[Studies on cerebral visual evoked potentials in the differential diagnosis of macular edema and obscration amblyopia...

The cerebral cortex visual evoked potentials (VEP) to chess pattern reversion have been examined in 41 healthy children (41 eyes) and in 25 children (25 eyes) with artiphakia after traumatic cataract extraction, with macular edemas (ME) in 12 of these and obscuration amblyopia (OA) in 13. Comparison of the amplitude-time parameters of the VEP and of treir relationship with the cell size and the chess pattern contrast has shown a characteristic feature of ME, i. e. an increased peak latency (PL) of the first negative deviation (H1 peak) of the VEP to reversion of the chess pattern with 90% contrast. The mean values of PLHI (M +/- m) have been as follows: 107.1 +/- 3.9 ms in children with ME, 93.1 +/- 2.3 ms in those with OA, and 84.9 +/- 0.8 ms in the controls. An elevation of PLHI over 100ms has been recorded in 9 of the 12 patients with ME and only in 1 child with OA. Involvement of the ganglion cells of the central area of the retina is considered as a possible reason of the detected VEP disorders in ME.