title: Restoration of corneal sensation with regional nerve transfers and nerve grafts: a new approach to a difficult problem.
abstract: OBJECTIVE
  Corneal anesthesia is recalcitrant to conventional treatment and can lead to permanent visual loss.
  
  
  OBJECTIVE
  To assess the outcomes of a novel sensory reconstructive technique for the treatment of corneal anesthesia.
  
  
  METHODS
  This prospective study evaluating a new technique was conducted at a tertiary referral center. Four eyes in 3 patients with corneal anesthesia underwent nerve transfers with nerve grafting to restore corneal sensation. Corneal sensory reconstruction was performed using a segment of the medial cutaneous branch of the sural nerve. Two patients with unilateral trigeminal nerve anesthesia-one following basal skull fracture and another following large posterior fossa tumor resection-underwent corneal sensory reconstruction using the contralateral supratrochlear nerve as the donor sensory nerve. One patient with a history of cerebellar hypoplasia and bilateral congenital corneal anesthesia underwent bilateral corneal sensory reconstruction using the respective ipsilateral supratrochlear nerves as the sensory donor nerves. Corneal anesthesia was evaluated preoperatively and postoperatively in the center of the cornea and in 4 corneal quadrants using a Cochet-Bonnet esthesiometer (Luneau). Complications of the procedure were also documented.
  
  
  METHODS
  Esthesiometry scores.
  
  
  RESULTS
  All eyes had prior complications of corneal anesthesia and had no measurable corneal sensation in the affected eye(s) preoperatively. Two patients-one with cerebellar hypoplasia and the other with posterior fossa tumor resection-had markedly improved corneal sensation 6 months postsurgery (3 eyes; mean [SD] central esthesiometry, 55 [5] mm). A third patient with a history of basal skull fracture underwent unilateral corneal neurotization and recovered 15-mm esthesiometry score centrally after 7.5 months of follow-up. None of the operated on eyes have developed corneal anesthesia-related complications since reconstruction.
  
  
  CONCLUSIONS
  Corneal sensory reconstruction provides corneal sensation in previously anesthetic corneas. This can be achieved with minimal morbidity using sural nerve grafts, which surgeons commonly use to reconstruct nerve gaps elsewhere. This multidisciplinary approach restores an ocular defense mechanism and may enable subsequent corneal transplant in these patients.
authors.affiliation: Department of Ophthalmology and Vision Sciences, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Uri
authors.initials: U
authors.lastname: Elbaz
authors.affiliation: Division of Plastic and Reconstructive Surgery, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Robert
authors.initials: R
authors.lastname: Bains
authors.affiliation: Division of Plastic and Reconstructive Surgery, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Zuker
authors.affiliation: Division of Plastic and Reconstructive Surgery, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Gregory H
authors.initials: GH
authors.lastname: Borschel
authors.affiliation: Department of Ophthalmology and Vision Sciences, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Asim
authors.initials: A
authors.lastname: Ali
mesh_terms: D000293:Adolescent; D002648:Child; D003315:Cornea / Q000294:innervation / Q000502:physiology*; D003316:Corneal Diseases / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D006987:Hypesthesia / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D016067:Nerve Transfer; D019635:Neurosurgical Procedures; D009882:Ophthalmic Nerve / Q000601:surgery*; D013508:Ophthalmologic Surgical Procedures; D011446:Prospective Studies; D013497:Sural Nerve / Q000637:transplantation*; D014321:Trochlear Nerve / Q000637:transplantation*