Rate and Pattern of Rim Area Loss in Healthy and Progressing Glaucoma Eyes

Abstract

Purpose: To characterize the rate and pattern of age-related and glaucomatous neuroretinal rim area changes in subjects of African and European descent.

Design: Prospective longitudinal study.

Participants: Two hundred ninety-six eyes of 157 healthy subjects (88 patients of African descent and 69 of European descent) and 73 progressing glaucoma eyes of 67 subjects (24 patients of African descent and 43 of European descent) from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study were included.

Methods: Global and sectoral rim areas were measured using confocal laser scanning ophthalmoscopy. Masked stereophotograph review determined progression of glaucomatous optic disc damage. The rates of absolute rim area loss and percentage rim area loss in healthy and progressing glaucomatous eyes were compared using multivariate, nested, mixed-effects models.

Main outcome measures: Rate of rim area loss over time.

Results: The median follow-up time was 5.0 years (interquartile range, 2.0-7.4 years) for healthy eyes and 8.3 years (interquartile range, 7.5-9.9 years) for progressing glaucoma eyes. The mean rate of global rim area loss was significantly faster in progressing glaucomatous eyes compared with healthy eyes for both rim area loss (-10.2×10(-3) vs. -2.8×10(-3) mm(2)/year, respectively; P < 0.001) and percentage rim area loss (-1.1% vs. -0.2%/year, respectively; P < 0.001), but considerable overlap existed between the 2 groups. Sixty-three percent of progressing glaucoma eyes had a rate of change faster than the fifth quantile of healthy eyes. For both healthy and progressing eyes, the pattern of rim area loss and percentage rim area loss were similar, tending to be fastest in the superior temporal and inferior temporal sectors. The rate of change was similar in progressing eyes of patients of African or European descent.

Conclusions: Compared with healthy eyes, the mean rate of global rim area loss was 3.7 times faster and the mean rate of global percentage rim area loss was 5.4 times faster in progressing glaucoma eyes. A reference database of healthy eyes can be used to help clinicians distinguish age-related rim area loss from rim area loss resulting from glaucoma.

Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1

Rates of sectoral rim area change (X10−3 mm2/year) in healthy eyes (left) and progressing glaucoma eyes (right). I = inferior; N = nasal; S = superior; T = temporal

Figure 2

Rates of sectoral percent rim area change (%/year) in healthy eyes (left) and progressing glaucoma eyes (right). I = inferior; N = nasal; S = superior; T = temporal.

Figure 3

Distribution of the rates of rim area change (X10−3 mm2/year) of progressing glaucoma eyes (upper panel) and healthy eyes (lower panel). Left line represents 1st quantile (1% fastest healthy eyes, −11.5 ×10−3 mm2/year) and middle line represents 5th quantile (−6.7 ×10−3 mm2/year) criteria calculated using healthy eyes data. 66% of progressing glaucoma eyes had a rate of change faster than the 5th quantile; 38% of progressing glaucoma eyes had a rate of change faster than the 1st quantile.

Figure 4

Distribution of the rates of percent rim area change (%/year) of progressing glaucoma eyes (upper panel) and healthy eyes (lower panel). Left line represents 1st quantile (1% fastest healthy eyes, −1.2 %/year) and middle line represents 5th quantile (−0.8 %/year) criteria calculated using healthy eyes data. 56% of progressing glaucoma eyes had a rate of change faster than the 5th quantile; 41% of progressing glaucoma eyes had a rate of change faster than the 1st quantile.