LASER-INDUCED CHORIORETINAL VENOUS ANASTOMOSIS FOR NONISCHEMIC CENTRAL RETINAL VEIN OCCLUSION - EVALUATION OF THE COMPLICATIONS AND THEIR RISK-FACTORS

PURPOSE: To evaluate the complications of laser induced chorioretinal venous anastomosis in nonischemic central retinal vein occlusion (CRVO ) and to identify the associated risks. METHODS: A retrospective conse cutive series of 91 eyes (91 patients) with nonischemic CRVO with a me an +/- SD duration of 15.0 +/- 15.2 weeks (range, 3 to 72 weeks) and c orrected visual acuity reduced to 20/100 or less because of perfused m acular edema were reviewed. All eyes had one or more anastomotic attem pts using argon laser (combined with Nd-YAG laser in 46 eyes) and a mi nimum of 12 months of follow up. RESULTS: Successful chorioretinal ven ous anastomoses were created in 49 eyes (54%), Eighteen eyes (20%) had neovascular complications. These consisted of intravitreal, intrareti nal, and subretinal neovascular membranes and were significantly assoc iated with retinal ischemia (P < .001). There was avascular fibrous ti ssue proliferation at the anastomotic site in eight eyes (9%), and it was not associated with retinal ischemia (P = .127), No eye developed further capillary nonperfusion once an anastomosis became functional, A chorioretinal venous anastomosis was associated with improved vision (P < .001); 84% of eyes had an average SD improvement of 4.3 +/- 3.8 lines (range, 2 to 20 lines), with the remaining 16% having no improve ment or reduced vision. CONCLUSION: The major vision-threatening compl ication of laser-induced chorioretinal venous anastomosis for nonische mic CRVO is neovascular membranes occurring at the anastomotic site; t hese are associated with retinal ischemia, Prompt laser photocoagulati on to areas of retinal ischemia that develop after the anastomotic att empt has been made may reduce the risk and severity of this complicati on. (Am J Ophthalmol 1998;126: 219-229. (C) 1998 by Elsevier Science I nc. All rights reserved.).