CORNEAL ASTIGMATISM AFTER SCLERAL BUCKLING SURGERY ASSESSED BY FOURIER-ANALYSIS OF VIDEOKERATOGRAPHY DATA

To evaluate quantitatively the changes in corneal curvature, including irregular astigmatism, after scleral buckling surgery for retinal det achment. Methods. In 29 eyes of 29 patients undergoing scleral explant surgery, videokeratographic measurements were carried out before and 1 week, 1 month, and 3 months after surgery. Using Fourier harmonic an alysis, dioptric data on mire rings were decomposed into spherical, re gular astigmatic, and irregular astigmatic (decentration and higher or der irregularity) components. Results. The irregular astigmatic compon ent significantly increased at 1 week postoperatively but returned to the preoperative level 1 month after surgery. The regular astigmatism also displayed a transient in crease up to 1 month after surgery. The increases in regular astigmatism were significant in eyes that had scl eral buckling of less than or equal to 180 degrees but not in eyes wit h buckles extending >180 degrees. Conclusion. Changes in irregular ast igmatism after retinal detachment surgery were quantitatively evaluate d. The scleral buckling surgery causes a transient increase in irregul ar astigmatism as well as regular astigmatism.