Corneal neurotisation is a new technique in Singapore

When the corneal nerves are damaged, the body is unable to sense trauma to the surface and corneal ulcerations result. In severe cases, irreversible corneal scarring leads to blindness. This condition is called “neurotrophic keratopathy” and results from many causes such as herpes infection, diabetes, multiple sclerosis and chemical burns. Within the brain, trauma, tumor or surgery can affect the 5th cranial nerve (trigeminal nerve) that supplies cornea sensation. If the 7th cranial nerve is also affected, as in facial paralysis, the inability to blink further compounds the problem as the eye is left unprotected.

Corneal neurotisation was first described in 1972 and has gained traction in recent years. It is a very important innovation that restores sensory input to a neurotrophic cornea. Basically, the cornea can “feel” again and sense trauma.

Using minimally invasive techniques, a sural nerve graft can be harvested from the leg to bridge from the normal side forehead. The nerve fibres are placed around the cornea. Nerve axons then regrow over 1 to 2 years at a rate of 1mm/day, and gradually the patient is able to regain corneal sensation. The incisions are hidden (such as under the eyebrow) and recovery is fast.

So far, corneal neurotisation is thought to be a safe and effective procedure. Meta-analyses show significant improvement in vision and corneal sensation. Understandably, this may be reduced in old patients or those with chronic illness such as diabetes, as their nerve regeneration may be weaker. With continued advances in understanding, success may still be within reach for these patients in the future.

We have started doing cases in Singapore in collaboration with eye surgeons. At the time of writing, our own results are still early. However, I am confident that in time, this technique will become progressively more established in Singapore, as it has in other countries all over the world.