Neuropathic ocular surface pain: Emerging drug targets and therapeutic implications

ABSTRACT

Introduction

Dysfunction at various levels of the somatosensory system can lead to ocular surface pain with a neuropathic component. Compared to nociceptive pain (due to noxious stimuli at the ocular surface), neuropathic pain tends to be chronic and refractory to therapies, making it an important source of morbidity in the population. An understanding of the options available for neuropathic ocular surface pain, including new and emerging therapies, is thus an important topic.

Areas covered

This review will examine studies focusing on ocular surface pain, emphasizing those examining patients with a neuropathic component. Attention will be placed toward recent (after 2017) studies that have examined new and emerging therapies for neuropathic ocular surface pain.

Expert opinion

Several therapies have been studied thus far, and continued research is needed to identify which individuals would benefit from specific therapies. Gaps in our understanding exist, especially with availability of in-clinic diagnostics for neuropathic pain. A focus on improving diagnostic capabilities and researching gene-modulating therapies could help us to provide more specific mechanism-based therapies for patients. In the meantime, continuing to uncover new modalities and examining which are likely to work depending on pain phenotype remains an important short-term goal

KEYWORDS:

• Ocular surface pain
• cornea
• dry eye disease
• nociceptive pain
• neuropathic pain
• treatment

Article highlights

• Dysfunction at several levels of the somatosensory system (peripheral ocular, peripheral periocular, central, or autonomic nerves) can lead to chronic ocular surface pain with a neuropathic component.

• While a number of first-line agents exist for each type of nervous injury, in patients with neuropathic ocular surface pain who cannot tolerate or are refractory to first-line pain modalities, alternative and adjuvant therapies may be considered.

• The use of alternative or adjunctive therapies heavily dependent on the likely location of the nervous lesion along the somatosensory pathway (e.g. peripheral, central, autonomic, etc.)

• While several alternative therapies have been identified, several emerging modalities are currently being studied in the pre-clinical stage and may be readily available for treatment of refractory pain in the near future.

• A patient-centered, comprehensive approach for multi-modal therapies must be applied over a continuum of time to ensure optimal outcomes in patients with chronic refractory ocular surface pain with a neuropathic component.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.