Ozmen Mehmet Cuneyt, Hondur Ahmet, Yilmaz Guldal, Bilgihan Kamil, Hasanreisoglu Berati
Department of Ophthalmology, Gazi University, Ankara 06500, Turkey.
Department of Pathology, Gazi University, Ankara 06500, Turkey.
Int J Ophthalmol. 2014 Dec 18;7(6):959-63. doi: 10.3980/j.issn.2222-3959.2014.06.08. eCollection 2014.
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.
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 30min intervals along with topical proparacaine drops with benzalkonium chloride, and 370 nm irradiation was performed for 30min, while riboflavin was instilled every 3min. Four eyes (group IV) received 48% ethanol for 30s without riboflavin and irradiation. Eyes were collected after 24h and examined histologically.
All eyes in group I showed keratocyte loss in the superficial 300 µ of corneal storma. In group II, 1-4 layers of epithelium were preserved and no keratocyte loss occurred. In group III, CXL after treatment with ethanol up to 24% concentration and up to 60s 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.
Incomplete excimer laser ablation of the epithelium or treatment with ethanol up to 24% concentration and up to 60s duration yielded no stromal keratocyte loss. To get the same histological appearance seen in epithelial debridement group, partial thickness excimer laser epithelial ablation or ethanol application is not adequate for transepithelial CXL.
在一项实验性兔研究中，评估使用准分子激光部分厚度消融或上皮乙醇应用进行经上皮角膜交联（CXL）后的组织学变化。
对24只兔的右眼进行研究。4只眼接受全层上皮清创术（I组）。4只眼接受准分子激光部分厚度上皮消融（II组）。12只眼用不同持续时间（30秒和60秒）和浓度（18%至48%）的乙醇进行处理（III组）。每隔30分钟应用核黄素，并联合使用含苯扎氯铵的丙美卡因滴眼液局部滴眼，进行30分钟的370纳米照射，同时每隔3分钟滴入核黄素。4只眼（IV组）接受48%乙醇处理30秒，不使用核黄素和照射。24小时后收集眼球并进行组织学检查。
I组所有眼在角膜基质浅层300微米处均出现角膜细胞丢失。II组保留了1至4层上皮，未发生角膜细胞丢失。III组中，用浓度高达24%且持续时间长达60秒的乙醇处理后进行CXL，未发现角膜细胞丢失。用48%及更高乙醇浓度处理后进行CXL，导致角膜浅层200微米至300微米处角膜细胞丢失。
上皮的准分子激光不完全消融或用浓度高达24%且持续时间长达60秒的乙醇处理，不会导致基质角膜细胞丢失。为了获得上皮清创术组所见的相同组织学外观，准分子激光部分厚度上皮消融或乙醇应用对于经上皮CXL来说并不充分。
