The cornea – the clear outer layer of the eye – is one of the most sensitive parts of the body (approximately 300 times more sensitive than skin). The tiniest fleck of dust can cause you to blink rapidly and tear up.
The cornea acts as the eye’s primary protector, shielding it from everyday hazards. It is filled with thousands of tiny nerve endings that set in motion protective actions, such as closing the eyelid or producing tears, whenever they detect even the slightest invader or problem.
When those nerves don’t function properly, it can lead to a variety of complications, including dry eye, poor wound healing, scarring, and, ultimately, vision loss.
Unfortunately, people with corneal nerve damage often don’t feel pain or discomfort early on because sensitivity of the cornea is reduced. But as the condition advances, blurred vision, red eyes, dry eyes, and sensitivity to light becomes common. If your cornea is injured, it likely will take longer to heal, making it more susceptible to long-term damage.
Treatment for nerve damage or nerve death has traditionally included lubricating eye drops, ointments, or keeping the eye partially or fully shut. Those treatments only address symptoms; they don’t return feeling to the eye.
But a new surgical procedure is revolutionizing cornea reinnervation. The UT Southwestern Department of Ophthalmology is one of only about a dozen medical centers in the United States that offers corneal neurotization surgery.
In this innovative approach, the eye surgeon transplants a nerve graft from the patient’s leg to restore sensation to the cornea, including blinking, tearing reflexes, and normal wound healing – without the need for a constant stream of eyedrops and ointments.
What to expect during corneal neurotization
Corneal neurotization surgery starts with a plastic surgeon harvesting a nerve graft from your leg. This nerve innervates a very small area of the skin around the ankle, so the loss of sensation will not impair function – you likely won’t notice its absence in the long term.
We then isolate the supratrochlear nerve, which supplies sensory innervation to the skin of the forehead and upper eyelid, on the unaffected side of your face and attach the nerve graft from the leg to it. The nerve graft is then passed under the skin and implanted around the affected cornea.
The procedure lasts 4-5 hours, and you will be under general anesthesia.
Over the next months, new nerve endings will grow into the cornea and restore sensation and healing capacity. How long this may take is different for each patient – on average, patients begin to notice restored feeling, regained blinking reflexes, and increased tear production within three to six months, with full nerve regrowth after 12 months.
You’ll be able to walk immediately after surgery and may be allowed to go home the same day – please plan for someone to drive you home. You’ll likely have some swelling and bruising around the eye for two to three weeks. The affected eye may be sutured shut temporarily to promote healing, and the suture is usually removed after 1-2 weeks.
Research shows a mean vision improvement of 41 percent, with younger patients experiencing the greatest benefits.
Causes and symptoms of corneal nerve damage
Many health conditions can damage the nerves serving the cornea. These can include:
- Viral infections, particularly the herpes simplex virus
- Surgery near or around the eye, such as surgery for cataracts, corneal transplants, orbital surgery, or laser eye surgery to correct vision
- Cancers of the eye and surrounding tissue
- Systemic diseases such as diabetes and multiple sclerosis
- Chemical or physical burns of the cornea
- Corneal dystrophies
- Injury and trauma to the eye and surrounding area
If not properly treated, permanent vision loss can occur as damage continues to build, leading to the cornea becoming scarred, irregularly shaped, or perforated.
Prior to corneal neurotization surgery, people with low or no corneal sensation must apply eyedrops or ointment regularly throughout the day, sometimes up to every 30 minutes, to prevent more damage and, ultimately, blindness.
Corneal neurotization surgery can fix the underlying problem while relieving symptoms. For most patients, the procedure eliminates their dependence on eyedrops and ointment by providing permanent protection to your cornea and vision.