Congenital Corneal Anesthesia and Neurotrophic Keratitis: Diagnosis and Management

Changes in bilateral tear film and corneal nerve stability in patients with unilateral neurotrophic keratitis

Objective

This study aimed to examine the bilateral stability of the tear film in patients with unilateral neurotrophic keratitis and to observe changes in corneal nerve and immune cells under confocal microscopy.

Methods

A prospective cross-sectional study included 63 patients with confirmed neurotrophic keratitis (NK) and 40 normal controls of similar sex and age. NK patients were divided into stage 1 and stage 2 based on the severity of the disease. Tear meniscus height (TMH), first non-invasive tear film break-up time (NIBUT-f), and corneal fluorescein staining were assessed. Corneal sensitivity was assessed using a Cochet-Bonnet esthesiometer. The corneal subbasal nerve plexus (SNP) and dendritic cells (DCs) were imaged using in vivo confocal microscopy (IVCM), and the SNP was analyzed using the fully automated corneal nerve analysis software "ACCmetric."

Results

Eyes with NK stage 2 showed worse performance in TMH, NIBUT-f, corneal fluorescein staining score, corneal sensitivity examination, SNP parameters, and DC density compared to NK stage 1 (all p < 0.001). The contralateral eyes of NK patients had significantly shorter NIBUT-f and higher dendritic cell density than controls (p < 0.001).

Conclusion

The contralateral eyes of NK patients are more prone to dry eye signs than those of normal subjects and should be monitored and treated promptly. Increased dendritic cell numbers in the contralateral eyes of NK patients suggest bilateral immune alterations in unilateral disease.

Neurotrophic keratopathy: Update in diagnosis and management

The cornea is the most densely sensory innervated tissue in the body. Sensory corneal nerves are essential to maintain ocular surface homeostasis and are involved in the blink reflex, tear production, and the release of trophic factors that are key in the wound healing process. Compromise of corneal sensory nerves leads to neurotrophic keratopathy (NK), an uncommon degenerative disorder that may lead to corneal epithelial breakdown, ulceration, corneal opacification, and even perforation. Management of this condition is difficult and visual disability often ensues in affected patients. While treatment has been traditionally focused in promoting epithelial healing, the past decade has seen a breakthrough in new medical and surgical therapies geared toward promoting corneal reinnervation. This review presents a comprehensive update on NK, focusing on current as well as potential new strategies for its diagnosis and management.

Effect of recombinant human nerve growth factor treatment on corneal nerve regeneration in patients with neurotrophic keratopathy

Introduction

Neurotrophic Keratopathy (NK) is a neurodegenerative corneal disease that results in diminished corneal sensation. Previous studies have found that Cenegermin 0.002%, a recombinant human nerve growth factor (rhNGF), improves corneal epithelial healing in stage 2 and 3 NK patients. However, rhNGF effect on corneal sensation and nerve regeneration has not been well established. Thus, this study aims to analyze the effect of rhNGF on corneal nerve regeneration using in vivo confocal microscopy (IVCM) and on corneal sensitivity in NK patients.

Methods

This is a retrospective, longitudinal, case-control study that included patients with NK, treated with rhNGF for at least 4 weeks, with pre- and post-treatment IVCM images available for analysis. Chart reviews were conducted documenting prior medical and surgical history, clinical signs and symptoms, and corneal sensation using Cochet-Bonnet esthesiometry. Corneal nerve parameters were assessed by IVCM. Sex- and age-matched reference controls were selected from a database of healthy subjects for comparison.

Results

The study included 25 patients, with 22 (88%) stage 1, two (8%) stage 2, and 1 (4%) stage 3 NK patients, with a median age of 64 years (range: 30-93 years). Total, main, and branch nerve densities [median (range) in mm/mm2] were lower in the NK group pre-treatment [2.3 (0.0-21.1); 1.7 (0.0-13.0); 0.5 (0.0-10.2); respectively] vs. controls [22.3 (14.9-29.0); 10.1 (3.2-15.4); and 12.1 (6.2-18.4), (p < 0.0001 for all), respectively]. Post-treatment nerve densities increased compared to pre-treatment to 5.3 (0.0-19.4, p = 0.0083) for total, 3.5 (0.0-13.2, p = 0.0059) for main, and 2.0 (0.0-10.4, p = 0.0251) for branch nerves, but remained lower than controls (p < 0.0001 for all). Corneal sensation increased from 2.3 ± 1.1 cm pre-treatment to 4.1 ± 1.4 cm post-treatment (p = 0.001). Median best corrected visual acuity significantly increased following rhNGF treatment from 0.4 (0.0-1.6) to 0.12 (-0.1 to 1.6) (p = 0.007).

Conclusion

Patients with NK treated with at least 4 weeks of rhNGF, showed a significant increase in corneal nerve densities after treatment. A significant increase in corneal sensation, as well as best corrected visual acuity, was observed following treatment.

Neurotrophic keratopathy: An updated understanding

PURPOSE

To propose an updated definition and staging system for neurotrophic keratopathy (NK) and provide consensus on diagnosis and treatment.

METHODS

A study group was convened to review the data pertinent to NK using a modified nominal group process. They proposed an updated definition for NK and a new 6-step staging system (Neurotrophic Keratopathy Study Group [NKSG] Classification) that can be used in conjunction with the different treatment options available currently or in the future.

RESULTS

NK is defined as the dysfunction of corneal innervation that results in dysregulation of corneal and/or cellular function. It is characterized by loss of corneal sensation and neuronal homeostasis, leading to eventual corneal epithelial breakdown and ultimately keratolysis if untreated. The NKSG classification emphasizes verifying corneal sensation early and distinguishes different epithelial and stromal aspects of NK with the following stages: stage 1 (altered sensation without keratopathy), stage 2 (epitheliopathy/punctate epithelial keratopathy [PEK] without stromal haze), stage 3 (persistent/recurrent epithelial defects without stromal haze), stage 4 (epitheliopathy/PEK or persistent/recurrent epithelial defects with stromal haze), stage 5 (persistent/recurrent epithelial defect with corneal ulceration), and stage 6 (corneal perforation). Treatment consists of a variety of modalities (both indirect and direct).

CONCLUSIONS

This updated definition and staging system will provide clinicians with the necessary information to diagnose and treat NK at an early stage before it becomes a sight-threatening disorder. It also provides a framework for evaluating current and future treatment options at distinct stages of the disease.

TFOS Lifestyle: Impact of contact lenses on the ocular surface

Several lifestyle choices made by contact lens wearers can have adverse consequences on ocular health. These include being non-adherent to contact lens care, sleeping in lenses, ill-advised purchasing options, not seeing an eyecare professional for regular aftercare visits, wearing lenses when feeling unwell, wearing lenses too soon after various forms of ophthalmic surgery, and wearing lenses when engaged in risky behaviors (e.g., when using tobacco, alcohol or recreational drugs). Those with a pre-existing compromised ocular surface may find that contact lens wear exacerbates ocular disease morbidity. Conversely, contact lenses may have various therapeutic benefits. The coronavirus disease-2019 (COVID-19) pandemic impinged upon the lifestyle of contact lens wearers, introducing challenges such as mask-associated dry eye, contact lens discomfort with increased use of digital devices, inadvertent exposure to hand sanitizers, and reduced use of lenses. Wearing contact lenses in challenging environments, such as in the presence of dust and noxious chemicals, or where there is the possibility of ocular trauma (e.g., sport or working with tools) can be problematic, although in some instances lenses can be protective. Contact lenses can be worn for sport, theatre, at high altitude, driving at night, in the military and in space, and special considerations are required when prescribing in such situations to ensure successful outcomes. A systematic review and meta-analysis, incorporated within the review, identified that the influence of lifestyle factors on soft contact lens dropout remains poorly understood, and is an area in need of further research. Overall, this report investigated lifestyle-related choices made by clinicians and contact lens wearers and discovered that when appropriate lifestyle choices are made, contact lens wear can enhance the quality of life of wearers.

Efficacy of Plasma Rich in Growth Factors (PRGF) in Stage 1 Neurotrophic Keratitis

Background/Aims

Neurotrophic keratitis (NK) is a neurodegenerative disease that can lead to corneal hypoesthesia, decreased tear production, and epitheliopathy. Based on the severity of ocular surface damage, NK is classified into 3 stages. Stage 1 NK is characterized by superficial punctate keratopathy, tear film instability, and reduced corneal sensation. The therapeutic efficacy of PRGF eye drops for NK stages 2 and 3 has been previously reported. In this study, we evaluated the efficacy and safety of autologous PRGF eye drops in improving corneal sensitivity and other ocular surface clinical signs in patients with stage 1 NK.

Methods

Retrospective chart review.

Results

26 eyes of 15 stage 1 NK patients (seven males, eight females), aged 76.3 ± 12.1 years, were included in the study. The mean treatment duration was 2 ± 1.8 months. With PRGF treatment, corneal sensitivity increased from 2.8 to 4.5 cm in 53.8% (14/26) (p < 0.01), TBUT increased from 3.6 to 5.0 s in 69.2% (18/26) (p < 0.01), and Schirmer score increased from 13.7 to 16.8 mm in 80.7% (21/26) of treated eyes (p < 0.01). Similarly, an improvement in corneal staining (punctate epithelial erosions) and MMP-9 levels was seen in 80.7% (n = 21) and 65.4% (n = 17) of treated eyes, respectively. BCVA improvement was seen in 26.9% of treated eyes (n = 7).

Conclusions

This study demonstrates the effective role of PRGF therapy in recovering corneal sensation and tear film function and in the healing of corneal erosions in stage 1 NK patients.

Prevalence and clinical characteristics of neurotrophic keratopathy in hispanic population in northeastern Mexico

PURPOSE

To evaluate the prevalence and clinical characteristics of neurotrophic keratopathy (NK) in northeastern Mexico.

METHODS

Retrospective cross-sectional study in which NK patients admitted to our ophthalmology clinic between 2015 and 2021 were consecutively enrolled. Data regarding demographics, clinical characteristics, and comorbidities were collected at the time diagnosis of NK was made.

RESULTS

In the period from 2015 to 2021, a total of 74,056 patients were treated and of these 42 had a diagnosis of neurotrophic keratitis. The prevalence found was 5.67 [CI95 3.95-7.38] in 10,000 cases. The mean age observed was 59 ± 17.21 years occurring more frequently in males in 59% and with corneal epithelial defects in 66.7%. The most frequent antecedents were the use of topical medications in 90%, the presence of diabetes mellitus 2 in 40.5% and systemic arterial hypertension in 26.2%. A higher proportion of male patients with corneal alterations and a higher proportion of female patients with corneal ulcerations and/or perforation were observed.

CONCLUSION

Neurotrophic keratitis is an underdiagnosed disease with a broad clinical spectrum. The antecedents that were contracted corroborate what was reported in the literature as risk factors. The prevalence of the disease in this geographical area was not reported, so it is expected to increase over time when searching for it intentionally.

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.

From bench to clinic: Emerging therapies for corneal scarring

Corneal diseases are one of the leading causes of moderate-to-severe visual impairment and blindness worldwide, after glaucoma, cataract, and retinal disease in overall importance. Given its tendency to affect people at a younger age than other blinding conditions such as cataract and glaucoma, corneal scarring poses a huge burden both on the individuals and society. Furthermore, corneal scarring and fibrosis disproportionately affects people in poorer and remote areas, making it a significant ophthalmic public health problem. Traditional medical strategies, such as topical corticosteroids, are not effective in preventing fibrosis or scars. Corneal transplantation, the only effective sight-restoring treatment for corneal scars, is curbed by challenges including a severe shortage of tissue, graft rejection, secondary conditions, cultural barriers, the lack of well-trained surgeons, operating rooms, and well-equipped infrastructures. Thanks to tremendous research efforts, emerging therapeutic options including gene therapy, protein therapy, cell therapy and novel molecules are in development to prevent the progression of corneal scarring and compliment the surgical options currently available for treating established corneal scars in clinics. In this article, we summarise the most relevant preclinical and clinical studies on emerging therapies for corneal scarring in recent years, showing how these approaches may prevent scarring in its early development.

Characteristics of the ocular surface in neurotrophic keratitis induced by trigeminal nerve injury following neurosurgery

Purpose

To analyse and quantify ocular surface parameters in patients with unilateral neurotrophic keratitis (NK) induced by trigeminal nerve injury post-neurosurgery.

Methods

The study included 26 unilateral NK patients who had undergone neurosurgery, and 20 matched normal controls. Demographic and clinical characteristics of all participants were collected and analysed. Slit-lamp examination, Cochet–Bonnet aesthesiometry, Keratograph 5 M, and LipiView interferometer were performed on both eyes of 17 mild NK patients. For nine moderate/severe NK patients, sub-basal nerve density was measured by in vivo confocal microscopy.

Results

Of the 26 patients, nine had acoustic neuroma, nine had trigeminal neuralgia, and eight had neoplasms. Facial nerve paralysis was observed in one of the 17 mild NK eyes (5.9%) and seven of the nine moderate/severe NK eyes (77.8%). Compared to contralateral and normal control eyes, 26 NK eyes showed significantly reduced sensitivity in five corneal regions (P < 0.05). Corneal sensitivity in moderate/severe NK eyes was significantly lower than in mild NK eyes (P < 0.05). Moderate/severe NK eyes had poor visual acuity, and their sub-basal nerve density was lower than that of the controls. The onset of the moderate/severe NK was from 0.5 to 24 months (median [Q1, Q3], 1 [0.5, 2.5] months) after neurosurgery. For the mild NK eyes, the number of total blinks, the first non-invasive tear breakup time (NITBUT) and average NITBUT were significantly lower than contralateral and normal control eyes (P < 0.05), and the number of partial blinks and partial blinking rate were significantly higher than the other two control groups (P < 0.05).

Conclusions

Patients with NK induced by trigeminal nerve injury following neurosurgery had decreased corneal sensitivity to various degrees accompanied by increased partial blinks and shortened NITBUT. The severity of NK is related to the severity of the corneal sensory impairment. Facial nerve paralysis can worsen the clinical progression of NK.

Trial registration Chinese Clinical Trial Registry (ChiCTR2100044068, Date of Registration: March 9, 2021).

Ophthalmic findings of congenital insensitivity to pain with anhidrosis with a novel neurotrophic tyrosine kinase receptor type 1 gene mutation: A case report

We report a case of congenital insensitivity to pain with anhidrosis (CIPA) with a novel neurotrophic tyrosine kinase receptor type 1 (NTRK1) gene mutation. The patient suffered from recurrent corneal ulcer. A slit-lamp examination revealed ciliary hyperemia, bulbar conjunctival edema, epithelial defect, and ulcer lesion in the inferior part of the cornea, local corneal stromal edema accompanied by new vascular growth in his affected eye. In addition, the corneal sensitivity and nerve fiber density decreased significantly in both eyes. Tear film break-up time and Schirmer’s I test were below lower limit. Moreover, the patient exhibited typical systemic features, including no normal response to pain stimuli, anhidrosis and self-injurious behavior. Gene sequencing revealed a compound-heterozygous mutations in NTRK1 gene: a missense mutation inherited from his mother (c.1750G > A, P.E584K) and a new splicing mutation inherited from his father (c.2187 + 5G > C). After 8 weeks of medication, the corneal ulcer basically healed. This study expands the spectrum of NTRK1 gene mutation associated with CIPA and provides a feasible approach for clinicians to treat patients with CIPA-related keratopathy.

Maternal serum eye drops to treat bilateral neurotrophic keratopathy in congenital corneal anesthesia: Case report and literature review

Purpose

To report the feasibility and the successful outcomes of a pediatric neurotrophic keratopathy (NK) owing to congenital corneal anesthesia (CCA) treated with allogeneic serum eye drops obtained from the mother as the only therapy.

Observations

A 18-month-old girl with generalized pain insensitivity presented with a large epithelial defect in the right eye (RE) and superficial punctate keratopathy (SPK) in the left eye (LE). Corneal sensitivity was completely absent in both eyes (BE). Peripheral serum eye drops obtained from the mother was prescribed and administered every 2 hours in BE. Two weeks after the beginning of treatment, compete healing of the epithelial defect in the RE was obtained, while the severity of the SPK in the LE markedly improved; in parallel, conjunctival hyperemia disappeared in BE. The treatment was continued over the course of 3 months with good tolerability and neither signs of recurrence of the epithelial defect nor other complications were noted.

Conclusions and Importance

Allogeneic serum eye drops obtained from the mother are effective in treating pediatric NK owing to CCA. This treatment may represent a readily available and inexpensive option when topical nerve growth factor is unavailable or corneal neurotization is not feasible.

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

PURPOSE

The purpose of this study was to describe an indirect corneal neurotization (CN) technique for congenital bilateral trigeminal anesthesia using the greater auricular nerve (GAN) as a donor.

METHOD

CN was performed to preserve the integrity of the only seeing eye in a 4-year-old boy with pontine tegmental cap dysplasia and bilateral trigeminal anesthesia. He had recurrent corneal ulceration and scarring despite full medical treatment. The GAN was used as a donor, and the sural nerve was harvested and used as a bridge which was tunneled to the sub-Tenon space in the inferior fornix. The fascicles were distributed into the 4 quadrants and sutured to the sclera near the limbus.

RESULT

This technique resulted in providing corneal sensation and improving stability of the epithelium. Corneal opacity gradually decreased allowing significant visual improvement evidenced in the early postoperative months.

CONCLUSIONS

Using the GAN technique for CN bypasses trigeminal innervation and has the potential to improve corneal sensation. The GAN is a large caliber nerve and provides a large amount of axons and robust neurotization. This technique would be desirable for cases with bilateral congenital trigeminal anesthesia, such as pontine tegmental cap dysplasia.

Neurotrophic keratopathy: Clinical presentation and effects of cenegermin

Purpose

To report on 4 patients (3 adults, 1 child) with neurotrophic keratopathy (NK) treated with cenegermin 20 μg/ml (Oxervate®), a recombinant human nerve growth factor (rhNGF), which was authorized by the European Medicines Agency for the treatment of neurotrophic keratopathy stage 2 and stage 3 of Mackie Classification in patients over 18 years of age.

Observations

Three patients with neurotrophic keratopathy stage 2 and 1 patient with neurotrophic keratopathy stage 3, who were treated with cenegermin eye drops 6 times daily for 8 weeks, were observed. Two patients suffered from herpetic keratitis and 2 patients from neurotrophic keratopathy secondary to orbital radiation. In addition to closure of epithelial defects, an increase of corneal sensitivity and improvement of visual acuity has been shown in all treated patients at the end of therapy. One patient reported on neuralgic pain as a side effect. The corneal epithelium remained closed during the follow-up period of 11 weeks, 31 and 32 months after cessation of therapy in 3 patients, respectively. In one patient, corneal erosion recurred 4 weeks after completion of treatment due to recurrent HSV keratitis, which resolved after therapy adjustment and the corneal epithelium remained closed for 35 weeks.

Conclusion

The cases presented suggest that treatment with cenegermin 20 μg/ml not only promotes corneal epithelial wound healing, but also significantly improves corneal sensitivity and visual acuity with minor side effects in adults and children.

Neurotrophic Keratitis in a Pediatric Patient With Goldenhar Syndrome and Trigeminal Aplasia Successfully Treated by Corneal Neurotization

Herein, the authors report an unusual case of a 6-year-old boy with right-sided Goldenhar syndrome and trigeminal nerve aplasia who developed neurotrophic keratopathy (NK). Despite the use of therapeutic contact lenses and multiple temporary tarsorrhaphy, NK worsened showing a central corneal scar, neovascularization, and significant stromal thinning, with risk of corneal perforation. Cochet-Bonnet esthesiometry revealed complete corneal anesthesia. To minimize additional corneal complications, the patient underwent indirect corneal neurotization by a sural nerve autograft anastomosed to the contralateral supratrochlear nerve. At 24-month follow up, no epithelial defects, complications, or recurrence were observed. Significant improvements in corneal sensitivity with esthesiometry score of 20 mm and reflex blinking were achieved. This case highlights corneal anesthesia should be suspected among Goldenhar syndrome ophthalmologic abnormalities and monitored before corneal changes become irreversible. Since corneal neurotization can successfully improve corneal sensation, it could be considered as an early therapeutic option to avoid refractory NK.

Long-term clinical efficacy of topical treatment with recombinant human nerve growth factor in neurotrophic keratopathy: a novel cure for a rare degenerative corneal disease?

Background

Neurotrophic keratopathy (NK) is a rare, degenerative ocular disease characterized by reduction or loss of corneal sensitivity and development of non-healing corneal epithelial defects and ulcers. Cenegermin, a recombinant human nerve growth factor (rhNGF) eye drop solution, is the first drug approved for the treatment of NK. The aim of our study is to evaluate the long-term efficacy of this innovative topical treatment in patients with NK.

Methods

Retrospective, consecutive, observational case series study from a single-center setting (Department of Sense Organs, University Sapienza of Rome, Rome, Italy). 18 patients with diagnosis of stage 2 or 3 NK, treated with Cenegermin 20 mcg/ml eye drops were followed for up to 48 months. Recurrence of lesion during follow-up was evaluated at 12, 24, 36, and 48 months. In addition, corneal sensitivity, Schirmer tear test, and visual acuity (VA) were recorded at baseline, end of treatment, and at 12, 24, 36, and 48 months.

Results

Three patients experienced recurrence of persistent epithelial defects (PEDs) within 12 months and one patient experienced recurrence of a corneal ulcer within 36 months. Corneal sensitivity was significantly improved at all timepoints (P < 0.05). Significant improvements in visual acuity and tear production were seen at the completion of treatment as well as at 12, 24, and 36 months (P < 0.05) when compared to baseline.

Conclusions

A single 8-week treatment regimen of Cenegermin eye drops has clinical efficacy that can persist for up to 48 months. The long-term clinical utility of treatment with Cenegermin for NK was demonstrated through the low rate of lesion recurrence along with improvements in corneal sensitivity and tear production.

[Modern capabilities in diagnosis and treatment of neurotrophic keratopathy]

In recent years, the problem of diagnosing and treating neurotrophic keratopathy (NK) has become relevant in view of its prevalence reaching 1.6-11.0 per 10000 people. While previously it was associated only with neuroparalytic keratitis, at present the violation of sensitive and trophic innervation of the cornea with the development of characteristic keratopathy is observed in many diseases and injuries of the organ of vision. Diagnosis of NK is based on anamnestic information and assessment of clinical and functional parameters: determination of the stability of the tear film, tear production and assessment of staining of the ocular surface with vital dyes. The main role in the diagnosis of NK belongs to corneal sensitivity determined with the Cochet-Bonnet esthesiometer. Treatment of NK is designed to restore or increase corneal sensitivity and involves tear replacement therapy, instillations of preparations derived from patient's own blood, anti-inflammatory, metabolic and antibacterial therapy. However, instillations of human erve growth factor (NGF) - the drug Cenegermin (registered in Europe in 2017 at a dose of 20 μg/ml under the name Oxervate), a recombinant form of human rhNGF from Escherichia coli bacteria - exhibit the highest pathogenetic orientation. Its «target» is the affected nerve fibers (specific receptors for their growth factor), which makes it possible to eliminate the violation of reparative processes in neural and epithelial cells. A high and long-term clinical efficacy of a course of six (with an interval of 2 hours) instillations of the drug for 8 weeks in the treatment of children and adults with NK has been established. Among the pathogenetically justified methods of surgical treatment, there is the so-called surgical neurotization of the cornea involving the contralateral supraorbital, supratrochlear, great auricular and other nerves, which has a long-term clinical effect.

Cytotoxicities and wound healing effects of contact lens multipurpose solution on human corneal epithelial cell

CLINICAL RELEVANCE

Contact lens multipurpose solutions (MPSs) contain several components that have the potential to cause corneal epithelial cell toxicity. Evaluating the components and the toxic effect of MPS should be considered for effective eye care.

BACKGROUND

The cytotoxic and wound healing effects of five commercially available MPSs on human corneal epithelial cells (HCECs) are is investigated.

METHODS

The following commercially available MPSs were used: Queen's PLURISOL®, Frenz®, Boston SIMPLUS®, DL+PLUS EYE® (DL), and NEW YORK DEFINE® (NY). The proliferation of HCECs exposed to each MPS for 1, 6, and 24 h and the cytotoxicity of these solutions were analyzed using methyl thiazolyl tetrazolium-based colorimetric and lactate dehydrogenase leakage assays, respectively. The cellular morphology was evaluated by inverted phase-contrast and electron microscopy. A scratch-wound assay was performed to measure wound widths 24 h after confluent HCEC monolayers were scratch-wounded.

RESULTS

The tested MPS had a time-dependent inhibitory effect on HCEC proliferation and cytotoxicity, significantly at 24 h after exposure (p< 0.05 in all MPSs). HCECs exposed to MPS detached from the bottom of the culture dishes, showed degenerative changes such as loss of microvilli, cytoplasmic vacuole formation and nuclear condensation, and decreased wound healing, compared to the controls (p< 0.001 in Boston, DL and NY). Among the tested MPS, DL and NY were more cytotoxic and showed less wound healing.

CONCLUSION

MPS has a toxic effect on HCECs, which is dependent on the concentration of the disinfecting component. Since the components that constitute the MPS are absorbed and retained in the lens, cautious scrutiny of the concentration and attention to lens cleaning are warranted to mitigate the related cytotoxicity.

Aftermarket effects of cenegermin for neurotrophic keratopathy in pediatric patients

PURPOSE

Neurotrophic keratopathy (NK) is a rare condition characterized by poor corneal sensation and healing. Cenegermin (topical recombinant nerve growth factor) has gained traction as a medical therapy for NK in recent years, and is FDA-approved for patients over two years old. However, no major trials have demonstrated the drug's efficacy in children. This study reviews the outcomes of cenegermin therapy in a pediatric patient population.

METHODS

Retrospective case series of patients from three tertiary referral institutions who 1) initiated an 8-week course of cenegermin therapy, and 2) were 18 years or less at time of treatment initiation.

RESULTS

Eight pediatric patients, with a total of nine affected eyes, underwent cenegermin therapy. All eight patients had previously trialed other NK-specific treatments, none of which had been entirely successful. Five patients (63%) completed the full eight-week therapy course. Five patients (63%) experienced clinical improvement not attributed to another treatment, through improved corneal ulcer stage (n = 5) and best-corrected visual acuity (n = 2). Clinical improvements persisted through a mean recurrence-free period of 10 months. Adverse effects reported during therapy included ocular pain, difficulty sleeping, and continued corneal thinning.

CONCLUSION

The results provide modest support for the use of cenegermin in pediatric patients with neurotrophic keratopathy. The primary benefit was an improvement in corneal epithelial stability. Clinicians should be aware that pre-existing corneal scarring in NK may significantly limit the ability of cenegermin alone to improve visual acuity, and should closely monitor the corneal epithelial status during therapy in pediatric patients.

Neurotrophic Keratopathy in Pediatric Patients

Purpose: This review provides an overview of the causes and treatment of neurotrophic keratopathy in the pediatric population.Methods: A thorough review of the current literature discussing neurotrophic keratopathy was conducted then summarized.Results:Fourty-nine papers were reviewed. Congenital and acquired causes of neurotrophic keratopathy exist in the pediatric population. Both medical and surgical approaches to treatment have been trialed, albeit to a limited extent, in pediatric patients. Conservative treatment includes topical lubrication and antibiotics to prevent concurrent infectious ulcer formation. Various neurotrophic factors have been trialed in the form of serum drops to restore corneal sensation when conservative measures fail. Surgically, different corneal neurotization techniques have been developed whereby a donor nerve is routed to the anesthetized cornea to restore innervation and sensation. Conclusions: Advances in the treatment of neurotrophic keratopathy have made corneal reinnervation and restoration of vision more easily attainable in pediatric patients.

Pediatric Use of Recombinant Human Nerve Growth Factor 20 μg/mL Eye Drops (Cenegermin) for Bilateral Neurotrophic Keratopathy in Congenital Corneal Anesthesia

PURPOSE

This study aimed to present the efficacy and safety of cenegermin eye drop (Oxervate; Dompè Farmaceutici, Milan, Italy) treatment in a pediatric patient affected by neurotrophic keratopathy (NK) with Goldenhar syndrome.

METHODS

This case reports an infant presenting ulceration and a small central opacity in the cornea of the right and left eyes, respectively. The NK bilaterally worsened despite the use of therapeutic contact lenses and temporary partial tarsorrhaphy. Magnetic resonance imaging showed absence and hypoplasia of the right and left trigeminal nerves, respectively. Cenegermin eye drops were administered 1 drop/each eye, 6 times daily for 8 weeks to promote corneal healing.

RESULTS

Complete healing was achieved in both eyes after treatment. During the 16-month follow-up period, no epithelial defect, recurrence, or complications were noticed, whereas corneal opacities progressively became clearer, although insignificant improvements in corneal sensitivity or in the reflex tearing were observed.

CONCLUSIONS

Cenegermin was effective in treating NK in an infant with Goldenhar syndrome.

Dorsolateral medullary infarction registry: a study protocol for a prospective, multicentric registry

Background

Dorsolateral medullary infarction is a typical cerebral infarction which is characterized by Wallenberg’s syndrome. Neurotrophic keratopathy is an uncommon consequence of dorsolateral medullary infarction. At present, the protocol is aimed to study the dynamic changes in corneal innervation and the ocular surface environment after dorsolateral medullary infarction.

Methods

This study will involve consecutive data from all medical records of patients within 7 days of acute dorsolateral medullary infarction onset at the Departments of Neurology from 10 collaborating stroke centers. Eligible patients will mainly be characterized based on detailed physical examinations, multimodal imaging, and corneal related examinations and patients will be followed-up for 2 years. Neurotrophic keratopathy after dorsolateral medullary infarction is the primary endpoint. The dynamic histological corneal innervation and ocular surface environment after dorsolateral medullary infarction will be observed during the follow-up period.

Discussion

This multicentric, prospective registry is the first to identify and characterize the dynamic changes of corneal innervation and the ocular surface environment after acute dorsolateral medullary infarction. The significance of the study is to emphasize that the curative effect is based on the doctors’ identification of the disease in the earliest stage before irreversible damage occurs to the cornea.

Trial registration

The registry was registered (ChiCTR-OPC-17,011,625) on June 11, 2017.

The surgical management of extra-cranial trigeminal nerve palsies: A retrospective case series

OBJECTIVES

To assess for functional improvement in outcomes following supermicrosurgical restoration across a cohort of patients with a spectrum of trigeminal nerve disorders.

PATIENTS & METHODS

In a retrospective case series over three years (2016-18), twenty patients were included in a cohort of trigeminal nerve palsy patients. Eleven patients with corneal anaesthesia underwent corneal neurotisation procedures and were followed up using Cochet-Bonnet aesthesiometry. Six patients with sensory trigeminal nerve injuries had direct nerve coaptation and neuroma excision. Three patients with trigeminal motor nerve palsies were followed up with photography for contour improvement.

RESULTS

Regarding corneal neurotisation, there was evidence of significant improvement in protective corneal sensation and also blinking frequency. Regarding facial sensory disturbances, all patients had full resolution of painful trigeminal neuroma symptoms. In two cases of iatrogenic trigeminal motor palsies with contour defects, adipo-fascial variants of the superficial circumflex iliac artery (SCIP) free flap achieved excellent restoration of facial contour in lieu of facial lipofilling. In another case of a necrotising infection of the head and neck with loss of all masticatory muscles, a free functional muscle using a chimaeric vastus lateralis-ALT flap was used to restore masticatory and facial movement in a single stage procedure.

CONCLUSION

Using combinations and permutations of current surgical techniques, it is possible to successfully restore both form and function for patients with sensory as well as motor trigeminal nerve palsies. This sets a precedent for the expansion of cranial nerve surgery as an evolving sub-speciality.

Acute neurotrophic keratitis with trigeminal trophic syndrome after craniotomy

We report the case of a child who, shortly after undergoing suboccipital craniotomy for resection of a medullary cavernoma, developed corneal and conjunctival epithelial breakdown of the right eye with ipsilateral facial hypoesthesia as well as erosions and crusting of the eyelids, nostril, and lips on the right side. This combination of findings likely results from acute injury to the ipsilateral trigeminal ganglion, leading to acute neurotrophic keratitis and trigeminal trophic syndrome.

Successful Treatment of a Pediatric Neurotrophic Keratopathy With Cenegermin

PURPOSE

We present a challenging case of a 9-year-old patient with refractory neurotrophic keratopathy (NK) who was successfully treated with cenegermin eye drops.

METHODS

A 7-year-old boy developed an ocular infection after a visit to a public swimming pool. After having been unsuccessfully treated for 2 years with antibiotics, steroids, and artificial tears, the patient presented to our clinic with a therapy-refractory NK. We initiated treatment with autologous serum eye drops that showed only weak response. Therefore, treatment with cenegermin eye drops was started.

RESULTS

After cenegermin therapy, a complete restoration of the corneal surface and an increase in visual acuity were achieved.

CONCLUSIONS

The use of cenegermin is effective in treating pediatric NK.

A case report of pediatric neurotrophic keratopathy in pontine tegmental cap dysplasia treated with cenegermin eye drops

RATIONALE

To report the management of recalcitrant neurotrophic keratopathy in a pediatric patient affected by pontine tegmental cap dysplasia (PTCD) using topical human recombinant nerve growth factor (hrNGF, Cenegermin 20 μg/ml). To the best of our knowledge the present case is one of the few described in patients with congenital NK treated with Cenegermin, and the first in a patient affected by PTCD.

PATIENT CONCERNS

A 9-year-old patient, affected by PTCD with bilateral cranial nerve V1 and VIII palsies, was referred to our hospital for visual disturbances and redness of the right eye due to persistent neurotrophic epithelial defect. The patient presented marked developmental delay, ataxia, bilateral hypoacusia, and bilateral corneal severe hypoaesthesia. Ocular history revealed multiple treatments in order to treat neurotrophic ulcer in the left eye. Four years later, he developed a persistent epithelial defect with corneal anesthesia in the right eye.

DIAGNOSES

The impaired trigeminal nerve function, due to the underlying congenital disease, led to the development of moderate NK (stage II) in the right eye and a mild NK (stage I) in the left eye.

INTERVENTIONS

Cenegermin 20 μg/ml eye-drop was administered in both eyes. Treatment was continued for 8 weeks. The patient was assessed after 4 and 8 week of treatment. At each follow-up visit, treatment efficacy and adverse events were evaluated.

OUTCOMES

The use of Cenegermin eye drops facilitated the remarkable resolution of the neurotrophic keratopathy and the improvement of corneal sensitivity in both eyes. No local or systemic adverse events were observed.

LESSONS

Topical Cenegermin 20 μg/ml was well-tolerated and may represent a valuable therapeutic option in the management of pediatric neurotrophic keratopathy.

Development of the neurotrophic keratopathy questionnaire: qualitative research

BACKGROUND

Neurotrophic keratopathy/keratitis (NK) is a rare disease of the cornea that can lead to anatomical loss of the eye. Little is known about the NK experience from the patients' perspective. The objectives of this study were to examine the symptomatic experience and impacts of NK on patients and assess the overall comprehension, relevance, and content validity of a new questionnaire.

METHODS

This was a cross-sectional, qualitative study conducted with NK patients with varying levels of disease severity, recruited from one clinical site. One-on-one interviews using concept elicitation and cognitive interviewing techniques were conducted.

RESULTS

Fourteen NK patients participated; 64.3% were female (n = 9), mean age was 65.7 ± 13.3, and 14.3% (n = 2), 21.4% (n = 3), and 64.3% (n = 9) were classified as Mackie stage I, stage II, or stage III, respectively. Participants reported 24 concepts, including: redness (n = 12, 86%), sensitivity to light (n = 11, 79%), general discomfort (n = 9, 64%), dry eye (n = 9, 64%), reduced visual acuity (n = 9, 64%), blurred vision (n = 8, 57%), and eye fatigue (n = 8, 57%). No new concepts were reported after the 13th interview. The most frequently reported impacts included frustration (n = 10, 71%), driving impairment (n = 8, 57%), reading impairment (n = 7, 50%), difficulty watching television (n = 7, 50%), and concern with potentially losing their eyesight due to NK (n = 6, 43%). Participants provided positive feedback on the draft NK Questionnaire (NKQ) and felt that it was comprehensive and relevant to their experience with NK. Additionally, the recall period, instructions, item concepts, and response options were well-understood by participants. Minor revisions were made to the tool for consistency (i.e., the timeframe "in the past 7 days" was added to items 12-14); item 14 was modified to include "how often"; examples were added to item 9.

CONCLUSIONS

The results of the concept elicitation portion of the qualitative study support the content validity of the draft NKQ. The clinically significant concepts identified in the literature and raised during concept elicitation are included as items in the questionnaire. Further assessment of the psychometric properties should be conducted in support of this new tool to measure the effect of new treatments on symptoms and impacts associated with NK.

Topical Recombinant Human Nerve Growth Factor (Cenegermin) for Neurotrophic Keratopathy: A Multicenter Randomized Vehicle-Controlled Pivotal Trial

PURPOSE

To evaluate the efficacy and safety of topical cenegermin (recombinant human nerve growth factor) in patients with neurotrophic keratopathy.

DESIGN

Multicenter, randomized, double-masked, vehicle-controlled trial.

PARTICIPANTS

Patients with neurotrophic persistent epithelial defect with or without stromal thinning.

METHODS

The NGF0214 trial, conducted among 11 sites in the United States, randomized 48 patients 1:1 to cenegermin 20 μg/ml or vehicle eye drops, 6 drops daily for 8 weeks of masked treatment. Follow-up was 24 weeks. Safety was assessed in all patients who received study drug. Efficacy was assessed by intention to treat.

MAIN OUTCOME MEASURES

The primary end point was healing of the neurotrophic lesion (persistent epithelial defect or corneal ulcer) after 8 weeks of masked treatment. Masked central readers measured neurotrophic lesions in randomized clinical pictures, then assessed healing status conventionally (<0.5 mm of fluorescein staining in the greatest dimension of the lesion area) and conservatively (0-mm lesion staining and no other residual staining). Secondary variables included corneal healing at 4 weeks of masked treatment (key secondary end point), overall changes in lesion size, rates of disease progression, and changes in visual acuity and corneal sensitivity from baseline to week 8.

RESULTS

Conventional assessment of corneal healing showed statistically significant differences at week 8: compared to 7 of 24 vehicle-treated patients (29.2%), 16 of 23 cenegermin-treated patients (69.6%) achieved less than 0.5 mm of lesion staining (+40.4%; 95% confidence interval [CI], 14.2%-66.6%; P = 0.006). Conservative assessment of corneal healing also reached statistical significance at week 8: compared to 4 of 24 vehicle-treated patients (16.7%), 15 of 23 cenegermin-treated patients (65.2%) achieved 0 mm of lesion staining and no other residual staining (+48.6%; 95% CI, 24.0%-73.1%; P < 0.001). Moreover, the conservative measure of corneal healing showed statistical significance at week 4 (key secondary end point). Compared to vehicle, cenegermin-treated patients showed statistically significant reductions in lesion size and disease progression rates during masked treatment. Cenegermin was well tolerated; adverse effects were mostly local, mild, and transient.

CONCLUSIONS

Cenegermin treatment showed higher rates of corneal healing than vehicle in neurotrophic keratopathy associated with nonhealing corneal defects.

[Pathogenesis and epidemiology of neurotrophic keratopathy]

Neurotrophic keratopathy (NK) is a degenerative corneal disease that is based on an impairment of the corneal innervation. The damage to the sensory innervation, which is delivered through the 1st branch of the trigeminal nerve (ophthalmic nerve), can occur throughout the entire length of the nerve from the nucleus in the brainstem, e.g. caused by brain tumors, to the terminal nerve fibers in the cornea, caused for example by refractive corneal surgery (e. g. LASIK). Due to the loss of the sensory innervation, a reduced lacrimation and a reduction in the secretion of trophic factors occur. This in turn inhibits the regeneration potential of the corneal epithelium. In the most severe cases of the disease, the reduction or loss of lacrimation, together with the impaired regeneration potential of the epithelial cells, can lead to persistent epithelial defects, ulcers and corneal perforation. The NK has a prevalence of 5 or fewer individuals per 10,000 and is classified as a rare, i. e. orphan disease (ORPHA137596). A fundamental understanding of the pathogenesis and epidemiology of NK supports the early diagnosis and therefore the initiation of a specific treatment.

Role of corneal nerves in ocular surface homeostasis and disease

Corneal nerves are key components of the physiological system that controls ocular surface homeostasis. The cornea is primarily innervated by the ophthalmic branch of the trigeminal nerves (cranial nerve V), which distend bilaterally from the pons. The nasociliary branch (afferent) of the ophthalmic nerve is sensory for cornea, eyelid and conjunctiva. These nerve fibres play a role in sensing temperature, chemical and mechanical stimuli, and pain, whereas, branches of the facial nerve (cranial nerve VII) contain motor nerves that control blinking and autonomic (sympathetic and a paucity of parasympathetic) fibres that stimulate tear production and secretion via feedback loops between the ocular surface, lacrimal glands and brain. Disruption of these nerves with interruption of neural feedback loops between the ocular surface and lacrimal glands can lead to corneal diseases such as dry eye disease (DED) and neurotrophic keratopathy (NK). Inversely, hypersensitivity of the nerve fibres and/or dysregulation of pain-controlling nervous centres may lead to neuropathic pain. Recently, medications that specifically target regeneration of corneal nerves have started to become available - and considering the high prevalence of diseases associated with corneal nerve dysfunction, these agents promise to fulfil a hitherto important unmet need. In this review, we explore the physiology of corneal nerves, the pathology of corneal nerve diseases and how these relate to neuropathic pain, NK and DED. We also discuss what novel treatments may be useful against diseases involving corneal nerves.

[Clinical picture and diagnosis of neurotrophic keratopathy]

BACKGROUND

Neurotrophic keratopathy is characterized by corneal surface alterations, persistent corneal epithelial defects and/or corneal ulcerations associated with corneal sensory abnormalities. Due to the variable clinical picture neurotrophic keratopathy is often overlooked or diagnosed too late in the course of the disease.

OBJECTIVE

Discussion of the clinical picture of neurotrophic keratopathy and recommendations for correct diagnosis.

MATERIAL AND METHODS

Analysis of the existing literature and discussion of basic recent publications.

RESULTS

Neurotrophic keratopathy is defined as a disease related to alterations in corneal nerves leading to impairment in sensory and trophic function with consequent breakdown of the corneal epithelium affecting health and integrity of the tear film, epithelium and stroma. It can occur with infections, autoimmune diseases, after trauma or ocular surgery, with intracranial neoplasia, in systemic diseases and genetic syndromes. It is classified into three stages: mild (epithelial changes without epithelial defects), moderate (epithelial defects) and severe (stromal involvement). The clinical hallmark is reduced or absent corneal sensation. Therefore, corneal sensitivity testing is essential in the diagnosis of neurotrophic keratopathy along with the patient history, clinical examination and diagnostic tests, such as vital stains and, if possible, in vivo confocal microscopy.

CONCLUSION

The correct diagnosis and classification of neurotrophic keratopathy enable a stage-adapted step-ladder therapeutic approach with subsequent reduction of progression and complications of the disease.

Update on corneal neurotisation

Corneal neurotisation describes surgical restoration of nerve growth into the cornea to restore corneal sensation and trophic function. It represents an exciting and effective emerging treatment for neurotrophic keratopathy. Techniques described to date involve either direct nerve transfer or an interpositional nerve graft coapted to a healthy donor nerve. We review the experience to date with particular emphasis on a detailed review of techniques, outcomes and current thoughts.

In vivo microscopic and optical coherence tomography classification of neurotrophic keratopathy

Neurotrophic keratopathy (NK) is a rare degenerative corneal disorder characterized by instability of epithelial integrity with consequent epithelial defects that can worsen up to persistent epithelial defects with stromal melting and ulceration. The pathogenesis of NK springs from a variable degree of damage to the trigeminal nerve plexus, leading to a reduction or total loss of corneal sensitivity. Mackie classification (1995) distinguishes three stages of NK, based on the severity of clinical presentation. The technological innovations in corneal diagnostic imaging allow clinicians to accurately study the morphometry and morphology of corneal structure with microscopic resolution. In this study, 45 patients affected by NK at different stages underwent in vivo confocal microscopy (IVCM) and anterior segment optical coherence tomography (AS-OCT) with particular attention to analyze subbasal nerve plexus fibers and the stromal structure. At the light of IVCM and AS-OCT observations, we propose a different staging of NK with respect to the Mackie's classification that takes into account the severity of subbasal nerve fibers damage and the extension in depth of stromal ulceration; this classification better defines, at the time of diagnosis, the cellular and structural alterations in the affected corneas, with possible prognostic and therapeutic values in the management of NK.

Evaluation of artificial tears on cornea epithelium healing

AIM

To observe the efficacy of different artificial eye drops on corneal epithelium healing in rabbit.

METHODS

Thirty-five rabbits with 6 mm diameter central corneal epithelium removed were randomly assigned to six groups: 0.9% normal saline (NS) group, 0.1% hyaluronate (HA) group, 0.3% HA group, Tears Naturale Free^® (TNF) group, 0.4% polyethylene glycol (PEG) group, 0.5% carboxymethyl cellulose (CMC) group and blank control group. Treatments were administered topically four times daily. Corneal epithelium healing was evaluated by the percentage reduction in wound area at 24, 36, 48, 60, and 72h after removal of the corneal epithelium. Cornea re-epithelialization was also assessed by histological analysis and electron microscopy.

RESULTS

All corneal wounds completely re-epithelialized in less than 72h. The average re-epithelialization time was 47.61±4.25h in the 0.3% HA group and 49.72±1.05h in the 0.9% NS group, followed by 0.1% HA, TNF, 0.4% PEG, 0.5% CMC, and lastly by the control group. Compared to the control group, there were significant differences among 0.3% HA, 0.9% NS, PEG, and TNF (P<0.05) groups. At the first 24h, re-epithelialization at the 0.3% HA, TNF, and 0.9% NS treatment groups were significantly faster than the other groups. At 48h post-wounding, corneal epithelium is nearly completing re-epithelialization at 0.3% HA and 0.9% NS treatment groups. Electron microscopy revealed that there were a large number of vacuoles in the cells of the 0.9% NS group at 72h.

CONCLUSION

Artificial tears promote corneal re-epithelium varied in the efficacy. Obviously, all artificial eye drops better than blank group. In the process of corneal healing, corneal epithelium cells suffered from hypoxia caused by NS.

Phase II Randomized, Double-Masked, Vehicle-Controlled Trial of Recombinant Human Nerve Growth Factor for Neurotrophic Keratitis

PURPOSE

To evaluate the safety and efficacy of topical recombinant human nerve growth factor (rhNGF) for treating moderate-to-severe neurotrophic keratitis (NK), a rare degenerative corneal disease resulting from impaired corneal innervation.

DESIGN

Phase II multicenter, randomized, double-masked, vehicle-controlled trial.

PARTICIPANTS

Patients with stage 2 (moderate) or stage 3 (severe) NK in 1 eye.

METHODS

The REPARO phase II study assessed safety and efficacy in 156 patients randomized 1:1:1 to rhNGF 10 μg/ml, 20 μg/ml, or vehicle. Treatment was administered 6 drops per day for 8 weeks. Patients then entered a 48- or 56-week follow-up period. Safety was assessed in all patients who received study treatment, whereas efficacy was by intention to treat.

MAIN OUTCOME MEASURES

Corneal healing (defined as <0.5-mm maximum diameter of fluorescein staining in the lesion area) was assessed by masked central readers at week 4 (primary efficacy end point) and week 8 (key secondary end point) of controlled treatment. Corneal healing was reassessed post hoc by masked central readers using a more conservative measure (0-mm staining in the lesion area and no other persistent staining).

RESULTS

At week 4 (primary end point), 19.6% of vehicle-treated patients achieved corneal healing (<0.5-mm lesion staining) versus 54.9% receiving rhNGF 10 μg/ml (+35.3%; 97.06% confidence interval [CI], 15.88-54.71; P < 0.001) and 58.0% receiving rhNGF 20 μg/ml (+38.4%; 97.06% CI, 18.96-57.83; P < 0.001). At week 8 (key secondary end point), 43.1% of vehicle-treated patients achieved less than 0.5-mm lesion staining versus 74.5% receiving rhNGF 10 μg/ml (+31.4%; 97.06% CI, 11.25-51.49; P = 0.001) and 74.0% receiving rhNGF 20 μg/ml (+30.9%; 97.06% CI, 10.60-51.13; P = 0.002). Post hoc analysis of corneal healing by the more conservative measure (0-mm lesion staining and no other persistent staining) maintained statistically significant differences between rhNGF and vehicle at weeks 4 and 8. More than 96% of patients who healed after controlled rhNGF treatment remained recurrence free during follow-up. Treatment with rhNGF was well tolerated; adverse effects were mostly local, mild, and transient.

CONCLUSIONS

Topical rhNGF is safe and more effective than vehicle in promoting healing of moderate-to-severe NK.

A study protocol for a multicentre randomised clinical trial evaluating the safety and feasibility of a bioengineered human allogeneic nanostructured anterior cornea in patients with advanced corneal trophic ulcers refractory to conventional treatment

INTRODUCTION

There is a need to find alternatives to the use of human donor corneas in transplants because of the limited availability of donor organs, the incidence of graft complications, as well as the inability to successfully perform corneal transplant in patients presenting limbal deficiency, neo-vascularized or thin corneas, etc. We have designed a clinical trial to test a nanostructured fibrin-agarose corneal substitute combining allogeneic cells that mimics the anterior human native cornea in terms of optical, mechanical and biological behaviour.

METHODS AND ANALYSIS

This is a phase I-II, randomised, controlled, open-label clinical trial, currently ongoing in ten Spanish hospitals, to evaluate the safety and feasibility, as well as clinical efficacy evidence, of this bioengineered human corneal substitute in adults with severe trophic corneal ulcers refractory to conventional treatment, or with sequelae of previous ulcers. In the initial phase of the trial (n=5), patients were sequentially recruited, with a safety period of 45 days, receiving the bioengineered corneal graft. In the second phase of the trial (currently ongoing), subjects are block randomised (2:1) to receive either the corneal graft (n=10), or amniotic membrane (n=5), as the control treatment. Adverse events, implant status, infection signs and induced neovascularization are evaluated as determinants of safety and feasibility of the bioengineered graft (main outcomes). Study endpoints are measured along a follow-up period of 24 months, including 27 post-implant assessment visits according to a decreasing frequency. Intention to treat, and per protocol, and safety analysis will be performed.

ETHICS AND DISSEMINATION

The trial protocol received written approval by the corresponding Ethics Committee and the Spanish Regulatory Authority and is currently recruiting subjects. On completion of the trial, manuscripts with the results of phases I and II of the study will be published in a peer-reviewed journal.

TRIAL REGISTRATION

CT.gov identifier: NCT01765244 (Jan2013). EudraCT number: 2010-024290-40 (Dec2012).

Recessive Mutation in a Nuclear-Encoded Mitochondrial tRNA Synthetase Associated With Infantile Cataract, Congenital Neurotrophic Keratitis, and Orbital Myopathy

PURPOSE

To report the ocular findings of a rare case of mutation in the nuclear-encoded mitochondrial aminoacyl-tRNA synthetase IARS2.

METHODS

A 33-year-old woman known for infantile cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia was referred to us for multiple failed corneal grafts and severe eye dryness.

RESULTS

The patient was found to have neurotrophic keratitis and corneal opacification.

CONCLUSIONS

Patients with this very rare mutation present with a myriad of ocular findings, including infantile cataract, neurotrophic keratitis, corneal opacification, and orbital myopathy.

Understanding the Pathogenesis of Neurotrophic Keratitis: The Role of Corneal Nerves

Neurotrophic keratitis (NK) is a rare degenerative disease of the cornea caused by trigeminal nerve damage, which leads to loss of corneal sensitivity, corneal epithelium breakdown, and poor healing. Though extremely uncommon, NK is increasingly recognized for its characteristics as a distinct and well-defined clinical entity rather than a rare complication of various diseases that can disrupt trigeminal innervation. Indeed, the defining feature of NK is loss of corneal sensitivity, and its clinical findings do not correlate with the wide range of systemic or ocular conditions that underlie trigeminal nerve damage. Despite increasing awareness of NK as a distinct condition, its management continues to be challenged by the lack of treatments that target nerve regeneration. This review focuses on the role of corneal nerves in maintaining ocular surface homeostasis, the consequences (such as alterations in neuromediators and corneal cell morphology/function) of impaired innervation, and advances in NK diagnosis and management. Novel therapeutic strategies should aim to improve corneal innervation in order support corneal renewal and healing. J. Cell. Physiol. 232: 717-724, 2017. © 2016 Wiley Periodicals, Inc.

Ipsilateral supraorbital nerve transfer in a case of recalcitrant neurotrophic keratopathy with an intact ipsilateral frontal nerve: A novel surgical technique

Purpose

To report a case of regained corneal sensation and function in a patient with neurotrophic keratopathy due to direct damage to the long ciliary nerves by performing a corneal neurotization procedure using ipsilateral supraorbital nerve. Surgical technique is described in detail as well as a review of the literature on corneal neurotization.

Observations

A patient with devastating corneal anesthesia and poor visual acuity refractory to other treatments underwent a new surgical technique involving an ipsilateral supraorbital nerve transfer to the surrounding limbus to restore corneal sensation. At 8 months follow up, there was resolution of corneal stromal opacification documented with photographs and greatly improved corneal sensation by testing with a wisp of cotton in all 4 quadrants. Her visual acuity had improved, and at two years she was stable with even more improvement in visual acuity and ocular surface health.

Conclusions and importance

We present the first successful case of corneal neurotization with ipsilateral supraorbital nerve in a patient with corneal anesthesia from a local injury to the long ciliary nerves. Our case demonstrates that the described method of corneal neurotization is a viable option for patients with recalcitrant neurotrophic keratopathy and an intact ipsilateral frontal nerve.