I read the article with interest on hemi-central retinal artery occlusion in young adults by Rishi et al.
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. 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.
1. Rishi P, Rishi E, Sharma T, Mahajan S. Hemi-central retinal artery occlusion in young adults Indian J Ophthalmol. 2010;58:425–32
2. Mann I The development of human eye. 19643rd ed London British Medical Association:128
3. Hayreh SS, Hayreh MS. Hemi central retinal vein occlusion, abstracted Invest Ophthalmol Vis Sci. 1979;18(ARVO suppl):170
4. Chopdar A. Dual trunk central retinal vein Incidence in clinical practice Arch Ophthalmol. 1984;102:85–7
5. Chopdar A. Hemi central retinal vein occlusion, pathogenesis, clinical features, natural history and incidence of dual trunked central retinal vein Trans Ophthalmol Soc U K. 1982;102:241–8