Purpose
To investigate and compare visual field (VF) progression rate of different VF regions according to glaucomatous optic disc phenotypes (Nicolela & Drance classification) in open-angle glaucoma (OAG) patients with baseline intraocular pressure (IOP) in normal statistical range (≥70%) experiencing VF progression assessed by Humphrey VF analyzer
Methods
OAG patients with VF progression by event-based analysis and a minimum of 5 VF tests over at least 2 years were initially classified as focal, concentric, myopic, senile sclerotic groups according to optic disc appearance as described by Nicolela and Drance. After adjusting covariates- age, sex, laterality, spherical equivalent (SE), baseline/mean follow-up IOP, baseline VF global indices, using linear mixed-effects model, VF progression rate was evaluated with respect to mean thresholds of overall and regional clusters in central 10 and peripheral 10 to 24 degrees, and compared among different groups. VF Progression rate was defined significant with negative slope having following significance level (p < 0.05 for overall, P<0.025 for central and peripheral clusters).
Results
121 eyes (58 focal, 22 concentric, 41 myopic) were included in the analysis with a mean follow-up period of 6.1 years and a mean number of VF tests of 6.3. Myopic group was younger (42.5 years) and more myopic (-5.0 D) than focal (55.5 years, -0.7 D) and concentric (53.7 years, -1.1 D) groups, but other demographic factors were not significantly different among the groups. All groups showed significant rate of VF progression over time (P<0.025). In overall VF area, concentric group showed faster VF progression (-0.54 dB/year) than focal (-0.44 dB/year) or myopic (-0.36 dB/year) groups. In central 10 degrees, focal group showed fastest VF progression rate (-0.55 dB/year) whereas concentric group showed fastest progression rate (-0.57 dB/year) in peripheral 10 to 24 degrees. Among various covariates, age (p<0.01) and initial MD (P<0.01) were associated with faster VF progression rate at all clusters. Myopic group showed slowest progression rate in both central and peripheral area (-0.35 dB/year).
Conclusions
In progressive patients with OAG, glaucomatous optic disc classification based on phenotypes may be useful in terms of predicting VF progression rate at different VF areas (central vs. peripheral).
Keywords: 627 optic disc •
758 visual fields