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 detachment. 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 analysis, dioptric data on mire rings were decomposed into spherical, regular astigmatic, and irregular astigmatic (decentration and higher order irregularity) components. Results. The irregular astigmatic component 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 scleral buckling of less than or equal to 180 degrees but not in eyes with buckles extending >180 degrees. Conclusion. Changes in irregular astigmatism after retinal detachment surgery were quantitatively evaluated. The scleral buckling surgery causes a transient increase in irregular astigmatism as well as regular astigmatism.