[Monitoring the progress of lens opacities in cases of senile cataract by retro-illumination photography (author's transl)].

A follow-up study of lens opacities, utilizing retro-illumination photography with the fundus camera is described. After giving technical details, results are discussed and possible errors pointed out. If evaluation by planimetry or other devices is not possible, a useful procedure is the evaluation of simultaneous projected slides by a group of ophthalmologists not directly involved in the trial. This is demonstrated by testing the effect of 1-hydroxy-pyrido-(3,2alpha)-5-phenoxazone-3-carboxylic acid on the progress of senile cataract in a total of 48 eyes. Together with slit image photography of Brown (2, 3) the method of retro-illumination photography of the lens presented in this paper is a definite improvement in demonstrating the temporal course of cataract development.