PMC

Visual field global indices provide an indication of visual field abnormality relative to an age-matched normative database. Absolute defect status (left panel) is an indication of general visual field loss, with increasingly negative numbers associated with greater levels of visual field loss. Pattern deviation (right panel) describes areas of local visual field loss, with increasingly positive numbers associated with higher levels of localised visual field loss. For both panels data points more to the left indicate greater loss of visual field sensitivity. The grey bands indicate the mean ±2 standard deviations of the older control data.

Paracentral and peripheral visual field loss definitions.
Representative grey scale and pattern deviation plot for peripheral visual field loss (A) and paracentral visual field loss (B) in two right eyes.
A. The red boxes indicate each possible peripheral visual field loss region, including inferior and superior nasal steps, temporal wedge and Bjerrum regions. A cluster of three or more points with sensitivity of −5 decibels (dB) or greater in any of these regions represents peripheral visual field loss. In this case, there is visual field loss in the inferior nasal step zone.
B. The blue boxes indicate the superior and inferior paracentral visual field loss regions. A cluster of three or more points with sensitivity of −5 dB or greater in either of these regions represents paracentral visual field loss. In this case, there is visual field loss in the inferior paracentral region. There is overlap between the paracentral zone and Bjerrum areas consisting of the second row of points. In order for the Bjerrrum area to be considered to be involved there must be at least one point in the third row from the top or bottom that has a retinal sensitivity of −5 dB or more.
This figure illustrates the approach used for Humphrey visual fields. Subjects with other types of perimetric data (such as the Dicon or Octopus visual fields) were included and a similar strategy was used to grade the equivalent of the pattern deviation plot. Less than 1% of visual fields were kinetic tests and they were excluded from analyses related to pattern of field loss.

Frequency of sub-categories of types of visual loss in the sample of older adults who meet World Health Organization low vision criteria or have a visual field defect from a neurological condition. 1a: Full field with decreased acuity (visual field test done). 1b: Likely full field with decreased acuity (visual field test not done). 2a: Center field distortion (visual acuity between 0.33 and 0.10). 2b: Center field defect with absolute scotoma (visual acuity worse than 0.10). 2c: Peripheral field loss with or without center field distortion (visual field test done). 2d: Likely peripheral field loss with or without center field distortion (visual field test not done). 3a: Peripheral field defect without decreased acuity (visual acuity better than 0.33). 3b: Peripheral field defect with decreased acuity (visual acuity 0.33 or worse). 4: Any visual field defect due to a cortical event.

A Relationship between visual field loss at end of study and rate of MD progression in AGC patients. Spearman’s correlation coefficient r = 0.60; p < 0.0001. B Relationship between visual field loss at end of study and rate of MD progression in COGS patients. Spearman’s correlation coefficient r = 0.33; p < 0.0001. C Distribution of final MD. D Relationship between initial MD and rate of MD progression.