Healing of resistant corneal neurotrophic ulcers using a matrix regenerating agent

Herpes simplex keratitis: A brief clinical overview

The aim of our minireview is to provide a brief overview of the diagnosis, clinical aspects, treatment options, management, and current literature available regarding herpes simplex keratitis (HSK). This type of corneal viral infection is caused by the herpes simplex virus (HSV), which can affect several tissues, including the cornea. One significant aspect of HSK is its potential to cause recurrent episodes of inflammation and damage to the cornea. After the initial infection, the HSV can establish a latent infection in the trigeminal ganglion, a nerve cluster near the eye. The virus may remain dormant for extended periods. Periodic reactivation of the virus can occur, leading to recurrent episodes of HSK. Factors triggering reactivation include stress, illness, immunosuppression, or trauma. Recurrent episodes can manifest in different clinical patterns, ranging from mild epithelial involvement to more severe stromal or endothelial disease. The severity and frequency of recurrences vary among individuals. Severe cases of HSK, especially those involving the stroma and leading to scarring, can result in vision impairment or even blindness in extreme cases. The cornea's clarity is crucial for good vision, and scarring can compromise this, potentially leading to visual impairment. The management of HSK involves not only treating acute episodes but also implementing long-term strategies to prevent recurrences and attempt repairs of corneal nerve endings via neurotization. Antiviral medications, such as oral Acyclovir or topical Ganciclovir, may be prescribed for prophylaxis. The immune response to the virus can contribute to corneal damage. Inflammation, caused by the body's attempt to control the infection, may inadvertently harm the corneal tissues. Clinicians should be informed about triggers and advised on measures to minimize the risk of reactivation. In summary, the recurrent nature of HSK underscores the importance of both acute and long-term management strategies to preserve corneal health and maintain optimal visual function.

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.

Neurotrophic keratopathy: current challenges and future prospects

Neurotrophic keratopathy (NK), or neurotrophic keratitis, is a degenerative condition that results from decreased innervation to the cornea. The cornea is innervated by the ophthalmic branch of the trigeminal nerve. Neurotrophic keratopathy is most commonly caused by herpes keratitis however, any condition that disrupts the normal corneal innervation can cause NK. Neurotrophic keratopathy is a clinical diagnosis and is classified into three stages based on the disease severity. Stage 1 has mild epithelial defects, such as punctate keratopathy, stage 2 disease has persistent epithelial defects, and stage 3 is defined by the presence of ulcers. Current treatment modalities consist of medical and surgical options. Stage 1 is treated with lubrication through artificial tears, eyelid taping, and punctal plug/cautery. Stage 2 treatment can involve therapeutic contact lenses, topical autologous or allogenic serum, tarsorrhaphy, botulinum toxin injections, and possibly anti-inflammatory medications. Stage 3 disease may require human nerve growth factor, amniotic membrane transplantation, conjunctival flap, or corneal neurotization. New therapies, such as matrix regenerating therapy, plasma rich in growth factors, Thymosin β4, Substance P/Insulin like growth factor-1, and nicergoline represent exciting future options.KEY MESSAGESNeurotrophic keratopathy is a rare degenerative disease defined by decreased innervation to the cornea that is associated with significant morbidity.Treatment options range from lubrication alone to various medical and surgical treatments.Matrix regenerating therapy, plasma rich in growth factors, Thymosin β4, Substance P/Insulin like growth factor-1, and nicergoline are exciting novel therapies that will influence how neurotrophic keratopathy is treated in the future.

New Pharmacological Approaches for the Treatment of Neurotrophic Keratitis

Neurotrophic keratitis (NK) is a rare degenerative condition that is caused by damage to the trigeminal nerve, with partial or complete loss of corneal sensory innervation. The loss of innervation leads to impaired healing of corneal epithelium, which subsequently results in punctate epithelial erosions, persistent epithelial defects, corneal ulcers and corneal perforation. Management of NK is often supportive and aims to promote epithelial healing and prevent progression of disease. Multiple novel pharmacological approaches have been proposed to address the underlying pathophysiology of NK, which are discussed in this paper.

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.

Advances in the Medical Management of Neurotrophic Keratitis

Neurotrophic Keratitis (NK) is a degenerative disorder of the cornea characterized by decreased or absent sensory corneal innervation, corneal epitheliopathy and impaired healing.The clinical presentation of NK can range from persistent epithelial defects to corneal perforation and management is often both challenging and protracted. Historically, the management of NK has consisted of non-specific strategies to facilitate corneal epithelial healing such as lubrication, bandage contact lenses and tarsorrhaphy. Recent advances in the development of therapeutics for NK have provided new and efficacious targeted strategies for its management.In this article, we review recombinant human nerve growth factor (Cenegermin), currently approved for clinical use in the United States and Europe, as well as other promising therapeutic options that are in pre-clinical development such as thymosine β4, connexin43 inhibitors, and artificial extracellular matrix components.

Management of corneal neurotrophic ulcers with Cacicol®-RGTA (ReGeneraTing Agent): a case series

PURPOSE

Neurotrophic corneal ulcers are difficult to treat, and the conventional treatment often results in failure. A new matrix regenerating agent ("ReGeneraTing Agents"), Cacicol® (Laboratoires Théa), has demonstrated good results over the last few years. Therefore, the aim of this study was to evaluate the response to Cacicol® in a series of cases with neurotrophic corneal ulcers.

METHODS

Retrospective case series looking at 11 patients with corneal ulcers unresponsive to conventional therapy that underwent treatment with Cacicol®. One cycle included 1 drop every two days for 5 days.

RESULTS

The range of conventional therapy prior to Cacicol® was 0-91 days. On introducing Cacicol® 82% (9/11) of the cases were cured, and 18% (2/11) failed, requiring an amniotic membrane transplant or penetrating keratoplasty. The healing only required one cycle of Cacicol® in 67% (6/9) of the patients. More than one cycle of Cacicol® was needed in 45% (5/11) patients. One corneal bacterial ulcer responded favourably and one case related to Acanthamoeba did not respond. Most of the patients improved or maintained their visual acuity.

CONCLUSION

Cacicol® was a useful therapy in a high number of difficult neurotrophic corneal ulcers, including corneal infections. Some cases may require more than one cycle of Cacicol® or used as first-line treatment in order to achieve the desired result.

Recent innovations with drugs in clinical trials for neurotrophic keratitis and refractory corneal ulcers

Introduction: Corneal ulcers normally resolve spontaneously because of the proliferative ability of the corneal epithelium; however, sometimes, epithelial healing is diminished, even when standard treatments are administered. Hence, the treatment of refractory corneal ulcers is challenging and is the subject of ongoing efforts in preclinical and clinical development. Emerging treatment approaches include thymosine β4, CODA001, and topical insulin. Cenegermin eye drops, containing recombinant human nerve growth factor and ReGenerating Agent, a matrix therapy agent, have recently been commercialized for the treatment of moderate to severe neurotrophic keratitis in adults.Areas covered: We describe emerging therapeutic approaches for the management of refractory corneal ulcers and treatments recently introduced to the market. Pubmed and Clinicaltrial.gov databases were first searched including the terms: "corneal ulcer" or "neurotrophic keratopathy" and "treatment." Each treatment was searched in the same databases separately.Expert opinion: Affections of the sensory corneal nerves are the main factor contributing to the pathophysiology of neurotrophic keratopathy; this explains the healing difficulties of this form of ulcer. Cenegermin is a promising therapy acting as a neurotrophic agent for corneal healing. ReGenerating Agent has led to rapid pain relief and corneal healing, but randomized clinical trials are still necessary for further assessment.