Corneal Neurotization

Corneal neurotization is a procedure that restores sensation to a numb cornea of an adult or child. The cornea is the central area of the eye. This is done by using a small nerve graft from the leg to guide nerve growth from a nearby sensory nerve in the face. The nerve regrowth is guided directly into the effected cornea to restore sensation to the eye. This restores protective blink reflex, tearing reflex, and normal wound healing permanently.

Why the procedure is performed

  • Corneal sensation is required for blinking, as well as reflex tearing. Without corneal sensation, protective blink reflex and reflex tearing are not possible. Corneal sensation is also needed for wound healing the cornea that has been injured. Without these functions, the cornea is at risk for permanent injury, scarring and blindness.
  • The lack of corneal sensation can occur from trauma or intracranial surgery.
  • This procedure is done to restore sensation to cornea, which in turn restores protective blink reflex, tearing and wound healing. While ointments/drops, protective contacts and corneal transplantation are standard treatment for patients with an insensate cornea, these treatments are not a permanent solution. Corneal neurotization restores corneal sensation, making it a permanent and definitive treatment options.

Risks

  • The donor nerve, also called the sural nerve, is taken from the lower leg for the procedure. This results is a small area over the outer foot and ankle with decreased sensation. This is not functionally impairing and most patient do not notice it long-term.
  • Small incisions are used for the procedure, both at the lower leg for nerve harvest and at the upper eyelid creases for placement of the nerve. These typically heal well and are inconspicuous.
  • As with all surgeries, small risks of infection and discomfort are possible, but low risk. Antibiotics and pain medication are provided to assist with healing and recovery.

Before the procedure

  • You will meet the plastic surgeon and ophthalmologist for evaluation to ensure your candidacy for the procedure. You will then see an occupational therapist for sensory mapping, which will help determine which facial sensory nerve is best used for the nerve regeneration.
  • Finally, before the procedure, you will have an evaluation by an anesthesiologist and the surgical team to complete the necessary paperwork for surgery.

After the procedure

  • You will have a soft bandage on your leg that will be removed at the first clinic appointment. The eyelid incisions will also be evaluated at the first clinic appointment after surgery.
  • The nerve regrowth will begin to occur immediately after surgery and will take several months to reach the cornea. The time for full nerve growth is different for each patient, but on average is three to six months, and all have full nerve growth by 12 months after surgery.
  • The first sensation you will likely feel will be dryness and discomfort of the eye for the first time. This is the beginning of protective blink reflex, increased tear production and healing of your previous cornea injuries.

Outlook (Prognosis)

  • Patients that undergo surgery will have partial to complete return of corneal sensation between three and six months after surgery on average and up to 12 months after surgery.

 

Reference/Citations

  1. Allevi F, Fogagnolo P, Rossetti L, Biglioli F. Eyelid reanimation, neurotisation, and transplantation of the cornea in a patient with facial palsy. BMJ Case Rep. 2014;2014.
  2. Bains RD, Elbaz U, Zuker RM, Ali A, Borschel GH. Corneal neurotization from the supratrochlear nerve with sural nerve grafts: a minimally invasive approach. Plast Reconstr Surg. 2015;135(2):397e-400e.
  3. Catapano J, Antonyshyn K, Zhang JJ, Gordon T, Borschel GH. Corneal Neurotization Improves Ocular Surface Health in a Novel Rat Model of Neurotrophic Keratopathy and Corneal Neurotization. Invest Ophthalmol Vis Sci. 2018;59(11):4345-4354.
  4. Catapano J, Scholl D, Ho E, Zuker RM, Borschel GH. Restoration of Trigeminal Cutaneous Sensation with Cross-Face Sural Nerve Grafts: A Novel Approach to Facial Sensory Rehabilitation. Plast Reconstr Surg. 2015;136(3):568-571.
  5. Elbaz U, Bains R, Zuker RM, Borschel GH, Ali A. Restoration of corneal sensation with regional nerve transfers and nerve grafts: a new approach to a difficult problem. JAMA Ophthalmol. 2014;132(11):1289-1295.
  6. Fung SSM, Catapano J, Elbaz U, Zuker RM, Borschel GH, Ali A. In Vivo Confocal Microscopy Reveals Corneal Reinnervation After Treatment of Neurotrophic Keratopathy With Corneal Neurotization. Cornea. 2018;37(1):109-112.
  7. Lambley RG, Pereyra-Munoz N, Parulekar M, Mireskandari K, Ali A. Structural and functional outcomes of anaesthetic cornea in children. Br J Ophthalmol. 2015;99(3):418-424.