Comparative study of conjunctival limbal transplantation not associated with the use of amniotic membrane transplantation for treatment of total limbal deficiency secondary to chemical injury.

PURPOSE: The aim of this study was to compare the outcome of conjunctival limbal transplantation with and without the use of amniotic membrane (AM) transplantation for the treatment of limbal deficiency after chemical burns to the eyes. METHODS: This is a retrospective, comparative, interventional case series that included 34 eyes (34 patients) with total limbal deficiency after chemical burns, who were submitted to conjunctival limbal transplantation. Two groups were formed: group 1 (15 eyes) limbal transplantation associated with AM transplantation and group 2 (19 eyes) only limbal transplantation. Success and failure rates, epithelialization time, and visual acuity were compared between the 2 groups. RESULTS: The mean follow-up period was 19.71 ± 5.6 months in group 1 and 18.26 ± 7.78 months in group 2. The proportion of conjunctival limbal autograft and living-related conjunctival limbal allograft was similar in both groups (P = 0.914). Time until complete epithelialization of the corneal surface was significantly longer in group 1 (P = 0.007). Graft survival was similar in both groups (P = 0.581). Failure rate was also similar in both groups (P = 0.232). The most common cause of failure was transplanted stem cell depletion in group 1 (20% of cases) and rejection in group 2 (10.5%). The visual acuity improved postoperatively in 12 eyes (80%) in group 1 and 16 (84.2%) in group 2 (P = 0.430). CONCLUSIONS: Results with the use of AM associated with conjunctival limbal transplantation in ocular surface reconstruction were similar to those obtained with limbal transplantation alone. Both techniques were found to be satisfactory for ocular surface reconstruction in patients with total limbal deficiency after chemical burns.

Transplantation of conjunctival epithelial cells cultivated ex vivo in patients with total limbal stem cell deficiency.

PURPOSE: To report the outcomes of transplantation of autologous conjunctival epithelial cells cultivated ex vivo (EVCAU) in patients with total limbal stem cell deficiency (LSCD). METHODS: EVCAU were cultivated on denuded human amniotic membrane and transplanted in 12 eyes of 10 patients with total LSCD. We evaluated the improvement in the defined clinical parameters of LSCD (loss of corneal epithelial transparency, superficial corneal neovascularization and epithelial irregularity/recurrent epithelial breakdown), vision acuity, impression cytology, immunocytochemical analysis (CK3/CK19), and the appearance of a regular hexagonal basal layer of cells on corneal confocal microscopy. Histologic and immunohistochemical features were studied in 3 corneal buttons of patients submitted to penetrating keratoplasty after EVCAU. RESULTS: Cultivated conjunctival epithelium formed 4 to 5 layers with the formation of basement membrane-like structures. Immunocytochemical analysis showed positivity for CK3, CK19, MUC5AC, Ki-67, P63, and ABCG2. The improvement of the clinical parameters for this treatment in our cohort was 10 of 12 (83.3%) in a mean follow-up time of 18.5 months (range, 15-26 months), and these eyes showed an improvement in impression cytology, immunocytochemistry, and in vivo confocal analysis. Corneal buttons showed a well-formed epithelium with 5 to 6 layers, with rare cells periodic acid-Schiff+, and positivity for CK3, CK19, P63, connexin 43, and MUC5AC. CONCLUSION: We demonstrated the preliminary results of transplantation of EVCAU for corneal surface reconstruction in cases with total LSCD. Future studies are needed to further assess the long-term efficacy of this procedure.