Multifocal Electroretinograms in Patients with Branch Retinal Vein Occlusion

ABSTRACT

PURPOSE: To evaluate the damage to the inner retina in patients with branch retinal vein occlusion (BRVO), we recorded multifocal electroretinograms (mfERG) and analyzed the waveform changes of the first and the second order kernel responses. METHODS: Eight eyes of patients with unilateral BRVO were included. Fourteen eyes of 14 normal subjects were also tested as controls. VERIS system was used to record mfERG. The first and the second order kernel responses of each quadrant were averaged. Averaged responses were compared with those of the contralateral eyes and normal control eyes. RESULTS: The amplitudes of averaged tracing decreased in the N1, P1, and N2 of the first order kernel responses in the affected quadrant in comparison with those of contralateral and normal control eyes (P<0.05). Prolongation of latency was noted in N1, P1 and N2 in the affected quadrant. In the second order kernel responses of the affected quadrant, no responses were found in four patients. The delay in latency and the decrease in amplitude were more marked in the second order kernel responses than in the first order kernel responses (P<0.01). CONCLUSIONS: The first order mfERG components decreased in amplitude and increased in latency, with N2 being the most severely affected. And the second order mfERG components were more decreased in the affected area in patients with BRVO. These results suggested that the second order kernel responses may reflect the condition of the inner retina better than the first order kernel responses.