Retinal sensitivity after resolution of the macular edema associated with retinal vein occlusion

To study the correlation of retinal sensitivity with both morphologic changes in the macula and status of retinal capillary perfusion, after resolution of the macular edema associated with retinal vein occlusion (RVO).

Retinal sensitivity in the macular area was examined with the Micro Perimeter 1 in 24 eyes after resolution of the macular edema associated with RVO. Using spectral-domain optical coherence tomography, 6 mm × 6 mm areas of macula were examined with 256 sequential horizontal scans. Condition of the photoreceptor layer was evaluated depending upon detection of the junctions between inner and outer segments of the photoreceptors (IS/OS). Fluorescein angiography was performed in 19 eyes.

Mean retinal sensitivity on the affected side of the retina was significantly decreased (p < 0.001). On the affected side, the mean retinal sensitivity within the area of deteriorated IS/OS was significantly less (3.8 ± 4.8 dB) than that within areas with complete IS/OS (10.1 ± 6.4 dB, p < 0.001). Mean retinal sensitivity within nonperfused areas was extremely low (0.3 ± 1.3 dB), compared with that in perfused retina (10.9 ± 5.9 dB, p < 0.001). In eyes with a broken foveal capillary ring (FCR), the marked decline in retinal sensitivity was seen within the area where the FCR was broken; this was not seen in eyes with an intact FCR.

Retinal function was decreased markedly in areas with a damaged photoreceptor layer due to RVO, and was lethally decreased within nonperfused areas. Due to the various limitations of the current study, including implementation of fluorescein angiography in limited number of eyes, wide range of follow-up, and heterogeneity of pretreatments, further prospective studies are necessary to confirm the current findings.