Neuropathic symptoms of the ocular surface: dryness, pain, and itch.

Purpose Of Review: This review aims to describe the recent findings on epidemiology, pathophysiology, and management of neuropathic symptoms of the ocular surface, with a focus on potential similarities between sensations of dry eye, pain and itch.

Recent Findings: A narrative review of the literature was undertaken. Key references from research in dry eye, neuropathic symptoms of the ocular surface, ocular pain and itch, as well as general references on itch and pain neurobiology were included.

Traumatic brain injury, dry eye and comorbid pain diagnoses in US veterans.

Aims: The purpose of the study is to evaluate the relationship between dry eye (DE) and pain diagnoses in US veterans with and without traumatic brain injury (TBI).

Methods: Retrospective cohort study of veterans who were seen in the Veterans Administration Hospital (VA) between 1 January 2010 and 31 December 2014. Veterans were separated into two groups by the presence or absence of an International Classification of Diseases, Ninth Revision diagnosis of TBI and assessed for DE and other comorbidities.

Epidemiology of discordance between symptoms and signs of dry eye.

Background/aims: The frequent lack of association between dry eye (DE) symptoms and signs leads to challenges in diagnosing and assessing the disease.

Methods: Participants underwent ocular surface examinations to evaluate signs of disease and completed questionnaires to assess ocular symptoms, psychological status and medication use. To assess nociceptive system integrity, quantitative sensory testing (QST), including vibratory and thermal threshold measures and temporal summation of pain were obtained at the forearm and forehead.

Evidence that Dry Eye Represents a Chronic Overlapping Pain Condition.

Recent data suggest that corneal somatosensory dysfunction may be the underlying cause of severe dry eye symptoms in the absence of ocular surface pathology seen in a subset of patients diagnosed with “dry eye syndrome.” This subset of patients tends to demonstrate a unique constellation of symptoms that are persistent, more severe, and generally respond poorly to current dry eye therapies targeting inadequate or dysfunctional tears. A growing body of literature suggests that symptoms in these patients may be better characterized as neuropathic ocular pain rather than dry eye.

TFOS DEWS II pain and sensation report.

Pain associated with mechanical, chemical, and thermal heat stimulation of the ocular surface is mediated by trigeminal ganglion neurons, while cold thermoreceptors detect wetness and reflexly maintain basal tear production and blinking rate. These neurons project into two regions of the trigeminal brain stem nuclear complex: ViVc, activated by changes in the moisture of the ocular surface and VcC1, mediating sensory-discriminative aspects of ocular pain and reflex blinking. ViVc ocular neurons project to brain regions that control lacrimation and spontaneous blinking and to the sensory thalamus.

Updates in Ocular Surface Tumor Diagnostics.

Purpose: To evaluate technologies and techniques available for the diagnosis of ocular surface tumors.

Methods: A review of the literature from 1947 to 2017, through the PubMed Database, was conducted in order to evaluate current diagnostic methods for ocular surface tumors.

Results: Ocular surface squamous neoplasia, conjunctival melanoma, and conjunctival lymphoma are the three most common ocular surface malignancies.

Application of Scanning Electron Microscopy With Energy-Dispersive X-Ray Spectroscopy for Analyzing Ocular Surface Particles on Schirmer Strips.

Purpose: To demonstrate the application of scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM/EDS) for analyzing Schirmer strips for particle concentration, size, morphology, and type distribution.

Methods: A cross-sectional design was used. Patients were prospectively recruited from the Miami Veterans Affairs (VA) Healthcare System eye clinic, and they underwent a complete ocular surface examination.

Role of high resolution optical coherence tomography in diagnosing ocular surface squamous neoplasia with coexisting ocular surface diseases.

Purpose: Coexistence of an ocular surface disease can mask the typical features of ocular surface squamous neoplasia (OSSN). The purpose of this study was to evaluate high resolution optical coherence tomography (HR-OCT) as an adjunct in the detection and differentiation of OSSN within coexisting ocular surface pathologies.

Methods: Retrospective study of 16 patients with ocular surface disease and lesions suspicious for OSSN that were evaluated with HR-OCT.

Sub-basal Corneal Nerve Plexus Analysis Using a New Software Technology.

Purpose: To study sub-basal corneal nerve plexus (SCNP) parameters by in vivo corneal confocal microscopy using a new software technology and examine the effect of demographics and diabetes mellitus (DM) on corneal nerves morphology.

Methods: A Confoscan 4 (Nidek Technologies) was used in this cross-sectional study to image the SCNP in 84 right eyes at the Miami Veterans Affairs eye clinic. Images were analyzed using a new semiautomated nerve analysis software program (The Corneal Nerve Analysis tool) which evaluated 9 parameters including nerve fibers length (NFL) and nerve fibers length density (NFLD).

Intracorneal and Intraocular Invasion of Ocular Surface Squamous Neoplasia after Intraocular Surgery: Report of Two Cases and Review of the Literature.

Purpose: The aim of this paper was to describe 2 cases of ocular surface squamous neoplasia (OSSN) of the conjunctiva with intracorneal and intraocular extension following intraocular surgery.

Methods: We conducted a clinical pathological retrospective case series.

Results: Case 1 underwent cataract surgery in the setting of an unnoticed adjacent OSSN.

Diagnosis and Medical Management of Ocular Surface Squamous Neoplasia.

Introduction: Topical chemotherapy has gained popularity among clinicians for the treatment of ocular surface squamous neoplasia (OSSN). The principal topical chemotherapy agents used in the management of OSSN are interferon-α2b, 5-fluorouracil, and mitomycin C. High-resolution optical coherence tomography (HR-OCT) is a non-invasive technique that can differentiate OSSN from other ocular surface lesions.

The Association of Dry Eye Symptom Severity and Comorbid Insomnia in US Veterans.

Purpose: To investigate the association between dry eye (DE) and insomnia symptom severity.

Methods: Cross-sectional study of 187 individuals seen in the Miami Veterans Affairs eye clinic. An evaluation was performed consisting of questionnaires regarding insomnia (insomnia severity index [ISI]) and DE symptoms, including ocular pain, followed by a comprehensive ocular surface examination.

Barriers to Glaucoma Medication Compliance Among Veterans: Dry Eye Symptoms and Anxiety Disorders.

Objective: To identify barriers to compliance of medical treatment for glaucoma among veterans.

Methods: Patients with glaucoma from the Miami Veterans Affairs Eye Clinic (n=74) filled out a 63-question survey regarding dry eye symptoms, concurrent systemic disease, and medications. The association between glaucoma medical compliance was defined as self-reported adherence to drop regimens greater than 75% of the time.

Immunosuppression as a Possible Risk Factor for Interferon Nonresponse in Ocular Surface Squamous Neoplasia.

Purpose: The mechanism by which ocular surface squamous neoplasia (OSSN) responds to topical interferon-alpha-2b (IFNα2b) is not known. We report the cases of 3 immunosuppressed patients whose tumors did not respond to topical IFNα2b therapy. The purpose of this series is to shed light on potential mechanisms of IFNα2b in OSSN.

Evidence of central sensitisation in those with dry eye symptoms and neuropathic-like ocular pain complaints: incomplete response to topical anaesthesia and generalised heightened sensitivity to evoked pain.

Objective: To evaluate how closely neuropathic-like ocular pain (NOP) symptoms align with a metric of central sensitisation (ie, the presence of persistent ocular pain after topical anaesthetic placement) in individuals with dry eye (DE) symptoms.

Design: Cross-sectional study of 224 individuals with DE symptoms seen in the Miami Veterans Affairs eye clinic. An evaluation was performed consisting of questionnaires regarding DE symptoms, NOP descriptors and evoked pain sensitivity testing on the forehead and forearm, followed by a comprehensive ocular surface examination including corneal mechanical sensitivity testing.

Bulbar conjunctival microvascular responses in dry eye.

Purpose: Conjunctival microvascular responses may be a surrogate metric of efferent neural pathway function innervating the ocular surface as changes in blood flow occur within seconds after a stimulus. As somatosensory dysfunction may partially underlie dry eye (DE), in this study we evaluate whether bulbar conjunctival microvascular alterations correlate with various aspects of DE.

Methods: Fifty-six DE patients were prospectively recruited from a Veterans Affairs ophthalmology clinic over an 11-month period.

Longitudinal Examination of Frequency of and Risk Factors for Severe Dry Eye Symptoms in US Veterans.

Importance: Dry eye syndrome is a common condition that affects millions of individuals. Many cross-sectional studies have evaluated risk factors for dry eye severity, but few have assessed risk factors or symptom progression over time.

Objectives: To assess symptom progression in dry eye syndrome and determine risk factors associated with severe symptoms at 1 year.

Assessment of Somatosensory Function in Patients With Idiopathic Dry Eye Symptoms.

Importance: Somatosensory dysfunction likely underlies dry eye (DE) symptoms in many individuals yet remains an understudied component of the disease. Its presence has important diagnostic and therapeutic implications.

Objective: To assess the integrity of nociceptive system processes in persons with DE and ocular pain using quantitative sensory testing (QST) techniques applied at a site remote from the eye.

High-Resolution Optical Coherence Tomography in the Differentiation of Inflammatory Versus Noninflammatory Peripheral Corneal Thinning.

Purpose: To evaluate whether high-resolution optical coherence tomography (HR-OCT) can aid in differentiation of inflammatory versus noninflammatory causes of peripheral corneal thinning.

Methods: Retrospective chart review of 10 patients with peripheral corneal thinning and their respective slit-lamp photographs and HR-OCT images.

Results: Ten patients were identified who had peripheral corneal thinning and HR-OCT images.

Frequency and risk factors associated with dry eye in patients attending a tertiary care ophthalmology center in Mexico City.

Purpose: The purpose of this study was to ascertain the frequency and risk factors of dry eye (DE) among patients attending a tertiary care ophthalmology center in Mexico.

Methods: Approximately 338 consecutive new patients attending a tertiary care ophthalmology center in Mexico City underwent an ocular surface examination, which included tear film break-up time, fluorescein corneal staining, Schirmer's test, and evaluation of meibum quality. Symptoms of DE were evaluated by the Ocular Surface Disease Index and Dry Eye Questionnaire-5.

Compliance and Subjective Patient Responses to Eyelid Hygiene.

Objectives: Lid hygiene is a commonly prescribed first-line therapy in patients with lid margin disease, yet compliance with therapy is not well characterized. The goals of this study were to assess patient compliance with lid hygiene and evaluate which factors predict a favorable symptomatic response to treatment.

Methods: This was a cross-sectional study of patients seen in the Miami Veterans Affairs eye clinic between August and December 2014.

Conjunctival Intraepithelial Neoplasia with Mucoepidermoid Differentiation: A Case Report of a Subtle Lesion.

Objective: To describe the clinical presentation, diagnostic imaging, and treatment options of conjunctival intraepithelial neoplasia (CIN) with mucoepidermoid differentiation, an in situ stage of mucoepidermoid carcinoma of the conjunctiva (MCC).

Results: We report the case of an 86-year-old man presenting with a subtle limbal lesion that had only mild erythema and elevation. Based on a few atypical clinical features and an abnormal ultrahigh-resolution optical coherence tomography (UHR OCT), an incisional biopsy was performed revealing CIN with mucoepidermoid differentiation.

Atypical Fibroxanthoma of the Conjunctiva in Xeroderma Pigmentosum.

Background: Atypical fibroxanthoma (AFX) is a pleomorphic tumor that most commonly presents in the elderly and arises on sun-exposed skin.

Methods: We report a case of a 24-year-old white male with xeroderma pigmentosum (XP), who developed an AFX of the conjunctiva, and review the literature.

Results: The patient presented with a rapidly growing conjunctival mass which was surgically excised and found to be AFX.

ω-3 Tear Film Lipids Correlate With Clinical Measures of Dry Eye.

Purpose: ω-3 and ω-6 polyunsaturated fatty acids modulate inflammatory processes throughout the body through distinct classes of lipid mediators that possess both proinflammatory and proresolving properties. The purpose of this cross-sectional study was to explore the relationship between lipid profiles in human tears and dry eye (DE) symptoms and signs.

Methods: Forty-one patients with normal eyelid and corneal anatomy were prospectively recruited from a Veterans Administration Hospital over 18 months.

Patients with more severe symptoms of neuropathic ocular pain report more frequent and severe chronic overlapping pain conditions and psychiatric disease.

Objective: To study chronic pain and mental health profiles in patients with dry eye (DE) symptoms, comparing those with high and low levels of neuropathic ocular pain (NOP) complaints.

Design: Cross-sectional study of 181 patients with DE symptoms (dry eye questionnaire score ≥6) seen in the Miami Veterans Affairs eye clinic. An evaluation was performed consisting of questionnaires regarding DE symptoms, NOP complaints (burning, sensitivity to wind, light and cold/hot temperatures) and pain elsewhere in the body (non-ocular).