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EW CORNEA 32 January 2018 by Rich Daly EyeWorld Contributing Writer initial observation after sural nerve transplantation," Dr. Al-Ghoul said. Dr. Borschel has observed no decline in his patients' function for as long as 5 years postop. Improvements needed Dr. Borschel said surgeons still need to determine how to make the pro- cedure effective for all patients. "We have noticed that about 5% do not regain excellent sensa- tion," Dr. Borschel said. The novel nature of the technique means more understanding is needed of who the ideal candidates are. "We have be- gun a series of animal studies in my laboratory to determine how best to improve function in patients." "In terms of the procedure itself, from a corneal perspective, understanding where to exactly place the nerve tissue on the eye is needed as we are not yet sure where the ideal location is," Dr. Al-Ghoul said. EW Reference 1. Elbaz U, et al. Restoration of corneal sensa- tion with regional nerve transfers and nerve grafts: a new approach to a difficult problem. JAMA Ophthalmol. 2014;132:1289–95. Editors' note: Dr. Al-Ghoul has finan- cial interests with Allergan (Dublin, Ireland), Alcon (Fort Worth, Texas), and Santen Pharmaceutical (Osaka, Japan). Drs. Ali and Borschel have no financial interests related to their comments. Contact information Al-Ghoul: ahmedalghoul@gmail.com Ali: asim.ali@sickkids.ca Borschel: borschel@gmail.com juxtaposing the sural nerve tissue, conjunctival thickening and edema can be pronounced and result in potential dellen formations that would require trimming back the sural nerve tissue further from the cornea. "The main contraindications would be doing this in an unstable neurotrophic melt that has not completely stabilized," Dr. Al-Ghoul said. "Another contraindication is in diabetics who typically have sig- nificant peripheral neuropathy that results in poor outcomes." Relative contraindications include patients with neurotroph- ic keratopathies stemming from either herpes simplex or zoster that has not been fully controlled with antiviral and anti-inflammatory treatments. "It's important to place patients on proper therapeutics in such cases ideally for at least 3–6 months prior to suggesting this treatment," Dr. Al-Ghoul said. One of the three patients with a history of herpes disease on whom Dr. Al-Ghoul performed the proce- dure developed stromal neovascu- larization that accompanied corneal nerve distribution peripherally. Permanent effect? Dr. Al-Ghoul has been perform- ing the technique for more than 2 years and found stable restoration of corneal sensation in most of his patients. In one case of herpes zoster induced NTK, a recurrence of central melt occurred that required AMT tissue that resulted in stabilization of corneal tissue. "He appeared to still have per- sistent sensitization afterward as per permanent visual loss to a recently developed graft-based procedure. The technique involves nerve transfers with nerve grafting to restore corneal sensation. Corneal sensory reconstruction is performed using a segment of the medial cuta- neous branch of the sural nerve. A prospective study evaluating the technique was published in JAMA Ophthalmology and found that in four eyes of three patients with corneal anesthesia, three eyes of two patients had markedly improved corneal sensation at 6 months post- op, and a third patient recovered 15 mm esthesiometry score centrally 7.5 months postop. 1 Gregory Borschel, MD, associ- ate professor of plastic surgery, Uni- versity of Toronto, and The Hospital for Sick Children, Toronto, Canada, has found any patient with neuro- trophic cornea or corneal anesthesia from any cause could be a candidate for the procedure. The experience of Ahmed Al-Ghoul, MD, clinical lecturer, University of Calgary, Canada, has shown that the patients best suited for the procedure are those with an iatrogenic cause to the neurotrophic process who are not responsive to conventional medical therapeutics. The ideal surgical team for the procedure, according to Dr. Al-Ghoul, would include a plastic surgeon to harvest the sural nerve, an oculoplastic surgeon to attach the sural nerve tissue to either the ipsilateral or contralateral supra- orbital/supratrochlear nerves, and a corneal surgeon to manage the corneal recovery process before and after the procedure. Asim Ali, MD, associate profes- sor of ophthalmology, University of Toronto, and The Hospital for Sick Children, said the joint effort extends from the preop workup to the surgery itself and finally to the postop care. "This collaborative approach has allowed us to treat every patient with this condition we have met," Dr. Ali said. So far, Dr. Borschel has seen no significant side effects from his patients—apart from temporary incisional pain. However, he noted that active corneal ulceration must be controlled prior to surgery. Dr. Al-Ghoul warned that occasionally, in the process of Surgeons describe how to get the best results from a new technique for corneal sensory reconstruction A lthough corneal senso- ry reconstruction can provide corneal sensation in previously anesthetic corneas, good prepara- tion is required for the best results, surgeons say. To tackle the recalcitrant chal- lenge of corneal anesthesia, some surgeons have turned from conven- tional treatments that can lead to Using grafts for corneal sensory reconstruction S ome of the toughest patients to treat as a cornea and external disease specialist are those with neurotroph- ic corneal disease. Etiologies for developing a neurotrophic cornea include having prior herpes zoster ophthalmicus or herpes simplex virus keratitis, diabetes, acoustic neuroma resection or other neurosurgical procedures (i.e., cranial nerve 5 decom- pression for trigeminal neuralgia), and even after scleral buckle surgery. Treatment modalities are supportive in nature such as using lubrication, serum tears, scleral lens- es, or tarsorrhaphies, and in cases where persistent epithelial defects occur, amniotic membrane may assist in temporizing the problem. Patients who develop corneal scarring have a poor prognosis from corneal transplants. While not FDA approved but coming down the pipeline, recombinant human nerve growth factor may be benefi- cial. Many ophthalmologists are not aware that there is a procedure involving the use of peripheral nerve grafts to reconnect and reinnervate corneas that are neurotrophic. Asim Ali, MD, and Gregory Borschel, MD, were the first to achieve success with this technique termed "corneal neurotization." In this month's "Cornea editor's corner of the world," they discuss the technique and their results. Ahmed Al-Ghoul, MD, also describes which patients are contraindi- cated and the learning curve involved. This surgery certainly provides some hope for a group of patients who have few options. Clara Chan, MD, Cornea editor Cornea editor's corner of the world " In terms of the procedure itself, from a corneal perspective, understanding where to exactly place the nerve tissue on the eye is needed as we are not yet sure where the ideal location is. " —Ahmed Al-Ghoul, MD

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