Detection of microaneurysms causing macular edema associated with branch retinal vein occlusion using optical coherence tomography and optical coherence tomography angiography and the effect of focal photocoagulation

To determine the efficacy of focal photocoagulation for microaneurysms causing macular edema associated with branch retinal vein occlusion. We also compared the efficacy of treatment with fluorescein angiography (FA) as a method of targeting microaneurysms with the use of optical coherence tomography (OCT) and OCT angiography (OCTA). This retrospective study included 45 eyes with macular edema caused by microaneurysms. All eyes received focal photocoagulation for microaneurysms, with FA used to detect microaneurysms in 19 eyes and OCT/OCTA in 26 eyes, depending on the treatment time. Eyes with only focal leakage on FA and eyes with edema relatively confined to the microaneurysm area on OCT/OCTA were included in this study. Eyes without macular edema in the fovea after 12 months of focal photocoagulation alone were classified as responsive. Eyes with residual edema or with additional anti-VEGF therapy during the study were classified as unresponsive. Ten eyes (52.6%) in the FA group and 12 eyes (46.2%) in the OCT/OCTA group were responsive (P = 0.6676). In responsive eyes, both FA and OCT/OCTA groups had significantly improved visual acuity at 12 months. In unresponsive eyes, visual acuity improved significantly in the FA group but not in the OCT/OCTA group. The combination of OCT and OCTA can be used to identify edema-causing microaneurysms without the use of FA. However, compared to FA, OCT and OCTA alone may not clearly distinguish between cases in which focal photocoagulation is indicated and those in which it is not.