[Changes in bulbus geometry after conventional detachment surgery. Study using video keratoscopy].

Conventional detachment surgery produces scleral indentation and can therefore lead to changes in the geometry of the bulbus. The aim of this research was to analyze the influence of scleral buckling (group A) and encircling elements (group B) on corneal topography, surgical induced astigmatism and axial length. In 19 cases with peripherally detached retinas we performed keratometry, videokeratoscopy and measured axial length preoperatively in the first week as well as 1 and 3 months postoperatively. Total preoperative astigmatism in group A was 0.49 D and in Group B 0.84 D. The surgically induced astigmatism calculated by vectoral analysis was in the first postoperative week 0.98 D and 1.92 D. 1 month postoperatively it was 0.74 D and 1.26 D, and after 3 months 0.89 D and 1.31 D. There was minimal change in the average axial length: 0.09 mm reduction in group A and 0.21 mm increase in group B after 3 months. Computerized videokeratoscopy was very effective in determining this slight, surgically induced astigmatism.