No abstract

Curved lamellating keratotomy gives stable postoperative refractive results without significantly affecting endothelial cell count or visual acuity.

Even the morphologically normal pupil shows a change in motility postoperatively. We believe that the reason for this is the mechanical manipulation of the iris during cataract operation. During this, the sensitive dilator muscle of the pupil is affected, leading to temporary or permanent changes in pupillary function. The change in motility of the contralateral, non-operated eye cannot be easily explained. The pupil size is important for the visual process and alteration of its function allows an evaluation of the quality of the operation.

Our preliminary results indicate that the mechanically guided motor trephine, used under optimal conditions, is a suitable cutting device and may improve the outcome of penetrating keratoplasty; however, further investigation of this new approach is necessary.

A special experiment was constructed to measure the influence of factors such as trephine diameter, revolutions per second, sharpness, and cutting pressure on the incision velocity and incision time for a number of trephine specimens. These measurements show the characteristics of trephines. Different degrees of sharpness were determined by comparison of the characteristics. The dependency of rotation moment transferred to tissue, of revolutions per second, and of incision power is discussed. The results are discussed, and proposals are made to increase safety by application of motor trephines and to develop them further.