PURPOSE To determine how photorefractive keratectomy (PRK) and mitomycin C (MMC) affect corneal nerves and their regeneration over time after surgery. METHODS Twenty-eight New Zealand rabbits had corneal epithelial scraping with (n = 3) and without (n = 3) MMC 0.02% or -9.00 diopter PRK with (n = 6) and without (n = 16) MMC 0.02%. Corneas were removed after death and corneal nerve morphology was evaluated using acetylcholinesterase immunohistochemistry and beta-III tubulin staining after 1 day for all groups, after 1 month for PRK with and without MMC, and 2, 3, and 6 months after PRK without MMC. Image-Pro software (Media Cybernetics, Rockville, MD) was used to quantitate the area of nerve loss after the procedures and, consequently, regeneration of the nerves over time. Opposite eyes were used as controls. RESULTS Epithelial scraping with MMC treatment did not show a statistically significant difference in nerve loss compared to epithelial scraping without MMC (P = .40). PRK with MMC was significantly different from PRK without MMC at 1 day after surgery (P = .0009) but not different at 1 month after surgery (P = .90). In the PRK without MMC group, nerves regenerated at 2 months (P < .0001) but did not return to the normal preoperative level of innervation until 3 months after surgery (P = .05). However, the morphology of the regenerating nerves was abnormal-with more tortuosity and aberrant innervation compared to the preoperative controls-even at 6 months after surgery. CONCLUSIONS PRK negatively impacts the corneal nerves, but they are partially regenerated by 3 months after surgery in rabbits. Nerve loss after PRK extended peripherally to the excimer laser ablated zone, indicating that there was retrograde degeneration of nerves after PRK. MMC had a small additive toxic effect on the corneal nerves when combined with PRK that was only significant prior to 1 month after surgery. [J Refract Surg. 2018;34(12):790-798.].

中文翻译：

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屈光性角膜切除术和丝裂霉素C对角膜神经及其再生的影响。

目的确定术后屈光性角膜切除术（PRK）和丝裂霉素C（MMC）如何影响角膜神经及其再生。方法28只新西兰兔在（n = 3）和（n = 3）MMC 0.02％的情况下角膜上皮刮擦，或在（n = 6）和（n = 16）MMC 0.02％的情况下（-9.00屈光度PRK）。死亡后去除角膜，对所有组在第1天后，有和无MMC的PRK术后1个月，无MMC的PRK的术后2、3和6个月，用乙酰胆碱酯酶免疫组织化学和β-III微管蛋白染色评估角膜神经形态。手术后使用Image-Pro软件（Media Cyber​​netics，Rockville，MD）对神经丢失的区域进行定量，并因此对神经随时间的再生进行定量。相反的眼睛用作对照。结果与不使用MMC的上皮刮擦相比，使用MMC的上皮刮擦没有显示出统计学上的显着差异（P = .40）。带有MMC的PRK与没有MMC的PRK在术后1天有显着差异（P = .0009），但在术后1个月无差异（P = .90）。在没有MMC组的PRK中，神经在2个月时再生（P <.0001），但直到术后3个月才恢复到正常的术前神经支配水平（P = .05）。然而，再生神经的形态是异常的-与术前对照相比甚至在手术后6个月也有更多的曲折和异常的神经支配。结论PRK对角膜神经有负面影响，但在兔子手术后3个月它们会部分再生。PRK周围神经延伸至准分子激光消融区后，神经丢失，表明PRK后神经发生逆行变性。与PRK联合使用时，MMC对角膜神经有较小的附加毒性作用，这种作用仅在手术后1个月之前显着。[J Refract Surg。2018; 34（12）：790-798。]。