Hemi-central retinal artery occlusion in young adults

Dear Editor,

I read the article with interest on hemi-central retinal artery occlusion in young adults by Rishi et al.[1]

This condition is unlikely to occur on ground of embryology, as the central retinal artery develops from a single hyaloid artery and enters the lamina cribrosa, and divides further into its principal branches. However, one may have a hemi-central retinal vein occlusion because two veins develop on either side of the hyaloid artery, which exit from the lamina cribrosa after joining to form a single central retinal vein. Occasionally, they may not come closer to unite and exit the lamina cribrosa separately, thus creating two central retinal veins.[2–4] The clinical pathology produced by such an anomaly has been extensively reported.[5] These cases reported here is early branching of the central retinal artery prior to its entry through the lamina cribrosa. In case 1, Fig. 1 shows associated choroidal infarct of the upper half of the fundus. Fig. 2 shows that the upper artery is a cilioretinal artery, whereas the lower one is the true central retinal artery. The fluorescein angiography in Fig. 3 shows the upper artery brighter than the lower, indicating that this is an earlier branch. Cases 2–4 are identical to case 1 and all of them are associated with choroidal and retinal ischemia.