Bilgihan K, Bilgihan A, Hasanreisoğlu B, Turkozkan N
Gazi University Medical School, Ankara, Turkey.
Br J Ophthalmol. 1998 Mar;82(3):300-2. doi: 10.1136/bjo.82.3.300.
The free radical balance of the eye may be changed by excimer laser keratectomy. Previous studies have demonstrated that excimer laser keratectomy increases the corneal temperature, decreases the superoxide dismutase activity of the aqueous, and induces lipid peroxidation in the superficial corneal stroma. Aldehyde dehydrogenase (ALDH) and glutathione S-transferase (GST) are known to play an important role in corneal metabolism, particularly in detoxification of aldehydes, which are generated from free radical reactions.
In three groups of guinea pigs mechanical corneal de-epithelialisation was performed in group I, superficial corneal photoablation in group II, and deep corneal photoablation in group III, and the corneal ALDH and GST activities measured after 48 hours.
The mean ALDH and GST activities of group I and II showed no differences compared with the controls (p > 0.05). The corneal ALDH activities were found to be significantly decreased (p < 0.05) and GST activities increased (p < 0.05) in group III.
These results suggest that excimer laser treatment of high myopia may change the ALDH and GST activities, metabolism, and free radical balance of the cornea.
准分子激光角膜切削术可能会改变眼部的自由基平衡。先前的研究表明，准分子激光角膜切削术会提高角膜温度，降低房水中超氧化物歧化酶的活性，并诱导角膜浅层基质中的脂质过氧化。已知醛脱氢酶（ALDH）和谷胱甘肽S-转移酶（GST）在角膜代谢中起重要作用，特别是在自由基反应产生的醛的解毒过程中。
在三组豚鼠中，第一组进行机械性角膜上皮剥脱，第二组进行角膜表面光凝，第三组进行角膜深层光凝，并在48小时后测量角膜ALDH和GST活性。
第一组和第二组的平均ALDH和GST活性与对照组相比无差异（p>0.05）。第三组中，角膜ALDH活性显著降低（p<0.05），GST活性升高（p<0.05）。
这些结果表明，准分子激光治疗高度近视可能会改变角膜的ALDH和GST活性、代谢及自由基平衡。
