Single and multilayer amniotic membrane transplantation for persistent corneal epithelial defect with and without stromal thinning and perforation

AIMS: To evaluate the efficacy of amniotic membrane transplantation (AMT) in persistent corneal epithelial defect with or without stromal thinning and corneal perforation. METHODS: 28 patients (28 eyes) with persistent corneal epithelial defect unresponsive to medical treatment were given preserved human amniotic membrane transplants. The patients were divided into three groups: group A, persistent corneal epithelial defect 10 eyes; group B, epithelial defect with stromal thinning 13 eyes; and group C, corneal perforation five eyes. AMT was performed using one layer in group A and multilayers in group B and C. The causes of persistent epithelial defect were neurotrophic keratopathy (24 eyes), limbal deficiency (six eyes), exposure keratopathy (four eyes), and Mooren's ulcer (one eye). RESULTS: Success was noted in 82.1% (23/28 eyes) in all groups, with 80% (8/10 eyes), 84.6% (11/13 eyes), and 80% (4/5 eyes) in groups A, B, and C respectively, with a mean follow up of 10.9 months (1-30 months). The mean epithelialisation time after AMT was 2.1 weeks. The healing times of groups B and C are also significantly shorter than group A (p=0.017 and 0.018, respectively). Corneal stromal thickness was significantly increased in all cases in groups B and C (p=0.006). Those with corneal perforation in group C were completely healed by multilayer AMT. There was no difference in the epithelialisation time between successful cases treated by a single operation (17 eyes) or repeated operation (six eyes). Vision improved in 18.9% (8/28 eyes) and worsened as a result of cataract formation in 2.3% (1/28 eyes). Failure was noted in 17.9% (5/28 eyes), because of corneal infection (two eyes), neurotrophic keratopathy with and without limbal deficiency (two eyes), and intractable corneal perforation (one eye). No patient developed major immediate postoperative complications or graft rejection. CONCLUSION: Amniotic membrane can successfully treat refractory corneal epithelial defect by promoting epithelial healing and thus prevent corneal perforation. It can be used as a treatment for corneal perforation by restoring corneal stromal thickness so that emergency penetrating keratoplasty can be avoided.