[The worth of anti-cataract drugs]

Lens opacities in the elderly occur as different types of cataracts in various regions of the lens. This variation is the manifestation of different pathomechanisms. None of the "anti-cataract" preparations on the market at present state the particular pathomechanism or type of cataract for which its application is recommended. Investigations to elucidate the mode of action by preclinical studies or adequate experimental cataract models have only been carried out in a few cases. For most of the preparations, the determination of the efficacy of the "component substances" or of "the substances supposed to be effective" at the target site of the lens is not even available. For about 10 years now, procedures have been at hand for performing objective tests on the efficacy of anticataract preparations. These qualifications have so far been met by only four of the licensed anticataract preparations. In these cases, it was shown that the progress of disturbances or opacities localized in certain defined layers of the lens could be delayed. However, there is still no preparation available that might be considered as generally effective in cases of "senile cataract". Also, experimental research and the development of novel substances have been only successful in certain cataract models with defined types of opacities. It is therefore questionable whether ophthalmologists should further prescribe preparations with the diffuse indication "senile cataract", especially as verification of their efficacy and preclinical data are often missing.