Risk factors for unilateral retinal nerve fiber layer defect progression in patients with bilateral primary open-angle glaucoma

Abstract

Purpose : To investigate the risk factors for unilateral retinal nerve fiber layer defect (RNFLD) progression in patients with bilateral primary open-angle glaucoma (POAG).

Methods : We included patients showing unilateral RNFLD progression in eyes with bilateral POAG who were followed up for more than 5 years. Patients underwent stereo disc photography, retinal nerve fiber layer photography (RNFLP), and Humphrey visual field (HVF). In addition, spectral-domain optical coherence tomography was performed for lamina cribrosa (LC) examination. LC abnormalities were defined as disinsertion, hole, and defect in LC. Progression was determined as an appearance of a new RNFLD, enlargement and deepening of RNFLD on RNFLP Cox proportional hazards regression analysis was performed to determine the risk factors for progression.

Results : A total of 23 patients with the mean follow-up period of 8.8 ± 1.9 years were included. There were no significant difference in the baseline (15.4 ± 3.2 vs 16.0 ± 3.3 mmHg, P = 0.262) and mean follow-up IOPs (13.2 ± 2.1 vs 12.9 ± 2.4, P = 0.236) between eyes with and without progression. The percentage of eyes showing LC abnormality was similar between eyes with (65.2%) and without (52.2%) progression (P = 0.55). However, larger number of eyes with optic disc hemorrhage (ODH) was found in progression group than in non-progression group (52.2% vs 17.3%, P = 0.013). A multivariate Cox proportional hazard model revealed that ODH (hazard ratio = 5.182, 95% confidence interval 1.339 – 12.058 P = 0.017) was significantly associated with unilateral RNFLD progression.

Conclusions : In patients with bilateral POAG, eyes showing ODH should be carefully monitored for structural progression.