RESUMO
Corneal neuropathic pain (CNP) is a poorly defined disease entity characterised by an aberrant pain response to normally non-painful stimuli and categorised into having peripheral and central mechanisms, with the former responding to instillation of topical anaesthetic. CNP is a challenging condition to diagnose due to numerous aetiologies, an absence of clinical signs and ancillary tests (in vivo confocal microscopy and esthesiometry), lacking the ability to confirm the diagnosis and having limited availability. Symptomatology maybe mirrored by severe and chronic forms of dry eye disease (DED), often leading to misdiagnosis and inadequate treatment. In practice, patients with suspected CNP can be assessed with questionnaires to elicit symptoms. A thorough ocular assessment is also performed to exclude any co-existent ocular conditions. A medical and mental health history should be sought due to associations with autoimmune disease, chronic pain syndromes, anxiety and depression. Management begins with communicating to the patient the nature of their condition. Ophthalmologists can prescribe topical therapies such as autologous serum eyedrops to optimise the ocular surface and promote neural regeneration. However, a multi-disciplinary treatment approach is often required, including mental health support, particularly when there are central mechanisms. General practitioners, pain specialists, neurologists and psychologists may be needed to assist with oral and behavioural therapies. Less data is available to support the safety and efficacy of adjuvant and surgical therapies and the long-term natural history remains to be determined. Hence clinical trials and registry studies are urgently needed to fill these data gaps with the aim to improve patient care.
RESUMO
AIM: To identify and assess the quality of current validated questionnaires that could be used to evaluate ocular neuropathic pain and its associated aetiologies. METHODS: A literature search was performed on MEDLINE, PubMed, EMBASE, PsycINFO and The Cochrane Library. Articles evaluating questionnaires for ocular neuropathic pain and its associated aetiologies were included. Data on psychometric properties, validity, and reliability of the questionnaires was extracted and analysed using a set of quality criteria. Clinical and demographical associations with ocular neuropathic pain were also reviewed. RESULTS: The search generated 1738 results with 61 publications meeting the inclusion criteria. The 61 publications covered 28 questionnaires including 3 ocular pain, 12 dry eye disease, 2 blepharitis, 2 refractive surgery, 3 contact lens wear, 3 Sjogren's Syndrome, and 3 that were non-disease-specific. Only 57 publications provided enough data on psychometric properties and validity of the questionnaire to be included for quality assessment. The Contact Lens Discomfort Index (CLDI) had the highest rated psychometric properties, whereas the English version of the Ocular Comfort Index (OCI) provided the most data on psychometric properties (9 out of 10 criteria). Most ocular pain and disease-specific questionnaires contained appropriate items to assess ocular pain in specific populations. However, non-disease-specific ophthalmic questionnaires demonstrated poor reliability and validity when evaluating ocular pain. CONCLUSION: Ocular pain questionnaires can potentially diagnose ocular neuropathic pain. Disease-specific questionnaires were limited to their target populations, and non-disease-specific ophthalmic questionnaires were unreliable. Further studies are required to determine the most appropriate questionnaire to evaluate ocular neuropathic pain.