amniotic membrane transplantation in acute ocular chemical burns

purpose: to evaluate the role of amniotic membrane transplantation (amt) in acute ocular chemical burns. methods: patients with grade ii-iv (gii-giv) ocular chemical burns (roper-hall classification) of less than two weeks’ duration underwent amt in addition to medical therapy. patients were followed for at least 6 months and evaluated for ocular pain, visual acuity, epithelial defect healing, symbelpharon formation, and corneal opacity and neovascularization. results: twelve eyes of 8 patients (6 male, 2 female) with mean age of 28.75±11.8 (range 12-44) years were operated. mean duration between chemical burn and surgery was 2.5±3.3 days (range, 2 hours to 10 days). mean follow up period was 11.5±1.5 (range 10-13) months. the chemical agent was acidic in six eyes and alkaline in the other six. ocular burns were gii in one eye, giii in four eyes and giv in seven eyes. pain and discomfort decreased in all patients. visual acuity improved completely in the eye with gii burn. it also improved in three eyes and remained unchanged in one eye with giii burn. in eyes with giv burn, two underwent tectonic corneal grafts due to perforation and two were phthisical, however visual acuity decreased in two and increased in one of the remaining eyes. the epithelial defect healed within 6 days in the eye with gii burn. mean time for healing was 53.75±5.2 days in eyes with giii burn. keratolimbal allograft surgery was performed in one eye with persistent epithelial defect and severe corneal thinning. in the other two eyes, the epithelium healed in 70 and 75 days. corneal neovascularization was seen in two eyes with giii and all eyes with giv burns. corneal opacity developed in all eyes with giii and giv burns. only mild symblepharon was seen in four eyes with giv burn. conclusion: amt seems to be effective in pain reduction and prevention of symblepharon formation. it seems ineffective in preventing corneal opacification and neovascularization. the role of amt in accelerating epithelial healing and improving visual acuity in patients with gii and giii ocular burns needs to be evaluated in a clinical trial. it seems that prevention of symblepharon formation is the only role of amt in eyes with giv chemical burns.