Corneal Neurotization Using the Great Auricular Nerve for Bilateral Congenital Trigeminal Anesthesia

Insights on the Choice and Preparation of the Donor Nerve in Corneal Neurotization for Neurotrophic Keratopathy: A Narrative Review

The article introduces neurotrophic keratopathy (NK), a condition resulting from corneal denervation due to various causes of trigeminal nerve dysfunctions. Surgical techniques for corneal neurotization (CN) have evolved, aiming to restore corneal sensitivity. Initially proposed in 1972, modern approaches offer less invasive options. CN can be performed through a direct approach (DCN) directly suturing a sensitive nerve to the affected cornea or indirectly (ICN) through a nerve auto/allograft. Surgical success relies on meticulous donor nerve selection and preparation, often involving multidisciplinary teams. A PubMed research and review of the relevant literature was conducted regarding the surgical approach, emphasizing surgical techniques and the choice of the donor nerve. The latter considers factors like sensory integrity and proximity to the cornea. The most used are the contralateral or ipsilateral supratrochlear (STN), and the supraorbital (SON) and great auricular (GAN) nerves. Regarding the choice of grafts, the most used in the literature are the sural (SN), the lateral antebrachial cutaneous nerve (LABCN), and the GAN nerves. Another promising option is represented by allografts (acellularized nerves from cadavers). The significance of sensory recovery and factors influencing surgical outcomes, including nerve caliber matching and axonal regeneration, are discussed. Future directions emphasize less invasive techniques and the potential of acellular nerve allografts. In conclusion, CN represents a promising avenue in the treatment of NK, offering tailored approaches based on patient history and surgical expertise, with new emerging techniques warranting further exploration through basic science refinements and clinical trials.

Corneal Neurotization for Neurotrophic Keratopathy: A Multicentre Experience

PURPOSE

Corneal neurotization is an emerging technique that offers potential for visual rehabilitation in neurotrophic keratopathy. This study reports on a multicenter experience and outcomes for both direct and indirect methods of corneal neurotization.

METHODS

Retrospective case series. Sixteen patients with neurotrophic keratopathy who underwent corneal neurotization across 5 centers in Australia and Israel were identified for inclusion. Corneal neurotization was performed via direct neurotization from the ipsilateral or contralateral supraorbital/supratrochlear nerve or by the use of an interpositional sural nerve graft. Change in corneal sensitivity (measured in millimeters by the Cochet-Bonnet aesthesiometer), visual acuity, and corneal health.

RESULTS

Over a mean follow-up period of 31.3 months (range: 3 months-8 years), mean corneal sensitivity improved from 3.6 mm (range: 0-25 mm) to 25.3 mm (range: 0-57 mm). Visual acuity improved on average from 20/380 to 20/260. Twelve of 16 patients (75.0%) improved in at least 2 out of the 3 main outcome measures. Nine patients (56.3%) showed an improvement in visual acuity; 13 (81.3%) showed an improvement in average corneal sensitivity; and 11 (68.8%) showed an improvement in corneal health. There were no intraoperative or postoperative complications.

CONCLUSIONS

Corneal neurotization is an emerging surgical treatment option for the management of neurotrophic keratopathy. With appropriate case selection, outcomes are favorable and complication rates are low, for a condition that is otherwise challenging to manage. Patients with severe neurotrophic keratopathy should be considered for this surgical treatment option.

Central sleep apnea in patients with pontine tegmental cap dysplasia treated with supplemental oxygen: a case report

This is the first case report of sleep-disordered breathing in patients with pontine tegmental cap dysplasia, a very rare neurological disorder characterized by an anatomic malformation in the pons. Patients present with hypotonia, cognitive dysfunction, and cranial nerve palsies (eg, hearing loss, trigeminal anesthesia, and swallow dysfunction). Extensive studies have demonstrated the relevance of different pontine neuronal nuclei in breathing regulation, which are structurally abnormal in pontine tegmental cap dysplasia. We present detailed polysomnography data for 3 patients aged 41 years, 20 years, and 1.5 years revealing significant central sleep apnea. We discuss our experience with managing their sleep-disordered breathing in the setting of multiple cranial nerve palsies and corneal anesthesia, and its relative contraindication of noninvasive positive pressure ventilation treatment.

CITATION

Ju Wang J-D, Doherty D, Ramirez J-M, Chen M. Central sleep apnea in patients with pontine tegmental cap dysplasia treated with supplemental oxygen: a case report. J Clin Sleep Med. 2023;19(4):843-849.

Corneal Neurotization—Indications, Surgical Techniques and Outcomes

Corneal neurotization is a promising surgical approach for the treatment of moderate to severe neurotrophic keratopathy. This technique aims to restore corneal sensation by transferring healthy nerves, either directly or via a conduit, to the anesthetic cornea. This review provides a report on the current state of development, evidence, and experience in the field. We summarize the data available from clinical reports and case series, placing an emphasis on the diversity of the surgical techniques reported. While these data are encouraging, they also highlight the need for a consensus in reporting outcomes and highlight how the next step will involve validating putative outcome parameters when researching and reporting corneal neurotization surgery.

Bilateral Corneal Neurotization for Ramos-Arroyo Syndrome and Developmental Neurotrophic Keratopathy: Case Report and Literature Review

PURPOSE

The purpose of this study was to report the use of bilateral corneal neurotization for neurotrophic keratitis in the setting of Ramos-Arroyo syndrome.

METHODS

The case report and surgical technique are described in detail in this article, as well as a review of the literature on corneal neurotization for congenital corneal anesthesia.

RESULTS

We report a 17-year-old patient who underwent bilateral corneal neurotization for neurotrophic keratitis secondary to corneal anesthesia in Ramos-Arroyo syndrome. Corneal neurotization was performed with great auricular nerve transfers extended by sural nerve autografts.

CONCLUSIONS

We present the treatment of neurotrophic keratopathy with corneal neurotization in a patient with Ramos-Arroyo syndrome. We describe how bilateral corneal neurotization using the great auricular nerve technique is a safe and effective procedure for patients with congenital/developmental corneal anesthesia.