It remains unclear whether reduced retinal blood flow and smaller arterioles, reported to exist in patients with open-angle glaucoma (OAG), are a cause or a consequence of ganglion cell loss. We examined whether baseline retinal vessel diameters were related to incident (i)OAG or incident optic disc changes in a population-based sample.
In the prospective population-based Rotterdam Study, baseline diameters of retinal arterioles and venules (1990-1993) were measured in digitized images of 3469 persons (aged 55 years and older) at risk for OAG. The follow-up examinations took place from 1997 to 1999. iOAG was based on the presence of incident glaucomatous visual field loss and/or incident glaucomatous optic neuropathy. Changes in neuroretinal rim, cup area, or vertical cup-to-disc ratio were calculated with a semiautomated image analyzer in 2782 persons.
After a mean follow-up time of 6.5 years, 74 participants had iOAG. At baseline, the mean arteriolar diameter was 147.5 +/- 14.2 microm (SD) and the venular, 222.9 +/- 20.0 microm. Neither arteriolar diameters (odds ratio [OR] per SD decrease: 0.82; 95% confidence interval [CI]: 0.66-1.03) nor venular ones (OR per SD increase: 1.20; 95% CI: 0.95-1.53) were significantly related to iOAG. Baseline retinal vessel diameters did not predict changes in the optic disc. Additional adjustment for cardiovascular risk factors did not alter these results.
The data show that baseline retinal vessel diameters did not influence the risk of iOAG or incident optic disc changes. These data provide no evidence for a retinal vascular role in the pathogenesis of OAG.