Central Retinal Artery Occlusion with Sparing of the Cilioretinal Artery: A Case Report

Abstract

Background: Central retinal artery occlusion is an ophthalmic emergency that commonly presents with sudden, painless monocular visual loss due to acute retinal ischaemia. Visual prognosis is often poor; however, the presence of a cilioretinal artery may preserve macular perfusion and contribute to better central visual function. Case Presentation: A 44-year-old male with a history of hypertension and irregular use of antihypertensive medication presented with sudden, painless loss of vision in the right eye for five days. On examination, his blood pressure was 160/104 mmHg. Best-corrected visual acuity was 6/9 in the right eye and 6/6 in the left eye. Intraocular pressure was 9 mmHg in both eyes. A relative afferent pupillary defect was present in the right eye, while anterior segment examination was unremarkable bilaterally. Fundus examination of the right eye showed generalised retinal whitening with sparing in the distribution of a cilioretinal artery, while the left eye was normal. Optical coherence tomography of the right eye demonstrated inner retinal hyperreflectivity in the affected retinal area, with relative preservation corresponding to the cilioretinal artery territory. Laboratory investigations showed dyslipidaemia and a mildly reduced estimated glomerular filtration rate. Echocardiography revealed features of hypertensive heart disease, while further cardiovascular and neurological evaluation was advised. The patient was started on antihypertensive therapy with nifedipine and losartan/hydrochlorothiazide. Conclusion: This case illustrates central retinal artery occlusion with cilioretinal artery sparing and relatively preserved visual acuity. Recognition of this anatomical variant is clinically important for diagnosis, prognosis, counselling, and systemic vascular risk assessment.