Exploring a possible retinal hemodynamic contribution to the pathogenesis of neovascular age-related macular degeneration (AMD), a recent study has found that the presence of a cilioretinal artery is associated with a lower risk of developing choroidal neovascularization (CNV)—but not central geographic atrophy (CGA). A cilioretinal artery, present in approximately 20% of the population, could enhance oxygen tension in the macula and protect against the development of CNV.
To analyze this association, researchers used Age-Related Eye Disease Study (AREDS) fundus photographs as well as study data obtained from the National Eye Institute’s Online Database of Genotypes and Phenotypes website.
In AREDS participants with AMD, only 22.0% (n = 1,531) of graded eyes had a cilioretinal artery; only 26.9% had a cilioretinal artery in one eye, and 8.4% had the vessel in both eyes.
At randomization, eyes with a cilioretinal artery had a lower prevalence of CNV (5.0% vs. 7.6%) but no difference in CGA (1.1% vs. 0.8%). In eyes without late AMD, those with a cilioretinal artery also had a lower mean AMD severity score. At five years, at-risk eyes with a cilioretinal artery had lower rates of progression to CNV (4.1% vs. 5.5%) but, again, no statistical difference in developing CGA (2.2% vs. 2.7%) or change in AMD severity score. In patients with a unilateral cilioretinal artery, eyes with the vessel showed a lower prevalence of CNV than fellow eyes (4.7% vs 7.2%).
The researchers concluded that while this association does not indicate causality, the findings shed some light on the vascular contribution to AMD pathogenesis and warrant further investigation into the role retinal circulation plays in the development of neovascular AMD.
|Snyder K, Yazdanyar A, Mahajan A, Yiu G. Association between the cilioretinal artery and choroidal neovascularization in age-related macular degeneration: a secondary analysis from the age-related eye disease study. JAMA Ophthalmol. July 5, 2018. [Epub ahead of print].|