Sex and age differences in symptoms and signs of dry eye disease in a Norwegian cohort of patients

Sex Differences in the Prevalence of Meibomian Gland Dysfunction: A Mini Review

PURPOSE

In this review, we aimed to investigate the literature on sex-specific prevalence of meibomian gland dysfunction (MGD) and to determine whether women or men are more at risk for MGD.

METHODS

A search was conducted on PubMed using the terms: (Sex OR Gender OR prevalence) AND (Meibomian gland).

RESULTS

Twenty-four relevant studies on MGD prevalence were identified, including 10 population-based and 14 hospital-based studies. Among the population-based studies, five studies reported higher rates among men, three studies found no differences, and one study observed higher rates among women. In the hospital-based studies, 10 studies reported no difference, two found higher rates among men, and one found higher among women. In the reviewed literature, there was a considerable variation between studies in terms of quality, sample size, age ranges, diagnostic criteria.

CONCLUSIONS

While most of the population-based studies suggest a higher prevalence among men, the majority of clinic-based studies show no significant difference. Further research with larger samples and standardized criteria is needed to determine whether men are indeed more susceptible to MGD.

Characteristics of the Ocular Surface in Myopic Child Candidates of Orthokeratology Lens Wear

INTRODUCTION

The purpose of this study was to investigate the characteristics of objective ocular surface parameters using non-invasive objective instruments in children with myopia who are candidates for orthokeratology lens wear.

METHODS

Children with myopia who are candidates for orthokeratology lens wear were retrospectively investigated. The subjects were divided into three age groups. The Keratograph 5M and LipiView interferometry were used to assess non-invasive tear meniscus height (TMH), non-invasive tear film break-up time (NIBUT), conjunctival hyperemia redness score (RS), meibomian gland loss (MGL) score, lipid layer thickness (LLT), and blink pattern analysis, including the number of partial blinks (PB) and total blinks (TB), as well as the partial blink rate (PBR).

RESULTS

A total of 1119 children with myopia (2070 eyes) aged 7-18 years were selected. The mean TMH, NIBUT, and LLT of the subjects was 0.21 mm, 12.45 s, and 65.28 nm, respectively. The mean RS and upper and lower MGL scores were 0.64, 1.00, and 1.06, respectively. The mean PB, TB, and PBR was 5.13, 6.46, and 0.81, respectively. Age was significantly correlated to all ocular surface parameters (p = 0.00), except for PB. NIBUT and LLT did not differ between male participants and female participants (all p > 0.05). TMH, RS, and upper and lower MGL were significantly higher in male participants than in female participants (all p < 0.01). In addition, NIBUT was positively associated with TMH (r = 0.13, p = 0.00) and LLT (r = 0.28, p = 0.00). Both upper and lower MGL were positively correlated with TMH, PB, and TB (all p = 0.00), whereas upper MGL was negatively correlated with NIBUT and LLT (all p < 0.05). TB was negatively correlated with NIBUT and LLT (all p = 0.00). PB had no relation with TMH, NIBUT, and LLT (all p > 0.05). In addition, PBR was positively correlated with NIBUT and LLT (all p = 0.00) but not with TMH, RS, or MGL (all p > 0.05). Overall, 57.00% had a TMH ≤ 0.2 mm, 43.20% had a NIBUT ≤ 10 s, 48.10% had an LLT ≤ 60 nm, and 88.10% had a PBR > 0.4.

CONCLUSIONS

Child orthokeratology candidates have enhanced tear secretion and increased meibomian gland deficiency with aging. In addition, the adult dry eye diagnostic criteria may apply to orthokeratology candidates aged 12-18 years but should be lower for younger candidates. Given the proportion of abnormal risk, it is necessary to assess tear film status and blink pattern by reliable and feasible objective examination before fitting orthokeratology.

Prevalence and Determinants of Symptomatic Dry Eye Disease Among Adult Urban Residents of High-Altitude Areas of Southwest Saudi Arabia - A Survey

Purpose

To estimate the prevalence and determinants of Ocular Surface Disease Index (OSDI) score based dry eye disease (DED) among the adult urban population of four cities located at high altitudes in Southwest Saudi Arabia.

Methods

This cross-sectional survey was held in 2023. OSDI questionnaire was used to collect the responses of the adult participants. The score was further graded into none, mild, moderate, and severe DED to estimate age-sex-adjusted DED prevalence. The OSDI score was correlated to demographic (age group, gender, education, occupation, city) and risk factors like smoking and co-morbidities.

Results

Of the 401 adults, 388 (response rate of 97.8%) participated. The age-sex-adjusted prevalence of mild, moderate, and severe DED was 21.7%, 13.1%, and 32%, respectively. The median ODSI score was 22.9 [Interquartile range (IQR) 10.4; 47.9)]. The score was significantly higher in females (Mann-Whitney U-test P = 0.038), residents of Taif city (KW P = 0.05), those with primary/middle school education (Kruskal-Wallis P = 0.004), comorbidities like hypertension, asthma (KW P < 0.001) and risk factors like past refractive surgeries, arthritis (KW P = 0.013). Education status (P <0.001) [B = -9.0 95%] and presence of comorbidity (P = 0.022), [B = -0.823] were significant predictors of DED.

Conclusion

The prevalence of DED and severe grade was high. The level of education and presence of comorbidities significantly influenced DED in the adult urban Saudi population of cities at high altitudes.

Isolation and Identification of a Novel Anti-Dry Eye Peptide from Tilapia Skin Peptides Based on In Silico, In Vitro, and In Vivo Approaches

Tilapia skin is a great source of collagen. Here, we aimed to isolate and identify the peptides responsible for combating dry eye disease (DED) in tilapia skin peptides (TSP). In vitro cell DED model was used to screen anti-DED peptides from TSP via Sephadex G-25 chromatography, LC/MS/MS, and in silico methods. The anti-DED activity of the screened peptide was further verified in the mice DED model. TSP was divided into five fractions (TSP-I, TSP-II, TSP-III, TSP-IV, and TSP-V), and TSP-II exerted an effective effect for anti-DED. A total of 131 peptides were identified using LC/MS/MS in TSP-II, and NGGPSGPR (NGG) was screened as a potential anti-DED fragment in TSP-II via in silico methods. In vitro, NGG restored cell viability and inhibited the expression level of Cyclooxygenase-2 (COX-2) protein in Human corneal epithelial cells (HCECs) induced by NaCl. In vivo, NGG increased tear production, decreased tear ferning score, prevented corneal epithelial thinning, alleviated conjunctival goblet cell loss, and inhibited the apoptosis of corneal epithelial cells in DED mice. Overall, NGG, as an anti-DED peptide, was successfully identified from TSP, and it may be devoted to functional food ingredients or medicine for DED.

Design guidelines for limiting and eliminating virtual reality-induced symptoms and effects at work: a comprehensive, factor-oriented review

Virtual reality (VR) can induce side effects known as virtual reality-induced symptoms and effects (VRISE). To address this concern, we identify a literature-based listing of these factors thought to influence VRISE with a focus on office work use. Using those, we recommend guidelines for VRISE amelioration intended for virtual environment creators and users. We identify five VRISE risks, focusing on short-term symptoms with their short-term effects. Three overall factor categories are considered: individual, hardware, and software. Over 90 factors may influence VRISE frequency and severity. We identify guidelines for each factor to help reduce VR side effects. To better reflect our confidence in those guidelines, we graded each with a level of evidence rating. Common factors occasionally influence different forms of VRISE. This can lead to confusion in the literature. General guidelines for using VR at work involve worker adaptation, such as limiting immersion times to between 20 and 30 min. These regimens involve taking regular breaks. Extra care is required for workers with special needs, neurodiversity, and gerontechnological concerns. In addition to following our guidelines, stakeholders should be aware that current head-mounted displays and virtual environments can continue to induce VRISE. While no single existing method fully alleviates VRISE, workers' health and safety must be monitored and safeguarded when VR is used at work.

Age Associations with Dry Eye Clinical Signs and Symptoms in the Dry Eye Assessment and Management (DREAM) Study

Purpose

To evaluate how increasing age is associated with dry eye disease (DED) signs and symptoms in the Dry Eye Assessment and Management (DREAM) study. This study was undertaken to better understand how DED signs and symptoms differ across decades of life with goals to help assess detection and treatment of DED.

Design

Secondary analysis of the DREAM study.

Subjects

One hundred twenty, 140, 185, and 90 participants aged < 50, 50 to 59, 60 to 69, and ≥ 70 years, respectively.

Methods

We performed a secondary analysis of data from the DREAM study, a multicenter randomized clinical trial, to evaluate the effect of omega-3 fatty acid supplementation for the treatment of DED. At baseline, 6 months, and 12 months follow-up, participants underwent an assessment of DED symptoms and signs using Ocular Surface Disease Index, Brief Pain Inventory, tear break-up time (TBUT) (in seconds), Schirmer test with anesthesia (mm/5 minutes), conjunctival staining, corneal staining, meibomian gland dysfunction evaluation, and tear osmolarity (mOsm/l). Multivariable generalized linear regression models were used to compare DED symptoms and signs across the 4 age groups among all participants and by sex.

Main Outcome Measures

Scores of DED symptoms, individual signs, and composite scores of DED signs.

Results

Among 535 patients with DED, increasing age was significantly associated with worse TBUT (P = 0.01), corneal staining (P < 0.001), a composite severity score of DED signs (P = 0.007), and tear osmolarity (P = 0.001). Similar significant differences were found across 4 age groups of 334 women in TBUT, corneal staining score, composite severity score of DED signs, and tear osmolarity (all P < 0.05) but not in men.

Conclusion

We found that corneal staining, TBUT, tear osmolarity, and a composite severity score of DED signs were significantly more severe with increasing age in women but not in men; worsening symptoms did not increase with increasing age.

Financial Disclosures

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Clinical observation of tear film breakup time with a novel smartphone-attachable technology

PURPOSE

To demonstrate the practicability of a portable instrument in assessing tear film breakup time (TFBUT): a lens attachment for smartphones (LAS).

METHODS

By applying LAS in combination with the iPhone 12 pro, and a recordable slit-lamp microscope, we obtained TFBUT videos from 58 volunteers. The comparison between the conventional slit-lamp microscope and LAS by an experienced ophthalmologist. Moreover, we also invited an ophthalmic postgraduate student and an undergraduate student with no clinical experience to assess TFBUT in those videos. The inter-observer reliability was assessed using intraclass correlation coefficients (ICC).

RESULTS

The TFBUT of 116 eyes in total was recorded. Reliability indexes were adequate. The Spearman's correlation analysis and the intraclass correlation coefficient suggested a strong correlation between the 2 modalities (Right eye: Spearman's r = 0.929, 95% confidence interval (CI) = 0.847-0.963, ICC = 0.978, p < 0.001; Left eye: Spearman's r = 0.931, 95% CI = 0.866-0.964, ICC = 0.985, p < 0.001;). Between instruments, the majority of TFBUT measurements showed good agreement on Bland Altman plot. A high concordance was observed in TFBUT, when assessed by an ophthalmologist and an ophthalmic postgraduate student (Left eye: LAS ICC = 0.951, p < 0.001; Left eye: slit-lamp microscope ICC = 0.944, p < 0.001).

CONCLUSIONS

Compared with the conventional slit-lamp microscope, the LAS has sufficient validity for evaluating TFBUT in clinics or at home.

Comparative study of cyclosporine A liposomes and emulsions for ophthalmic drug delivery: Process optimization through response surface methodology (RSM) and biocompatibility evaluation

Herein, cyclosporine A loaded liposomes (CsA-Lips) were fabricated aimed at improving the biocompatibility of the ophthalmic formulation and getting rid of the direct contact of ocular tissues with irritant excipients. Response surface methodology was exploited in order to investigate the influence of miscellaneous factors on the key characteristics of CsA-Lips. Ratio of EPC:CsA, ratio of EPC:Chol, and stirring speed were selected as the independent variables, while size, drug-loading content (DL), and drug-loading content (DL) loss rate were applied as the response variables. In case of the maximal lack-of-fit p-value and minimum sequential p-value, quadratic model was regarded as the fittest model to analyze the data. The correlation of independent variables with response variables was described by three-dimension surface figures. Optimized formulation for CsA-Lips was obtained with ratio of EPC:CsA set as 15, ratio of EPC:Chol set as 2, and stirring speed set as 800 rpm. The particle size of CsA-Lips was 129.2 nm after optimalization while their TEM images exhibited spherical unilamellar vesicles with clearly shell-core structure. CsA released more rapidly from CsA-Lips in comparison with self-made emulsion and Restasis®. Besides, minimum cytotoxicity of CsA-Lips was perceived via both MTT method and LDH method, indicating the excellent compatibility of the ophthalmic formulation. Simultaneously, CsA-Lips showed enhanced nonspecific internalization in the cytoplasm with a time-dose-dependent manner. In conclusion, CsA-Lips could be adhibited as the hopeful ophthalmic drug delivery system clinically for dry eye syndrome (DES).

The Prevalence of Symptomatic Dry Eye Disease Among Coal Workers in Huainan Region of China

Purpose

To investigate the prevalence and influencing factors of symptomatic dry eye disease (DED) in Chinese coal workers.

Methods

The prevalence of symptomatic DED in coal workers was investigated by using the questionnaire of Ocular Surface Disease Index (OSDI) and the influencing factors were explored.

Results

The prevalence of symptomatic DED was 50.7% in coal workers. Of the influencing factors of symptomatic DED, the level of dust exposure had an odds ratio (OR) of 1.26, the time of dust exposure had an OR of 1.02, and the age had an OR of 1.03.

Conclusion

There was a high morbidity of symptomatic DED among coal workers and the level and the time of dust exposure and the age of coal workers had important effects.

Predicting an unstable tear film through artificial intelligence

Dry eye disease is one of the most common ophthalmological complaints and is defined by a loss of tear film homeostasis. Establishing a diagnosis can be time-consuming, resource demanding and unpleasant for the patient. In this pilot study, we retrospectively included clinical data from 431 patients with dry eye disease examined in the Norwegian Dry Eye Clinic to evaluate how artificial intelligence algorithms perform on clinical data related to dry eye disease. The data was processed and subjected to numerous machine learning classification algorithms with the aim to predict decreased tear film break-up time. Moreover, feature selection techniques (information gain and information gain ratio) were applied to determine which clinical factors contribute most to an unstable tear film. The applied machine learning algorithms outperformed baseline classifications performed with ZeroR according to included evaluation metrics. Clinical features such as ocular surface staining, meibomian gland expressibility and dropout, blink frequency, osmolarity, meibum quality and symptom score were recognized as important predictors for tear film instability. We identify and discuss potential limitations and pitfalls.

Ocular surface health of the Finnish elderly population

PURPOSE

The aim of this study was to describe the clinical ocular surface characteristics in a population-based sample of Finnish elderly people.

METHODS

This cross-sectional study included 601 subjects (335 females, 266 males) born between the years 1933-1956 and living in Savitaipale, Finland. Ocular surface health was evaluated using a comprehensive set of diagnostic tests. Previous dry eye (DE) diagnosis and history of drug treatment of DE were also recorded. Differences between sexes were estimated with Wilcoxon rank sum test and Fisher's exact test.

RESULTS

Overall, 10% and 33% of people displayed signs of DE and ocular surface disease (OSD), respectively, and 30% had been previously diagnosed with DE and 36% used some form of drugs for DE. Men displayed more severe signs of meibomian gland dysfunction, blepharitis and conjunctival redness (p < 0.001), while women had higher scores in corneal staining (p = 0.005) and OSD Index (p < 0.001).

CONCLUSION

Signs of OSD and DE are common among the Finnish elderly population. However, the diagnosis is affected by the diagnostic criteria used and significant differences exist between sexes. Although women were more frequently diagnosed with DE and OSD and experienced more ocular surface irritation, men had more often lid and meibomian gland-related issues. The current diagnostic criteria of DE pose a risk of misclassifying men, who commonly display less severe symptoms in comparison with women yet exhibit more severe clinical signs associated especially with the lid margin.

Sex-based differences in conjunctival goblet cell responses to pro-inflammatory and pro-resolving mediators

Many conjunctival inflammatory diseases differ between the sexes and altered conjunctival goblet cells (CGCs) response is often involved. Inflammation is initiated by the release of pro-inflammatory mediators and terminated by the biosynthesis of specialized pro-resolution mediators (SPMs). Herein, we determined the sex-based difference in the responses of CGCs to inflammatory stimuli or pro-resolving lipid SPMs and their interaction with sex hormones. GCs were cultured from pieces of human conjunctiva in RPMI media. CGCs were transferred 24 h before the start of experiments to phenol red-free and FBS-free media to minimize exogenous hormones. RT-PCR, immunofluorescence microscopy (IF), and Western Blot (WB) were performed to determine the presence of sex hormone receptors. Cellular response to pro-inflammatory stimuli or SPMs was studied by measuring the increase in intracellular [Ca²⁺] ([Ca²⁺]_i) using fura 2/AM microscopy. Use of RT-PCR demonstrated estrogen receptor (ER) α in 4/5 males and 3/3 females; ERβ in 2/4 males and 2/3 females; and androgen receptors (AR) in 3/3 male and 3/3 female CGCs. Positive immunoreactivity by IF and protein expression by WB was detected using antibodies for the ERα and ERβ in 3/3 males and 3/3 females, while AR were only present in males. Significantly different Ca²⁺ responses between sexes were found with carbachol only at 10^–3 M, but not with histamine or leukotriene (LT) B₄ at any concentration used. Incubation with dihydrotestosterone (DHT), estrone (E1), or estradiol (E2) at 10^–7 M for 30 min significantly inhibited the LTB₄-stimulated [Ca²⁺]_i increase in male and female CGCs. Incubation with DHT, E1, and E2 overnight significantly inhibited the LTB₄ response in females, while DHT and E2 significantly inhibited the LTB₄ response in males. The SPM lipoxin A₄ (LXA₄) (10^–9–10⁻⁸ M), but not the resolvins D1 or D2, induced an [Ca²⁺]_i increase that was significantly higher in males compared to females. We conclude that male and female CGCs showed differences in the expression of sex hormone receptors. Treatment with sex hormones altered pro-inflammatory mediator LTB₄-induced response. Males compared to females have a higher response to the ω-6-fatty acid derived SPM LXA₄, indicating males may terminate inflammation in conjunctival goblet cells faster than females.

The Eyelid Meibomian Gland Deficiency in Fucosyltransferase 1 Knockout Mice

To investigate the effect of fucosyltransferase (FUT) 1-mediated fucosylation on meibomian glands (MG), we first confirmed that FUT1 and its fucosylated products were expressed in the eyelid, conjunctiva and skin in wild-type (WT) mice, whereas their mRNA and protein levels were downregulated in Fut1 knock-out (KO) mice. We then evaluated age-dependent changes in the total and acinar areas of MG, meibocyte differentiation, lipid synthesis, and eyelid inflammation and oxidative stress in Fut1 KO and WT mice. Results show that both the total and acinar areas of MG were smaller in Fut1 KO mice than in WT mice in all evaluated age groups. Meibocyte differentiation, lipid-producing capacities and the enzyme levels responsible for lipid synthesis were reduced in Fut1 KO mice, compared to WT controls. The levels of pro-inflammatory cytokines and oxidative-stress-related markers were elevated in the eyelids and MG of FUT1 KO mice. These findings demonstrate the physiologic function of FUT1-mediated fucosylation in MG development and function, and indicate its potential role in ocular surface homeostasis.

Utilizing Baidu Index to Investigate Seasonality, Spatial Distribution and Public Attention of Dry Eye Diseases in Chinese Mainland

Purpose

To explore the characteristics of spatial-temporal prevalence and public attention of dry eye diseases (DED) through Baidu Index (BI) based on infodemiology method.

Methods

The data about BI of DED were collected from Baidu search engine using "Dry eye diseases" as keyword. The spatial and temporal distribution of DED were analyzed through timeseries data decomposition as well as spatial autocorrelation and hotspot detection of BI about DED. The most popular related words and demographic characteristics were recorded to determine the public attention of DED.

Results

The trends of BI about DED in Chinese mainland had gradually increased over time with a rapid increase from 2012 to 2014 and in 2018. The results of timeseries decomposition indicated that there was seasonality in the distribution of BI about DED with the peak in winter, especially in northern regions. The geographic distribution demonstrated the search activities of DED was highest in the east of Chinese mainland while lowest in the west. The vast majority of people searching for DED were teenagers (20-29 years), with a predominance of females. Glaucoma, keratitis and conjunctivitis were the diseases most often confused with DED, and the artificial tears were the most common treatment for DED in Chinese mainland according to the BI about DED.

Conclusions

The analysis revealed the seasonality, geographic hotspots and public concern of DED through BI in Chinese mainland, which provided new insights into the epidemiology of DED.

Relationships between Symptoms and Signs of Dry Eye Using Symptom Assessment in Dry Eye Questionnaires

Purpose: To investigate the pattern of Symptom Assessment in Dry Eye (SANDE) questionnaire symptom scores in dry eye disease (DED) patients and to assess the relationships with several dry eye signs.Methods: The medical records of 173 patients with DED were analyzed retrospectively. Each patient’s SANDE score and history of autoimmune disease and ocular surgery were investigated, and Schirmer’s test, tear film breakup time (TBUT), ocular surface staining score (OSS), tear osmolarity, and tear MMP-9 test were assessed. The distribution of SANDE scores and relationships between the SANDE score and various dry eye signs were analyzed. The relationships between the SANDE scores of TBUT (< 5 / ≥ 5) and OSS (< 3 / ≥ 3) subgroups were compared.Results: The average SANDE score was 52.6 ± 28.1. The SANDE scores were significantly higher in OSS ≥ 3 than in OSS < 3 (79.1 ± 21.6 vs. 51.1 ± 27.6, p = 0.030), and TBUT ≥ 5 had marginally significantly lower SANDE scores than TBUT < 5 (47.2 ± 25.6 vs. 55.6 ± 29.0, p = 0.050). TBUT was significantly negatively (R = -0.151, p = 0.024) correlated with the SANDE score, while OSS was marginally significantly positively (R = 0.111, p = 0.073) correlated. As OSS increased, the SANDE scores tended to increase (p for trend = 0.008). Other dry eye signs were not associated with the SANDE score.Conclusions: The DED symptom score from the SANDE questionnaire was related to TBUT and OSS, but there was still a discrepancy between the symptoms and signs of DED.

Dry eye disease and proteomics

Dry eye disease (DED) is a highly prevalent disease worldwide mostly associated with age, though other factors such as screen use and contact lens wear explain why it is increasingly diagnosed in younger people. DED also disproportionately affects women. Symptoms include eye dryness, burning, pain and sensitivity to light that can significantly affect quality of life. This condition may progress to cause lasting damage to the ocular surface if left untreated. Currently, diagnosis is through assessment of signs and symptoms determined by clinical tests and questionnaires. However, there is considerable overlap between normal and DED result distributions of currently available metrics as signs and symptoms fluctuate over time and with disease severity. Importantly, the non-targeted approach of proteomics means that significant changes in novel proteins may be discovered. Proteomics is a powerful tool that has been applied to the field of DED to understand changes at a biochemical level, uncover new disease biomarkers and determine the success of clinical interventions. While individual proteins may not be sensitive enough when used as single biomarkers, proteomics opens the possibility to uncover several relevant proteins that may be combined in a panel to provide more accurate diagnostic value i.e. parallel testing. In this review we discuss the use of proteomics in DED research and the potential for application of proteomic results in the clinic. We also identify shortcomings and future avenues for research.

Economic burden and loss of quality of life from dry eye disease in Canada

Objective

To describe the direct and indirect cost estimates of dry eye disease (DED), stratified by disease severity, and the impact of DED on quality of life (QoL) in Canadian patients.

Methods and analysis

A prospective, multicentre, observational, cross-sectional study was conducted at six sites across Canada. Eligible patients completed a 20 min survey on demography, general health, disease severity, QoL and direct (resource utilisation and out-of-pocket expenses for the past 3–24 months) and indirect costs (absenteeism and presenteeism based on Work Productivity and Activity Impairment questionnaire responses). Subgroup analyses were performed according to DED severity and presence of Sjögren’s syndrome.

Results

Responses from 146 of 151 participants were included in the analysis. DED was rated as moderate or severe by 19.2% and 69.2% of patients, respectively. Total mean annual costs of DED were $C24 331 (Canadian dollars) per patient and increased with patient-reported disease severity. Mean (standard deviation [SD]) indirect costs for mild, moderate and severe disease were $C5961 ($C6275), $C16 525 ($C11 607), and $C25 485 ($C22,879), respectively. Mean (SD) direct costs were $C958 ($C1216), $C1303 ($C1574) and $C2766 ($C7161), respectively. QoL scores were lowest in patients with Sjögren’s syndrome (8.2% of cohort) and those with severe DED.

Conclusion

This study provides important insights into the negative impact of DED in a Canadian setting. Severe DED was associated with higher direct and indirect costs and lower QoL compared with those with mild or moderate disease. Increased costs and poorer QoL were also evident for patients with DED plus Sjögren’s syndrome versus DED alone.