ANALYSIS OF THE ELECTRORETINOGRAM IN TOXOPLASMA RETINOCHOROIDITIS

The decision to use therapy in toxoplasma retinochorioiditis depends o n the location of the active lesion and the presence of vitreous activ ity. In eyes with dense vitreous clouding it can be difficult to see w hether the macular region is involved or not. In theory the localisati on of a lesion can be estimated on the basis of the flash ERG. The sta ndard flash electroretinogram was recorded in 23 patients with inactiv e toxoplasma retinochorioiditis lesions in the retina. In 17 cases a l esion was present within the central 12-degrees of the visual field, 8 of these had a reduced photopic ERG. In 15 patients lesions were foun d outside the central 12-degrees, in 8 of whom the scotopic ERG was re duced. We conclude that the ERG can be of use in indicating the scar l ocation in patients with dense vitreous clouding.