A new treatment for corneal thinning using a biocompatible cross linker and femtosecond laser

Abstract

Purpose: Corneal stromal thinning such as keratoconus can be treated by allogeneic corneal transplantation. However, there remain many problems such as immune rejection and the shortage of donor corneas. We investigated a new treatment for corneal thinning using a biocompatible cross linker and femtosecond laser (FSL) in rabbit eye.

Methods: A circular horizontal lamellar dissection (8.0-mm diameter) was created at one-half the thickness of the stroma using FSL (N=14). Biocompatible cross linker and type 1 atelocollagen were injected into the stromal interlayer (N=9). In control eyes, nothing was injected (N=5). Reconstructed corneas were assessed with slitlamp photograph and optical coherence tomography (OCT), and corneal thickness was measured with pachymeter before and 1 and 4 week(s) after injection. Histological examination was performed in enucleated eyes 4 weeks postoperatively.

Results: The average corneal thickness before and 1 and 4 week(s) after injection were 325, 531, and 400-μm in the treated eyes, and 315, 343, 329-μm in the control eyes. The treated corneas were significantly thicker than those in the control eyes on 1 and 4 week(s) postoperatively (p=0.00003, 0.00002; t-test with Bonferroni correction). Slit lamp photograph showed slight opacity was found in the cornea of injected eyes. Artificial corneal stromal layer was observed in the treated eyes with OCT and histological examination. Immunohistochemistry revealed that there was no inflammation in the treated corneas.

Conclusions: A new method with a biocompatible cross linker and FSL might be effective for thickening of corneal stroma in rabbit eye.

Keywords: 484 cornea: stroma and keratocytes • 687 regeneration • 607 nanotechnology