop mean (7.6%, range 2.5 to 15%).
  • Comments:
  • Selecting patients based on good surgical outcome (VA 20/20) may have biased results and limits generalizability of findings to the typical preoperative situation. Glare scores improved after cataract removal. No indication as to whether patients had glare symptoms and if these resolved postop.Technician performing the glare testing was masked, making this a stronger study design.
  • Reference:
  • Elliott, Hurst, and Weatherill, 1990.
  • Study Design:
  • Case series (cross-sectional).
  • Patients:
  • 33 patients with cataract in at least 1 eye.
  • Type of Glare Test:
  • Mentor brightness acuity meter: reduction in VA (GDVA);reduction in CS (GDCS).
  • Severity and Type of Cataract:
  • VA range =6/4 to 6/36.
  • Type of Comorbid Ocular Pathology:
  • Exclude patients with high intraocular pressure, retinal disease, refractive error >+/-6.00, amblyopia, monophakia, abnormal neural function, poor general health.
  • Visual Acuity Without Glare:
  • N/A.
  • Postoperative Visual Acuity or "Gold Standard":
  • N/A.
  • Findings:
  • Patients also completed questionnaire on vision-related functional disability. Correlation (r) = 0.61 between worse eye GDVA and near vision and r =0.57 between worse eye GDVA and discrimination.r = 0.45 between worse eye GDCS and discrimination. These correlations were slightly higher than those between VA and the same functional disabilities (r = 0.46 and 0.41, respectively).
  • Comments:
  • Moderately strong association between GDVA and near vision and between GDVA and GDCS and discrimination. No statistical test performed to determine whether the differences in magnitude of correlations are statistically significant (e.g., between glare/functional disability vs. VA/functional disability).Cannot determine if differences in the correlation coefficients are clinically significant even if they are statistically significant. There are no postop data. No data (scatter plots) or confidence intervals provided, just p values; so difficult to assess validity of analysis conclusions.
  • Reference:
  • Elliott, Hurst, and Weatherill, Levin, 1989.
  • Study Design:
  • Case series.
  • Patients:
  • 38 patients, good VA and with other visual symptoms.
  • Type of Glare Test:
  • Innomed TVA -- glare mode.
  • Severity and Type of Cataract:
  • Severity: VA 20/25 to 20/70.Type: opalescent nuclear.
  • Type of Comorbid Ocular Pathology:
  • None.
  • Visual Acuity Without Glare:
  • 20/25 to 20/70.
  • Postoperative Visual Acuity or "Gold Standard":
  • Postop VA: 20/15 to 20/30.
  • Findings:
  • Preop contrast sensitivity (15%, glare mode) ranged from 20/80 to 20/2000. Postop CS (10% glare mode) ranged from 20/15 to 20/70 for all 38 patients.
  • Comments:
  • No report of whether patients' visual symptoms resolved postop.All 38 patients had mild cataracts and no other ocular pathology, making it difficult to apply the results to a broader range of patients seen in practice.
  • Note:
  • BAT = Brightness acuity tester. CS = Contrast sensitivity. GD[subCS] = Glare disability as measured by reduction in contrast sensitivity. GD[subVA] = Glare disability as measured by reduction in visual acuity. HM = Hand motion. PSC = Posterior subcapsular. SD = Standard deviation. Se = Sensitivity. 1-Se = False negative rate. Sp = Specificity. 1-Sp = False positive rate. TVA = True Vision Analyzer. VA = Visual acuity.

Attachment 4. Literature Review Evidence: Potential Vision Testing

  • Reference:
  • Goldmann, Chrenkova, and Cornaro, 1980.
  • Study Design:
  • Case series.
  • Patients:
  • 41 patients.
  • Type of Potential Vision Test:
  • Lotmar interferometer.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • Not given.
  • Postoperative Visual Acuity:
  • Yes.
  • Findings:
  • Correlation between preop and postop IA was r=0.41:correlation between preop IA and postop VA, r=0.54; test performs worse with dense cataract.
  • Comments:
  • Performance is only fair in predicting postop vision.
  • Reference:
  • Fukuhara, Oozato, Nojima et al., 1983.
  • Study Design:
  • Cross-sectional.
  • Patients:
  • N=52 eyes (12 patients with unilateral cataracts); no indication of number of patients.
  • Type of Potential Vision Test:
  • VEP using laser speckled pattern.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • Not given for 12 eyes; 20/200 or worse for 40 eyes.
  • Postoperative Visual Acuity:
  • 20/20 to CF.
  • Findings:
  • PredictionPreop VA >=20/40Postop VA <20/40
    Good255
    Poor07
    Total2512
    Sensitivity = 25/25 = 1.0
    Specificity = 7/12 = 0.58
  • Comments:
  • For 12 unilateral cataract patients, equation predicting postop VA, using VEP, correlated highly (r=0.74) with postop VA. Predictive equation, if validated, useful only in patients with unilateral cataracts. Data suggest VEP may be sensitive for detecting patients with good postop VA. However, type of cataract not specified. Only by counting the number of eyes given in the tables can the sample size be discerned. Unclear how many pairs of eyes are from how many subjects.
  • Reference:
  • Faulkner, 1983.
  • Study Design:
  • 2 case series.
  • Patients:
  • 137 cataract eyes.
  • Type of Potential Vision Test:
  • Rodenstock retinometer.
  • Severity and Type of Cataract:
  • Severity: 20/70 to LP.Type: 60 eyes -- immature cataracts and normal maculas; 77 eyes -- 5 mature and 29 immature cataracts and other pathology.
  • Type of Comorbid Ocular Pathology:
  • Macular scars; degeneration or holes; amblyopia; retinal atrophy; cystoid macular edema, etc.
  • Preoperative Visual Acuity:
  • 20/70 to LP.
  • Postoperative Visual Acuity:
  • 20/20 to CF.
  • Findings:
  • In the 60 eyes with immature cataracts and normal maculas, the retinometer predicted postop VA within 1 line in 53 (88%) and 2 lines in 7 (12%).In the 77 eyes, 55 had other pathology. In 53 of the 55 (96%), the retinometer predicted better VA (by >= 2 lines) than was achieved postop. In 9 patients, the retinometer predicted worse VA than achieved (by >= 2 lines). These patients had mature cataracts or pupils were not dilated.
  • Comments:
  • Presentation of data is unclear.
  • Reference:
  • Essock, Williams, Enoch et al., 1984.
  • Study Design:
  • Case series.
  • Patients:
  • 15 patients.
  • Type of Potential Vision Test:
  • Two-dot Vernier acuity.
  • Severity and Type of Cataract:
  • Severity: VA 20/25 to 20/1,000.Type: mostly nuclear.
  • Type of Comorbid Ocular Pathology:
  • None.
  • Preoperative Visual Acuity:
  • 20/25 to 20/1,000.
  • Postoperative Visual Acuity: Postop VA:
  • not given. Gold standard: preop Snellen acuity and postop Vernier acuity.
  • Findings:
  • Correlation between preop Vernier and preop Snellen acuity, r=0.83. Cataract removal decreased the thresholds, size of gap, and steepness of the curves for Vernier acuity.
  • Comments:
  • No evidence given for whether preop Vernier acuity predicted postop acuity.
  • Reference:
  • Enoch, Bedell, and Kaufman, 1979.
  • Study Design:
  • Case series.
  • Patients:
  • 61 patients (85 eyes) from 2d study.
  • Type of Potential Vision Test:
  • Interferometer (laser).
  • Severity and Type of Cataract:
  • Severity: VA 20/20 to LP.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • Landolt VA 20/20 to LP.
  • Postoperative Visual Acuity:
  • 6/6 to CF.
  • Findings:
  • PredictionPreop VA >=6/12Postop VA <6/12
    >=6/12190
    <6/1243
    Total233
    Sensitivity = 19/23 =0.83
    Specificity = 3/3 =1.0
  • Comments:
  • Only 26 eyes of 21 patients had data given to calculate Se and Sp. Data on the other 40 patients were excluded, raising a question about possible selection bias (i.e., perhaps only those with good operative outcomes were included).
  • Reference:
  • Dubey, Masani, and Shroff, 1983.
  • Study Design:
  • Case series.
  • Patients:
  • 100 cataract eyes.
  • Type of Potential Vision Test:
  • Maddox rod.Retinometer. 2-point discrimination.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • Not given. No pre, intra, or postop problems.
  • Preoperative Visual Acuity:
  • Not given.
  • Postoperative Visual Acuity:
  • 20/20 to 20/200.
  • Findings:
  • Maddox Rod PreopPostop VA >=20/30Postop VA <20/30Total
    Grade I80181
    Grade II01919
    Total8020100
    Sensitivity = 80/80 =1.0
    Specificity = 19/20 = 0.95
    Retinometer PreopPostop VA >=20/30Postop VA <20/30Total
    >=6/918018
    <6/9622082
    Total8020100
    Sensitivity = 18/80 = 0.22
    Specificity = 20/20 = 1.0
  • Comments:
  • Only a few subjects gave consistent answers for 2-point discrimination.Maddox rod is sensitive and specific for this limited group of patients.
  • Reference:
  • Datiles, Edwards, Kaiser-Kupfer et al., 1987.
  • Study Design:
  • Consecutive case series.
  • Patients:
  • 27 patients (35 eyes).
  • Type of Potential Vision Test:
  • PAM laser interferometer.
  • Severity and Type of Cataract:
  • Severity: a) mild to moderate cataracts, N = 17 patients. b) severe cataract, N = 15 patients. Type: not given.
  • Type of Comorbid Ocular Pathology:
  • a) Myopia, diabetes, retinal diseases. b) Myopia.
  • Preoperative Visual Acuity:
  • a) 20/60 to CF at 18 inches. b) CF or worse.
  • Postoperative Visual Acuity:
  • a) All patients were 20/20 or better. b) All patients were 20/30 or better.
  • Findings:
  • a) PAM -- 16/17 patients with mild to moderate cataracts were correctly predicted to be 20/40 or better (sensitivity = 0.94). b) PAM -- 5/15 severe cataract patients were predicted correctly to be 20/40 or better (sensitivity = 0.33). The other 10 were predicted to be worse than 20/40 and all turned out to be 20/30 or better (false negative rate = 0.67). Laser -- 8/15 were correctly predicted to do well. 7/15 were wrongly predicted to have bad outcome (false negative rate = 0.47).
  • Comments:
  • a) For patients with mild/moderate cataract and no comorbidity, PAM correctly predicted good outcome. No data about patients predicted to have poor outcome show good outcomes. Laser results are similar to PAM. b) Patients predicted to do well did well. For patients who were predicted to do poorly, test was correct only 1 out of 3 times (i.e., high false negative rate). Both instruments do well when there is mild/moderate cataract and there is no comorbidity; did not do well when patients had severe cataract.
  • Reference:
  • Cruz and Adachi-Usami, 1989.
  • Study Design:
  • Case series.
  • Patients:
  • N = 22, unilateral mature senile cataract with good VA in other eye and normal preop ERG. N = 11, subnormal ERG preop.
  • Type of Potential Vision Test:
  • Electroretinogram.
  • Severity and Type of Cataract:
  • Mature cataract.
  • Type of Comorbid Ocular Pathology:
  • Diabetic retinopathy; choroidal detachment or degeneration, branch vein occlusion in the 11 patients with subnormal ERGs.
  • Preoperative Visual Acuity:
  • Not given.
  • Postoperative Visual Acuity:
  • 20/20 to >=20/50.
  • Findings:
  • ERGPostop VA >20/20Postop VA <20/50Total
    Normal22022
    Subnormal31013
    Total251035
    Sensitivity = 22/25 = 0.88
    Specificity = 10/10 = 1.0
    Prevalence of good outcome = 71%
  • Comments:
  • Highly selected group of patients (33 out of 153) with no indication that the study was prospective. Significant bias in the Se and Sp likely given selection of patients and lack of masking.
  • Reference:
  • Cohen, 1976.
  • Study Design:
  • Case series.
  • Patients:
  • 163 eyes.
  • Type of Potential Vision Test:
  • Interferometer (laser).
  • Severity and Type of Cataract:
  • Severity: VA 20/50 to LP.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • 28 eyes had macular degeneration, diabetic retinopathy, chorioretinal degeneration, sarcoid, etc.
  • Preoperative Visual Acuity:
  • 20/50 to LP.
  • Postoperative Visual Acuity:
  • 20/25 to LP.
  • Findings:
  • Postop VA was within 1 line of predicted acuity for 86% of eyes (140/163).
    PAPostop VA >=20/50Postop VA <20/50
    >=20/501223
    <20/502315
    Total14518
    Sensitivity = 122/145 = 0.84
    Specificity = 15/18 = 0.83
    Prevalence of good outcomes = 89%
  • Comments:
  • Test was correct 98% of the time when it predicted a good outcome but only 39% of the time when it predicted a bad outcome.
  • Reference:
  • Minkowski, Palese, and Guyton, 1983.
  • Study Design:
  • Case series.
  • Patients:
  • 59 patients, 66 eyes with cataract (and strong suspicion of posterior pole disease for 35 eyes).
  • Type of Potential Vision Test:
  • Potential acuity meter.
  • Severity and Type of Cataract:
  • Severity: not given.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Senile macular degeneration (20), high myopia (7), glaucoma (5), other (8).
  • Preoperative Visual Acuity:
  • 20/50 to CF 1 foot.
  • Postoperative Visual Acuity:
  • --
  • Findings:
  • PAM>=20/40<20/40Total
    >=20/4038240
    <20/406511
    Total44751
    Sensitivity = 38/44 = 0.86
    Specificity = 5/7 = 0.71
    Prevalence of good outcomes = 86%
  • Comments:
  • a) 15 eyes were excluded from the analysis, making it difficult to know what sensitivity and specificity were in the original patient population. b) Predicted postop visual acuity was less accurate for patients with dense cataracts (VA worse than 20/200).
  • Reference:
  • Miris and Missotten, 1982.
  • Study Design:
  • Case series.
  • Patients:
  • 62 eyes.
  • Type of Potential Vision Test:
  • Blue field entoptoscope.Color perception test (RG).
  • Severity and Type of Cataract:
  • Congenital, traumatic, and senile cataracts.
  • Type of Comorbid Ocular Pathology:
  • Myopic choroidal dystrophy, congenital glaucoma, amblyopia, etc. (N = 6 eyes).
  • Preoperative Visual Acuity:
  • 2/10 to LP.
  • Postoperative Visual Acuity:
  • Range or individual acuities not given.
  • Findings:
  • BFEPostop VA >=6/9Postop VA <6/9Total
    +27027
    -27633
    Total54660
    Sensitivity = 27/54 = 0.5
    Specificity = 6/6 = 1.0
    Prevalence of good outcomes = 90%
    RGPostop VA >=7/10Postop VA <7/10Total
    +50454
    -426
    Total54660
    Sensitivity = 50/54 = 0.93
    Specificity = 2/6 = 0.33
  • Comments:
  • BFE is not sensitive in detecting good outcomes in a group of patients with a 90% prevalence of good outcomes. RG test is sensitive but not specific. Neither test seems to perform well when cataract is dense (HM or worse).
  • Reference:
  • Murphy, 1983.
  • Study Design:
  • Case series.
  • Patients:
  • 101 eyes cataract.
  • Type of Potential Vision Test:
  • Blue field entoptoscope.
  • Severity and Type of Cataract:
  • Severity: 20/60 to LP. Type: PSC, nuclear, cortical.
  • Type of Comorbid Ocular Pathology:
  • Senile macular degeneration, diabetic maculopathy, optic atrophy, macular pucker.
  • Preoperative Visual Acuity:
  • 20/60 to LP.
  • Postoperative Visual Acuity:
  • 20/20 to CF.
  • Findings:
  • BFEPostop VA >=20/40Postop VA <20/40Total
    +77582
    -17219
    Total947101
    Sensitivi ty = 77/94 = 0.82
    Specificity = 2/7 = 0.28
    (assuming data are complete)
  • Comments:
  • BFE results depend on type and severity of cataract. BFE performs poorly in patients with dense cataracts.Using consecutive cases vs. selected cases makes this a stronger study design.
  • Reference:
  • Sinclair, Loebl, and Riva, 1979.
  • Study Design:
  • Consecutive case series.
  • Patients:
  • N = 154 patients (only reported on 136 eyes).
  • Type of Potential Vision Test:
  • BFE.2-light discriminator.Color perception.Purkinje vascular entoptic phenomenon.
  • Severity and Type of Cataract:
  • Severity: 20/70 to LP.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Macular degeneration, diabetes, myopia, retinal disease.
  • Preoperative Visual Acuity:
  • 20/70 to LP.
  • Postoperative Visual Acuity:
  • 20/40 or better N = 118. 20/50 or worse N = 18.
  • Findings:
  • BFE:Postop MacularPostop Macular
    Strong Light Function (+)Function (-)Total
    +48149
    -3912
    Total511061
    Sensitivity = 48/51 = 0.94
    Specificity = 9/10 = 0.90
    Of the patients who turned out to have poor macular function (N = 10), the blue field
    test identified 75% (weak light) to 90% (strong light).
  • Comments:
  • In patients with good macular function, all the tests were good predictors of good postop outcome. In patients with poor macular function, BFE was best of the tests. BFE test was fairly good among the patients for whom results were reported. However, 25% of patients predicted to have poor postop macular function have good macular function. BFE results were not reported for 50% of eyes in the study. This may have biased the results.
  • Reference:
  • Skalka, 1981b.
  • Study Design:
  • Case series.
  • Patients:
  • 150 patients.
  • Type of Potential Vision Test:
  • Blue field entoptoscope.Visually evoked responses.
  • Severity and Type of Cataract:
  • Severity: VA 20/20 to LP.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • 20/50 to LP.
  • Postoperative Visual Acuity:
  • 20/20 to LP.
  • Findings:
  • 1 Preop VA 20/400
    or better: BFEPostop VA >=20/40Postop VA <20/40Total
    +/- [1]??102
    -7512
    Total??114
    Negative predictive value = 5/12 = 0.042.
    [1] +/- refers to positive or equivocal results of BFE test.
    2 Preop VA CF or
    worse: BFEPostop VA>=20/40Postop VA <20/40Total
    +/- [1]??11
    -18725
    Total??36
    Negative predictive value = 7/25 = 0.28.
    [1] +/- refers to positive or equivocal results of BFE test.
  • Comments:
  • Data not presented. The predictive values are highly dependent on the prevalence of an outcome.
  • Reference:
  • Tabbut and Lindstrom, 1986.
  • Study Design:
  • Case series.
  • Patients:
  • 100 eyes in 93 patients.
  • Type of Potential Vision Test:
  • Laser interferometry.
  • Severity and Type of Cataract:
  • Not clear.
  • Type of Comorbid Ocular Pathology:
  • Good mix (glaucoma, corneal abnormality, macular degeneration, diabetic retinopathy, etc.).
  • Preoperative Visual Acuity:
  • --
  • Postoperative Visual Acuity:
  • Data presented in a confusing manner.
  • Findings:
  • In patients with least dense cataract (good preop VA), prediction was very good.
    Predicts ImprovementPostop Improvement
    YesNo
    Yes773
    No155
    Total928
    Predicted
    Sensitivity = 77/92 = 0.84.
    Specificity = 5/8 = 0.62.
    In patients with least dense cataract (good preop VA) prediction was very good.
  • Comments:
  • Predictive accuracy was poor in patients who had dense cataract; tended to predict that patients would not do well postop but many did well. Accurate in patients with mild to moderate cataracts; predicted that they would all do well and they did well.
  • Reference:
  • van Lith and Hekkert-Wiebenga, 1983.
  • Study Design:
  • Case series.
  • Patients:
  • 14 normal patients; 97 cataract eyes.
  • Type of Potential Vision Test:
  • Visually evoked potentials.
  • Severity and Type of Cataract:
  • Severity: 20/20 to 20/200 visual acuity.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • 20/20 to 20/200.
  • Postoperative Visual Acuity:
  • Postop VA: N/A. Gold standard: N/A.
  • Findings:
  • Testing parameters are given for percent contrast and size of pattern. Stimuli most useful in evaluating patients with cataracts that did not seem dense enough to explain the low visual acuity.
  • Comments:
  • Only patients with normal vision after surgery were included in the study. This limits the clinical relevance and generalizability of the findings.
  • Reference:
  • Whitaker and Deady, 1989.
  • Study Design:
  • Case series.
  • Patients:
  • 35 patients (35 eyes).
  • Type of Potential Vision Test:
  • Displacement threshold acuity.
  • Severity and Type of Cataract:
  • Severity: graded 1 (mild) to 3 (severe).Type: nuclear (15), PSC (8), cortical (3).
  • Type of Comorbid Ocular Pathology:
  • None.
  • Preoperative Visual Acuity:
  • 6/12 to HM.
  • Postoperative Visual Acuity:
  • 6/5 to 6/15.
  • Findings:
  • Mild association between preop displacement thresholds and acuity levels (r = 0.37).Strong association between preop and postop displacement thresholds (r = 0.67).Insignificant (r not given) correlation between preop thresholds and postop acuity.
  • Comments:
  • Patients with ocular pathology (N = 11) were not included in the results, limiting the generalizability of the findings. The association between preop and postop thresholds does not indicate whether the test is useful in predicting postop acuity.
  • Reference:
  • Vrijland and van Lith, 1983.
  • Study Design:
  • Case series.
  • Patients:
  • 203 cataractous eyes referred by ophthalmologists for testing.
  • Type of Potential Vision Test:
  • Electroretinogram.Visually evoked responses.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • Not given.
  • Postoperative Visual Acuity:
  • Not given.
  • Findings:
  • ERGPostop VA >=20/40Postop VA <20/40Total
    75-100%10011111
    <75%613192
    Total16142203
    Sensitivity = 100/161 = 0.62
    Specificity = 31/42 = 0.74
    VERPostop VA >=20/40Postop VA <20/40Total
    <21 micro-V16016
    <=21 micro-V13552187
    Total15152203
    Sensitivity = 16/151 = 0.1
    Specificity = 52/55 = 1.0.
  • Comments:
  • Data given in percentages (%). Raw numbers were calculated from the percentage. Highly selective group of patients (those referred for ERG -- about 10% of patients with senile cataract) limits the applicability of the results. ERG (Sp = 0.74) and VER (Se = 1.0) are good at identifying those who will not have good postop VA.
  • Reference:
  • Grignolo, Moscone, Sobrero et al., 1988.
  • Study Design:
  • Case series.
  • Patients:
  • 53 patients (7 excluded because lens too dense).
  • Type of Potential Vision Test:
  • Lotmar visometer.Blue field entoptoscope.
  • Severity and Type of Cataract:
  • Severity: 1/10 to LP.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • 1/10 to LP.
  • Postoperative Visual Acuity:
  • Postop VA 1/10 to 4/50.
  • Findings:
  • 7 patients did not have visometry because of dense cataracts.
    BFEPostop VA >=5/6Postop VA <=4/10Total
    +41950
    -2810
    Total431760
    Sensitivity = 41/43 = 0.95
    Specificity = 8/17 = 0.47
    LotmarPostop VA >=5/10Postop VA <=4/10Total
    +32436
    -51217
    Total371653
    Sensitivity = 32/37 = 0.86
    Specificity = 12/16 = 0.75.
  • Comments:
  • Both tests are often inaccurate in their prediction of postop VA.
  • Reference:
  • Christenbury and McPherson, 1985.
  • Study Design:
  • Case series.
  • Patients:
  • 108 patients.
  • Type of Potential Vision Test:
  • Potential acuity meter.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • 20/60 to 1/200.
  • Postoperative Visual Acuity:
  • Not given.
  • Findings:
  • PAMPostop VA >20/40Postop VA <20/40Total
    >20/4048452
    <20/40??40
    Total??92
    Positive predicti ve value = 48/52 = 0.92.
    92 of 100 patients had postop VA within 1 line or better of predicted acuity.
    8 patients had cataract s too dense for using the meter.
  • Comments:
  • The article reports positive predictive values, which are highly dependent on the prevalence of good postop outcomes. Data regarding accuracy of prediction that postop outcome will be poor are not provided. Unable to use PAM in patients with dense cataracts.
  • Reference:
  • Spurny, Zaldivar, Belcher et al., 1986.
  • Study Design:
  • Case series.
  • Patients:
  • 54 eyes in 50 patients. Only 39 of those related to cataract.
  • Type of Potential Vision Test:
  • Potential acuity meter.Lotmar.
  • Severity and Type of Cataract:
  • Severity: VA 20/20 to CF.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Some had comorbidity; 12 had no comorbidity.
  • Preoperative Visual Acuity:
  • 20/25 to 20/400. 20/40 to CF at 1 foot.
  • Postoperative Visual Acuity:
  • N = 12 had no disease other than cataract 20/20 to 20/80. Patients with comorbidity (N = 27) had 20/20 to 20/200.
  • Findings:
  • For all patients combined, sensitivity = 15/28 = 0.54, specificity = 11/12 = 0.92. Positive predictive value = 15/16 = 0.93. Negative predictive value = 11/24 = 0.45. Prevalence of good outcome = 70% (good outcome = postop VA<=20/40).
  • Comments:
  • When PAM predicted that a good outcome would occur, it tended to be correct. When it predicted a bad outcome, a good outcome occurred over 1/2 the time. Predictive values are highly dependent on the prevalence of a good outcome.
  • Reference:
  • Halliday and Ross, 1983.
  • Study Design:
  • Consecutive case series.
  • Patients:
  • 50 patients with cataract.
  • Type of Potential Vision Test:
  • Two interferometers: Haag-Streit visometer; Rodenstock retinometer.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • 12 patients suspected to have comorbid eye disease.
  • Preoperative Visual Acuity:
  • Not given.
  • Postoperative Visual Acuity:
  • 20/20 to CF.
  • Findings:
  • For both interferometers, the achieved acuity was often quite different from the predicted acuity. Less than 45% of the eyes achieved the predicted acuity +/- 25%. Rodenstock: sensitivity = 0.65, specificity = 0.43. Haag-Streit: sensitivity = 0.72, specificity = 0.30.
  • Comments:
  • Use of consecutive patients makes this a stronger study design than if selected patients had been used. Predictive accuracy of the tests is poor.
  • Reference:
  • Miller, Graney, Elam et al., 1988.
  • Study Design:
  • Case series.
  • Patients:
  • 82 patients (82 eyes).
  • Type of Potential Vision Test:
  • Laser interferometer;potential acuity meter; clinical judgment of ophthalmologists on the result of the interferometer and PAM.
  • Severity and Type of Cataract:
  • Severity: median VA 20/100.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • 62/82 eyes had no comorbidity. 20 eyes: corneal disease (5); retinal disease (10); or both (2)3 retinas not visualized.
  • Preoperative Visual Acuity:
  • 20/20 to CF or worse. No data on distribution of preop VA.
  • Postoperative Visual Acuity:
  • Distribution of postop VA not reported. Median VA was 20/40.
  • Findings:
  • 11% of eyes had same or worse VA postop.Exact prediction occurred with: PAM -- 11%, laser -- 15%, and clinical judgment -- 15% of eyes (clinical judgment = PAM + laser + clinical judgment).Accurate prediction within 1 line occurred with: PAM -- 26%, laser -- 27%, and clinical judgment -- 57% of eyes.
  • Comments:
  • Ophthalmologist clinical judgment combined with the 2 potential vision tests was better than either of the 2 tests alone. When an ophthalmologist has information from both test results, she/he can predict correctly 1/2 the time. No data on how well ophthalmologist can predict without the results of the two potential vision tests. No data on sensitivity, specificity, or predictive values.
  • Reference:
  • Graney, Applegate, Miller et al., 1990.
  • Study Design:
  • Case series.
  • Patients:
  • 36 patients aged 70 and over and diagnosed presurgery to have retinal disease.
  • Type of Potential Vision Test:
  • Author's clinical index for patients with retinal disease.
  • Severity and Type of Cataract:
  • Severity: VA 0.13 +/- 0.11.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • All had retinal disease.
  • Preoperative Visual Acuity:
  • 0.13 +/- 0.11.
  • Postoperative Visual Acuity:
  • 64% were worse than 20/40 postop.
  • Findings:
  • Combination of 3 clinical variables was a good predictor of surgical outcome (sensitivity = 0.83, specificity = 0.85). Of the patients who had successful surgeries (VA 20/40 or better), 83% were predicted to succeed by the index. Everyday activities of daily living (ADLs) and mental status (SPMSQ) were evaluated. Only 4 of the 14 everyday activities could be assessed because patients were relatively independent. Traveling independently beyond walking distance and independent shopping improved. Mental status did not improve significantly.
  • Comments:
  • Only study to examine functional impairments.Authors did univariate statistics on 15 variables without doing a correction for multiple comparisons. If done, only preop VA would reach statistical significance. For the logistic regression model, there were too few subjects for 5 variables. Thus, results may not be reproducible. The predictive model needs to be validated using a second sample of patients before being considered for clinical use.
  • Reference:
  • Bernth-Petersen and Naeser, 1982.
  • Study Design:
  • Case series.
  • Patients:
  • 90 cataract patients.
  • Type of Potential Vision Test:
  • Lotmar visometer.
  • Severity and Type of Cataract:
  • Severity: immature vs. mature.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Macular disease (14 patients).
  • Preoperative Visual Acuity:
  • N/A.
  • Postoperative Visual Acuity:
  • <=2.0 to 1.20.
  • Findings:
  • Postop VA <0.5 Postop VA >=0.5
    Pre-IA(poor)(good)Total
    <0.5 (poor)7714
    >=0.5 (good)73845
    Total144559
    Sensitivity = 7/14 = 0.5
    Specificity = 38/45 = 0.84
    24 (27%) patients could not see the fringes, thus only 66 patients remained in the
    study; however, 1 died and 6 had postop complications, leaving a total of 59.
  • Comments:
  • Predictive accuracy of the test was poor.27% of patients dropped out of study, introducing a possible selection bias and limiting the generalizability of the findings.
  • Reference:
  • Goldstein, Jamara, Hecht et al., 1988.
  • Study Design:
  • Consecutive case series.
  • Patients:
  • 40 eyes; patients requested surgery.
  • Type of Potential Vision Test:
  • SITE IRAS hand-held interferometer;Haag-Streit Lotmar visometer.
  • Severity and Type of Cataract:
  • Severity: 20/50 to LPType: not given.
  • Type of Comorbid Ocular Pathology:
  • 6 patients had photopsia, postop trauma, macular degeneration, or amblyopia.
  • Preoperative Visual Acuity:
  • 20/50 or worse.
  • Postoperative Visual Acuity:
  • 20/15 to CF 1 foot.
  • Findings:
  • 1. SITE IRASPostop VA >=20/40Postop VA <20/40Total
    <=20/4021324
    >20/40628
    Total27032
    Sensitivity = 21/27 = 0.77
    Specificity = 2/5 = 0.40
    2. Haag-StreitPostop VA >=20/40Postop VA <20/40Total
    >=20/4021425
    >20/40516
    Total26531
    Sensitivity = 21/26 = 0.77
    Specificity = 1/5 = 0.20.
  • Comments:
  • 5 eyes removed from study to "reduce testing variability." Data missing on 4 other eyes with VA of CF 10 or worse. This introduces possible selection bias.Both tests are poor predictors of postop VA. In only 57% and 43% of eyes did the tests predict within 2 lines of postop VA.
  • Reference:
  • Graney, Applegate, Miller et al., 1988.
  • Study Design:
  • Consecutive case series with explicit inclusion/exclusion criteria.
  • Patients:
  • Training set (N = 157). Testing set (N = 96).
  • Type of Potential Vision Test:
  • Clinical index -- age, Snellen, visual acuity, number of medications, frequency of reading newspaper.Laser interferometer.Potential acuity meter.
  • Severity and Type of Cataract:
  • Severity: not given. Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • Training: 0.2 +/- 0.2. Testing: 0.2 +/-0.1.
  • Postoperative Visual Acuity:
  • Training: 0.6 +/- 0.2. Testing: 0.5 +/-0.2.
  • Findings:
  • Training set: Percentage of patients predicted within 1 line:
    a) CI, 72%;
    b) LI, 37%;
    c) PAM,
    33%
    Positive Negative
    PredictivePredictive
    SensitivitySpecificity Value Value
    CI96%23%56%88%
    LI43%90%95%24%
    PAM50%81%93%25%
  • Testing set: a) Clinical index -- 61% predicted within 1 line (sensitivity = 91%, specificity = 26%, positive predictive value = 60% negative predictive value = 69%).
  • Comments:
  • For clinical index there was a high false (positive) rate (i.e., predicted that patients would do well who did not do well). Accuracy of LI and PAM was low when they predicted a poor outcome.
  • Reference:
  • Lischwe and Ide, 1988.
  • Study Design:
  • Case series.
  • Patients:
  • 56 patients (8 with capsular opacities).
  • Type of Potential Vision Test:
  • Blue field entoptoscope. Slides with moving corpuscle.
  • Severity and Type of Cataract:
  • Severity: clear media.Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Macular degeneration, diabetes, histoplasmosis, retinal vein occlusion.
  • Preoperative Visual Acuity:
  • Not given.
  • Postoperative Visual Acuity:
  • Not given (scattergram indicates 20/20 to LP).
  • Findings:
  • For patients with 20/200 or better postop VA.
    BFEPostop VA >=;20/40Postop VA <20/40Total
    Slide 4 or less23023
    Slide 5 or greater81018
    Total311041
    Sensitivity = 23/31 = 0.74
    Specificity = 10/10 = 1.0
    Positive predictive value = 23/23 = 100%
    Negative predictive value = 10/18 = 56%.
  • Comments:
  • False positive and false negative rates were not calculated correctly. The paper reports positive and negative predictive values. 15 patients with preop VA worse than 20/200 were excluded and 8 patients with capsular opacities included. The predictive value of a positive was high and predictive value of negative was low, but generalizability of findings is questionable.
  • Reference:
  • Severin and Severin, 1988b.
  • Study Design:
  • Case series.
  • Patients:
  • 186 patients (210 eyes).
  • Type of Potential Vision Test:
  • Potential acuity meter.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • Macular degeneration.
  • Preoperative Visual Acuity:
  • Yes.
  • Postoperative Visual Acuity:
  • Yes.
  • Findings:
  • 26% of cases predicted VA precisely.78% of cases predicted VA within 2 lines.Ability to predict final VA better in patients with mild to moderate cataracts.8/10 false positives (overly optimistic) had macular degeneration.
  • Comments:
  • Not stated whether ARMD was determined a) in all or only some patients, b) with or without knowledge of PAM result, c) preop or postop.
  • Reference:
  • Weinstein, 1977.
  • Study Design:
  • Case series.
  • Patients:
  • 52 cataract patients.
  • Type of Potential Vision Test:
  • Visually evoked potentials.
  • Severity and Type of Cataract:
  • Severity: 20/70 to CF.Type: Not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • 20/70 to CF.
  • Postoperative Visual Acuity:
  • 20/15 to CF.
  • Findings:
  • VEPPostop VA>=20/50Postop VA <20/50TotalNormal9413Abnormal347Total12820Sensitivity = 9/12 = 0.75Specificity = 4/8 = 0.5.
  • Comments:
  • 34 of 52 of the subjects (65%) did not have postop data. Results presented for only 20 eyes. Predictive accuracy was low among patients for whom data are reported.
  • Reference:
  • Ing, 1986.
  • Study Design:
  • Case series.
  • Patients:
  • 32 cataract patients, 33 eyes.
  • Type of Potential Vision Test:
  • Potential acuity meter.
  • Severity and Type of Cataract:
  • Severity: mixed.Type: mixed; dense cataracts excluded.
  • Type of Comorbid Ocular Pathology:
  • 3 patients with moderately advanced dry atrophic macular degeneration.
  • Preoperative Visual Acuity:
  • 20/50 to 20/300.
  • Postoperative Visual Acuity:
  • No individual values given.
  • Findings:
  • Unable to calculate sensitivity and specificity from data given. In 31 of 33 eyes, achieved acuity was within 2 lines of predicted acuity (off by 3 lines in the other 2). 3 eyes achieved less than the predicted acuity. PAM tended to underestimate rather than overestimate outcome.
  • Comments:
  • Dense cataracts excluded. Patients selected over 16-month period -- relatively long time period to obtain only 33 patients; possible that patient recruitment may have been selective.
  • Reference:
  • Adams and Shock, 1986.
  • Study Design:
  • Case series.
  • Patients:
  • 101 cataract patients.
  • Type of Potential Vision Test:
  • Flying Corpuscle Viewer (entoptic device).
  • Severity and Type of Cataract:
  • Not stated.
  • Type of Comorbid Ocular Pathology:
  • Cystoid macular edema (2 patients); macular pucker (1 patient); diabetic maculopathy (1 patient).
  • Preoperative Visual Acuity:
  • Not given.
  • Postoperative Visual Acuity:
  • "Good" (VA >=20/40 at 6 months) or "poor."
  • Findings:
  • Device PredictedPostop VA "Good"Postop VA "Poor&"
    >=20/406120
    <20/40418
    Total6538
    Sensitivity = 19/23 = 0.83
    Specificity = 3/3 = 1.0.
  • Comments:
  • No information on type or severity of cataract; no controls for case severity; operative procedures varied considerably; predictive accuracy is low.
  • Reference:
  • Davis, Sherman, Bass et al., 1991.
  • Study Design:
  • Case series.
  • Patients:
  • 124 cataract patients undergoing surgery. 112 patients included in analyses.
  • Type of Potential Vision Test:
  • Snellen visual acuity, potential acuity meter, laser interferometer, blue field entoptoscope, bright flash visually evoked potentials.
  • Severity and Type of Cataract:
  • All types.
  • Type of Comorbid Ocular Pathology:
  • 38 (34%) had macular, optic nerve, or optic pathway disease.
  • Preoperative Visual Acuity:
  • 20/200 or lower.
  • Postoperative Visual Acuity:
  • Average = 20/40.
  • Findings:
  • Neither PAM nor LI provide good prediction of VA improvement, especially for patients with preop VA worse than 20/200. Prediction better for mild to moderate cataracts.Multiple regression analysis to predict postop VA using data from all tests performed better than any single test. Snellen, VA, LI, and VEP better than PAM and BFE for prediction.
  • Comments:
  • Presentation of data difficult to interpret. All graphical representations of correlation.
  • Reference:
  • Morris, Klett, Gieser et al., 1991.
  • Study Design:
  • Case series.
  • Patients:
  • 15 patients, 15 eyes.
  • Type of Potential Vision Test:
  • Laser interferometer, contrast sensitivity function.
  • Severity and Type of Cataract:
  • Severity: 20/70 to 20/200, N = 11; worse than 20/200, N = 4; Type: mixed.
  • Type of Comorbid Ocular Pathology:
  • Varied with patient.
  • Preoperative Visual Acuity:
  • Isolated retina contrast sensitivity function.
  • Postoperative Visual Acuity:
  • Optical-plus-retinal contrast sensitivity function.
  • Findings:
  • In 11 of 15 patients, postop CSF was predicted accurately. 3 out of 4 inaccurate predictions were in patients with VA <20/200.
  • Comments:
  • 25% of cases lost to followup.
  • Reference:
  • Bryant, 1985.
  • Study Design:
  • Case series.
  • Patients:
  • 101 patients.
  • Type of Potential Vision Test:
  • Lotmar interferometer.
  • Severity and Type of Cataract:
  • Severity: mixed. Type: nuclear and posterior subcapsular.
  • Type of Comorbid Ocular Pathology:
  • Macular disease.
  • Preoperative Visual Acuity:
  • Yes.
  • Postoperative Visual Acuity:
  • Yes.
  • Findings:
  • Normal macula (N = 60): 80% of cases within 2 lines of predicted VA;48% of cases predicted VA precisely.Abnormal macula (N = 41): 66% within 2 lines (too optimistic in 44%, too pessimistic in 22%);34% precise;the more severe the macular disease, the greater the likelihood of being too optimistic.Overall (N = 101): ability to predict final VA better with better preop vision, unreliable prediction at 20/200 or less;with increased density of cataract, prediction too pessimistic; no difference for PSC or nuclear.
  • Comments:
  • Retrospective (i.e., postop) grading of macular disease limits conclusions that can be drawn.
  • Reference:
  • Carpel and Henderson, 1986.
  • Study Design:
  • Case series.
  • Patients:
  • 100 patients.
  • Type of Potential Vision Test:
  • Potential acuity meter.
  • Severity and Type of Cataract:
  • Severity: not given.Type: nuclear sclerosis, posterior subcapsular, cortical, combination.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • Not given.
  • Postoperative Visual Acuity:
  • Not given.
  • Findings:
  • PAM was not obtained in 5 cases where VA was CF or worse.In 82 of 95 cases (86%, the PAM prediction was within 3 lines of postop acuity.
  • Comments:
  • Within 3 lines of predicted is not a very accurate level of prediction, and this was achieved in only 86pct of cases.
  • Reference:
  • Enoch, Williams, Essock et al., 1985.
  • Study Design:
  • Cross-sectional.
  • Patients:
  • Not given. Impossible to determine total.
  • Type of Potential Vision Test:
  • Vernier acuity,gap test, perimetry test.
  • Severity and Type of Cataract:
  • Severity: not given. Type: not given.
  • Type of Comorbid Ocular Pathology:
  • Not given.
  • Preoperative Visual Acuity:
  • 20/20 to 20/1000.
  • Postoperative Visual Acuity:
  • Not given.
  • Findings:
  • Majority of graphs describe a single patient or 2 to 4 patients. Preop Snellen acuity and optimum vernier acuity are strongly correlated (r = 0.83).
  • Comments:
  • Too few patients in any one analysis to draw conclusions. Little information about predicting postop acuity.
  • Reference:
  • Baraldi, Enoch, and Raphael, 1986.
  • Study Design:
  • Case series.
  • Patients:
  • 10 patients.
  • Type of Potential Vision Test:
  • Gap test using vernier acuity.
  • Severity and Type of Cataract:
  • Severity: 20/70 to 20/1000. Type: posterior subcapsular.
  • Type of Comorbid Ocular Pathology:
  • None.
  • Preoperative Visual Acuity:
  • 20/700 to 20/1000.
  • Postoperative Visual Acuity:
  • 20/25 or better.
  • Findings:
  • Each graph includes only 1 or 2 patients.
  • Comments:
  • Graphs for only 5 of the 10 patients are given. Too few patients to draw any firm conclusions.
  • Reference:
  • Enoch, Williams, Essock et al., 1985.
  • Study Design:
  • Case series.
  • Patients:
  • 15 patients.
  • Type of Potential Vision Test:
  • Gap test (vernier acuity).Perimetry test.
  • Severity and Type of Cataract:
  • Not given.
  • Type of Comorbid Ocular Pathology:
  • None.
  • Preoperative Visual Acuity:
  • 20/25 to 20/1000.
  • Postoperative Visual Acuity:
  • Not given.
  • Findings:
  • No evaluation of predictive accuracy of test results.
  • Comments:
  • This study is a description of the results given by these tests, not an evaluation of their ability to predict postop VA. Moreover, too few patients to draw any firm conclusions.
  • Reference:
  • Angra and Pal, 1990.
  • Study Design:
  • Case series.
  • Patients:
  • 20 phakic controls (no medical opacity).20 aphakic controls.20 grade I cataracts. 20 grade II cataracts.20 grade III cataracts. 20 grade III cataract surgery. 20 grade IV cataract surgery.
  • Type of Potential Vision Test:
  • Laser interferometer.
  • Severity and Type of Cataract:
  • See grades I to IV (mildly diminished fundus to no red fundus glow visible).
  • Type of Comorbid Ocular Pathology:
  • Not given. No patients with abnormal maculas included.
  • Preoperative Visual Acuity:
  • 6/26 to 6/6 (grade III cataract surgery patients) only.
  • Postoperative Visual Acuity:
  • Cannot tell.
  • Findings:
  • For cataract patients receiving surgery, 35% of cases were predicted accurately; 50% were predicted to have lower VA than achieved, and 15% were predicted to have higher VA than achieved.
  • Comments:
  • Patients dropped from analysis if they had preoperative or postoperative complications. No raw data provided. Definitions of "accurate," "lower," and "higher" predictions not provided. Difficult to interpret writeup.
  • Note:
  • ARMD = Atrophic retinal macular degeneration. BFE = Blue field entoptoscope. CF = Count fingers. CI = Clinical index. CSF = Contrast sensitivity function. ERG = Electroretinogram. HM = Hand motion. IA = Interference visual acuity. LI = Laser interferometer. LP = Light perception. PA = Potential acuity. PAM = Potential acuity meter. PSC = Posterior subcapsular. RG = Retinogram. Se = Sensitivity. Sp = Specificity. VA = Visual acuity. VEP = Visually evoked potentials. VER = Visually evoked responses.

Attachment 5. Literature Review Evidence: Potential Vision and Macular Degeneration

  • Reference:
  • Faulkner, 1983.
  • Number of Eyes With Macular Degeneration:
  • 35.
  • Type of Macular Degeneration:
  • 29 eyes, macular degeneration not defined.2 eyes, geographic atrophy of pigment epithelium of macular; 3) 4 eyes, serous detachments of sensory epithelium of macular.
  • Type of Potential Vision Test:
  • Rodenstock laser interferometer.
  • Findings:
  • When MD not defined, predicted to within 1 line of Snellen acuity in 26/27 eyes, predicted within 2 lines in 28/29.For geographic atrophy of pigment epithelium of macular, postop VA poorer than predicted.No data given for other eyes.
  • Comments:
  • Did not define macular degeneration.No data given for geographic atrophy of pigment epithelium of macular.
  • Reference:
  • Spurny, Zaldivar, Belcher et al., 1986.
  • Number of Eyes With Macular Degeneration:
  • 10.
  • Type of Macular Degeneration:
  • Not defined.
  • Type of Potential Vision Test:
  • Lotmar interferometer.Potential acuity meter.
  • Findings:
  • Lotmar predicted better acuity than achieved in 6/10 eyes; worse than achieved in 2/10. Potential acuity meter predicted better acuity than achieved in 1/10 eyes; worse than achieved in 8/10.
  • Comments:
  • Neither instrument useful in patients with macular degeneration.
  • Reference:
  • Bernth-Petersen and Naeser, 1982.
  • Number of Eyes With Macular Degeneration:
  • 14.
  • Type of Macular Degeneration:
  • Not defined.
  • Type of Potential Vision Test:
  • Lotmar interferometer.
  • Findings:
  • No data given.
  • Comments:
  • Authors concluded instrument not useful in patients with macular degeneration.
  • Reference:
  • Cohen, 1976.
  • Number of Eyes With Macular Degeneration:
  • 14.
  • Type of Macular Degeneration:
  • Macular degeneration identified preop, but not defined; 11/14 eyes had preop VA of CF or HM.
  • Type of Potential Vision Test:
  • Laser interferometer.
  • Findings:
  • Predicted visual acuity within 2 lines in 10/14 eyes.
  • Comments:
  • Reasonably good predictor considering poor preop acuities.
  • Reference:
  • Tabbut and Lindstrom, 1986.
  • Number of Eyes With Macular Degeneration:
  • 5.
  • Type of Macular Degeneration:
  • Not defined.
  • Type of Potential Vision Test:
  • Laser interferometer.
  • Findings:
  • Predicted better acuity than achieved in 3 patients. Predicted within 1 line in 2 patients.
  • Comments:
  • Small number of eyes studied.
  • Reference:
  • Halliday and Ross, 1983.
  • Number of Eyes With Macular Degeneration:
  • 12.
  • Type of Macular Degeneration:
  • Macular degeneration not specified; included with other eye disease.
  • Type of Potential Vision Test:
  • Two interferometers: 1) Haag-Streit visometer, 2) Rodenstock retinometer.
  • Findings:
  • No data specific to macular degeneration.
  • Comments:
  • --
  • Reference:
  • Goldstein, Jamara, Hecht et al., 1988.
  • Number of Eyes With Macular Degeneration:
  • 3.
  • Type of Macular Degeneration:
  • Not defined.
  • Type of Potential Vision Test: Two interferometers:
  • SITE IRAS hand-held,Haag-Streit Lotmar visometer.
  • Findings:
  • No data given.
  • Comments:
  • Authors concluded neither instrument useful in patients with macular degeneration.
  • Reference:
  • Minkowski, Palese, and Guyton, 1983.
  • Number of Eyes With Macular Degeneration:
  • 20.
  • Type of Macular Degeneration:
  • Age-related macular degeneration or drusen.
  • Type of Potential Vision Test:
  • Potential acuity meter.
  • Findings:
  • Results not reported separately for eyes with macular degeneration.
  • Comments:
  • --
  • Reference:
  • Severin and Severin, 1988b.
  • Number of Eyes With Macular Degeneration:
  • Number of eyes with macular degeneration cannot be determined from paper. Total of 210 eyes of 186 consecutive patients.
  • Type of Macular Degeneration:
  • Not defined.
  • Type of Potential Vision Test:
  • Potential acuity meter.
  • Findings:
  • 8/10 eyes incorrectly predicted to have good results had senile macular degeneration.
  • Comments:
  • No information on how many eyes had senile macular degeneration in total population.
  • Reference:
  • Ing, 1986.
  • Number of Eyes With Macular Degeneration:
  • 3.
  • Type of Macular Degeneration:
  • Moderately advanced dry atrophic macular degeneration.
  • Type of Potential Vision Test:
  • Potential acuity meter.
  • Findings:
  • Postop VA was predicted within 2 lines in all 3 patients.
  • Comments:
  • --
  • Reference:
  • Murphy, 1983.
  • Number of Eyes With Macular Degeneration:
  • 3.
  • Type of Macular Degeneration:
  • Not defined.
  • Type of Potential Vision Test:
  • Blue field entoptoscope.
  • Findings:
  • Prediction was correctly positive for one eye. No data on whether 2 negative predictions were correct.
  • Comments:
  • --
  • Reference:
  • Sinclair, Loebl, and Riva, 1979.
  • Number of Eyes With Macular Degeneration:
  • 8.
  • Type of Macular Degeneration:
  • 5 disciform; 3 atrophic.
  • Type of Potential Vision Test:
  • Blue field entoptoscope.
  • Findings:
  • Results for eyes with macular degeneration not analyzed separately.
  • Comments
  • --
  • Reference:
  • Skalka, 1981b.
  • Number of Eyes With Macular Degeneration:
  • 4.
  • Type of Macular Degeneration:
  • Postop diagnosis.
  • Type of Potential Vision Test:
  • Blue field entoptoscope.
  • Findings:
  • All (4) patients had negative or equivocal test preop.
  • Comments:
  • No analyses as to whether predictions correct.
  • Reference:
  • Lischwe and Ide, 1988.
  • Number of Eyes With Macular Degeneration:
  • 33.
  • Type of Macular Degeneration:
  • Not defined.
  • Type of Potential Vision Test:
  • Blue field entoptoscope.
  • Findings:
  • 7/33 correctly predicted to have positive results.
  • Comments:
  • --
  • Note:
  • CF = Count fingers. HM = Hand motion. MD = Macular degeneration. VA = Visual acuity.

Attachment 6. Literature Review Evidence: Specular Microscopy

  • Reference:
  • Azen, Hurt, Steel et al., 1983.
  • Study Design:
  • Case series.
  • Study Population Number and Type:
  • 70 eyes; 67 patients, mean age 73, range 51-95. All received preop specular microscopy.
  • Preoperative Specular Microscopy Measure:
  • Cell count (mean +/- SE).
  • Exposure/Intervention:
  • Extracapsular cataract extraction and posterior chamber lens implant.
  • Findings:
  • One patient with postop CD but no information on preop specular microscopy for that patient.
  • Comments:
  • Gives no information related to sensitivity/specificity; does not relate preop specular microscopy results to postop clinical outcome; does not report distribution of preop specular microscopy results on patients with good clinical outcomes.
  • Reference:
  • Bates, Cheng, and Hiorns, 1986.
  • Study Design:
  • Substudy of randomized controlled trial.
  • Study Population Number and Type:
  • 274 eyes; 268 patients, mean age 72, range 55 to 89; preop specular microscopy on 9 patients with CD, 117 patients without CD.
  • Preoperative Specular Microscopy Measure:
  • Cell count (mean +/- SD).
  • Exposure/Intervention:
  • Intracapsular cataract extraction and contact lens;intracapsular cataract extraction and iris-supported lens implant; extracapsular cataract extraction and iridocapsular lens implant.
  • Findings:
  • There were 9 patients with postop CD; 117 without; no difference in mean preop cell count of the 2 groups.
  • Comments:
  • Data do not permit estimation of sensitivity/specificity; findings suggest specular microscopy does not discriminate between patients who will vs. will not develop CD.
  • Reference:
  • Bates and Cheng, 1988.
  • Study Design:
  • Substudy of randomized controlled trial (same as Bates, Cheng, and Hiorns, 1986).
  • Study Population Number and Type:
  • Same as Bates, Cheng, and Hiorns, 1986. Preop specular microscopy on 3 groups: 9 with CD, 7 with high cell loss, 15 normal controls.
  • Preoperative Specular Microscopy Measure:
  • Cell morphology (numerous measures).
  • Exposure/Intervention:
  • Same as Bates, Cheng, and Hiorns, 1986.
  • Findings:
  • No statistically significant differences for any preop morphologic measure except mean area of smallest cell (greater in CD patients than in controls).
  • Comments:
  • Data do not permit estimation of sensitivity and specificity; data suggest preop morphology cannot predict postop outcome, but sample size is too small to draw valid conclusions.
  • Reference:
  • Stur, 1988.
  • Study Design:
  • Case series.
  • Study Population Number and Type:
  • 161 eyes; mean age 72; 2/3 women. 146 eyes had preop specular microscopy (including 3 patients excluded from main analysis).
  • Preoperative Specular Microscopy Measure:
  • Cell count (mean +/- SD). Cell morphology (numerous measures).
  • Exposure/Intervention:
  • Intracapsular cataract extraction with anterior chamber lens implant.
  • Findings:
  • 3 patients had postop CD; 2 had low preop cell counts; 1 had normal preop cell count (exact cell counts not given).
  • Comments:
  • Data do not permit estimation of sensitivity and specificity; too few patients to draw valid conclusions.
  • Reference:
  • Kraff, Sanders, and Lieberman, 1980.
  • Study Design:
  • Nonrandomized controlled trial.
  • Study Population Number and Type:
  • 1,027 patients; 564 with preop and postop specular microscopy; 300 more patients had preop but no postop specular microscopy.
  • Preoperative Specular Microscopy Measure:
  • Cell count (mean +/- SD).
  • Exposure/Intervention:
  • Intracapsular cataract extraction.Anterior chamber phacoemulsification. Posterior chamber phacoemulsification. Cataract extraction with lens implant (with preop and postop specular microscopy).
  • Findings:
  • 5 patients had postop CD. Of these, there were preop specular microscopy on 3; all 3 had abnormal preop specular microscopy (1 with uncountable cells), 1 had preop cell count less than 1,000/mm[sup 2] but cornea remained clear.
  • Comments:
  • Suggests cell count might be predeterminant of corneal decompensation, but too few patients with evaluable data to draw valid conclusions.
  • Reference:
  • Rao, Aquavella, Goldberg et al., 1984.
  • Study Design:
  • Case series.
  • Study Population Number and Type:
  • 118 eyes; 102 patients, mean age 65.8, range 51-86. All patients had preop and postop specular microscopy.
  • Preoperative Specular Microscopy Measure:
  • Cell count, cell morphology (mean and range).
  • Exposure/Intervention:
  • Intraocular lens implant.
  • Findings:
  • 40 eyes with postop CD and 78 without; no significant difference in cell count of the 2 groups; patients with CD had greater variation in preop cell area.
  • Comments:
  • Data do not permit estimation of sensitivity and specificity; cell count not of value; morphology may be of value; lens used in study is no longer used because of high complication rate.
  • Reference:
  • Bourne and Kaufman, 1976.
  • Study Design:
  • Case series.
  • Study Population Number and Type:
  • 16 patients (age 16 to 80). All had preop specular microscopy.
  • Preoperative Specular Microscopy Measure:
  • Cell count for individual patients.
  • Exposure/Intervention:
  • Intracapsular cataract extraction or phacoemulsification.
  • Findings:
  • No patients had CD; 3 patients had low (abnormal) preop cell count (<1,500).
  • Comments:
  • Small sample size; data suggest preop cell count has low specificity but give no information for sensitivity.
  • Reference:
  • Irvine, Kratz, and O'Donnell, 1978.
  • Study Design:
  • Case series.
  • Study Population Number and Type:
  • 23 patients.
  • Preoperative Specular Microscopy Measure:
  • Cell count for individual patients.
  • Exposure/Intervention:
  • Intracapsular cataract extraction or phacoemulsification, lens implant in 14 of 23.
  • Findings:
  • No patients had CD; all patients had normal preop specular microscopy.
  • Comments:
  • Data suggest good specificity but followup only 2-3 weeks. Too small a sample to draw valid conclusions. No information for sensitivity analysis.
  • Note:
  • CD = Corneal decompensation (e.g., bullous keratopathy, corneal edema). SD = Standard deviation. SE = Standard error.

Attachment 7. Literature Review Evidence: Anesthesia

  • Reference:
  • Karhunen and Orko, 1981.
  • Study Design:
  • Randomized controlled trial.
  • Study Population:
  • 150 female patients, age = 72+/-7.
  • Exposure/Intervention:
  • Atropine (local), pethidine with/without droperidol (local), atropine (general), pethidine (general).
  • Outcome Measures:
  • Nausea and vomiting.
  • Findings:
  • Droperidol appeared to reduce nausea in early postop time periods, but only statistically significant between local group with droperidol and general group without.
  • Comments:
  • Although this was a randomized trial, there were too many confounding variables (should have been 2x2 factorial design; general vs. local with and without droperidol). No discussion of type II error as possible reason for lack of differences in some analyses. Needs multivariate analysis because of possible effects of other analgesics given.
  • Reference:
  • Redmond and Dallas, 1990.
  • Study Design:
  • Clinical series -- comparative study.
  • Study Population:
  • 100 Caucasian patients, mean age = 76.6 (57 to 96 range), age and sex ratios equivalent.
  • Exposure/Intervention:
  • Retrobulbar vs. nonretrobulbar (subconjunctival bupivicaine) anesthesia.
  • Outcome Measures:
  • Visual acuity; astigmatism complications.
  • Findings:
  • No statistically significant differences in improvement of visual acuity or postop astigmatism. Complications included vitreous loss (3 retro, 2 nonretro), iris prolapse (1 retro), 2 wound leaks (retro), 2 residual cortex (nonretro). Surgeon's opinion -- retro caused more stress than nonretro.
  • Comments:
  • Not a prospective randomized study. An unknown number of cases were excluded from analysis retrospectively. This could have been subject to bias. No discussion of type II error. No discussion of baseline differences in visual acuity or systemic disease.
  • Reference:
  • Smith, 1990.
  • Study Design:
  • Uncontrolled trial (pseudocontrol groups).
  • Study Population:
  • 208 eyes (193 patients, 118 female, 75 male, mean age 70.5, range 46 to 90, SD 14.5). Main series, 165 patients (175 eyes); 26 patients (30 eyes).
  • Exposure/Intervention:
  • Nonretrobulbar anesthesia. Pseudocontrols: 30 eyes (general anesthesia); 3 eyes (retrobulbar).
  • Outcome Measures:
  • Visual acuity complications.
  • Findings:
  • There were few complications with nonretrobulbar anesthesia: 1 had convulsive hand movement during surgery; vitreous loss in 3 eyes; 1 had pain. No vitreous loss in general anesthesia cases. No obvious differences in postop visual acuity in 3 groups of patients, but no statistical analysis was performed. Nonretrobulbar technique was considered acceptable.
  • Comments:
  • Not designed as a controlled trial, but used two comparison groups as a reference. This was really a Phase I/II study and needs confirmation by a larger randomized controlled trial.
  • Reference:
  • Whitsett, Balyeat, and McClure, 1990.
  • Study Design:
  • Double-blind randomized controlled trial.
  • Study Population:
  • 100 patients (no description).
  • Exposure/Intervention:
  • Retrobulbar vs. peribulbar local anesthesia.
  • Outcome Measures:
  • Anesthesia efficacy (globe akinesia, lid akinesia, globe anesthesia). Supplemental anesthesia. Complications.
  • Findings:
  • No statistically significant differences between groups for any outcomes measured."No serious or potentially catastrophic complications."
  • Comments:
  • Although this was a prospective double-blind randomized controlled trial, there was no discussion of patient populations, pre/postop visual acuity, function, or astigmatism. No discussion of statistical methods used. They did acknowledge small sample size and possible bias because of unblinded observers.
  • Reference:
  • Hamilton, Gimbel, and Strunin, 1988.
  • Study Design:
  • Consecutive series 1/2/84 to 4/8/88. Block type chronologically assigned A through E.
  • Study Population:
  • 12,000 patients; about 70-were+/-70 years old; female, male rates, 62:38.
  • Exposure/Intervention: Blocks:
    1. retrobulbar plus 7th nerve block (N = 3,595);
    2. increased volume retrobulbar block (N = 1,640);
    3. dual peribulbar block (2 intraorbital) (N = 3,478);
    4. dual peribulbar block (1 intraorbital, 1 through upper eyelid)(N = 2,226);
    5. custom block (peribulbar plus retro is necessary)(N = 1,061).

Outcome Measures:

  1. Block score.
  2. Complications:
    • brain stem anesthesia;
    • other CNS spread;
    • spread to contralateral orbit;
    • moderate retrobulbar hemorrhage;
    • eyelid conjunctivitis and peribulbar ecchymoses;
    • extraocular muscle paresis;
    • shivering;
    • scleral perforation;
    • optic atrophy;
    • vasovagal problems;
    • "breakthrough" pain.

Findings:

  1. Blocks A and B achieved best scores.
  2. 6/3,595 Block A and 2/1,640 Block B patients had brain stem anesthesia;2 and 3 patients, respectively, had other CNS spread.
  3. 15/1,640 Block B patients had extraocular muscle paresis (compared with 4, 3, and 1 with blocks C, D, and E).
  4. Shivering highest with Block E (0.64%).
  5. Vasovagal problems ranged from 0.5 to 0.85%
  6. "Breakthrough" pain significantly greater with A and B compared with C, D, and E; A was significantly worse than B.

Comments:

  • Study not masked so classification of complications subject to bias.
  • Numbers of complications small in each group; statistical comparisons between groups difficult.
  • No data on visual outcome or relationship between complications and postop vision.
  • Complications in chronologically "early" block methods: no way to differentiate between chronologic effect (learning cause) and anesthetic effect.

  • Reference:
  • Backer, Tinker, Robertson et al., 1980.
  • Study Design:
  • Case series (comparative).
  • Study Population:
  • 1a) 288 ophthalmic operations (local anesthesia) with prior myocardial infarction (195 patients); 69% males; 90% >60 years of age; mean age 72 years; 18% had diabetes; 40% had angina. 1b) 26 additional operations (21 patients) had general anesthesia (prior myocardial infarction). 2) Other series of 587 nonophthalmic operations; 79% males; mean age = 67 years; 21% had diabetes; 34% had angina.
  • Exposure/Intervention:
  • 1a) Ophthalmic surgery under local anesthesia. 1b) Ophthalmic surgery under general anesthesia. 2) Nonophthalmic surgery under general or major regional anesthesia.
  • Outcome Measures:
  • Complications (postop reinfarction).
  • Findings:
  • No postop reinfarctions among local/retrobulbar or general anesthesia ophthalmic operations. 6.1% reinfarction rate in nonophthalmic surgery group.3.3% reinfarction rate when only procedures >=2 hrs. are included; 3.6% when eliminating "risky" upper abdominal, thoracic, or greater vessel operations of >=3 hrs.
  • Comments:
  • All retrospective comparisons. Too few ophthalmic procedures under general anesthesia with prior myocardial infarctions to expect any reinfarctions. Comparison of ophthalmology surgery with other types is subject to many confounding variables. This question may be researched through a meta-analysis. Will need many prospective clinical trials to find enough reinfarctions to draw conclusions.
  • Reference:
  • Meyers, 1979.
  • Study Design:
  • Case series (comparative).
  • Study Population:
  • Approximately 1,300 patients; mean age = 68 years.
  • Exposure/Intervention:
  • Intraocular surgery -- 300 patients with standby anesthesiologist, 1,000 patients without standby (both groups had retrobulbar block).
  • Outcome Measures:
  • Complications.
  • Findings:
  • Without standby: 5.6% complication rate (mostly life threatening); 13% complications in nonstandby group, but excluded patients with tachycardia who were taking anticholinergic medications. Authors claim standby group did better.
  • Comments:
  • Needs validation through randomized controlled trial. No discussion of baseline differences other than similarities in age. Why were tachycardia patients excluded from analysis of standby group? No indication that standby group was superior.
  • Reference:
  • Whittpen, Rapoza, Sternberg et al., 1986.
  • Study Design:
  • Consecutive series; different surgeons.
  • Study Population:
  • 3,123 patients requiring retrobulbar injections. Group 1 patients (N = 2,235) had a variety of procedures including cataract surgery. All Group 2 patients (N = 388) underwent retinal reattachment or vitrectomy. Serum values of 20 "control"; patients (noncases) also used.
  • Exposure/Intervention:
  • Group 1: 2% lidocaine + 0.75% bupivicaine + hyaluronidase. Group 2: 4% lidocaine + 0.75% bupivicaine + hyaluronidase. All patients received preop sedation.
  • Outcome Measures:
  • Respiratory arrest.
  • Findings:
  • 2/2,235 Group 1 patients had respiratory arrest (p = 0.003) vs. 7/888 Group 2 patients. 4/7 Group 2 patients had diabetes mellitus.No sign differences in age, sex between groups.No increase in serum levels of lidocaine or bupivicaine in cases compared with 20 "control" patients.
  • Comments:
  • Patients in Groups 1 and 2 had different surgeries and may have had different comorbidities associated with risk of respiratory arrest. Not clear if 20 "controls" were noncases from Groups 1 and 2.Not specific to cataract patients. Respiratory arrest not defined. Retrobulbar injection not defined or carried out by same surgeons. Cannot differentiate between technique effect and anesthesia effect.
  • Reference:
  • Whittpen, Rapoza, Sternberg et al., Weiss and Deichman, 1989.
  • Study Design:
  • Single-blind randomized controlled trial (surgeon blinded).
  • Study Population:
  • 79 patients, unknown characteristics.
  • Exposure/Intervention:
  • Retrobulbar vs. periocular anesthesia.
  • Outcome Measures:
  • Complications: supplemental anesthesia, chemosis.
  • Findings:
  • Only 1 patient in retrobulbar group had complication (tachycardia). 8/39 vs. 11/39 in retrobulbar vs. periocular patients required supplemental anesthesia (p>0.10, not significant); less chemosis in retrobulbar group (p<0.001); otherwise, no statistically significant difference between groups.
  • Comments:
  • No discussion of population characteristics or differences thereof. No consideration of type II error. No evaluation of pre/postop visual acuity, visual function, astigmatism.
  • Note:
  • CNS = Central nervous system. SD = Standard deviation.