Does amniotic membrane transplantation improve the outcome of autologous limbal transplantation?

Abstract

To evaluate the additional benefits of amniotic membrane transplantation (AMT) when combined with conjunctival limbal autograft (CLAU) in the treatment of chronic chemical burns. Thirty eyes of 30 rabbits underwent a chemical burn to create limbal deficiency. Forty-five days later, the animals were randomized into three groups of 10 rabbits each. Eyes from group 1 were treated with CLAU, group 2 underwent CLAU and AMT, and group 3 served as control without surgery. Corneal vascularization and opacity were documented with external photographs at postoperative days 30, 60, and 90. The rabbits were killed 3 months after surgery, and their corneas divided into two halves. One half was prepared for hematoxylin-eosin and periodic acid-Schiff staining and the other for frozen sections and immunostaining with AM3 (to MUC 5AC mucin) and AE5 (to K3 keratin). Final clinical outcome was also scored using external photographs at the last follow-up examination. After chemical burn, all groups showed similar degrees of conjunctivalization. After transplantation, corneal vascularization was worse in controls at 60 and 90 days (p < 0.001). At 30 days, eyes from group 1 had less corneal opacity (p < 0.05). At 90 days, corneal opacity was worse in controls but the same in groups 1 and 2 (p < 0.05). At the same time, limbal deficiency was significantly worse in controls (p < 0.05) but similar between groups 1 and 2. Corneal phenotype was present in 70% of the eyes in group 1, 50% in group 2, but in 10% of the controls. Clinical success with clear corneas was significantly more common in groups 1 and 2 when compared with controls (p < 0.001). CLAU is effective in treating limbal deficiency. The concurrent AMT does not add benefits in this rabbit model of chemical burns.