The persistence of buckle height in relation to orientation of buckle fixation. An ultrasonographic study.

Forty phakic myopic eyes of 40 patients with rhegmatogenous retinal detachment were included in a prospective clinical trial designed to evaluate the changes in buckle height after retinal detachment surgery. The age of the patients ranged between 50 and 75 years. The eyes were divided into two groups (A and B) according to the orientation of sponge fixation. In group A (20 eyes) the sponge fixation was circumferential, while in group B (20 eyes) radial. A-scan ultrasonography was used for the measurements of buckle height 1, 3, 6, 12, and 18 months postoperatively. At all times of measurement, the buckle height presented a statistically significant difference between the patients of group A and B. More specifically, radial fixation produced a significantly lower scleral indentation compared with that produced by circumferential fixation. After a lapse of 18 months, the buckle height in group B retained 41% of its original value compared with that of group A which retained 66%.