Abstract
Purpose :
To investigate risk factors for visual field decay measured with the Glaucoma Rate Index (GRI) in open angle glaucoma patients.
Methods :
Open-angle glaucoma patients with a minimum of 6 visual fields (VF) and 3 years of follow-up were included. A point-wise rate of change (PRC) was estimated with an exponential fit and expressed as %/year change of the age-location matched normal. PRCs were used to calculate the Glaucoma Rate Index (GRI) for each eye. The GRI was normalized to maximum and minimum rates set by a simulated VF series to a scale of −100 (fastest decay) to +100 (fastest improvement). The relationship between GRI and clinical variables (age, race, glaucoma type, baseline mean deviation (MD), mean intraocular pressure (IOP), standard deviation of IOP, peak IOP, central corneal thickness (CCT) were investigated with linear mixed models.
Results :
1413 eyes of 793 patients with a mean (± SD) age of 63.3 (± 11.0) years and a mean MD −4.2 (± 5.2) dB were analyzed. The mean number of VFs was 13.7 (± 6.1), and mean follow-up duration was 11.4 (± 3.8) years. The mean GRI was −9.3 (± 17.6), and the proportion of eyes with worsening (GRI ≤ −6), not changing (−6 < GRI < 10), and improving (GRI ≥ 10) VFs was 41.0 %, 56.6 %, and 2.4 %, respectively. Worsening eyes were further partitioned into slow and fast decay (GRI < −37) based on previous work. The number of slowly decaying eyes was 469 (33%) and that of fast decaying eyes was 111 (7.9 %). In the univariable model, older age (p < 0.001), baseline MD (p=0.021), CCT (p = 0.020), diagnosis of exfoliation glaucoma (p=0.145), peak IOP (p < 0.001) and SD of IOP (p < 0.001) were potentially associated with a more negative GRI, while mean IOP was not significant (p = 0.672). In the multivariable model, older age (p = 0.001) and peak IOP (p = 0.002) were associated with rate of visual field decay.
Conclusions :
In this cohort, older age, and peak IOP were associated with faster glaucoma progression. Fast decaying eyes were older, had worse baseline MD, and had a higher peak IOP than the others. More aggressive treatment of such patients should be considered to slow visual disability.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.