Purpose: To compare differences in retinal arterial and venular caliber (RAC and RVC respectively) between fellow eyes with glaucoma of asymmetric severity.
Methods: We included subjects with bilateral primary glaucoma that had vertical cup-disc ratios (VCDR) >0.2 between both eyes, or visual field (VF) mean deviation (MD) >6.0 decibels (dB) between both eyes.
Results: Among 158 subjects, the average RAC in glaucoma eyes was 131.5 ± 17.8 μm vs 141.6 ± 18.8 μm in fellow eyes with mild disease (p < 0.001). RVCs in glaucoma eyes were 201.0 ± 21.4 μm vs 211.7 ± 25.3 μm in fellow eyes with mild disease (p < 0.001). This relationship held in clustered linear regression models adjusted for age, gender, vascular risk factors, visual acuity, axial length, and intraocular pressure, with RVCs narrower in eyes with worse disease vs mild disease. Eyes with worse disease had greater VCDR (0.9 ± 0.1 vs 0.7 ± 0.1, p < 0.001), and worse VF MD (-18.5 ± 8.6 vs -6.6 ± 5.6, p < 0.001).
Conclusion: In glaucoma with asymmetric severity between fellow eyes, retinal vascular caliber is less in the eye with more severe disease.