Y S Choi1, J Y Kim, W R Wee, J H Lee. 1. Department of Ophthalmology, College of Medicine, Chungbuk National University, Cheongju, South Korea.
Abstract
PURPOSE: We investigated the influence of amniotic membrane application on corneal wound healing after excimer laser photorefractive keratectomy (PRK) in rabbits. METHODS: PRK of -9.9 D with an optical zone of 5.0 mm was performed on each right eye of 34 pigmented rabbits, which had been divided into two groups. In 17 eyes, preserved human amniotic membrane was applied in such a way that it covered the entire cornea for 48 h (amniotic group), and the other eyes formed the control group. The area of epithelial defect, inflammatory cell infiltration, the number of anterior stromal keratocytes, and corneal haze were evaluated. RESULTS: In all animals, the epithelium had healed completely within 3 days, and there was no difference between the two groups. At postoperative 12 and 24 h, the numbers of stromal inflammatory cells in the amniotic group were significantly lower than those in the control group (p = 0.009), and the numbers of anterior stromal keratocytes were significantly higher (p < 0.05). At postoperative weeks 2, 4, 6, 8, and 12, corneal haze scores in the amniotic group were lower than those in the control group (p < 0.05), and at postoperative week 12, the number of anterior stromal keratocytes in the amniotic group was significantly lower than that in the control group (p = 0.002). CONCLUSION: The application of amniotic membrane after PRK reduces keratocyte proliferation and corneal haze during corneal wound healing, possibly by reducing the infiltration of inflammatory cells and loss of keratocytes in the ablation area during the early postoperative period.
PURPOSE: We investigated the influence of amniotic membrane application on corneal wound healing after excimer laser photorefractive keratectomy (PRK) in rabbits. METHODS: PRK of -9.9 D with an optical zone of 5.0 mm was performed on each right eye of 34 pigmented rabbits, which had been divided into two groups. In 17 eyes, preserved human amniotic membrane was applied in such a way that it covered the entire cornea for 48 h (amniotic group), and the other eyes formed the control group. The area of epithelial defect, inflammatory cell infiltration, the number of anterior stromal keratocytes, and corneal haze were evaluated. RESULTS: In all animals, the epithelium had healed completely within 3 days, and there was no difference between the two groups. At postoperative 12 and 24 h, the numbers of stromal inflammatory cells in the amniotic group were significantly lower than those in the control group (p = 0.009), and the numbers of anterior stromal keratocytes were significantly higher (p < 0.05). At postoperative weeks 2, 4, 6, 8, and 12, corneal haze scores in the amniotic group were lower than those in the control group (p < 0.05), and at postoperative week 12, the number of anterior stromal keratocytes in the amniotic group was significantly lower than that in the control group (p = 0.002). CONCLUSION: The application of amniotic membrane after PRK reduces keratocyte proliferation and corneal haze during corneal wound healing, possibly by reducing the infiltration of inflammatory cells and loss of keratocytes in the ablation area during the early postoperative period.