Costagliola C, Di Giovanni A, Rinaldi M, Scibelli G, Fioretti F
Eye Clinic, II University of Naples, Italy.
Surv Ophthalmol. 1997 Nov;42 Suppl 1:S133-40. doi: 10.1016/s0039-6257(97)80036-7.
Fifty male albino rabbits were studied. Ten animals served as controls. Forty animals were prepared to receive photorefractive keratectomy (PRK), including anesthesia, scraping of the corneal epithelial cells, etc. Twenty of these animals then received PRK with energy delivered by excimer laser (pulse rate = 20 Hz, fluence 250 mJ/cm2; number of pulses = 6032; cumulative UV dose = 1508J/cm2). The other 20 animals were exposed to the same operating microscope light as the PRK-treated animals, but they did not receive PRK. All three groups were divided into halves: the first half was immediately analyzed at 0 time, and the second half was observed 1 year later. Samples of aqueous humor and lens were analyzed. The levels of reduced and oxidized glutathione, hydrogen peroxide, ascorbic acid, and malondialdehyde were determined. Excimer laser-induced ultrastructural modifications of the lens, verified through scanning electron microscopy, were studied at the same intervals. Immediately after PRK, the biochemical parameters studied, both in aqueous humor and in lens of treated animals, showed significant differences. One year later, the observed biochemical variations in lens were still present, whereas aqueous humor values did not significantly differ from control values. Ultrastructural abnormalities of the lens appeared only 1 year after PRK In the animals that received only the preparation for PRK the biochemical and ultrastructural differences did not significantly vary as compared to the data obtained from control animals. These findings suggest that the biochemical and ultrastructural lens alterations induced by PRK may represent events relevant to cataractogenesis in the rabbit.
对50只雄性白化兔进行了研究。10只动物作为对照。40只动物准备接受准分子激光角膜切削术（PRK），包括麻醉、刮除角膜上皮细胞等。其中20只动物随后接受了准分子激光能量的PRK治疗（脉冲频率 = 20Hz，能量密度250mJ/cm²；脉冲数 = 6032；累积紫外线剂量 = 1508J/cm²）。另外20只动物暴露于与接受PRK治疗的动物相同的手术显微镜光下，但未接受PRK治疗。所有三组均分为两半：前半部分在0时刻立即进行分析，后半部分在1年后进行观察。对房水和晶状体样本进行分析。测定还原型和氧化型谷胱甘肽、过氧化氢、抗坏血酸和丙二醛的水平。通过扫描电子显微镜验证的准分子激光诱导的晶状体超微结构改变，在相同间隔时间进行研究。PRK治疗后立即，所研究的生化参数，在治疗动物的房水和晶状体中均显示出显著差异。1年后，晶状体中观察到的生化变化仍然存在，而房水值与对照值无显著差异。晶状体的超微结构异常仅在PRK治疗1年后出现。在仅接受PRK准备的动物中，与从对照动物获得的数据相比，生化和超微结构差异没有显著变化。这些发现表明，PRK诱导的晶状体生化和超微结构改变可能代表与兔白内障形成相关的事件。
