• Written By:
    Cornea/External Disease, Oculoplastics/Orbit

    Investigators describe the outcomes of a minimally invasive surgical technique using acellular nerve allograft to re-establish corneal sensibility in patients with neurotrophic keratopathy.

    Study design

    This retrospective case series included 7 neurotrophic keratopathy patients who underwent acellular nerve allograft (Avance Nerve Graft, AxoGen) coapted to an intact supraorbital, supratrochlear or infraorbital nerve. The etiologies within the cohort varied greatly, and included prior vestibular schwannoma, history of multiple ocular surgeries, insulin-dependent diabetes, herpes zoster ophthalmicus and central trigeminal nerve injury

    Donor nerve pedicles were isolated from each patient using a transpalpebral or transconjunctival approach. The authors evaluated preoperative and postoperative corneal sensibility, ocular surface parameters and BCVA. Follow-up ranged from 3 to 10 months.

    Outcomes

    Corneal sensibility, assessed via Cochet-Bonnet measurements, was restored in all 7 patients. Six out of seven demonstrated improved vision. All five patients who had preoperative epithelial defects resolved following the neurotization procedure.

    Limitations      

    The procedure carries the risk of neuroma formation secondary to neurorrhaphy as well as permanent numbness and parasthesia in the area of the donor nerve dermatome. The authors point out that the maximum length of the nerve allograft is 7 cm, which may not be sufficient for all patients. An extended follow-up may be necessary to demonstrate the long-term survivability and function of acellular nerve graft in comparison to nerve autografts.

    Clinical significance

    This study is the largest case series thus far illustrating the use of a nerve allograft for corneal neurotization. Using a nerve allograft maintains a minimally invasive surgical profile with shorter surgical times and does not require coordination of care with other subspecialties for autograft harvesting. Consequently, more surgeons may consider neurotization for those individuals with severe neurotrophic keratopathy.