Corneal topographic changes after retinal and vitreous surgery.

PURPOSE

To investigate the topographic changes in the cornea after retinal and vitreous operations.

DESIGN

Observational prospective case series.

PARTICIPANTS

The study population included 46 patients after vitreoretinal surgery: 11 underwent pneumatic retinopexy, 10 underwent vitrectomy, and 25 underwent scleral buckling procedure.

METHODS

The corneal topography was measured by videokeratography with the absolute program and evaluated statistically by a quantitative comparative method, which was developed for this study, for the whole and the central cornea.

MAIN OUTCOME MEASURES

The corneal topographic changes were measured in diopters (D), evaluating and comparing the preoperative and postoperative measurements.

RESULTS

None of the operative procedures changed the shape of the whole cornea. Vitrectomy induced radial steepening of the central cornea 1.2 to 1.6 D, corresponding to the scleral sutures. Central steepening (average, 2.2 D) was also noted in the first week after circular buckling, but it flattened (average, 1.4 D) after 1 to 3 months. When an additional radial or circumferential buckling element was added to the circular buckle, steepening of the entire cornea and radial steepening of the central cornea (average, 0.6-0.8 D) occurred in the first week and flattened or returned to baseline after 1 to 3 months. There was no correlation between the location of the additional buckling element and the corneal topographic change.

CONCLUSIONS

Corneal videokeratography is a useful tool for evaluating the postoperative corneal curvature. It showed that vitreoretinal surgery alters the shape of the cornea when buckling or scleral sutures are used, but pneumatic retinopexy does not.