Background: Corneal epithelium is renewed by stem cells (SC) that reside at the corneal limbus. Reduced number of SC or their abnormal function lead to the ocular surface disease called limbal stem cell deficiency (LSCD), characterized by corneal conjunctivalization, vascularization, persistent epithelial defects, chronic inflammation, and loss of vision. In a case of total unilateral LSCD, autologous transplantation of limbal epithelial stem cells (LESC) from the healthy eye is needed. We describe the surgical technique of choice for autologous limbal transplantation, called conjunctival limbal autograft (CLAU) that we combined with amniotic membrane (AM) use. 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 fibrovascular pannus from the diseased corneal surface and the harvesting of two conjunctival-limbal grafts from the healthy eye. The grafts are then transplanted on to the limbal area of the recipient eye. AM is used as a patch to cover the denuded cornea and limbal grafts, as well as a barrier preventing the conjunctival epithelium from encroaching on to the temporal and nasal side of the corneal surface. In the donor eye, AM is used to cover the donor sites. CLAU with the use of AM was performed in 3 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 3–6 days postoperatively to assess the growth of new epithelium from the limbal grafts. In all patients the ocular surface was covered with another AM until the cornea was completely epithelized and the new epithelium stable. In one patient the corneal regrafting and cataract removal was performed subsequently.Results: CLAU was successful in 2 patients and partially successful in 1 patient during the follow up. In all cases the growth of new epithelium from the limbal grafts was noted on day 3–6 after CLAU. The cornea was completely epithelized within 2 weeks in 2 patients and after 35 days in one patient. In two patients the corneal epithelium remained clear, smooth and stable during the follow up of 3.5 years and 4 months, respectively. In one patient, uneven epithelium probably representing a mosaic of corneal and conjunctival cells was noted in the central corneal region, where a small corneal ulcer developed 5 months after CLAU. In donor eyes no postoperative complications were noted, the donor sites epithelized within few days.Conclusions: Autologous limbal transplantation according to CLAU surgical technique combined with the use of AM is a successful and safe therapy for restoring corneal surface in total unilateral LSCD after chemical injury. It enables further surgical procedures for restoring the vision such as corneal transplantation and cataract surgery.
Co-expression of SARS-CoV-2 entry genes in the superficial adult human conjunctival, limbal and corneal epithelium suggests an additional route of entry via the ocular surface