Conjunctival-limbal autograft in total unilateral limbal stem cell deficiency

Abstract

Background: The corneal epithelium is renewed by stem cells (SCs) that reside in the corneal limbus. Absence or dysfunction of limbal SCs or their niche leads to the ocular surface disease called limbal stem cell deficiency (LSCD), clinically characterized by corneal conjunctivalization, vascularization, persistent epithelial defects, chronic inflammation, and loss of vision.Total unilateral LSCD is treated by autologous transplantation of limbal epithelial stem cells (LESC) obtained from the healthy other eye.We describe the treatment of choice for unilateral LSCD, i.e. the combination of autologous limbal transplantation, called conjunctival limbal autograft (CLAU) and the use of amniotic membrane (AM). We present the results of CLAU in three patients with total unilateral LSCD due to chemical injury.

Methods: Autologous limbal transplantation CLAU begins with the removal of the fibrovascular pannus from the diseased corneal surface and the harvesting of two conjunctival-limbal grafts from the healthy eye. The grafts are then transplanted onto the limbal area of the recipient eye. AM is used as a patch to cover the denuded cornea and limbal grafts, and serves as a barrier preventing the conjunctival epithelium from encroaching onto the temporal and nasal sides of the corneal surface. In the donor eye, AM is used to cover the donor sites. The combination of CLAU and AM transplanation was used in three patients with unilateral LSCD due to chemical eye injury. In one patient, limbal transplantation was combined with symblepharon lysis for entropium repair. In all cases AM was removed three to six days postoperatively to assess the growth of new epithelium from the limbal grafts. In all patients the ocular surface was covered with another AM that was left in place until the cornea was completely epithelialized and the new epithelium stabilized. One patient required subsequent corneal regrafting and cataract removal.

Results: During the follow up period CLAU proved successful in two patients and partially successful in one patient. In all cases the growth of new epithelium from the limbal grafts was noted on days three to six after CLAU. The cornea completely epithelialized within two weeks in two patients and within 35 days in one patient. In two patients the corneal epithelium remained clear, smooth and stable during the follow up of three and a half years and four months, respectively. In one patient, uneven epithelium, probably representing a mosaic pattern of corneal and conjunctival cells, was noted in the central corneal region, where a small corneal ulcer developed five months after CLAU. In the donor eyes no postoperative complications were noted, the donor sites epithelialized within a few days.

Conclusions: Autologous limbal transplantation using the combination of CLAU and the use of AM is a successful and safe therapy for restoring corneal surface in total unilateral LSCD after chemical injury. It enables surgeons to perform further surgical procedures for restoring the vision, such as corneal transplantation and cataract surgery.