Research: Lipid-lowering drugs for the treatment of diabetic corneal neuropathy

Cornea is the transparent part of the eye that has the most abundant nerve supply in the body. In diabetes mellitus, prolonged elevated blood sugar levels injure nerves throughout the body, including corneal nerves. Such corneal nerve damage affects about 47-64% of diabetes patients, and is often underdiagnosed as patients are often asymptomatic. These patients have decreased corneal sensation which predisposes them to non-healing corneal ulcers, infection, or even perforation – all of which may significantly affect their vision.   

 

Currently, the treatment for diabetic corneal neuropathy focuses mainly on relieving symptoms such as eye irritation or dryness. The only FDA-approved drug to treat cornea nerve damage (nerve growth factor eye drops) are expensive, require frequent application, and are not available in Singapore. Hence, there is a crucial need to find an effective and affordable alternative. 

One of the causes of cornea diabetic neuropathy is increased lipid levels. As such Assoc Prof Liu Yu-Chi (SERI) and Dr Tan Hong Chang (SGH) decided to investigate the effects of fenofibrate, a drug that regulates lipid and glucose metabolism, on corneal nerve regeneration.

The study involved 30 patients with type II diabetes, and after 30 days of oral fenofibrate treatment, significant stimulation of corneal nerve regeneration and reduction in nerve edema were observed. The treatment also improved the morphology of corneal epithelial cells, suppressed inflammation, increased tear break-up time, and reduced surface damage. Proteomic analysis revealed that fenofibrate affected neuronal pathways, lipid metabolism, and exhibited anti-inflammatory and anti-coagulation properties. 

Assoc Prof Liu and Dr Tan add: “Poorly controlled diabetes damages corneal nerves. There is no treatment for diabetic corneal neuropathy, but we discovered that the damaged nerves regenerated following treatment with the lipid-lowering drug-fenofibrate”.

They believe that fenofibrate could be a promising treatment for diabetic corneal neuropathy, but further large-scale trials are necessary.

The findings of this study provide a potential novel treatment option for diabetic corneal neuropathy, improving ocular surface integrity. Future research will involve randomized controlled trials and may offer significant cost-saving benefits for patients with diabetic ocular surface conditions.

For more information, watch this video as Assoc Prof Liu Yu-Chi discusses on her research work (internet access required):