神经生长因子对准分子激光治疗性角膜切削术后角膜修复的作用

Effects of nerve growth factor on corneal tissue reparation after phototherapeutic keratectomy

目的探讨神经生长因子(nerve growth factor,NGF)对准分子激光治疗性角膜切削术(phototherapeutic keratectomy,PTK)后伤口愈合及透明度恢复的影响。方法建立30只新西兰白兔PTK模型,术后右眼滴用自制NGF滴眼液,左眼滴用人工泪液作为对照眼。于术后不同时间分别进行裂隙灯、光学显微镜、722光栅分光光度计及扫描电镜检查。结果2组均于术后3～7d角膜上皮全部愈合,差异无统计学意义(P>0.05)。实验组术后不同波长的角膜透明度高于对照组,差异有统计学意义(P<0.05)。HE染色光镜观察发现对照组上皮细胞过度增生较重。扫描电镜显示,术后4周NGF组角膜上皮细胞层基本恢复正常,对照组角膜上皮表面的微绒毛及微皱褶仍然相对较少。结论NGF通过改善伤口愈合的微环境,抑制角膜上皮细胞的过度增生,调节伤口愈合,从而促进PTK后角膜透明度的恢复。

Objective To investigate the effects of nerve growth factor （NGF） on the corneal wound healing and transparency after phototherapeutic keratectomy （PTK）. Methods Thirty New Zealand rabbits were used as superficial corneal scar models by burning with volume fraction 8.17% sulfiic acid,and then treated with PTK in two weeks. The eyedrops including NGF were topically applied to the right eyes （ experimental group ）, and artificial tears were applied to the left eyes （ control group）. At 1 week,2 weeks,4 weeks, 8 weeks, 12 weeks and 16 weeks, the changes of reepithelialization were examined by slit-lamp microscope, corneal transparency was measured using an optimeter,and corneal wound healing was evaluated by HE staining. At 1 week and 4 weeks, the corneal epithelial cells were examined by scaning electron micro- scope （SEM）. Results The corneal epithelium wound in two groups were all healed from 3 days to 7 days postoperatively, there was no difference between two groups（P〉0.05 ）. The corneal transparency under different wave length ranging from 400 nm to 700 nm in experimental group was higher than that in control group postoperatively, the difference between two groups was significant in statistic postoperatively （ P 〈 0.05 ）. The excessive epithelial hyperplasia was more remarkable in control group after operation by HE staining. SEM examination showed that, the corneal epithelial cells were similar to the normal in experimental group at 4 weeks postoperatively, and micovilli on the surface of corneal epithelium in control group were still less than those in experimental group. Conclusion NGF can inhibit the corneal epithelial hyperplasia by improving the microenvironment of corneal tissue reparation, reduce scar formation and accelerate corneal transparency after PTK. [Ree Adv Ophthalmol 2007;27（2） ：110-112]