What is corneal neurotization and who needs it?

Preop of an eye with neurotrophic keratopathy.People who have experienced loss of sensation through the 5th cranial nerve (called, the trigeminal nerve) are prone to having loss of sensation to the delicate cornea of the eye. This is the colored portion of the eye and where vision occurs. When this happens, the ability to protect the eye by way of the blink reflex is lost. In the past, this led to irreversible blindness due to progressive scarring of the cornea.

Corneal neurotization is a sophisticated procedure designed to restore sensation and reverse vision-impairing scarring of the eye (called neurotrophic keratopathy) by delivering sensation to the affected cornea.

 

How is corneal neurotization performed?

Corneal neurotization requires one side of the face to be unaffected in order to borrow the nerve supply. A nerve graft is harvested from the leg, called the sural nerve.

Sural nerve graft harvest from leg for facial paralysis reconstruction.

This nerve only provides a small amount of sensation to the top and outer part of the foot. Therefore, sacrificing it does not lead to any lasting disability.

Simultaneously, the area of the eyebrow on the unaffected side is prepared by isolating a branch of the trigeminal nerve, called the supratrochlear nerve. This becomes our donor nerve. Small incisions are then placed in the upper eyelid crease on both sides to pass the nerve graft underneath the skin. The sural nerve graft is then carefully divided into smaller branches and stitched underneath the outer lining of the sclera (called conjunctiva). This is done around the entire cornea. On the donor nerve side, the sural nerve graft is stitched to the side of the supratrochlear nerve and will gain innervation from it over time.

Corneal neurotization of an eye with neurotrophic keratopathy.

 

How long does it take to see the effects?

It takes approximately 9-12 months for the nerve input to pass through the graft and into the cornea. Benefits can be seen for several years thereafter.

Before and after photo of patient following corneal neurotization for neurotrophic keratopathy.

 

Is corneal neurotization dangerous?

All surgeries carry some risk. However, corneal neurotization has a very low risk of damaging the eye further. Scars tend to heal unnoticeably, and there is no discernible loss of sensation from using either the sural nerve or the supratrochlear nerve.

 

What is the recovery like?

Recovery from corneal neurotization is relatively straightforward. Patients may walk immediately after surgery and can even go home the same day. Dr. Panossian will provide additional instructions on caring for the surgical areas. Generally, there is to be no aggressive physical activity or heavy lifting for 4-6 weeks. Rubbing of the incisions is discouraged. Patients are encouraged to shower on the first postoperative day. Pain is also minimal. You will be given pain medications and eye lubricant prior to going home.

 

What are the risks and complications of corneal neurotization?

Perhaps the greatest complication of corneal neurotization is inadvertent damage of the eye itself. This is a very rare phenomenon. Another issue may be poor re-innervation of the cornea despite normal healing. If this were to happen, then there would be no discernible change in corneal sensation from preop.

Additional risks are quite minor and include typical risks of any surgery. This includes bleeding, infection, poor scarring, and anesthesia difficulties. Preoperative assessment by a qualified primary care doctor usually will suffice prior to undergoing surgery in order to minimize complications.

Dr. Panossian is internationally-recognized for his work in facial paralysis and corneal neurotization. He is an expert in microsurgery and peripheral nerve surgery, which are vital to the success of this very unique procedure. If you are experiencing corneal sensitivity issues, please contact us today to immediately schedule a consultation.