Combined cilioretinal artery and vein occlusion and glaucoma: genetics in two siblings

Abstract

PurposeHere we present two siblings with combined cilioretinal artery and vein occlusion (CLARVO), with genetic confirmation of glaucoma as the underlying etiology and discovering of two novel variants of CARD10 and OLFM2.MethodsAncillary tests were performed to rule out other etiologies, and genetic tests using next generation sequencing (NGS) were performed in the two siblings. An extensive literature research was performed of similar cases of CLARVO and glaucoma, as well as the genetics (NCBI Genes Database) found in our patients.ResultsIn April 2016, a 39‐years‐old man and a 45‐year‐old woman came to the Emergency Room referring visual loss on their right eye, also both with an onset of the symptoms differing only two weeks. They denied any abnormalities, recent travels or drugs abuse. On the examination, both presented CLARVO in the right eye, a more severe condition in the female patient along with lower visual acuity. Both patients showed a pigmentary dispersion glaucoma with a higher cup‐to‐disc ratio in their right eye. IOP was controlled with medical treatment, and in the female peripheral iridotomies and selective trabeculoplasty were also needed. A genetic analysis with NGS showed variants of CARD10 (pThr436Met) in both siblings, and in OLFM2 (p.ARg460=) in the female. These genes have been related to a higher risk of increased IOP (CARD10) and normal development of the structures of the eye (OLFM2). Also, OLFM2 has been recently linked to vascular smooth muscle cells regulation.ConclusionsCLARVO is a rare entity. As in other vascular retinal diseases, like in retinal vein occlusion, even in younger patients, classic predisposing factors like glaucoma should be considered. When available, genetic tests should be performed, especially in presumed familiar association. The combination of the genetic variants in our patients could be related to both a higher predisposition of high‐pressure glaucoma, along with an increased susceptibility of the retinal vasculature; however, further research is needed to confirm this association between CLARVO and glaucoma.