Format

Send to

Choose Destination
Invest Ophthalmol Vis Sci. 2018 Jan 1;59(1):439-445. doi: 10.1167/iovs.17-22390.

The Effective Dynamic Ranges for Glaucomatous Visual Field Progression With Standard Automated Perimetry and Stimulus Sizes III and V.

Author information

1
Department of Ophthalmology, University of Iowa, College of Medicine, Veterans Administration Hospital, Iowa City, Iowa, United States.
2
Department of Neurology, University of Iowa, College of Medicine, Veterans Administration Hospital, Iowa City, Iowa, United States.
3
Department of Biostatistics, College of Public Health, University of Iowa, Iowa City, Iowa, United States.
4
School of Health Professions, Peninsula Allied Health Centre, Plymouth University, Plymouth, Devon, United Kingdom.

Abstract

Purpose:

It has been shown that threshold estimates below approximately 20 dB have little effect on the ability to detect visual field progression in glaucoma. We aimed to compare stimulus size V to stimulus size III, in areas of visual damage, to confirm these findings by using (1) a different dataset, (2) different techniques of progression analysis, and (3) an analysis to evaluate the effect of censoring on mean deviation (MD).

Methods:

In the Iowa Variability in Perimetry Study, 120 glaucoma subjects were tested every 6 months for 4 years with size III SITA Standard and size V Full Threshold. Progression was determined with three complementary techniques: pointwise linear regression (PLR), permutation of PLR, and linear regression of the MD index. All analyses were repeated on "censored'' datasets in which threshold estimates below a given criterion value were set to equal the criterion value.

Results:

Our analyses confirmed previous observations that threshold estimates below 20 dB contribute much less to visual field progression than estimates above this range. These findings were broadly similar with stimulus sizes III and V.

Conclusions:

Censoring of threshold values < 20 dB has relatively little impact on the rates of visual field progression in patients with mild to moderate glaucoma. Size V, which has lower retest variability, performs at least as well as size III for longitudinal glaucoma progression analysis and appears to have a larger useful dynamic range owing to the upper sensitivity limit being higher.

PMID:
29356822
PMCID:
PMC5777662
DOI:
10.1167/iovs.17-22390
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center