AIM: To evaluate the histological changes after transepithelial corneal crosslinking(CXL) using partial thickness excimer laser ablation or epithelial ethanol application in an experimental rabbit study.METHODS: Right...AIM: To evaluate the histological changes after transepithelial corneal crosslinking(CXL) using partial thickness excimer laser ablation or epithelial ethanol application in an experimental rabbit study.METHODS: Right eyes of twenty-four rabbits were studied. Four eyes received total epithelial debridement(group I). Four eyes received partial thickness epithelial ablation with excimer laser(group II). Twelve eyes were treated with different durations(30s and 60s) and concentrations(18% to 48%) of ethanol(group III).Riboflavin was applied for 30 min intervals along with topical proparacaine drops with benzalkonium chloride,and 370 nm irradiation was performed for 30 min, while riboflavin was instilled every 3min. Four eyes(group IV)received 48% ethanol for 30 s without riboflavin and irradiation. Eyes were collected after 24 h and examined histologically.RESULTS: All eyes in group I showed keratocyte loss in the superficial 300 μ of corneal storma. In group II, 1-4layers of epithelium were preserved and no keratocyte loss occurred. In group III, CXL after treatment with ethanol up to 24% concentration and up to 60 s revealed no keratocyte loss. CXL after treatment with 48% and higher ethanol concentrations yielded keratocyte loss in the superficial 200 μ to 300 μ of cornea.CONCLUSION: Incomplete excimer laser ablation of the epithelium or treatment with ethanol up to 24%concentration and up to 60 s duration yielded no stromal keratocyte loss. To get the same histological appearance seen in epithelial debridement group, partial thicknessexcimer laser epithelial ablation or ethanol application is not adequate for transepithelial CXL.展开更多
文摘AIM: To evaluate the histological changes after transepithelial corneal crosslinking(CXL) using partial thickness excimer laser ablation or epithelial ethanol application in an experimental rabbit study.METHODS: Right eyes of twenty-four rabbits were studied. Four eyes received total epithelial debridement(group I). Four eyes received partial thickness epithelial ablation with excimer laser(group II). Twelve eyes were treated with different durations(30s and 60s) and concentrations(18% to 48%) of ethanol(group III).Riboflavin was applied for 30 min intervals along with topical proparacaine drops with benzalkonium chloride,and 370 nm irradiation was performed for 30 min, while riboflavin was instilled every 3min. Four eyes(group IV)received 48% ethanol for 30 s without riboflavin and irradiation. Eyes were collected after 24 h and examined histologically.RESULTS: All eyes in group I showed keratocyte loss in the superficial 300 μ of corneal storma. In group II, 1-4layers of epithelium were preserved and no keratocyte loss occurred. In group III, CXL after treatment with ethanol up to 24% concentration and up to 60 s revealed no keratocyte loss. CXL after treatment with 48% and higher ethanol concentrations yielded keratocyte loss in the superficial 200 μ to 300 μ of cornea.CONCLUSION: Incomplete excimer laser ablation of the epithelium or treatment with ethanol up to 24%concentration and up to 60 s duration yielded no stromal keratocyte loss. To get the same histological appearance seen in epithelial debridement group, partial thicknessexcimer laser epithelial ablation or ethanol application is not adequate for transepithelial CXL.
