Omega-3s help recover corneal nerve sensitivity

Cornea: fish oil reactivates nerve sensitivity

Combined treatment withOmega-3 DHA and PEDF growth factor helps corneal nerves regenerate and regain sensitivity after laser eye surgeries. A group of researchers, coordinated by Haydee Bazan of the Louisiana State University Health Sciences Center in New Orleans, USA, published the results of a study conducted on rabbits in the pages of the Archives of Ophthalmology. Once confirmed in humans, these findings will mean a new approach to regenerating ocular nerves and preventing the onset of disorders such asdry eye.

Corneal surgery: what happens to the nerves

Some nerve cells know how to grow and repair themselves after being damaged: peripheral nerves regenerate more easily than those in the central nervous system. Research is making great efforts to understand how to help nerves recover sensation after trauma, such as that associated with surgery. Advances in this area would make it possible to prevent some complications associated with eye operations or some diseases of the surface of the eye itself. One case studied is that of the cornea, the transparent layer that covers the eye and is rich in nerve fibers. During corneal surgeries, such as corrective laser surgeries, these nerves can be damaged. The sensitivity of the cornea may decrease when damaged and problems may arise, such as reduced tear production, which in turn promotes disorders such as dry eye syndrome.

The Role of Omega-3s

A mixture of DHA (docosahexaenoic acid, one of the Omega-3s in which fatty fish are rich) and pigment epithelium-derived growth factor (PEDF) applied to the eye after surgery allows almost complete ^nerve regeneration2. Preliminary studies show this. In this new research, Bazan and colleagues analyzed the function of regenerated corneal nerves after surgical damage in rabbits treated with PEDF and DHA. To do so, they stimulated blinking in the treated eye: if the rabbit did not blink, the cornea was considered insensitive. At 8 weeks after the procedure, the scientists thus showed that the corneal nerves of the DHA- and PEDF-treated animals not only regenerated but were as sensitive as healthy eyes. However, the process takes time:

- After 4 weeks, the sensitivity of the damaged cornea was low;

- after 6 weeks was about 70% of the sensitivity of the healthy eye.

In contrast, the regeneration process is faster: only 72 hours after surgery, the corneas of rabbits treated with Omega-3 and growth factors had healed almost completely.

Nerves healed and functioning thanks to omega-3s

Our results show that DHA used in combination with PEDF promotes healing of damaged corneal nerves. It allows, at the same time, complete functional recovery. The finding paves the way for new Omega-3-based treatments to prevent the side effects of invasive eye surgeries.

Source 

1. Cortina MS, He J, Li N, Bazan NG, Bazan HE, "Recovery of corneal sensitivity, calcitonin gene-related peptide-positive nerves, and increased wound healing induced by pigment epithelial-derived factor plus docosahexaenoic acid after experimental surgery," Arch Ophthalmol. 2012 Jan;130(1):76-83. Epub 2011 Sep 12 

2. Cortina MS, He J, Li N, Bazan NG, Bazan HE, "Neuroprotectin D1 synthesis and corneal nerve regeneration after experimental surgery and treatment with PEDF plus DHA," Invest Ophthalmol Vis Sci. 2010 Feb;51(2):804-10. Epub 2009 Sep 24