Post-LASIK DHA May Aid Corneal Healing

NEW ORLEANSAdministration of docosahexaenoic acid (DHA) appears support corneal nerve regeneration, which could help address complications such as dry eye syndrome and soreness associated with photorefractive keratectomy or LASIK surgery. The PUFA Newsletter reported on a trial out of Louisiana State University Health Sciences Center that looked at whether administration of DHA and/or pigment epithelial-derived factor (PEDF), a nerve growth agent, affected regeneration of corneal nerves in rabbits (Prostaglandins Leukot Essent Fatty Acids 2010; DOI:10.1016/j.plefa.2010.02.004). Researchers also examined mechanisms of action by looking at levels of corneal neuroprotecting D1 (NPD1), a product of DHA metabolisms that has neuroprotective and anti-inflammatory actions (Invest Ophthalmol Vis Sci. 2010;51:804-10).

Exposure to PEDF and DHA was carried out using collagen shields secured on the rabbit cornea after the animals were subject to LASIK. Treatment with PEDF plus DHA significantly increased stromal nerve regeneration by more than three times that seen with just the treatment vehicle. Further, the combination treatment increased the subepithelial nerve area to 29 percent compared to 10 percent in the vehicle only group; stromal nerves also increased by 19 percent. However, PEDF or DHA alone did not increase corneal nerve regeneration, suggesting a synergistic effect.

In the mechanism of action study, the researchers examined the NPD1 content of corneas treated with DHA only compared to those that had the combined treatment; combined treatment significantly increased the number of superficial epithelial cells at six weeks, consistent with a healthier corneal epithelium.

The PUFA Newsletter report concluded the results suggest nerve regeneration following LASIK surgery could be enhanced with the application of PEDF plus DHA, which could also reduce or prevent the development of post-surgery dry eye syndrome.