Abstract
Purpose: :
To compare the difference in retinal vascular caliber between fellow eyes in persons with glaucoma of asymmetric severity.
Methods: :
This was clinical case series with subjects enrolled prospectively. For this analysis, subjects were included if a) one eye was diagnosed with primary open angle glaucoma (POAG), normal tension glaucoma (NTG) or primary angle closure glaucoma (PACG) while the other eye was normal, b) both eyes were diagnosed with POAG, NTG or PACG but the difference in vertical optic cup-disc ratio was more than 0.2 or c) both eyes were diagnosed with POAG, NTG or PACG but the difference in Humphrey Visual Field Mean Deviation between 2 eyes was more than 6.0. Pair-wise t test was used to compare retinal vascular caliber between eyes with more severe glaucoma and fellow eyes with milder or no disease. Clustered linear regression adjusted for age, race, gender and vascular risk factors was also used to compare two eyes while controlling the intra-subject correlation.
Results: :
A total of 252 subjects were enrolled. Retinal vascular caliber was narrower in eyes with more severe glaucoma compared to fellow eyes with less severe or no glaucoma (arteriolar caliber was 134.11 ± 19.06 vs 144.40 ± 20.39 µm, p<0.001; and venular caliber was 204.49 ± 22.76 vs 215.22 ± 24.97 µm, p<0.001). This relationship was similar in clustered linear regression models adjusted for age, gender, race and vascular risk factors, with retinal vascular caliber narrower in eyes with more severe glaucoma compared to fellow eyes (arteriolar caliber was 136.81 µm vs 146.98 µm p<0.001; and venular caliber was 201.73 µm vs 212.33µm p<0.001).
Conclusions: :
In persons with asymmetric glaucoma between eyes, retinal vascular narrowing is more severe in the eye with more severe glaucoma. This suggests that quantitative assessment of retinal vascular caliber may be a measure of severity of glaucomatous optic neuropathy.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • optic nerve • retina