African Descent and Glaucoma Evaluation Study (ADAGES): Rate and Pattern of Rim Area Loss in Normal and Progressing Eyes

Abstract

 

Purpose

 

To compare the rate and pattern of rim area (RA) loss in normal and glaucomatous subjects of African Descent (AD) and European Descent (ED).

 

Methods

 

Global and sectoral RA was measured using HRTII. Progression of glaucomatous optic disc damage was determined by stereophoto review. The rates of RA loss and %RA loss in normal and progressing glaucomatous eyes were compared using multivariable mixed-effects models.

 

Results

 

506 eyes of 264 normal subjects (139 AD and 125 ED) and 74 progressing glaucoma eyes of 68 subjects (24 AD and 44 ED) were included. Mean age was 47.9 years (range 18.3-85.4) in the normal group and 59.7 years (25.9-80.6) in the progressing group. The median (inter-quartile range) follow-up time was 5.0 years (2.9-6.9) for normal eyes and 8.2 years (7.1-9.9) for progressing eyes. The mean rate of global RA loss was significantly faster in progressing eyes compared with normal eyes for both RA loss (-0.01mm2/year vs. -0.004mm2/year, P=0.000) and %RA loss (-1.03%/year vs. -0.2%/year, P=0.000). For both normal and progressing eyes, the pattern of RA loss and %RA loss was similar; it tended to be faster in the temporal, temporal inferior and temporal superior regions than in the nasal regions. In the normal group, the estimated mean rate of global RA loss and %RA loss were faster in eyes of subjects of ED compared with subjects of AD (-0.0058 mm2/year vs. -0.0025mm2/year, P=0.003, and -0.28%/year vs. -0.09%/year, P=0.074). No statistically significant difference in rate of RA loss or %RA loss was found between progressing eyes of ED and AD subjects.

 

Conclusions

 

Compared with normal eyes, the rate of RA loss was 2.5 times faster and the rate of %RA loss was 5.2 times faster in progressing glaucoma eyes. Given that the pattern of faster loss in temporal sectors was similar in both groups, it is important to evaluate the magnitude of RA loss to help differentiate normal aging from glaucoma progression. In addition, studies assessing the pattern of RNFL damage in healthy eyes are needed to determine whether the faster change in the temporal region is specific to CSLO HRT measurements or to the aging process. The trend of a faster mean rate of RA loss in ED compared to AD normal eyes should be replicated in an independent study.

 

 

 

Keywords: 550 imaging/image analysis: clinical • 552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 413 aging