Fundus photographic, fluorescein angiographic, and indocyanine green angiographic signs in successful laser chorioretinal venous anastomosis for central retinal vein occlusion

Objective: To describe the fundus signs and angiographic signs that accompany development of a laser-induced chorioretinal venous anastomosis in central retinal vein occlusion and to describe the chronology of the signs. Design: Noncomparative, consecutive case series. Participants: Fifteen eyes of 15 patients were treated, Intervention: The argon laser was used in the original method of McAllister and Constable to form an anastomosis in five eyes, and the modified method of McAllister involving the argon laser followed by the YAG laser was used for ten eyes. Main Outcome Measures: Changes in vessel diameters, retinal blood flow, and morphology of anastomosis over time as documented photographically and angiographically. Results: The earliest fluorescein angiographic sign of success is a hyperfluorescent spindle at 1 week. The earliest indocyanine green angiographic sign is direct connection of retinal venous and choroidal venous circulations at 2 weeks. The earliest fundus photographic and, hence, ophthalmoscopic sign is asymmetry in venous diameter at the disc at 3 weeks. No sign is present in all successful cases, The most commonly observed sign is fluorescein flow around a corner in a retrograde direction toward the anastomosis in 80% of cases. Drainage of only a fraction of the retina occurred in 93% of cases. Fifteen eyes with successful anastomoses had mean improvement of 2.3 +/- 2.4 (standard deviation [SD]) Snellen lines of best-corrected visual acuity compared to 0.2 +/- 2.3 (SD) lines for 9 eyes with unsuccessful anastomoses (P = 0.0439). Conclusion: Recognition of the variety and typical chronology of postoperative fundus and angiographic signs in laser-induced chorioretinal anastomosis will help prevent premature retreatment and guide appropriately timed additional treatment for failed initial attempts. Fluorescein angiography and indocyanine green angiography are necessary components of intensive postoperative follow-up of these patients. The follow-up care is more difficult than the technical aspects of the surgery itself. Successful anastomoses help by taking part of the flow away from the compromised central vein, not by providing global venous bypass. This technique remains controversial, unproven, and in need of a randomized clinical trial to determine its role in the management of nonischemic central retinal vein occlusion.