Corneal astigmatism after scleral buckling surgery assessed by Fourier analysis of videokeratography data.

PURPOSE

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 increase up to 1 month after surgery. The increases in regular astigmatism were significant in eyes that had scleral buckling of < or =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.