Restoration of corneal sensitivity is of utmost importance to maintain corneal homeostasis following any injury or insult, for which, both corneal nerve regeneration and re-innervation are essential. Fibrosis poses a major impediment for re-innervation. We have in this study evaluated the influence of various nerve growth factors and corneal fibrosis on corneal nerve regeneration and reinnervation following lamellar flap surgery (LFS) and its modulation using antifibrotic drug pirfenidone. To achieve this, trigeminal ganglion cells were treated with pirfenidone, NGF, and NT-3 to evaluate their effect on trigeminal cell neurite growth. Following LFS, the gene expression of nerve growth factors NGF, BDNF and NT-3, Gap 43, Nogo-A and profibrotic factors Tenascin C, TGF-beta 1 were evaluated with and without pirfenidone. Wound fibrosis and corneal nerve regeneration using pirfenidone following LFS were evaluated by staining whole corneal mounts with α SMA and β tubulin 3. Safety of NGF and pirfenidone topical drops in normal unoperated cornea and its efficacy in enhancing corneal healing was evaluated following LFS. Our study shows, pirfenidone did not influence trigeminal cell neurite elongation; NGF and NT-3 significantly enhanced trigeminal cell neurite elongation. NT-3 also significantly increased neurite branching. There was significant increase in the gene expression of NGF, BDNF, NT-3, Gap- 43, TGF beta-1, Tenascin C, Nogo-A genes in the operated cornea compared to normal cornea, treatment of operated corneas with pirfenidone prevented the increased expression of these genes except Gap 43 which remained unchanged. The treatment of operated eyes with combination of NGF and pirfenidone positively influenced corneal healing compared to treatment with NGF alone, and had no adverse influence on the cornea. Pirfenidone appreciably reduced corneal fibrosis which aided in re-innervation. Both NGF and NT3 positively influence trigeminal neurite elongation. NGF and pirfenidone have complementary influence on corneal wound healing.

中文翻译：

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减轻纤维化-层状皮瓣手术后角膜重新神经支配的障碍。

恢复角膜敏感性对于任何受伤或侮辱后维持角膜动态平衡至关重要，为此，角膜神经再生和重新支配都是必不可少的。纤维化是重新神经支配的主要障碍。在这项研究中，我们评估了各种神经生长因子和角膜纤维化对片状皮瓣手术（LFS）后角膜神经再生和神经支配及其对抗纤维化药物吡非尼酮的调节的影响。为此，用吡非尼酮，NGF和NT-3处理三叉神经节细胞，以评估它们对三叉神经突神经生长的影响。LFS后，在有和没有吡非尼酮的情况下评估神经生长因子NGF，BDNF和NT-3，Gap 43，Nogo-A和纤维化因子Tenascin C，TGF-beta 1的基因表达。LFS后，通过用αSMA和β微管蛋白3染色整个角膜支架，评估使用吡非尼酮的伤口纤维化和角膜神经再生。在LFS后，评估NGF和吡非尼酮局部滴眼液在正常未手术角膜中的安全性及其增强角膜愈合的功效。我们的研究表明，吡非尼酮不影响三叉神经细胞神经突伸长；NGF和NT-3显着增强了三叉神经突突的伸长。NT-3还显着增加了神经突分支。与正常角膜相比，手术角膜中NGF，BDNF，NT-3，Gap-43，TGFβ-1，腱生蛋白C，Nogo-A基因的基因表达显着增加，用吡非尼酮治疗手术角膜可预防这些基因的表达增加，但Gap 43保持不变。与单独使用NGF相比，使用NGF和吡非尼酮的组合治疗手术眼睛对角膜愈合有积极影响，并且对角膜无不利影响。吡非尼酮明显减少了角膜纤维化，有助于再神经支配。NGF和NT3都正面影响三叉神经突的伸长。NGF和吡非尼酮对角膜伤口愈合有互补的影响。