Abstract
Abstract: :
Purpose: To evaluate the additional benefit of amniotic membrane transplantation (AMT) when combined with conjunctival limbal autograft (CLAU) in the treatment of chemical burns. Methods: Thirty eyes of thirty rabbits underwent a chemical burn with 1 N NaOH to create limbal deficiency. Forty-five days later, the animals were randomized into 3 groups of ten rabbits each. The eyes from group 1 were treated with CLAU, group 2 underwent CLAU and AMT and the group 3 served as the control without surgery. Corneal vascularization and opacity were documented with external pictures at postoperative 30, 60 and 90 days. The rabbits were sacrificed three months after surgery and the corneas divided into two halves. One half of the cornea was prepared for hematoxylin-eosin and PAS staining. The other half was prepared for frozen sections and submitted to immunohistochemical staining with AM3 (to MUC 5AC) and AE5 (to K3 keratin) monoclonal antibodies. The final clinical outcome was also evaluated and scored using the external photographs at the last follow up. Results: After the chemical burn, all groups presented with similar degrees of conjunctivalization. After transplantation, the corneal vascularization was worse in the control group 3 at sixty and ninety days (P<0.001). Thirty days after treatment, the eyes from group 1 had less corneal opacity (P<0,05). The corneal opacity was worse in the control eyes of group 3, but was the same in groups 1 and 2, ninety days after treatment (P<0,05). Limbal deficiency was significantly worse in the group 3 controls (P<0,05), but was similar between group 1 and group 2. The corneal phenotype was present in 70% of the eyes from group 1, 50% from group 2, but 70% of the the control group 3. Clinical success with clear corneas was significantly higher in group 1, followed by group 2 and group 3 controls (P<0,001). Conclusion: Our results indicate that CLAU is effective in treating limbal deficiency, but additional AMT does not add more benefits in this rabbit model of chemical burns. The extent of limbal deficiency created in this rabbit model may have influenced the outcome of evaluating the efficacy of these two surgical procedures.<br /
Keywords: 372 cornea: epithelium • 316 animal model • 375 cornea: surface mucins