Abstract
A laser-induced, chorioretinal, venous anastomosis can improve the retinal circulation in some patients with central retinal vein occlusion.1 Report of a Case A nondiabetic 80-year-old woman had an asymptomatic central retinal vein occlusion in her left eye. It was diagnosed during her scheduled 6-month follow-up visit with her general ophthalmologist. On her initial visit, she was using dorzolamide hydrochloride, 2%, and timolol, 0.5%, combination eyedrops at night in both eyes for her glaucoma. Her visual acuity was 20/20 OU and her intraocular pressure was 14 mm Hg OU. She had retinal hemorrhages in all 4 quadrants with dilated retinal veins. Fluorescein angiography showed a retinal recirculation time of 10 seconds, and the average central foveal thickness with Stratus optical coherence tomography was normal at 218 μm. One month later, her visual acuity decreased to 20/70 OS and she had increased retinal hemorrhage and cystoid macular edema. The retinal veins were dilated, including the tributary connecting the inferotemporal branch retinal vein to the central retinal vein (Figure 1A). The average central foveal thickness on Stratus optical coherence tomography had increased to 511 μm. Fluorescein angiography was not repeated. She was treated with 2 laser spots inferior to the optic nerve at a site where a retinal vein crossed over a choroidal vein.2 The first laser spot intentionally ruptured the Bruch membrane and the second laser spot intentionally nicked the retinal vein, causing a localized retinal hemorrhage. Results Following laser therapy, because of poor visual acuity and persistent macular edema, the left eye was treated with intravitreous bevacizumab, 1.25 mg/0.05 mL once every 6 weeks for 3 treatments, and then with intravitreous triamcinolone, 0.2 mg/0.05 mL once 6 months following laser therapy. Despite maximal topical therapy, the patient's intraocular pressure remained in the mid 20 mm Hg for 4 months following the intravitreous triamcinolone injection. Seven months after laser therapy, her visual acuity had improved to 20/50 OS. The tributary connecting the inferotemporal branch retinal vein to the central retinal vein was narrowed (Figure 1B). Video Comment In response to the central retinal vein occlusion in this patient, 2 venous chorioretinal anastomoses formed: one at the laser site inferior to the optic disc and the other at the superior edge of the optic disc. Consequently, the retinal circulation segmented into 2 distinct zones, each with different venous drainage. Between these 2 zones, a watershed developed. After the 2 chorioretinal anastomoses matured, blood flow through the venous tributary that bridged the watershed zone—the tributary connecting the inferotemporal branch retinal vein to the central retinal vein—was very slow (Figure 2B). The slow blood flow made that blood vessel susceptible to venous stasis-induced thrombosis, narrowing, and subsequent partial occlusion. This case illustrates retinal venous remodeling over time in response to modification of the retinal circulation. Video References 1. McAllister IL, Constable IJ. Laser-induced chorioretinal venous anastomosis for treatment of nonischemic central retinal vein occlusion. Arch Ophthalmol. 1995;113(4):456-4627710396PubMedGoogle ScholarCrossref 2. Cohen SM. Indocyanine green angiography of a laser-induced retinal-choroidal venous anastomosis. Ophthalmic Surg Lasers. 1997;28(1):65-669031308PubMedGoogle Scholar
Journal
JAMA Ophthalmology
– American Medical Association
Published: Mar 1, 2013
Keywords: vascular remodeling,anastomosis, surgical,lasers,central retinal vein occlusion