Periarteriolar-Sparing Retinal Edema in Acute Central Retinal Artery Occlusion

Abstract

A 56-year-old man was referred to our hospital about 48 h after sudden onset of painless central visual loss in his right eye (OD) on a winter morning. He had a more than 25-year history of systemic hypertension and smoking. Funduscopic observation showed striated retinal whitening in the macular region, faint cotton-wool patches around the optic disc, and segmental narrowing of the retinal arteries near the optic disc edge. Based on the pattern of onset and fundus findings, he was diagnosed with vasospastic acute central retinal artery occlusion OD, and a venous drip injection of prostaglandin E1 was started immediately. Optical coherence tomography showed bands of high and low density in the inner retina arranged alternately in the edematous area; the bands corresponded to edematous and nonedematous areas, respectively, and geographically to venules and arterioles, respectively. The best-corrected visual acuity of 0.03 at referral improved to 0.5, and the striated retinal edema and most cotton-wool patches resolved 1 month after onset. The oxygen pressure gradient in the capillary networks due to differences in the distance from the arterioles may be the mechanism of this unique periarteriolar-sparing retinal edema pattern.

Keywords: Central retinal artery occlusion; Periarteriolar-sparing retinal edema; Prostaglandin E1; Spectral-domain optical coherence tomography.

Fig. 1

Striated retinal whitening around the fovea and faint cotton-wool patches around the optic disc are observed at the initial visit (a). The green arrow corresponds to the scan direction in d. Spastic arteries are seen near the optic disc (b, arrows). In a horizontal foveal SD-OCT scan, edematous changes that correspond to hyperreflectivity are seen in the inner retina (c). In a horizontal macular SD-OCT scan 0.5 disc diameter above the fovea, the hyperreflectivity and hyporeflectivity correspond to edematous and nonedematous areas of the inner retina, respectively (d). A comparison of a and d shows that the distributions of the hyperreflectivity and hyporeflectivity coincide with the distributions of the venules (blue arrowheads) and arterioles (red arrowheads), respectively. Fluorescein angiography performed at the initial visit shows a filling defect in the capillary networks in the macular region during the early phase (e). One month after the start of systemic PGE1 therapy, the striated retinal edema pattern resolved (f) and thinning of the inner retina is seen on the SD-OCT image (g).