Multifocal electroretinograms in patients with retinal vein occlusion

PURPOSE: To investigate waveform changes of multifocal electroretinograms(mERG) in patients with retinal vein occlusion(RVO). METHODS: Nine eyes of 8 patients with RVO and 29 eyes of 29 normal subjects were examined using mERG. An array of 103 hexagonal elements was displayed on a monitor. mERG latencies(ms) and response densities (nV/deg2) were measured for center area(Ct) and for each of four quadrant areas. The peak and troughs were named N1, P1 and N2, consecutively. RESULTS: In pathological quadrants, although the response densities were abnormal in only one eye, latencies of the N2 and P1 were prolonged in 7 eyes and in 2 eyes, respectively(over 1 SD-2 SD). The latencies were significantly prolonged compared with those of normal eyes(p < or = 0.03, U-test). On the other hand, in the central area, although the latencies were abnormal in 3 eyes, the response densities were reduced in 6 eyes(over 1 SD-2 SD). The response densities were significantly reduced compared with those of normal eyes(p < or = 0.024, U-test). CONCLUSIONS: Both peak latencies in pathological quadrants and response densities in the central retinal area can be sensitive indicators of retinal dysfunction caused by RVO. The mERG system is useful for detecting local retinal dysfunction in patients with RVO.