[Indications for cataract surgery].

Progress in surgical methods and advances in the correction of aphakia with contact lenses or intraocular lenses on the one hand, and the greater demands made by patients on the other are the reasons why the cataract surgery is indicated much earlier today than 20 years ago. Occupational considerations and the visual acuity required to keep a driver's licence may be determining factors in the timing of surgery and the choice of one or the other methods o correcting aphakia. To advise the patient correctly, an accurate preoperative assessment of the visual function which can be expected postoperatively has be made. Of the preoperative examinations, results with the test wih the Moiré pattern following Lotmar are mentioned. If the patient's occupation places high demands on visual acuity, as e.g. for bus drivers - 1.0 on the better and 0.8 on the second eye - it seems less risky to go for a contact lens than for an intraocular lens (cystoid macular edema!). Advantages and disadvantages and the special indications and contraindications of correction with cataract glasses, with contact lenses or with different types of intraocular lenses are tabulated. The mathematical conditions which sampling statistics and the success rates of different types of intraocular lenses and surgical procedures have to fulfill, such as extracapsular versus intracapsular cataract extraction, are explained in order to provide a basis of knowledge rather than merely belief. Finally, the indications for different types of surgery in special situations and with different forms of cataract are described, e.g. phakolytic glaucoma, subluxation and luxation of the lens and congenital cataracts.