Central Retinal Vein Occlusion With Signs of Ocular Hypoperfusion After Parent Artery Occlusion for a Traumatic Carotid-Cavernous Fistula: A Case Report

A carotid-cavernous fistula (CCF) can cause a wide range of ocular complications, including venous stasis retinopathy, secondary glaucoma, and central retinal vein occlusion (CRVO).Retinal complications have been reported after endovascular closure of the shunt, but there are few reports describing the ophthalmic course of an eye in which the shunt persisted and in which parent artery occlusion of the internal carotid artery was required.A 63-year-old man was diagnosed with a traumatic right internal carotid artery CCF after a road traffic injury and underwent endovascular treatment on the second and third days after the injury.Because both the transvenous and the transarterial approaches were unsuccessful, parent artery occlusion of the right internal carotid artery was performed.According to the report from the referring institution, occlusion of the shunt was incomplete, and shunt flow into the right superior ophthalmic vein persisted.Angiography approximately six months after the injury confirmed the residual shunt, and no further endovascular treatment was considered feasible.Two months later, the patient noticed decreased vision in the right eye, presented to a local ophthalmologist, and was referred to our department.At presentation, best-corrected visual acuity was 0.2 (logMAR 0.70) in the right eye, and the intraocular pressure (IOP) was 14 mmHg.The right eye showed dilated episcleral vessels, dilated retinal veins, attenuated retinal arteries, retinal hemorrhages extending from the posterior pole to the periphery, and marked macular edema, but venous tortuosity was not prominent.The pupillary light reflex was reduced, and pharmacologic mydriasis was poor, without posterior synechiae or iris atrophy.Spontaneous pulsation of the central retinal artery was present in the affected eye and was augmented by gentle digital pressure, whereas no pulsation was seen in the fellow eye.On widefield fluorescein angiography, dye first entered the central retinal artery 20.1 seconds after the start of injection and complete arterial filling was reached at 25 seconds; numerous microaneurysms were seen from the posterior pole to the mid-periphery, with widespread vascular leakage and reduced perfusion of the retinal capillary network.The fellow eye showed only a few microaneurysms and scattered hard exudates, consistent with mild nonproliferative diabetic retinopathy.The patient had type 2 diabetes mellitus, untreated for approximately 10 years and restarted after the current injury, and hypertension.An intravitreal injection of an aflibercept biosimilar 2 mg was given on the day of presentation, followed by panretinal photocoagulation (PRP) delivered in four sessions for a total of 1,580 burns.Twenty-five days after the injection, the macular edema had clearly decreased but had not completely resolved, and it had recurred by day 67.Throughout the course, the IOP remained consistently lower in the affected eye than in the fellow eye.No iris or angle neovascularization was observed.In this eye, findings of CRVO coexisted with findings suggesting reduced ocular perfusion pressure.Even in a patient with systemic risk factors, local factors should be considered when the findings are confined to, or markedly more severe in, one eye.When no further treatment of the causative lesion is possible, management of the ocular complications is limited to ophthalmic measures, and their effects and limitations must be evaluated separately.