Can Corneal Nerves Regenerate? Yes they can.


There are many causes of corneal nerve injury or neuropathy. Corneal surgery, such as LASIK, PRK, RK, can cause nerve injury. So can trauma, diabetes, chronic dry eye disease. It is well known that the nerves can grow back. However, the question is how do they grow back and what can make them grow back faster and more robust (ie, not abnormal). 

The answer is to provide an excellent environment of nutrients around the nerves to help them grow properly. The key nutrients are likely:

1. Nerve Growth Factor

2. Glial-cell-derived neurotrophic factor (GDNF)

3. Stem Cells

Note & References:

Manipulating the activity of a gene called LIM domain kinase 1, or Limk1. Limk1 controls the rate of nerve growth by regulating the activity of a protein called cofilin. Cofilin plays a key role in a process known as actin polymerization, or “treadmilling,” which enables nerves to extend thread-like projections over long distances to form neural networks.

Butler’s new paper builds on these findings by showing that Limk1 and cofilin also control the rate of growth of peripheral nerves during both development and regeneration.

2016 May;10(5):428-36.

 doi: 10.1002/term.1756. Epub 2013 May 31.

Effect of platelet-rich plasma (PRP) concentration on proliferation, neurotrophic function and migration of Schwann cells in vitro



Platelet-rich plasma (PRP) contains various growth factors and appears to have the potential to promote peripheral nerve regeneration, but evidence is lacking regarding its biological effect on Schwann cells (SCs). The present study was designed to investigate the effect of PRP concentration on SCs in order to determine the plausibility of using this plasma-derived therapy for peripheral nerve injury. PRP was obtained from rats by double-step centrifugation and was characterized by determining platelet numbers and growth factor concentrations. Primary cultures of rat SCs were exposed to various concentrations of PRP (40%, 20%, 10%, 5% and 2.5%). Cell proliferation assays and flow cytometry were performed to study to assess SC proliferation. Quantitative real-time PCR and ELISA analysis were performed to determine the ability of PRP to induce SCs to produce nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF). Microchemotaxis assay was used to analyse the cell migration capacity. The results obtained indicated that the platelet concentration and growth factors in our PRP preparations were significantly higher than in whole blood. Cell culture experiments showed that 2.5-20% PRP significantly stimulated SC proliferation and migration compared to untreated controls in a dose-dependent manner. In addition, the expression and secretion of NGF and GDNF were significantly increased. However, the above effects of SCs were suppressed by high PRP concentrations (40%). In conclusion, the appropriate concentration of PRP had the potency to stimulate cell proliferation, induced the synthesis of neurotrophic factors and significantly increased migration of SCs dose-dependently. Copyright © 2013 John Wiley & Sons, Ltd.

2021 Feb;203:108428.

 doi: 10.1016/j.exer.2020.108428. Epub 2021 Jan 2.

The effect of nerve growth factor on corneal nerve regeneration and dry eye after LASIK



Dry eye is the most common complication after refractive surgery, especially after laser in situ keratomileusis (LASIK), in which nerves may be cut when making the corneal flap. Nerve growth factor (NGF) has been demonstrated to stimulate corneal sensitivity and nerve regeneration and NGF has been suggested as a potential treatment for dry eye disease (DED). Hence, this study aimed to investigate the effect of NGF on corneal nerve regeneration, sensitivity and dry eye symptoms after LASIK, compared to hycosan and normal saline (NS) treatments. Thirty-eight New Zealand white rabbits that underwent LASIK procedures were randomly assigned to three groups. Each group underwent NGF, hycosan, and NS treatment. The nerve densities and the number of corneal sub-basal and superficial stromal nerves were measured with confocal microscopy, and the results were compared before surgery and at one month and three months postoperatively. Corneal sensitivity was assessed with an esthesiometer. The tear breakup time (TBUT) was recorded to check for signs of dry eye. The whole corneas of the experimental animals were excised at three months after the surgery for immunohistochemically analysis. After LASIK, treatment with NGF significantly accelerated the recovery of sub-basal and superficial stromal nerve densities and the numbers, compared to hycosan and NS treatments at one month and three months postoperatively (NGF vs. hycosan, P < 0.01 each; NGF vs. NS, P < 0.01 each). The recovery of corneal sensitivity was significantly enhanced in the NGF group compared to the hycosan or NS treatment groups after surgery (P < 0.05). Also, the TBUT data showed a statistically significant longer time in the NGF group at one month, and three months postoperatively (P < 0.05). Immunofluorescence analysis showed the nerve fiber quantity of the NGF group was larger than in the hycosan and NS groups. Taken together, the experimental results suggested that mNGF had an obvious effect on promoting corneal nerve repairing and the potential to improve dry eye in different periods following LASIK.

Shopping Cart