Crescentic Tuck in Lamellar Keratoplasty-A Novel Technique in a Case of Advanced Pellucid Marginal Corneal Degeneration.

PURPOSE: To describe a new surgical technique "crescentic tuck in lamellar keratoplasty" for the management of advanced pellucid marginal corneal degeneration (PMCD).

METHODS

A 45-year-old man with advanced PMCD and maximal thinning in the inferior juxtalimbal periphery underwent a crescentic lamellar keratoplasty in the right eye. Best-corrected visual acuity was 6/60 with no further improvement because of severe irregular astigmatism. Thinnest pachymetry in the peripheral cornea was 280 μm. Peripheral crescent-shaped lamellar corneal dissection of 3.5-mm width was performed, and an intrastromal pocket was fashioned from 4 to 8 O'clock, extending beyond limbus. A crescent-shaped donor corneal button of 3.5-mm width was denuded of its endothelium and beveled in inferior periphery to create a flange. The flange was tucked into the peripheral scleral pocket. The donor graft was secured to the host bed using 10-0 nylon interrupted sutures.

RESULTS

Donor cornea integrated with the host bed over time and best spectacle-corrected visual acuity at 1 year improved to 6/9 with -1.25/-3.5 D × 90°. The simK (simulated keratometry) changed from 41.6/56.3 diopters (D) to 45.1/50.6 D. The astigmatism reduced from 14.6 D to 5.5 D.

CONCLUSION

Crescentic tuck in lamellar keratoplasty provides good apposition of the donor lenticule and tectonic support to the peripheral thin cornea while preserving the peripheral limbal stem cells. Additionally, there is a significant reduction in the astigmatism, resulting in visual improvement.