Effect of peripheral subepithelial fibrosis on corneal transplant topography

Subepithelial fibrosis in the area of peripheral suture placement is an often overlooked phenomenon of healing following uneventful penetrating keratoplasty surgery. Three affected cornea transplant patients whose sutures had been removed were studied using videophotokeratoscopy before and after stripping of the subepithelial tissue with cellulose sponges and jeweler's forceps. All three showed relative flattening in the involved hemimeridian prior to treatment. Removal of the fibrotic tissue produced relative steepening in the same area. Overall graft astigmatism was essentially unchanged following the procedure in each patient. However, average central keratometric readings increased approximately 1 to 2 diopters in each patient, demonstrating that these peripheral changes have a direct influence on corneal power. The surface regularity index and surface asymmetry index values improved in two of the three patients and manifest spectacle visual acuity improved in each patient.