Central Retinal Vein Occlusion - Spontaneous Resolution

A 65 year-old man with hypertension and hypercholesterolemia complained of acute, painless loss of vision in the right eye. A nonischemic central retinal vein occlusion was discovered with visual acuity of 20/100. No relative afferent pupillary defect was present, there was no iris neovascularization, and the fundus examination showed macular edema as the cause of loss of vision. Fluorescein angiography showed good capillary perfusion. One month later the situation was unchanged and, after discussing alternatives, the patient elected to undergo laser chorioretinal venous anastomosis. Two sites were chosen for treatment. Neither site produced a successful anastomosis. Nevertheless, six months later all of the intraretinal hemorrhages had resolved, the macular edema had regressed, and the vision had returned to 20/25. These photographs document the spontaneous resolution of the central retinal vein occlusion. A - Fundus photograph of the right eye after following the patient for one month with no improvement. The visual acuity was 20/100. B - Fundus photograph of the left eye six months later after two unsuccessful attempts at creating an laser chorioretinal venous anastomosis (the black arrows). The vein occlusion and macular edema have spontaneously resolved. This case emphasizes the variable natural history of central retinal vein occlusion. In this case, a treatment was performed that failed to achieve its intended effect - the production of a chorioretinal venous anastomosis. Nevertheless, the central retinal vein occlusion resolved - clearly in a spontaneous manner. Had the anastomosis procedure worked, it is probable that the credit for improvement would have been attributed to the procedure, when, in fact, the eye was destined to spontaneously improve anyway. It is for this reason that any proposed therapy of central retinal vein occlusion with macular edema must be tested in a randomized, controlled trial with standard therapy (at the time of this case - observation; now, intravitreal injection of anti-vascular endothelial growth factor drugs) as a control arm. Without this rigorous approach, one cannot be sure that a good outcome is not just the natural history of the particular case.