Plasma Rich in Growth Factors enhances corneal nerve regeneration after experimental laser ablation in mice.

Abstract

Purpose : Abnormal corneal regeneration after injury or infection would compromise visual acuity due to improper wound healing and may result in neuropathic pain. Conventional treatments usually fail to restore the injured corneal tissue and there is a need for further research in effective treatments designed to enhance corneal nerve regeneration. In this study, we evaluated the efficacy of Plasma Rich in Growth Factors (PRGF) in a mouse model of corneal nerve regeneration and wound healing.

Methods : A surgical laser ablation (VISX S3, Johnson's & Johnson's) affecting the central cornea and subbasal nerve plexus of mice was used as a model of the nerve regeneration and wound-healing assay. Topical treatment with Plasma Rich in Growth Factors (PRGF; n=20) for 2 months was compared with human recombinant Nerve Growth Factor (hrNFG; n=20) and an untreated injured control (BSS; n=20). Corneal nerve regeneration and tissue repair were studied at 7, 15, 30 and 60 days after injury using immunofluorescence techniques. Specific antibodies to β-tubulin III, α-Smooth Muscle actin (αSMA), E-Cadherin and Ki67 were used. Morphometric analysis was performed using FIJI (ImageJ 1.51d, NIH). All experiments were conducted in compliance with the "ARVO Statement for the Use of Animals in Ophthalmic and Visual Research.

Results : At early stages of corneal nerve regeneration after laser ablation, the PRGF group showed a significant increase in subbasal nerve density compared with the hrNGF and BSS treated groups (p< 0.01 and p< 0.001 respectively 7 days after injury and p< 0.05 at 15 days). Normal epithelial cytoarchitecture and corneal thickness were achieved in PRGF-treated animals 7 days after injury. In addition, PRGF treatment reduced the occurrence of myofibroblasts compared to eyes irrigated with hrNGF and BSS (p< 0.01).

Conclusions : These results showed that PRGF enhances corneal nerve regeneration and epithelial wound healing soon after the injury, in asddition to reducing myofibroblast scarring after experimental laser injury, suggesting a possible beneficial effect on restoring transparency and function.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.