Evaluation of potential visual acuity in eyes with macular oedema secondary to retinal vein occlusion.

Purpose:  To evaluate the potential visual acuity (VA) of eyes with macular oedema (MO) associated with retinal vein occlusion (RVO). Methods:  Thirty-one eyes of 31 patients with MO associated with RVO were examined and then treated with an intravitreal injection of bevacizumab. Of these 31 eyes, 22 showed complete resolution of the MO at 1 month after treatment, at which time potential VA was determined; 12 eyes had good function and 10 had poor function at this time. Optical coherence tomography was used to detect the junctions between inner and outer segments of the photoreceptors (IS/OS) as a hallmark of integrity of the outer photoreceptor layer. Results:  In the poor function group, pretreatment VA was significantly worse (P = 0.0106) and pretreatment central macular thickness was significantly greater (P = 0.0121). Preservation of the foveal photoreceptor layer before treatment was associated closely with good visual function after resolution of MO, and IS/OS line beneath the fovea was detected more frequently before treatment in eyes with good function (P = 0.0053). Conclusions:  In eyes with MO associated with RVO, when the IS/OS line was detected beneath the fovea, they would be expected to have good vision after resolution of the MO.