Hayes Sally, O'Brart David P, Lamdin Letitia S, Doutch James, Samaras Kostas, Marshall John, Meek Keith M
School of Optometry and Vision Sciences, Cardiff University, Maindy Road, Cathays, Cardiff, Wales, United Kingdom.
J Cataract Refract Surg. 2008 Apr;34(4):657-61. doi: 10.1016/j.jcrs.2008.02.002.
To evaluate the importance of complete epithelial removal before riboflavin-ultraviolet-A (UVA) corneal collagen crosslinking therapy.
School of Optometry and Vision Sciences, Cardiff University, Wales, United Kingdom.
Riboflavin eyedrops were applied at 5-minute intervals for 35 minutes to the anterior corneal surface of 36 porcine eyes (12 with no epithelial trauma but treated with tetracaine eyedrops, 12 with superficial epithelial trauma but with an intact basal epithelium, and 12 with a fully removed epithelium). The corneal surface of 6 tetracaine-treated eyes, 6 eyes with superficial epithelial trauma, and 6 eyes with a fully removed epithelium was exposed to UVA light for 30 minutes during riboflavin administration. The light transmission spectra of the enucleated corneas were analyzed with a spectrophotometer and compared with those of 9 untreated porcine corneas.
Corneas with a fully removed epithelium treated with riboflavin showed an abnormal dip in the transmission spectrum between 400 nm and 510 nm (P<.01). This was attributed to the presence of riboflavin in the corneal stroma. The spectra of riboflavin-treated corneas with no epithelial trauma but tetracaine administration and those with superficial epithelial trauma did not differ from those of the non-riboflavin-treated controls. Exposure to UVA following riboflavin administration did not alter corneal light transmission.
Complete removal of the corneal epithelium is an essential component of riboflavin-UVA crosslinking therapy as superficial epithelial trauma and tetracaine administration alone are not sufficient to permit the penetration of riboflavin into the corneal stroma. Failure to achieve adequate stromal absorption of riboflavin may impair the efficacy of the crosslinking process.
评估在核黄素-紫外线A（UVA）角膜胶原交联治疗前完全去除上皮的重要性。
英国威尔士卡迪夫大学验光与视觉科学学院。
以5分钟的间隔向36只猪眼的角膜前表面滴注核黄素滴眼液，持续35分钟（12只无上皮损伤但用丁卡因滴眼液处理，12只存在浅表上皮损伤但基底上皮完整，12只上皮完全去除）。在滴注核黄素期间，对6只丁卡因处理的眼睛、6只存在浅表上皮损伤的眼睛和6只上皮完全去除的眼睛的角膜表面进行30分钟的UVA照射。用分光光度计分析摘除眼球的角膜的透光光谱，并与9只未处理的猪角膜的透光光谱进行比较。
用核黄素处理且上皮完全去除的角膜在400纳米至510纳米之间的透光光谱出现异常下降（P<0.01）。这归因于角膜基质中存在核黄素。未出现上皮损伤但使用丁卡因处理的核黄素处理角膜以及存在浅表上皮损伤的核黄素处理角膜的光谱与未用核黄素处理的对照角膜的光谱无差异。核黄素给药后暴露于UVA并未改变角膜透光率。
完全去除角膜上皮是核黄素-UVA交联治疗的重要组成部分，因为仅浅表上皮损伤和使用丁卡因不足以使核黄素渗透到角膜基质中。核黄素未能在基质中充分吸收可能会损害交联过程的疗效。
