Cilioretinal artery occlusion combined with central retinal vein occlusion - a report of two cases and review of the literature.

BACKGROUND: We describe the clinical findings and course of cilioretinal artery occlusion (CAO) combined with central retinal vein occlusion (CRVO) in two patients and present a review of the relevant literature.

HISTORY AND SIGNS: Case 1: An otherwise healthy 24-year-old woman presented to the emergency unit with a painless visual decrease in her right eye. Fundus examination revealed retinal edema due to CAO in association with signs of venous stasis. Fluorescein angiography (FA) showed a patent cilioretinal artery. Case 2: A heavy smoker, hypertensive, 59-year-old man was referred for sudden visual loss in his left eye. Fundus examination and FA revealed CAO and CRVO.

THERAPY AND OUTCOME: No treatment was applied for the first patient. Two weeks after diagnosis, retinal edema had subsided and only the signs of venous stasis were evident. The central scotoma remained unchanged. In the second patient, within the next three months, the development of retinal ischemia led to retinal neovascularization. Panretinal photocoagulation was applied. Visual acuity remained very low (light perception).

CONCLUSIONS: The combination of CAO and CRVO comprises a discrete clinical entity. In both our cases, FA did not show full obstruction of the cilioretinal artery. Even though many hypotheses have been postulated about this entity, it seems that it ensues from the increased intraluminal pressure in the retinal capillaries (due to the CRVO), which exceeds the pressure in the cilioretinal artery. Thus, it is probably a functional obstruction of the cilioretinal artery, although its pathogenesis remains controversial.