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

Dry eye in mind: Exploring the relationship between sleep and ocular surface diseases

PURPOSE

Dry Eye Disease (DED) is regarded as the most common ocular surface disease worldwide, entailing symptoms that have a major impact on the physical and psychological well-being of DED patients. In this context, the impact of sleep quality on DED has recently attracted attention. Indeed, although little is known about the mechanisms underlying the relationship between sleep and ocular surface diseases, recent evidence suggests that a reciprocal relationship exists between sleep quality and DED. Aim of the study was to investigate such relationship by means of both survey-based and instrumental analysis in a large population.

PATIENTS AND METHODS

The present cross-sectional study included 1182 DED patients who completed the Insomnia Severity Index (ISI) and the Ocular Surface Disease Index (OSDI) questionnaires. Moreover, tear break-up time (TBUT) and ocular surface staining (OSS) data of included patients were collected by physicians.

RESULTS

According to the findings of this study, in DED patients, the severity of dry eye symptoms and signs, assessed by OSDI score, TBUT, and ocular surface staining, is associated with more severe insomnia symptoms. Furthermore, higher severity of DED symptoms seems to be associated with the occurrence of nocturnal awakenings rather than with problems in falling asleep.

CONCLUSIONS

Present work contributes to the understanding of the complex relationship between DED and insomnia by showing that in a large population of DED patients, the more severe the insomnia, the more severe the DED symptoms and signs.

Association between sleep quality and dry eye disease: a literature review and meta-analysis

OBJECTIVE

The purpose of this article is to systematically review the association between dry eye and sleep quality.

METHODS

PubMed, EMBASE, Cochrane, Web of Science, and grey literature databases were searched for observational studies published before April 2023. Meta-analysis was performed using STAT15 software.

RESULTS

A total of 21 studies with 419,218 participants were included. The results showed that the dry eye subjects had a worse sleep quality than the healthy population, with poorer subjective sleep quality, longer sleep latency, and a higher risk of unhealthy sleep duration such as insufficient sleep or excessive sleep. The Pittsburgh Sleep Quality Index (PSQI) scores of the dry eye subjects were significantly higher than those of the control subjects (WMD = 1.78, 95%CI: 1.06, 2.50, P < 0.001). The dry eye subjects scored higher than the control subjects in sleep quality, sleep latency, and sleep disturbance in PSQI; there was no difference between the dry eye individuals and control subjects in sleep duration, sleep efficiency, daytime dysfunction, and sleep medication scores. The risk of sleep disorders in the dry eye subjects was significantly higher than that in the non-dry eye subjects (RR = 2.20, 95%CI: 1.78, 2.72, P < 0.001); the risk of insufficient sleep in the dry eye subjects was higher than that in the control subjects (RR = 3.76, 95%CI: 3.15, 4.48, P < 0.001), and the prevalence of excessive sleepiness in dry eye subjects was higher than that in the control subjects (RR = 5.53, 95%CI: 3.83, 7.18, P < 0.001). The ESS scores of the dry eye subjects were significantly higher than those of the control subjects (WMD = 3.02, 95%CI: 2.43, 3.60, P < 0.01).

CONCLUSION

Our meta-analysis suggests that individuals with dry eye have a worse sleep quality than the healthy population, with poorer subjective sleep quality, longer sleep latency, and higher risk of unhealthy sleep duration such as insufficient sleep or excessive sleepiness.

Associations between dry eye disease and sleep quality: a cross-sectional analysis

BACKGROUND/AIMS

To investigate relationships between dry eye (DE) disease and sleep quality, with a focus on which aspects of sleep most closely relate to DE.

METHODS

141 veterans (mean age: 56±5) seen at the Miami Veterans Affairs eye clinic filled out questionnaires to quantify the severity of DE symptoms (5-Item Dry Eye Questionnaire (DEQ-5) and Ocular Surface Disease Index (OSDI)) and ocular pain (Numerical Rating Scale (NRS) and Neuropathic Pain Symptom Inventory modified for the Eye (NPSI-E)). All individuals also underwent an ocular surface examination. Aspects of sleep quality were assessed using the Pittsburgh Sleep Quality Index (PSQI). DE metrics were examined by PSQI scores and subscores.

RESULTS

Most participants (76%) reported mild or greater DE symptoms (DEQ-5 ≥6). Overall, ocular symptoms were more related to sleep metrics than signs. The strongest DE symptom association was between the OSDI and sleep disturbances (PSQI subscore 5, r=0.49, p<0.0005). For DE signs, ocular surface inflammation and meibum quality were related to subjective sleep quality (PSQI subscore 1, r=0.29, p=0.03, for both). On linear regression analyses, most ocular symptom questionnaires remained associated with sleep disturbances (PSQI subscore 5: NRS (r=0.52, p<0.0005), DEQ-5 (r=0.36, p<0.0005), and OSDI (r=0.31, p<0.0005)). For DE signs, ocular surface inflammation and meibum quality remained associated with subjective sleep quality (r=0.26, p=0.01; r=0.46, p<0.0005, respectively).

CONCLUSION

DE symptom and ocular pain intensity were closely related to sleep metrics, most strongly to sleep disturbances. Relationships were weaker for DE signs, with subjective sleep quality relating to inflammation and meibum quality.

Effects of insomnia on symptomatic dry eye during COVID-19 in China: An online survey

Sleep is an essential determinant of health and quality of life. This study aimed to evaluate sleep disorders and symptomatic dry eye (DE) occurrence. This study was a cross-sectional survey of 1393 participants in China. The insomnia severity index (ISI) Questionnaire was used to evaluate sleep quality, and the ocular surface disease index (OSDI) questionnaire was used to assess DE symptoms. Subjects were divided into 2 groups based on subjects with and without symptomatic DE. The patients who had DE (10.48 ± 7.27) had substantially lower ISI scores compared to those without DE (3.57 ± 5.10) (P = .003). Furthermore, each ISI item and total ISI score was significantly correlated with OSDI dry eye severity and total OSDI dry eye score. Higher prevalence of insomnia was found in participants with symptomatic DE, and insomnia correlated significantly with DE symptoms. The present results suggest that clinicians and healthcare workers need to remember that DE and insomnia are highly co-existing health issues.

TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface

The word "elective" refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.

TFOS Lifestyle: Impact of lifestyle challenges on the ocular surface

Many factors in the domains of mental, physical, and social health have been associated with various ocular surface diseases, with most of the focus centered on aspects of dry eye disease (DED). Regarding mental health factors, several cross-sectional studies have noted associations between depression and anxiety, and medications used to treat these disorders, and DED symptoms. Sleep disorders (both involving quality and quantity of sleep) have also been associated with DED symptoms. Under the domain of physical health, several factors have been linked to meibomian gland abnormalities, including obesity and face mask wear. Cross-sectional studies have also linked chronic pain conditions, specifically migraine, chronic pain syndrome and fibromyalgia, to DED, principally focusing on DED symptoms. A systematic review and meta-analysis reviewed available data and concluded that various chronic pain conditions increased the risk of DED (variably defined), with odds ratios ranging from 1.60 to 2.16. However, heterogeneity was noted, highlighting the need for additional studies examining the impact of chronic pain on DED signs and subtype (evaporative versus aqueous deficient). With respect to societal factors, tobacco use has been most closely linked to tear instability, cocaine to decreased corneal sensitivity, and alcohol to tear film disturbances and DED symptoms.

Factors affecting the prevalence, severity, and characteristics of ocular surface pain

Introduction

Ocular surface pain has been traditionally lumped under the umbrella term "dry eye" (DE) but is now understood as its own entity and can occur in the absence or presence of tear dysfunction. Identifying patients at risk for the development of chronic ocular surface pain, and factors contributing to its severity are important in providing precision medicine to patients.

Areas covered

In this review, we discuss factors linked to the presence and severity of ocular surface pain, including eye related features, systemic characteristics, and environmental findings. We discuss corneal nerves, whose anatomic and functional integrity can be characterized through in vivo confocal microscopy images and testing of corneal sensitivity. We review systemic diseases that are co-morbid with ocular surface pain, including physical and mental health diagnoses. Finally, we identify environmental contributors, including air pollution, previous surgeries, and medications, associated with ocular surface pain.

Expert opinion

Intrinsic and extrinsic factors contribute to ocular surface pain and must be considered when evaluating an individual patient. These factors can inform the suspected etiology of the pain, and guide management decisions such as tear replacement or medications targeting nerve pain.

Anxiety and depression in dry eye patients during the COVID-19 pandemic: Mental state investigation and influencing factor analysis

Objective

Investigate the anxiety and depression states among dry eye (DE) patients during the COVID-19 outbreak and analyze their influence factors.

Methods

The study was conducted in a tertiary eye hospital in Tianjin, China from March–April 2021. Four hundred twenty-eight DE patients were tested with the Ocular Surface Disease Index, Short Healthy Anxiety Inventory, Hospital Anxiety and Depression Scale, and Pittsburgh Sleep Quality Index. Descriptive statistics was used to assess the difference between DE with depression or anxiety among different groups. And multiple linear regression was used to explore factors that influence anxiety and depression in DE patients.

Results

The incidence rates of anxiety and depression among DE patients during COVID-19 were 27.34 and 26.87%, respectively. The proportion with comorbid anxiety and depression was 24.30%. Patients' education level (t = −3.001, P < 0.05; t = −3.631, P < 0.05), course of disease (t = 2.341, P < 0.05; t = 2.444, P < 0.05), health anxiety (t = 3.015, P < 0.05; t = 2.731, P < 0.05), and subjective sleep quality (t = 3.610, P < 0.05; t = 4.203, P < 0.05) had certain influences on anxiety and depression.

Conclusion

The results showed that subjective symptoms of DE patients were related to depression and anxiety. Higher education, shorter disease duration, lower health anxiety levels, and better subjective sleep quality were associated with the reduced depressive and anxiety symptoms in DE patients. These findings could be deemed beneficial to the treatment and prevention of DE during the COVID-19 epidemic.

The Association Between Dry Eye and Sleep Disorders: The Evidence and Possible Mechanisms

Dry eye is a disease that severely affects patients' quality of life, increasing the global burden on public health and finance. There is growing evidence that a poor lifestyle is a significant risk factor for dry eye. Along with the development of society, sleep, as a way of life, is also constantly changing. The main manifestations of sleep disorders are reduced sleep time, circadian rhythm disturbances, and sleep breathing disturbances. Sleep disorders and their secondary systemic diseases have attracted wide attention in recent years. This review mainly explored the correlation between sleep disorders and dry eye, and found that sleep-related problems and other factors potentially leading from sleep disorders could be critical factors for dry eye. These results suggest that ophthalmologists should pay attention to the sleep health problems in patients with dry eye, and we hope that this paper can provide help for future research in this field.

Long-Term Trigeminal Nerve Stimulation as a Treatment for Ocular Pain

OBJECTIVES

Ocular pain symptoms (e.g., hypersensitivity to light and wind, "burning" sensations) can be debilitating and difficult to treat. Neuromodulatory therapies targeting sensory trigeminal and central pain pathways may help treat chronic ocular pain refractory to traditional therapies. The current study evaluates the long-term effects of a trigeminal neurostimulator (TNS) on ocular pain.

MATERIALS AND METHODS

Retrospective review of 18 individuals at the Miami Veterans Affairs Eye Clinic with chronic, severe ocular pain who were prescribed and used TNS at home for ≥3 months. The primary outcome measures were 1) ocular symptom intensity over a 24-hour recall period (dryness, pain, light sensitivity, wind sensitivity, burning; rated on 0-10 scales) captured pre-TNS and at monthly follow-up intervals and 2) side effects. The frequency and duration of TNS was a secondary outcome measure.

RESULTS

The mean age of the population (n = 18) was 57.5 years (range, 34-85 years) with a male majority (67%). Two individuals discontinued use due to lack of efficacy and one due to confounding health issues. Initial mean weekly frequency of TNS use was 3.7 ± 1.9 sessions of 25.8 min at month 1 and 2.7 ± 2.3 sessions of 28.0 min at month 6. At six months, pain intensity (↓ 31.4%), light sensitivity (↓ 36.3%), wind sensitivity (↓ 32.6%), and burning sensation (↓ 53.9%) were all decreased compared to baseline (p < 0.01 for all); greater decreases in ocular pain were noted in individuals with migraine (n = 10) than those without migraine (n = 8). No significant change was noted in mean dryness scores. Fifteen subjects experienced sedation with TNS use, persisting throughout the follow-up visits. No other adverse effects were communicated by any subjects.

CONCLUSION

Our study suggests TNS is a safe, adjunctive treatment option in individuals with severe, chronic ocular pain. Individuals demonstrated gradual, continual improvement in pain symptoms over time within a multimodal approach.

Relationship between unhealthy sleep status and dry eye symptoms in a Japanese population: The JPHC-NEXT study

PURPOSE

To investigate whether and how unhealthy sleep habits (i.e., the frequency of difficulty falling or staying asleep, and the frequency of waking up tired) and the duration of sleep are related to the prevalence of dry eye disease (DED) in a general population.

METHODS

This study included a total of 106,282 subjects aged 40-74 years who participated in a baseline survey of the Japan Public Health Center-based Prospective Study for the Next Generation. DED was defined as the presence of clinically diagnosed DED or severe symptoms. Multivariable-adjusted logistic regression models were used to assess the relationships of various components of sleep status with DED.

RESULTS

Higher frequencies of having difficulty falling or staying asleep, and waking up tired were significantly related to increased DED in both sexes (P_trend<0.001). Compared with those with 8 h/day of sleep, shorter sleepers had an increased prevalence of DED in both sexes, although DED was increased among men who slept ≥10 h/day. By comparing participants with the greatest vs. the least difficulty of falling asleep, the multivariable-adjusted odds ratios (95% confidence interval [CI]) were 2.23 (95% CI, 1.99-2.49) for men and 1.91 (95% CI, 1.76-2.07) for women. When analyzed separately, the magnitude of each relationship was stronger with severe DED symptoms than with clinically diagnosed DED.

CONCLUSIONS

Sleep deprivation and poor sleep quality were significantly related to DED in a Japanese population.

Association between dry eye disease, self-perceived health status, and self-reported psychological stress burden

Clinical relevance: Dry eye disease is a common chronic ocular condition, which is acknowledged to have adverse impacts on quality of life and work productivity.Background: The wide-reaching impacts of dry eye disease on mental health and quality of life have received growing attention in recent years. The purpose of this study was therefore to investigate the relationship between dry eye disease, self-perceived health status, and self-reported psychological stress burden.Methods: Three hundred and twelve community residents (178 females, 134 males; mean ± SD age, 38 ± 21 years) with no major systemic, ophthalmic, or psychiatric conditions (other than dry eye disease), were recruited in a cross-sectional study. Self-perceived health status and self-reported psychological stress burden were assessed, and dry eye symptomology, ocular surface characteristics, and tear film quality were evaluated for each participant within a single clinical session, in accordance with the global consensus recommendations of the Tear Film and Ocular Surface Society Dry Eye Workshop II reports.Results: Multivariate regression analysis, adjusted for age, sex, ethnicity, and contact lens wear, demonstrated that improved self-perceived health status was associated with decreased odds of dry eye disease, aqueous tear deficiency and meibomian gland dysfunction (all p < 0.05). Increased self-reported psychological stress burden was positively associated with dry eye disease, aqueous tear deficiency and meibomian gland dysfunction (all p ≤ 0.01).Conclusion: Dry eye disease is associated with poorer self-perceived health status and greater self-reported psychological stress burden. The findings of this study highlight the wide-reaching impacts of dry eye disease, and the importance of minimising the impacts of the condition with optimised management and actioning inter-disciplinary referral for affected patients where necessary.

The Association Between Dry Eye Disease With Depression, Anxiety and Sleep Disturbance During COVID-19

Objective: This study aimed to investigate the relationship between dry eye disease (DED) with anxiety and depression. Additionally, the mediating effect of sleep quality on this relationship was explored. Methods: 321 patients with DED were recruited from Tianjin Medical University Eye Hospital clinic and surveyed using demographic questionnaires, the Ocular Surface Disease Index (OSDI), Hospital Anxiety and Depression Scale (HADS), and Pittsburgh Sleep Quality Index (PSQI). Regression analysis and the bootstrap method were used to investigate the influence of sleep on the relationship between DED, anxiety and depression. Results: Among the patients with DED, 86 (26.79%), 85 (26.48%), and 54 (16.82%) patients presented with anxiety, depression, and both anxiety and depression respectively. The OSDI and PSQI score were positively correlated with depression and anxiety (all p < 0.01). The direct effects of OSDI on depression and anxiety were significant (P < 0.01). Additionally, the bootstrap test showed significant mediating effects of subjective sleep quality [95% CI [0.003-0.016] (depression); [0.001-0.011] (anxiety)] and sleep latency [95% CI [0.001-0.010] (depression); [0.001-0.008] (anxiety)]. These results indicated that the severity of DED symptoms, as measured by the OSDI score, affected anxiety and depression through a direct and an indirect pathway mediated by subjective sleep quality and sleep latency. Conclusions: The results indicated that there was a significant correlation between DED and anxiety and depression. Moreover, subjective sleep quality and sleep latency were a mediator of the relationship between DED symptoms and anxiety and depression.

Ocular Surface Pain: A Narrative Review

Ocular surface pain is a frequent cause of visits to an eye care provider and has a substantial impact on healthcare cost, yet a complete understanding of its causative factors and tools for diagnostic workup are notably missing in many eye clinics. The cornea has the densest sensory innervation in the human body and has the potential to be a powerful producer of pain. Pain can manifest as a result of a noxious stimulus or disruption in the ocular surface anatomy (nociceptive pain), or it can result from abnormalities in the ocular surface neurosensory apparatus itself (neuropathic pain). Novel advances in neurobiology have sought to differentiate the two entities, particularly to identify when chronic dry eye symptomatology is driven by neuropathic ocular pain. In this review, we seek to provide an overview of the prevalence, physiologic factors, and management of ocular surface pain complaints.

Association of Systemic Comorbidities with Dry Eye Disease

We investigated the association between dry eye disease and systemic comorbidities, including dry eye subtype, quality of life (QOL) and health utility among patients with dry eye disease. This cross-sectional, observational study enrolled 449 patients with dry eye disease (386 females; mean age, 62.6 ± 15.7 [range, 21–90] years). Ophthalmic examination findings included tear film break-up time (TBUT), Schirmer I value and keratoconjunctival staining score. QOL and health utility were evaluated using the Dry Eye-Related Quality-of-Life Score (DEQS) and Human Utility Index Mark 3 (HUI-3), respectively. Background information, including systemic comorbidities, was obtained. Prevalence of systemic comorbidities was 48.8% (219/449). No significant difference occurred between DEQS and systemic comorbidity. However, patients with dry eye disease and systemic comorbidities (depression and insomnia) exhibited significantly worse ocular surface parameters, particularly regarding TBUT, than those without. Dry eye disease with insomnia or depression comorbidity significantly correlated with friction-related diseases (including conjunctivochalasis or lid wiper epitheliopathy). A high prevalence of several systemic comorbidities occurred in patients with dry eye disease. This study shows an association between ocular signs and systemic comorbidities, particularly depression and insomnia. Ophthalmologists should be aware of patients’ systemic comorbidities in the diagnosis and management of dry eye disease.

Ocular Surface Changes in Prostaglandin Analogue-Treated Patients

Glaucoma is the second leading cause of blindness globally. Reducing intraocular pressure (IOP) has been acknowledged to be the main therapy for glaucoma. Prostaglandin analogues (PGAs) have become the first-line therapy for patients with glaucoma due to their powerful efficacy for lowering (IOP). However, usage of PGAs can also cause several notable side effects, including the changes in ocular surface. The relationship between PGAs and ocular surface changes is complicated and still remains unclear. In the present review, we summarize the recent studies of the effects of PGAs on ocular changes as well as the possible mechanisms that might provide new considerations during clinical medication.

Dry eye and sleep quality: a large community-based study in Hangzhou

Study Objectives

To investigate the relationship between dry eye and sleep quality in a large community-based Chinese population.

Methods

A total of 3,070 participants aged 18–80 were recruited from a community-based study in Hangzhou, China during 2016–2017. Sleep quality was evaluated using the Chinese version of the Pittsburgh Sleep Quality Index (CPSQI), and dry eye was evaluated using the Ocular Surface Disease Index (OSDI) questionnaire. Multivariable linear regression and logistic regression models were used to investigate the associations, adjusting for age, smoking, drinking, season, and other potential confounders.

Results

Overall, CPSQI score and sleep dysfunction were significantly associated with mild, moderate, and severe dry eye (ORs for CPSQI score: 1.07, 1.13, 1.14, all p < 0.001; for sleep dysfunction: 1.31, 1.73, 1.66, all p < 0.05). Furthermore, worse OSDI score was presented in participants with worse CPSQI score or sleep dysfunction (CPSQI score > 7) (β: 0.13, 0.54; all p < 0.001). In addition, six of the seven components of CPSQI showed significant associations with dry eye (all p < 0.001), except for the component of sleep medication use. Moreover, we observed significant associations of dry eye in all three subscales of OSDI with CPSQI score and sleep dysfunction.

Conclusion

Our large, community-based study showed a strong association between poor sleep quality and an increased severity of dry eye, suggesting that preventing either one of the discomforts might alleviate the other.

Sleep Disorders are a Prevalent and Serious Comorbidity in Dry Eye

Purpose

Sleep is an essential life habit and closely associated with lifespan, diabetes, hypertension, and mental health. Sleep disorders are a prominent, but overlooked problem in patients with dry eye disease (DED), characterized by a poor sleep index, short sleep duration, long sleep latency, and poor subjective sleep. DED and sleep disorders are more prevalent in women than men. Moreover, sleep quality in DED is worse than in other eye diseases, including glaucoma, retinal diseases, cataract, and allergic and chronic conjunctivitis.

Methods

We reviewed the literature for studies investigating sleep and health, eyes and sleep, and DED and sleep, in terms of systemic and eye health, especially in women.

Results

Two studies reported that approximately half of patients with DED suffer from poor sleep. The severity of mood disorders, including anxiety and depression, is correlated strongly with sleep disorders in DED, and the symptoms and signs of DED, especially pain, also are correlated with sleep quality. Sleep disorders are documented in primary Sjögren's syndrome and an association with sleep apnea and depression is suggested. Primary Sjögren's syndrome includes arthritis and other rheumatic disease causing pain and fatigue; however, how sicca contributes to sleep disorders is not known.

Conclusions

Possible explanations for sleep disorders in DED may be depression, pain, and eye exposure at night. Reciprocal effects may be expected and consultation-liaison psychiatry is recommended for the management of sleep disorders in DED. Topical medication and lid heating also may be advantageous for sleep quality in DED.

Do Sleep Disorders Positively Correlate with Dry Eye Syndrome? Results of National Claim Data

Purpose: Dry eye syndrome (DES) is a common disease with an increasing occurrence. Although DES symptoms are considered mild, it can reduce quality of life for individuals. Many studies on DES have been conducted, but these focused on the use of electronic devices. Here, we investigate an association between DES and sleep disorders in the context of emerging health issues. Methods: Our data came from the National Health Insurance Service (NHIS) National Sample Cohort, which included 44,366 patients and was based on a 1:1 matching method (sleep disorder patients vs. patients without sleep disorders) during 2012–2015. Using survival analysis with a Cox proportional hazard model, we identified an association of sleep disorders with DES. Results: About 16.7% of all patients were diagnosed with DES, and prevalence was higher in patients with sleep disorders (sleep disorders: 19.82%, no sleep disorders: 13.67%). Survival analysis showed that sleep disorders positively correlated with DES diagnosis (Hazard Ratio (HR): 1.320, 95% Confidence Interval (CI): 1.261–1.382, p-value < 0.0001). Positive trends were enhanced in males, younger patients, lower economic levels, and with higher severity of comorbid. Conclusions: Our findings suggest that sleep disorder was positively associated with DES. This correlation can be helpful in effective management of both sleep disorders and DES in South Koreans.

Air Pollutants are associated with Dry Eye Disease in Urban Ophthalmic Outpatients: a Prevalence Study in China

BACKGROUND

Although previous prevalence studies of DED were reported from some countries worldwide, national data are unavailable in China. We aimed to conduct an up-to-date national survey on the prevalence of DED in China and find out the potential risk factors including air pollutant.

METHODS

23,922 eligible outpatients were recruited from ophthalmic clinics of 32 cities in China in 2013 by registration orders. The patients' demographic characteristics, history of keratorefractive surgery, diseases and medication history were collected and the daily air pollutant data in 2013. Multivariate logistic analysis was performed to identify the potential risk factors associated with DED. The association between related factors and dry eye diseases subtypes evaluated as p value and odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

Among 23,922 outpatients, the prevalence of DED was 61.57%, and that of the male patients was 57.64% and of the female was 65.32% (P < 0.0001). Multivariate logistic regression suggested that the possible risk factors for DED included: female, older age, history of keratorefractive surgery, presence of arthritis, thyroid diseases, and antihistamine, diuretic, duodenal ulcer drugs, diazepam. Air pollutants including O3, PM2.5, and SO2 were also identified as the risk factors.

CONCLUSION

The prevalence of DED among ophthalmic outpatients in China was considerably high. Age, gender, history of keratorefractive surgery, diseases, medication history, and air pollutants were associated with DED prevalence.

Gray Matter Volume Changes in Patients With Acute Eye Pain: A Voxel-Based Morphometry Study

PURPOSE

The present study was attempted to compare the differences in gray matter volume (GMV) between the acute eye pain (EP) patients and the healthy controls (HCs) using voxel-based morphometry (VBM), and to explore the relationship with clinical features and behavioral performance.

METHODS

A total of 24 patients (17 males, 7 females) with acute EP and 24 (17 males, 7 females) age-, sex-, and education-matched HCs were recruited from the Ophthalmology Department of the First Affiliated Hospital of Nanchang University. Functional magnetic resonance imaging (fMRI) scans were conducted in all subjects. We analyzed the original three-dimensional (3D) T1 brain images by VBM and compared the GMV values with the HCs. The acute EP patients can be distinguished from the HCs by receiver operating characteristic (ROC) curve.

RESULTS

Compared with HCs, the acute EP patients had significantly lower GMV values in the brain regions of the left cerebellum posterior lobe, the left limbic lobe, the right insula, the left insula, the left thalamus, the left caudate, and the right cuneus. In addition, the WMV values of the whole brain in acute EP patients decreased slightly.

CONCLUSIONS

These results demonstrated that the acute EP patients showed an abnormal reduction in GMV in some brain regions, which might provide valuable information for further exploration of underlying neural mechanisms. These abnormal brain regions may reflect the functional disorders of acute EP patients in somatosensory, motor, cognitive functions, and so on.

TRANSLATIONAL RELEVANCE

The VBM study provides a diagnostic method for identifying the cause of acute EP, additionally, a novel direction was presented for further exploration of underlying neural mechanisms of acute EP.

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. In these patients, dry eye symptoms are often associated with numerous comorbid pain conditions and evidence of central pain processing abnormalities, where eye pain is just one of multiple overlapping peripheral manifestations. In this review, we discuss the concept and potential mechanisms of chronic overlapping pain conditions as well as evidence for considering neuropathic ocular pain as one of these overlapping pain conditions.

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. A dendrogram was used to investigate the linkage between TBI, DE, chronic pain and other comorbid conditions.

RESULTS

Of the 3 265 894 veterans seen during the 5-year period, 3.97% carried a diagnosis of TBI. Veterans with TBI were more likely to have a diagnosis of DE compared with their counterparts without TBI (37.2% vs 29.1%, p<0.0005). The association was stronger between TBI and ocular pain (OR 3.08; 95% CI 3.03 to 3.13) compared with tear film dysfunction (OR 1.09; 95% CI 1.07 to 1.10). Those with TBI were also about twice as likely to have a diagnosis of chronic pain, headache, depression or post-traumatic stress disorder compared with their counterparts without TBI. Cluster analysis of TBI, DE and pain diagnoses of interest revealed that central pain syndrome, cluster headache, sicca syndrome, keratoconjunctivitis sicca and late effect of injury to the nervous system (as can be seen after TBI) were all closely clustered together.

CONCLUSIONS

DE and pain disorders occur at higher frequencies in patients with a diagnosis of TBI, suggesting a common underlying pathophysiology.

Neuropathic pain and dry eye

Dry eye is a common, multifactorial disease currently diagnosed by a combination of symptoms and signs. Its epidemiology and clinical presentation have many similarities with neuropathic pain outside the eye. This review highlights the similarities between dry eye and neuropathic pain, focusing on clinical features, somatosensory function, and underlying pathophysiology. Implications of these similarities on the diagnosis and treatment of dry eye are discussed.

Noninvasive Electrical Stimulation for the Treatment of Chronic Ocular Pain and Photophobia

INTRODUCTION

"Dry eye" or "keratoconjunctivitis sicca" is a multifactorial disease estimated to have a worldwide prevalence of 5-33%. Conventional therapies targeting the ocular surface with artificial tears, anti-inflammatories, punctal closure, eyelid hygiene, and antibiotics do not provide relief in all patients, especially those with neuropathic-like ocular complaints (wind hyperalgesia and photophobia). We anticipated that ocular transcutaneous electrical nerve stimulation (TENS) would alleviate symptoms of ocular pain, photophobia, and dryness in these latter individuals.

METHODS

All individuals who received electrical stimulation between May 10, 2016 and April 6, 2017 for the treatment of chronic ocular pain at the oculofacial pain clinic of the Miami Veterans Administration Hospital were included in this retrospective review. All patients had symptoms of dryness along with other neuropathic-like symptoms (e.g., photophobia) and minimal signs of tear dysfunction. Ocular pain intensity, symptoms of dryness, and light sensitivity were compared pre-treatment and five min post-treatment via a two-tailed paired Student's t-test.

RESULTS

The use of TENS significantly reduced the mean pain intensity in both the right and left eyes five min after treatment compared to prior to treatment (p < 0.05, paired t-test). The use of TENS significantly decreased light sensitivity in both eyes (p < 0.05). The findings for symptoms of dryness, however, were equivocal with a significant decrease in the left eye but not the right (p < 0.05, paired t-test).

DISCUSSION

Our data indicate that TENS may similarly provide analgesia in patients with dry eye symptoms as it does for many other chronic pain conditions. Furthermore, the noted effect on symptoms of photophobia and dryness suggest that all may be linked by similar trigeminal-thalamic-cortical pathways. Prospective studies with electrical stimulation of dry eye are needed to further elucidate its benefit and mechanism of action.

Evidence that dry eye is a comorbid pain condition in a U.S. veteran population

A retrospective review of 3,265,894 veterans seen over a 5-year period demonstrates dry eye is associated with numerous chronic pain conditions implying shared mechanisms.

Introduction:

Recent evidence suggests that dry eye (DE) may be comorbid with other chronic pain conditions.

Objectives:

To evaluate DE as a comorbid condition in the U.S. veteran population.

Methods:

Retrospective review of veterans seen in the Veterans Administration Healthcare System (Veteran Affairs) between January 1, 2010, and December 31, 2014. Dry eye and nonocular pain disorders were ascertained by International Classification of Diseases, Ninth Revision (ICD-9) codes. Dry eye was further separated into ICD-9 codes representing tear film dysfunction or ocular pain. χ² and logistic regression analyses were used to examine frequency and risk of DE, ocular pain, and tear film dysfunction by pain disorders.

Results:

Of 3,265,894 veterans, 959,881 had a DE diagnosis (29.4%). Dry eye frequency increased with the number of pain conditions reported (P < 0.0005). Ocular pain was most strongly associated with headache (odds ratio [OR] 2.98; 95% confidence interval [CI] 2.95–3.01), tension headache (OR 2.64; 95% CI 2.58–2.71), migraine (OR 2.58; 95% CI 2.54–2.61), temporomandibular joint dysfunction (OR 2.39; 95% CI 2.34–2.44), pelvic pain (OR 2.30; 95% CI 2.24–2.37), central pain syndrome (OR 2.24; 95% CI 1.94–2.60), and fibromyalgia/muscle pain (OR 2.23; 95% CI 2.20–2.26), all P < 0.0005. Tear film dysfunction was most closely associated with osteoarthritis (OR 1.97; 95% CI 1.96–1.98) and postherpetic neuralgia (OR 1.95; 95% CI 1.90–2.00), both P < 0.0005.

Conclusions:

Dry eye, including both ocular pain and tear film dysfunction, is comorbid with pain conditions in this nationwide population, implying common mechanisms.

Possible association between subtypes of dry eye disease and seasonal variation

Purpose

The purpose of this study was to evaluate the influence of seasons on the signs and symptoms of dry eye disease (DED).

Methods

This is a cross-sectional, case-control study, and participants were non-DED subjects (n=1,916, mean age 54.4±14.4 years) and DED patients (n=684, 54.2±12.1 years) visiting six eye clinics at various practices and locations in Japan. We evaluated the signs and symptoms of DED and the seasons with the most severe results were compared to those with the least severe results in both groups. Main outcome measures were differences in the severity of the signs and symptoms of DED between the most and least severe seasons.

Results

The majority of DED symptoms were most severe during spring and least severe in summer. Significant differences between these two seasons were found for irritation (P=0.001), pain (P=0.007), blurring (P=0.000), and photophobia (P=0.007) in the DED group. Superficial punctate keratopathy (P=0.001) and tear break-up time (BUT; P=0.000) results also indicated that DED was most severe in spring. In contrast, fewer patients had low Schirmer test results in spring, although this was not statistically significant (P=0.061).

Conclusion

Our results demonstrated that the severity of DED is seasonal, which may explain the increase of short BUT-type DED cases observed in spring when air pollen counts are highest.

The Relationship Between Ocular Itch, Ocular Pain, and Dry Eye Symptoms (An American Ophthalmological Society Thesis)

PURPOSE

To evaluate associations between sensations of ocular itch and dry eye (DE) symptoms, including ocular pain, and DE signs.

METHODS

A cross-sectional study of 324 patients seen in the Miami Veterans Affairs eye clinic was performed. The evaluation consisted of questionnaires regarding ocular itch, DE symptoms, descriptors of neuropathic-like ocular pain (NOP), and evoked pain sensitivity testing on the forehead and forearm, followed by a comprehensive ocular surface examination including corneal mechanical sensitivity testing. Analyses were performed to examine for differences between those with and without subjective complaints of ocular itch.

RESULTS

The mean age was 62 years with 92% being male. Symptoms of DE and NOP were more frequent in patients with moderate-severe ocular itch compared to those with no or mild ocular itch symptoms. With the exception of ocular surface inflammation (abnormal matrix metalloproteinase 9 testing) which was less common in those with moderate-severe ocular itch symptoms, DE signs were not related to ocular itch. Individuals with moderate-severe ocular itch also demonstrated greater sensitivity to evoked pain on the forearm and had higher non-ocular pain, depression, and post-traumatic stress disorders scores, compared to those with no or mild itch symptoms.

CONCLUSIONS

Subjects with moderate-severe ocular itch symptoms have more severe symptoms of DE, NOP, non-ocular pain and demonstrate abnormal somatosensory testing in the form of increased sensitivity to evoked pain at a site remote from the eye, consistent with generalized hypersensitivity.

Determinants of Ocular Pain Severity in Patients With Dry Eye Disease

PURPOSE

To quantify the severity of ocular pain in patients with dry eye disease (DED) and evaluate factors associated with pain severity.

DESIGN

Cross-sectional study.

METHODS

Eighty-four patients with DED were asked to score their severity level of ocular pain using a 10-point scale, with 10 indicating the most severe pain. All patients also had a comprehensive ophthalmic assessment including a detailed history, Ocular Surface Disease Index (OSDI) questionnaire, and ocular surface examination. Regression analysis was used to determine the factors associated with ocular pain severity.

RESULTS

The mean OSDI score was 45.6 ± 23.1. At least some degree of ocular pain (score >1) was reported by 88.1% of patients, including mild pain (scores 2-4) in 46.4%, moderate pain (scores 5-7) in 34.5%, and severe pain (scores 8-10) in 7.1% of patients. Ocular pain levels significantly correlated with the OSDI score (r_s = 0.49, P < .001). Regression analysis showed that the severity of ocular pain had a significant association with use of antidepressant medications (P = .045) but not with tear breakup time, corneal fluorescein staining, or ocular medications used by patients. In patients without pain, a significant correlation was seen between OSDI and corneal fluorescein staining scores (r_s = 0.67, P = .01). However, such a correlation was not observed in those with ocular pain.

CONCLUSIONS

A majority of patients with DED report some degree of ocular pain, which correlates only moderately with the OSDI score. Severity of ocular pain correlates with nonocular comorbidities such as use of antidepressant medications rather than with clinical signs of DED.

Association of dry eye disease with psychiatric or neurological disorders in elderly patients

Dry eye disease (DED) is a common disease that can impair quality of life significantly. Its prevalence increases with advancing age, and the economic burden of the disease on both a patient and the society is increasing with elongation of life expectancy. The diagnosis and treatment of DED are often difficult due to the discordance between symptoms and signs of the disease. Recent studies have suggested the role of neurological or psychological factors in the development of dry eye symptoms and discrepancy of the symptoms and signs, particularly in elderly patients. In this review, the authors discuss the association of DED with various psychiatric and neurological disorders. In addition to psychiatric conditions, including depression, anxiety, stress, posttraumatic stress disorder and sleep disorders, medications for the psychiatric disorders have association with DED. Neurological disorders, such as neuropathic pain, chronic pain syndrome, peripheral neuropathy and several central nervous system disorders, are related to DED. Treatment of DED, combined with psychiatric or neurological disorders, is also discussed. Attention should be paid to the DED patients with discordant symptoms and signs, and unsatisfactory response to conventional treatment for associated psychiatric or neurological disorders, as well as an integrated treatment approach, could be helpful for these patients.