[Changes in the visual field caused by lens opacities].

60 eyes with advanced opacity of the lens nucleus and a corrected visual acuity of at least 0.1 have been examined by Octopus perimetery before and after a cataract extraction with posterior chamber lens implantation. 20 eyes had chronic glaucoma with glaucomatous alterations of the optic nerve head. Our purpose was to determine the effect of lens opacities on the result of automated perimetry especially in view of glaucomatous field defects. The influence of the cataract on the differential light threshold in the whole field (30 degrees) area showed a wide variance. The calculated visual field indices loss variance (LV) and corrected loss variance (CLV) did not clearly separate glaucomatous from cataractous field changes. Often an exact analysis of the numerical printout of the visual field helps in finding of localized glaucomatous field defects.