Large Intereye Asymmetry in Vessel Density May Signal Glaucomatous Damage
By Lynda Seminara
Selected By: Richard K. Parrish II, MD
Journal Highlights
American Journal of Ophthalmology, June 2018
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Hou et al. measured intereye retinal vessel density of glaucomatous and healthy eyes to assess whether asymmetry may indicate early glaucomatous damage, which often is asymptomatic. They found that intereye asymmetry of vessel density is much greater in glaucoma suspects than in people with healthy eyes.
This cross-sectional study included 55 individuals with healthy eyes, 32 glaucoma suspects, and 66 patients with mild or moderate glaucoma. Age, sex, and racial distributions were comparable for the 3 cohorts. Retinal vessel density was measured using optical coherence tomography angiography (OCTA) of the macula and optic nerve head. Thickness of the peripapillary retinal nerve fiber layer and the macular ganglion cell complex was measured with spectral-domain OCT. Intereye asymmetry was calculated as the difference in vessel density and thickness between each subject’s eyes. Univariate and multivariate analyses were performed to compare findings.
Results showed substantial differences between the study groups. Univariate and multivariate analyses demonstrated that intereye asymmetry in both peripapillary and macular vessel density was significantly greater for glaucoma suspects than for individuals with healthy eyes, but intereye asymmetry in thickness was similar for these groups. For all thickness-related parameters, there were significant differences between glaucoma suspects and glaucoma patients, both with and without adjustment for confounders; median values for glaucoma patients were roughly double those for suspects.
Examining intereye asymmetry of retinal vessel density may be a helpful adjunct to glaucoma screening programs; a better understanding of events that precede the onset of glaucoma would facilitate early diagnosis. Longitudinal studies are needed to further characterize the relationship between intereye variation in vessel density and the development and progression of glaucoma.
The original article can be found here.