Central retinal vein occlusion associated with cilioretinal artery occlusion

Purpose: To describe the clinical characteristics and pathogenesis of central retinal vein occlusion (CRVO) associated with cilioretinal artery occlusion (CLRAO). Methods: The study included 38 patients (38 eyes) who had CRVO associated with CLRAO and were seen in our clinic from 1974 to 1999. At their first visit to our clinic, all patients provided a detailed ophthalmic and medical history and underwent comprehensive ophthalmic evaluation, color fundus photography, and fluorescein fundus angiography. At each follow-up visit, the same ophthalmic evaluations were performed, except for fluorescein fundus angiography. Results: Of 38 eyes, 30 had nonischemic CRVO, 5 had ischemic CRVO, and 3 had nonischemic hemi-CRVO. Patients with nonischemic CRVO were significantly younger (mean age +/- SD: 45.3 +/- 16.0 years) than those with ischemic CRVO (72.3 +/- 9.2 years; P = 0.001) and those with nonischemic hemi-CRVO (64.7 +/- 7.5 years; P = 0.018). At least one third of the patients gave a definite history of episode(s) of transient visual blurring before the onset of constant blurred vision. Initially, the ophthalmoscopic and fluorescein angiographic findings were similar to those seen in CRVO and hemi-CRVO, except that all these eyes had retinal infarct in the distribution of the cilioretinal artery; its size and site varied widely. Fluorescein angiography typically showed only transient hemodynamic block and not the typical CLRAO. During follow-up, visual acuity improved markedly in nonischemic CRVO (P < 0.001) and nonischemic hemi-CRVO but deteriorated in ischemic CRVO. Retinopathy resolved spontaneously in 22 eyes with nonischemic CRVO (mean duration +/- SD: 42.0+/-101.0 months), in 2 eyes with ischemic CRVO (15.4+/-4.5 months), and in 1 eye with nonischemic hemi-CRVO. Retinociliary collaterals developed in 30% of eyes with nonischemic CRVO, in 40% of eyes with ischemic CRVO, and in 66% of eyes with nonischemic hemi-CRVO. Conclusion: CRVO associated with CLRAO constitutes a distinct clinical entity. The pathogenesis of CLRAO in CRVO is due to transient hemodynamic blockage of the cilioretinal artery caused by a sudden sharp rise in intraluminal pressure in the retinal capillary bed (due to CRVO) above the level of that in the cilioretinal artery.