Effects of phytoestrogen supplementation in postmenopausal women with dry eye syndrome: a randomized clinical trial

Sex-related differences and hormonal effects in the Dry Eye Assessment and Management (DREAM) study

BACKGROUND/AIMS

To compare dry eye disease (DED) signs and symptoms between men and women, as well as between premenopausal and postmenopausal women, in the Dry Eye Assessment and Management (DREAM) study.

METHODS

434 women and 101 men self-reported prior medical history and underwent a standardised DED assessment using the Ocular Surface Disease Index, Brief Pain Inventory, Tear Break-Up Time (TBUT)(s), Schirmer's test 2 (mm/5 min), National Eye Institute-graded lissamine conjunctival staining, corneal staining, meibomian gland dysfunction evaluation and tear osmolarity (mOsms/L) at baseline, 6 months and 12 months. Multivariable linear regression models were used to compare these scores.

RESULTS

Women experienced significantly worse DED signs than men with lower Schirmer's test scores (9.27 vs 12.16; p<0.001), higher corneal staining scores (3.59 vs 2.70; p=0.006) and worse composite DED sign scores (0.52 vs 0.40; p<0.001). Postmenopausal women experienced significantly worse DED signs than premenopausal women with higher corneal staining scores (3.74 vs 2.58, p<0.001), higher conjunctival staining scores (2.80 vs 2.22, p<0.001), higher tear osmolarity (304 vs 299, p=0.004), lower TBUT (3.37 vs 3.93, p=0.047), worse meibomian gland dysfunction (3.05 vs 2.62, p=0.04) and worse composite DED sign scores (0.54 vs 0.42, p<0.001). There were no significant differences in DED symptoms between sex and between premenopausal and postmenopausal women (all p≥0.08).

CONCLUSION

In the DREAM study, women experienced more severe DED signs than men. Further, postmenopausal women presented with more severe DED signs than premenopausal women. Elucidating these differences may improve DED diagnosis and provide future direction in understanding sex-related differences in DED.

TRIAL REGISTRATION NUMBER

NCT02128763.

Meibography and tear function alterations in premature ovarian failure

PURPOSE

Premature ovarian failure (POF) is the deterioration of normal ovarian function before the age of 40. In the presence of chemotherapy, radiation, genetic factors, autoimmune conditions, hypoandrogenemia, hypoestrogenemia and increased gonadotropin hormones, dry eye with early menopause findings may be encountered. The goal of our study is to compare the tear film alterations and meibomian gland status of patients diagnosed with POF at the time of diagnosis with healthy volunteers.

METHODS

In our study, 90 patients with POF and 60 control patients were evaluated. Complete ophthalmologic examinations of the patients, ocular surface disease index (OSDI) score, Oxford score for corneal and conjunctival involvement, Schirmer 1 and 2 tests, noninvasive tear break-up time (BUT), lower lid meibomian drop out grades with noncontact meibography, and meibomian gland distortion and shortening scores were compared between the two groups.

RESULTS

The mean age was 29.49±2.92 years in the patient group and 29.37±2.85 years in the control group (P=0.830). OSDI scores were statistically significant higher in the patient group (32.11±18.88) compared to the control group (12.93±14.92) (P<0.001). On Oxford scoring, there was a significant increase in the patient group (P<0.001). There was no significant difference between the groups in terms of Schirmer 1 and 2 tests (P=0.195, P=0.117). NIBUT was significantly lower in the patient group (11.93±4.59) compared to the control group (18.72±5.38) (P<0.001). While there was no difference between the groups in terms of lower lid meiboscores or meibomian gland length (P>0.005), there was a significant deterioration in the patient group in the distortion grading showing the morphological evaluation of the meibomian glands (p=0.037). In the ROC analysis, OSDI score (AUC=0.816, P<0.0001) and NIBUT (AUC=0.820, P<0.0001) parameters showed high specifity and sensitivity for the disease.

DISCUSSION

Ocular surface damage and dry eye symptoms are observed more frequently in patients with POF. We believe that hormonal insufficiency may cause deterioration in tear film composition, ocular surface damage with changes in tear homeostasis, and a change in the structure of the meibomian glands, starting with distortion at an early age.

A new era in posterior segment ocular drug delivery: Translation of systemic, cell-targeted, dendrimer-based therapies

Vision impairment and loss due to posterior segment ocular disorders, including age-related macular degeneration and diabetic retinopathy, are a rapidly growing cause of disability globally. Current treatments consist primarily of intravitreal injections aimed at preventing disease progression and characterized by high cost and repeated clinic visits. Nanotechnology provides a promising platform for drug delivery to the eye, with potential to overcome anatomical and physiological barriers to provide safe, effective, and sustained treatment modalities. However, there are few nanomedicines approved for posterior segment disorders, and fewer that target specific cells or that are compatible with systemic administration. Targeting cell types that mediate these disorders via systemic administration may unlock transformative opportunities for nanomedicine and significantly improve patient access, acceptability, and outcomes. We highlight the development of hydroxyl polyamidoamine dendrimer-based therapeutics that demonstrate ligand-free cell targeting via systemic administration and are under clinical investigation for treatment of wet age-related macular degeneration.

Diurnal variations of tear film osmolarity on the ocular surface

The measurement of tear film osmolarity has been suggested as a gold standard in the diagnosis of dry eye. Many tear film physiological variables oscillate during the day. This review summarises current clinical knowledge regarding diurnal osmolarity variation in the tear film. A critical analysis is presented in respect of of sample size and characteristics, differences in the diurnal osmolarity variation on healthy versus altered tear film conditions or environment, and time of day and number of measurements undertaken. A comparison of 21 studies was made for studies in which one of the main objectives was to analyse the variance of tear film osmolarity at different time-points in a day on human cohorts. Tear film osmolarity appeard to be somewhat influenced by the time of day in healthy subjects and patients with ocular surface disease, or altered by environmental conditions. Both healthy and non-physiological tear film cohorts showed variations in results depending on the study: no variations during the day or statistically different values at some point in the day. These differences could be in the middle of the day or between the beginning and the end of the day, with higher values in the morning than in the afternoon, or even the opposite situation. The possibility of diurnal variations in tear film osmolarity should be considered by the clinician since the time of day when the tear film measurements are made can be critical in making the right diagnosis. Future studies in the diurnal variation field may have to use a well-established range of measurement time-points and a larger group of healthy subjects and and subjects who have a tear film altered by pathological or environmental conditions.

Sex Hormones, Growth Hormone, and the Cornea

The growth and maintenance of nearly every tissue in the body is influenced by systemic hormones during embryonic development through puberty and into adulthood. Of the ~130 different hormones expressed in the human body, steroid hormones and peptide hormones are highly abundant in circulation and are known to regulate anabolic processes and wound healing in a tissue-dependent manner. Of interest, differential levels of sex hormones have been associated with ocular pathologies, including dry eye disease and keratoconus. In this review, we discuss key studies that have revealed a role for androgens and estrogens in the cornea with focus on ocular surface homeostasis, wound healing, and stromal thickness. We also review studies of human growth hormone and insulin growth factor-1 in influencing ocular growth and epithelial regeneration. While it is unclear if endogenous hormones contribute to differential corneal wound healing in common animal models, the abundance of evidence suggests that systemic hormone levels, as a function of age, should be considered as an experimental variable in studies of corneal health and disease.

Therapie des Trockenen Auges

Die Therapie des Trockenen Auges stellt eine schwierige Aufgabe für den behandelnden Augenarzt dar. Fortschritte in unserem Verständnis der Risikofaktoren, der Ätiologie und Pathophysiologie des Trockenen Auges haben zu einer Weiterentwicklung der Behandlungsstrategien geführt. Vor Beginn der Therapie ist die korrekte Zuordnung in eine wässrig-muzinöse Tränenfilmdysfunktion (Mindersekretion), in eine lipidbedingte Tränenfilmdysfunktion (hyperevaporative Form durch eine abnormen Meibom-Drüsen-Physiologie) oder in eine variable Kombination wichtig. Unter Berücksichtigung aktueller Empfehlungen der DOG, des BVA und des TFOS DEWS II Unterausschusses wurde ein Behandlungsalgorithmus abgeleitet, der ein schrittweises Vorgehen je nach Schweregrad der Erkrankung darstellt.

The effect of hormone therapy on the ocular surface and intraocular pressure for postmenopausal women: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

The aim of the study was to investigate the impact of hormone therapy (HT) on the ocular surface and intraocular pressure in postmenopausal women.

METHODS

This systematic review and meta-analysis was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses Statement. PubMed, EMBASE, Cochrane Library of Systematic Reviews, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure were searched from inception to November 2019 without language restrictions. Only randomized controlled trials that evaluated the impact of HT on the ocular surface and intraocular pressure in postmenopausal women were eligible. The trials had to report at least one of the following outcomes: break-up time, Schirmer test, corneal staining, ocular surface symptom score, and intraocular pressure. Two investigators independently extracted the information, assessed the risk of bias, and evaluated the publication bias. All data were analyzed by Review Manager V.5.3. Sensitivity analysis and subgroup analysis were performed to find the source of heterogeneity and evaluate the different effects among subgroups.

RESULTS

Nine randomized controlled trials (N = 612) were included. The HT group showed significant improvements compared with the control group in break-up time (mean difference [MD] = 2.09, 95% confidence interval [CI] 1.00-3.19, P = 0.0002), Schirmer test without anesthesia (MD = 4.17, 95% CI 1.55-6.80, P = 0.002), Schirmer test with anesthesia (MD = 1.44, 95% CI 0.71-2.18, P = 0.0001), and corneal staining scores (standardized mean difference [SMD] = -0.85, 95% CI -1.39 to -0.30, P = 0.002). Moreover, significant beneficial effects were observed on all four symptoms, including dryness (SMD = -1.21, 95% CI -1.99 to -0.44, P = 0.002), foreign body sensation (SMD = -1.02, 95% CI -1.29 to -0.76, P < 0.00001), ocular fatigue (SMD = -1.74, 95% CI -2.12 to -1.36, P < 0.00001), and burning (SMD = -0.53, 95% CI -0.78 to -0.29, P < 0.0001) after HT. Subgroup analysis revealed that, in terms of break-up time, postmenopausal women younger than 55 years achieved more improvements (MD = 0.88, 95% CI 0.16-1.59, P = 0.02) than women older than 55 years old (MD = 2.60, 95% CI -1.34 to 6.55, P = 0.20), and the estrogen subgroup received more benefits (MD = 3.11, 95% CI 0.93-5.30, P = 0.005) than the estrogen plus progestogen subgroup (MD = 0.42, 95% CI -0.02 to 0.85, P = 0.06). Sensitivity analysis and subgroup analysis suggested that the heterogeneity might derive from the methodological quality, the age of participants, and the intervention of the control group. Intraocular pressure (MD = -1.54, 95% CI -3.39 to 0.32, P = 0.10) was not evidently decreased after HT. No more specific adverse events (relative risk  = 1.66, 95% CI 0.41-6.77, P = 0.48) were found in the HT group.

CONCLUSIONS

Our study revealed that HT could improve ocular surface function in postmenopausal women effectively and safely, especially for those who were younger than 55 years, and estrogen only showed more improvements than estrogen plus progestogen. The effectiveness of HT in treating dry eye in postmenopausal women is, however, still a controversial topic. In addition, we did not find HT led to a significant reduction of intraocular pressure.

Omega-3 and omega-6 polyunsaturated fatty acids for dry eye disease

BACKGROUND

Polyunsaturated fatty acid (PUFA) supplements, involving omega-3 and/or omega-6 components, have been proposed as a therapy for dry eye. Omega-3 PUFAs exist in both short- (alpha-linolenic acid [ALA]) and long-chain (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) forms, which largely derive from certain plant- and marine-based foods respectively. Omega-6 PUFAs are present in some vegetable oils, meats, and other animal products.

OBJECTIVES

To assess the effects of omega-3 and omega-6 polyunsaturated fatty acid (PUFA) supplements on dry eye signs and symptoms.

SEARCH METHODS

CENTRAL, Medline, Embase, two other databases and three trial registries were searched in February 2018, together with reference checking. A top-up search was conducted in October 2019, but the results have not yet been incorporated.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) involving dry eye participants, in which omega-3 and/or omega-6 supplements were compared with a placebo/control supplement, artificial tears, or no treatment. We included head-to-head trials comparing different forms or doses of PUFAs.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods and assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 34 RCTs, involving 4314 adult participants from 13 countries with dry eye of variable severity and etiology. Follow-up ranged from one to 12 months. Nine (26.5%) studies had published protocols and/or were registered. Over half of studies had high risk of bias in one or more domains. Long-chain omega-3 (EPA and DHA) versus placebo or no treatment (10 RCTs) We found low certainty evidence that there may be little to no reduction in dry eye symptoms with long-chain omega-3 versus placebo (four studies, 677 participants; mean difference [MD] -2.47, 95% confidence interval [CI] -5.14 to 0.19 units). We found moderate certainty evidence for a probable benefit of long-chain omega-3 supplements in increasing aqueous tear production relative to placebo (six studies, 1704 participants; MD 0.68, 95% CI 0.26 to 1.09 mm/5 min using the Schirmer test), although we did not judge this difference to be clinically meaningful. We found low certainty evidence for a possible reduction in tear osmolarity (one study, 54 participants; MD -17.71, 95% CI -28.07 to -7.35 mOsmol/L). Heterogeneity was too substantial to pool data on tear break-up time (TBUT) and adverse effects. Combined omega-3 and omega-6 versus placebo (four RCTs) For symptoms (low certainty) and ocular surface staining (moderate certainty), data from the four included trials could not be meta-analyzed, and thus effects on these outcomes were unclear. For the Schirmer test, we found moderate certainty evidence that there was no intergroup difference (four studies, 455 participants; MD: 0.66, 95% CI -0.45 to 1.77 mm/5 min). There was moderate certainty for a probable improvement in TBUT with the PUFA intervention relative to placebo (four studies, 455 participants; MD 0.55, 95% CI 0.04 to 1.07 seconds). Effects on tear osmolarity and adverse events were unclear, with data only available from a single small study for each outcome. Omega-3 plus conventional therapy versus conventional therapy alone (two RCTs) For omega-3 plus conventional therapy versus conventional therapy alone, we found low certainty evidence suggesting an intergroup difference in symptoms favoring the omega-3 group (two studies, 70 participants; MD -7.16, 95% CI -13.97 to -0.34 OSDI units). Data could not be combined for all other outcomes. Long-chain omega-3 (EPA and DHA) versus omega-6 (five RCTs) For long-chain omega-3 versus omega-6 supplementation, we found moderate certainty evidence for a probable improvement in dry eye symptoms (two studies, 130 participants; MD -11.88, 95% CI -18.85 to -4.92 OSDI units). Meta-analysis was not possible for outcomes relating to ocular surface staining, Schirmer test or TBUT. We found low certainty evidence for a potential improvement in tear osmolarity (one study, 105 participants; MD -11.10, 95% CI -12.15 to -10.05 mOsmol/L). There was low level certainty regarding any potential effect on gastrointestinal side effects (two studies, 91 participants; RR 2.34, 95% CI 0.35 to 15.54).

AUTHORS' CONCLUSIONS

Overall, the findings in this review suggest a possible role for long-chain omega-3 supplementation in managing dry eye disease, although the evidence is uncertain and inconsistent. A core outcome set would work toward improving the consistency of reporting and the capacity to synthesize evidence.

Hormone replacement therapy for dry eye disease patients: systematic review and meta-analysis

Hormone replacement therapy (HRT) is used by women to get relief from menopausal symptoms, including dry eyes. However, it is not entirely certain that HRT helps relieve dry eye disease (DED). The focus of this study is to systematically review the literature of the relevant studies to understand and determine the correlation between HRT and DED. Literature was systematically reviewed using Distiller SR. Meta-analysis was conducted using STATA 15.0. Standardized mean difference (SMD) and 95% confidence interval (CI) were calculated, and heterogeneity was assessed using statistics. Fixed-effect and random-effects models were computed based on heterogeneity. Subgroups analysis was done by follow-up. Our meta-analysis results indicated significant reduction in dry eye with HRT treatment at 1-month follow-up (SMD = -1.97; CI: -3.83, -0.11), a nonsignificant increase in tear breakup time at 3-month (SMD = -0.91; CI: -3.26, 1.44) and 6-month (SMD = -1.05; CI: -3.91, 1.82) follow-ups. Our meta-analysis results indicated a nonsignificant improvement in DED with HRT treatment at 1-month (SMD = -0.97; CI: -2.35, 0.4), 3-month (SMD = 0.19; CI: -0.91, 1.29), and 6-month (SMD = -0.48; CI: -1.39, 0.43) follow-ups.Overall, nonsignificant improvement in postoperative tear production, as well as tear breakup time, was seen after HRT treatment at follow-ups in dry eye patients. More good-quality randomized control trials are needed to make accurate conclusions.

Development and Long-Term Evaluation of Ocular Surface Conditions Using Ovariectomized Cynomolgus Monkey

OBJECTIVES

We aim to use the ovariectomized cynomolgus monkey to observe the effect of long-term changes of sex hormone levels on ocular surface.

METHODS

Six healthy adolescent cynomolgus monkeys were randomly assigned to control and experimental groups (n=3/group). Bilateral ovariectomy was performed in experimental group, and sham operation was performed on control animals with their ovaries reserved. The concentrations of serum estradiol and testosterone in cynomolgus monkeys' lower-limb venous were detected by radioimmunoassay before surgery, and at 6, 12, 18, and 24 months after the surgery. Phenol red cotton thread test, tear osmolarity, corneal fluorescein staining, and conjunctival impression cytology were performed to evaluate the ocular surface conditions before surgery, and at 6, 12, 18, and 24 months after the surgery. The histological examinations of the bulbar conjunctiva and labial glands tissues were performed at 12 and 24 months after the surgery.

RESULTS

There were no significant differences in the serum level of estradiol and testosterone between the experimental and control groups before surgery, at 6, and 12 months after surgery (P>0.05). Serum level of estradiol and testosterone were significantly less in experimental versus control group at 18 and 24 months after surgery (P<0.05). There was no significant differences in phenol red cotton between the experimental and control groups before surgery, at 6, 12, 18, and 24 months after surgery (P>0.05). Tear osmolarity had no significant differences between experimental and control group before surgery (P>0.05), and it was significantly higher in experimental versus control group at all four time-points after surgery (P<0.05). The number of conjunctival goblet cells had no significant differences between experimental and control group before surgery, at 6 months after surgery (P>0.05), and it was significantly lower in experimental versus control group at 12, 18, and 24 months after surgery (P<0.05). There were no significant differences in the corneal fluorescein staining score between the experimental and control groups before surgery, at 6, 12, and 18 months after surgery (P>0.05), and it was higher in experimental than control group at 24 months after surgery (P<0.05). In addition, inflammatory cell infiltration in bulbar conjunctiva and labial glands tissues was observed in experimental group and was unobserved in control group at 24 months after surgery.

CONCLUSIONS

Ovariectomy led to decreased sex hormone levels in cynomolgus monkey. In turn, tear osmolarity was increased, the number of conjunctival goblet cells were decreased, the corneal fluorescence staining was increased, and the pathological examination of the bulbar conjunctiva and labial glands tissues were abnormal, phenol red cotton thread test did not change significantly.

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.

Longitudinal changes in dry eye symptoms and signs following lifitegrast therapy and relationship to tear osmolarity

Background

This study measured longitudinal changes in dry eye disease (DED) symptoms and signs following lifitegrast therapy and assessed their relationship to tear osmolarity to test the hypothesis that a decline in tear osmolarity is a reliable leading indicator of subsequent improvement in DED symptoms and signs after initiating lifitegrast treatment.

Methods

This phase IV, prospective, single-arm, open-label, 12-week study enrolled subjects aged ≥18 years with eye dryness score ≥40 (0–100 VAS) and tear osmolarity ≥308 mOsm/L. Subjects were prescribed lifitegrast ophthalmic solution 5%, twice daily in each eye. DED symptoms were assessed via VAS at baseline and 2, 6, and 12 weeks. Signs included tear osmolarity, meibomian gland dysfunction, tear breakup time, and fluorescein corneal staining. In post-hoc analysis, subjects with ≥5 mOsm/L decrease in osmolarity over 12 weeks were Responders.

Results

Of 26 subjects in the intent-to-treat population, 23 were female; mean age was 67.4 years. Baseline mean±SD eye dryness was 68.7±16.5 and tear osmolarity was 317.8±8.5 mOsm/L. All seven symptoms (dryness, burning, foreign body sensation, pain, photophobia, itching, blurred vision) declined significantly (P<0.01) from baseline to 6 and 12 weeks. Signs did not change significantly. For 13 Responders, tear osmolarity decreased from baseline to 12 weeks (319.2±8.5 to 300.6±12.3 mOsm/L, P<0.001) and corneal staining trended toward improvement (1.1±0.9 to 0.6±0.7, P=0.136). Among Nonresponders, osmolarity increased from 316.4+8.7 to 329.6+13.9 (P<0.01) and corneal staining showed no change (1.3±0.8 to 1.0±0.7 at 12 weeks, P=0.293).

Conclusions

Lifitegrast reduced DED symptoms among subjects with moderate-to-severe disease (severity defined by VAS for eye dryness). Potential reasons that may underlie the dichotomous effect of drug treatment on tear osmolarity are discussed.

[Tear film analysis and evaluation of optical quality: A review of the literature (French translation of the article)]

Dry eye is a complex multifactorial disease of the ocular surface and tears. It is associated with ocular surface symptoms and is one of the most common causes for ophthalmologic consultation. Despite their frequent use in clinical practice, the usual tests to evaluate dry eye and ocular surface disease-history of symptoms, tear break-up time (TBUT), Meibomian gland evaluation, corneal fluorescein staining, Schirmer test-have shown low reproducibility and reliability. In addition, subjective symptoms are often weakly or poorly correlated with objective signs. Since the tear film is the first system through which light must pass, the optical quality of the eye is highly dependent on the homogeneity of the tear film. Various investigative methods have been developed to evaluate both the structural and functional quality of the tear film, such as corneal topography, interferometry, tear meniscus measurement, evaporation rate, tear osmolarity and even aberrometry. Some are easily accessible to clinicians, while others remain in the field of clinical research. All of these tests provide a better understanding of the pathophysiology of the tear film. This review hopes to provide an overview of the existing tests and their role in evaluating the significance of the tear film in visual function.

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.

Tear film analysis and evaluation of optical quality: A review of the literature

Dry eye is a complex multifactorial disease of the ocular surface and tears. It is associated with ocular surface symptoms and is one of the most common causes for ophthalmologic consultation. Despite their frequent use in clinical practice, the usual tests to evaluate dry eye and ocular surface disease-history of symptoms, tear break-up time (TBUT), Meibomian gland evaluation, corneal fluorescein staining, Schirmer test-have shown low reproducibility and reliability. In addition, subjective symptoms are often weakly or poorly correlated with objective signs. Since the tear film is the first system through which light must pass, the optical quality of the eye is highly dependent on the homogeneity of the tear film. Various investigative methods have been developed to evaluate both the structural and functional quality of the tear film, such as corneal topography, interferometry, tear meniscus measurement, evaporation rate, tear osmolarity and even aberrometry. Some are easily accessible to clinicians, while others remain in the field of clinical research. All of these tests provide a better understanding of the pathophysiology of the tear film. This review hopes to provide an overview of the existing tests and their role in evaluating the significance of the tear film in visual function.

The role of endocrine disruptors in ocular surface diseases

Endocrine disruptors are a group of compounds that occur in increasing amounts in the environment. These compounds change the hormone homeostasis of the target organs regulated by those hormones, mostly by binding to their receptors and affecting their signaling pathways. Among the hormones altered by endocrine disruptors are sex hormones, thyroid hormones, and insulin. Studies have documented abnormalities in the reproductive and metabolic systems of various animal species exposed to endocrine disruptors. Endocrine disruptors can play a significant role in ocular diseases once hormone deficiency or excess are involved in the mechanism of that disease. Cataracts, dry eye disease and retinal diseases, such as macular hole and diabetic retinopathy, are some of the frequent problems where hormones have been implicated. We found that some compounds function as endocrine disruptors in the metabolism of body organs and systems. The increasing frequency of dry eye and other ocular diseases indicates the need to better investigate the potential relationships beyond the isolated associations mentioned by patients and documented as rare case reports. The evidence from case-control studies and experimental assays can provide the information necessary to confirm the endocrine effects of these chemicals in the pathophysiology of dry eye disease. We hypothesize that endocrine disruptors may contribute to the increase of ocular diseases, such as dry eye disease, in recent years.

Sex hormone therapy's effect on dry eye syndrome in postmenopausal women: A meta-analysis of randomized controlled trials

THE PURPOSE OF THE STUDY T: o assess the efficacy of sex hormone therapy in the treatment of dry eye syndrome in postmenopausal women.The following electronic databases were searched without language restrictions: PubMed, Embase, Cochrane, and the Chinese Biomedical Database. Two reviewers collected all the literature, which was searched for relevance in English and Chinese from January 1990 to July 2017. Both of the reviewers screened documents independently, identifying the studies that met the inclusion criteria. Then, the included studies were evaluated, and the data were extracted and conversed dependently. Finally, Review Manager 5.3 (offered by the Cochrane collaboration) was used to complete the meta-analysis. An integrated mean difference (MD) with its corresponding 95% confidence interval (CI) was calculated.A total of 358 patients with dry eye were enrolled in 7 randomized controlled trials (RCTs). We observed statistically significant improvements in the Schirmer's test scores (MD, 2.06; 95% CI, 0.74-4.46; I = 97%; P = .006) after sex hormone treatment. However, the scores for tear breakup time (TBUT) (MD, 1.28; 95% CI, -1.03 to 4.68; I = 99%; P = .21) and the ocular comfort index (OCI) (MD, -1.12; 95% CI, -4.42 to 1.98; I = 95%; P = .48) were not improved.This meta-analysis of 7 RCTs suggests that sex hormone therapy may be associated with better Schirmer's test scores. However, no significant differences were detected in the TBUT and OCI test scores. Consequently, sex hormone therapy has a potentially useful role in the effective management of postmenopausal women with dry eye syndrome.

TFOS DEWS II Sex, Gender, and Hormones Report

One of the most compelling features of dry eye disease (DED) is that it occurs more frequently in women than men. In fact, the female sex is a significant risk factor for the development of DED. This sex-related difference in DED prevalence is attributed in large part to the effects of sex steroids (e.g. androgens, estrogens), hypothalamic-pituitary hormones, glucocorticoids, insulin, insulin-like growth factor 1 and thyroid hormones, as well as to the sex chromosome complement, sex-specific autosomal factors and epigenetics (e.g. microRNAs). In addition to sex, gender also appears to be a risk factor for DED. "Gender" and "sex" are words that are often used interchangeably, but they have distinct meanings. "Gender" refers to a person's self-representation as a man or woman, whereas "sex" distinguishes males and females based on their biological characteristics. Both gender and sex affect DED risk, presentation of the disease, immune responses, pain, care-seeking behaviors, service utilization, and myriad other facets of eye health. Overall, sex, gender and hormones play a major role in the regulation of ocular surface and adnexal tissues, and in the difference in DED prevalence between women and men. The purpose of this Subcommittee report is to review and critique the nature of this role, as well as to recommend areas for future research to advance our understanding of the interrelationships between sex, gender, hormones and DED.

TFOS DEWS II Tear Film Report

The members of the Tear Film Subcommittee reviewed the role of the tear film in dry eye disease (DED). The Subcommittee reviewed biophysical and biochemical aspects of tears and how these change in DED. Clinically, DED is characterized by loss of tear volume, more rapid breakup of the tear film and increased evaporation of tears from the ocular surface. The tear film is composed of many substances including lipids, proteins, mucins and electrolytes. All of these contribute to the integrity of the tear film but exactly how they interact is still an area of active research. Tear film osmolarity increases in DED. Changes to other components such as proteins and mucins can be used as biomarkers for DED. The Subcommittee recommended areas for future research to advance our understanding of the tear film and how this changes with DED. The final report was written after review by all Subcommittee members and the entire TFOS DEWS II membership.

Sleep and mood disorders in women with dry eye disease

The aim of the present study was to evaluate sleep and mood disorders in women aged 30–69 with dry eye disease (DED). All subjects underwent corneal examinations, with 890 completing a questionnaire regarding symptoms of DED and 213 completing both the Pittsburgh Sleep Quality Index (PSQI) and the Hospital Anxiety and Depression Scale (HADS) questionnaires. Subjects were then divided into three groups based on age (younger [30–45 years], perimenopausal [46–55 years], and older [56–69 years]), and comparisons were made among groups in subjects with and without DED. PSQI scores were significantly worse in subjects with (6.1 ± 2.9) than without (4.9 ± 2.7) DED (P = 0.003) and, in the younger group, HADS scores were worse in those with (13.2 ± 6.0) than without DED (9.7 ± 6.0) (P = 0.020). In contrast, there were no differences in mood indices between those with and without DED in the other groups. PSQI score was significantly correlated with HADS rather than ocular findings. In conclusion, sleep quality had deteriorated in women with DED. However, mood problems contributed more to sleep quality than ocular status, especially in those with DED in the younger group.

The Effect of Hormone Replacement Therapy on Dry Eye Syndrome Evaluated with Schirmer Test and Break-Up Time

Hormone replacement therapy (HRT) for dry eye syndrome (DES) is controversial in clinical practice. The goal of this study was to review relevant studies and analyze the pooled data to determine whether HRT is effective for DES. In this study, a literature search of PubMed, Embase, and Cochrane databases up to May 2015 was performed, with the search restricted to English language publications. The studies were screened after reading the abstract and full text. Only studies related to the effect of HRT on DES were included in the meta-analysis. Results of Schirmer tests with and without anesthetics and tear break-up time (BUT) values data were extracted and entered into RevMan software to meta-analyze the overall effect of HRT on DES. A total of 43 studies were identified, and 21 of these studies were found to be related to the effect of HRT on DES. Ultimately, 5 studies were included in the final meta-analysis. The pooled results revealed that HRT can affect Schirmer test results without anesthetics but does not affect Schirmer test results with anesthetics and BUT. The results indicate that HRT might improve DES symptoms when measuring basal tear production without anesthesia.

Effects of androgen on ultrastructure of corneal epithelium and function of the tear film in BALB/c mice

PURPOSE

The aim of this study was to investigate the effects of androgen on the ultrastructure of corneal epithelium and function of the tear film in a mouse model.

METHODS

Healthy adult male BALB/c mice were randomly apportioned to normal control, sham-operated, or orchiectomy groups. In the orchiectomy group, 4 subgroups with treatment [blank group, dihydrotestosterone (DHT) eye drop group, DHT injection group, and dimethyl sulfoxide (DMSO) eye drop group] were further established at 3 weeks after orchiectomy. Tear production, tear break-up time, and corneal fluorescein staining were evaluated in all groups at multiple time points. Serum androgen concentrations were measured by competitive radioimmunoassay, and ultrastructure of corneal epithelial cells was examined by transmission electron microscopy.

RESULTS

Before orchiectomy, the mean serum concentration of androgen was 43.4 ng/μL, which decreased to approximately 0 ng/μL at 1 week after orchiectomy. Significantly less tear production, shorter tear break-up time, higher corneal fluorescein staining score, shorter and flattened corneal epithelial microvilli, and looser intercellular desmosomes were observed in mice after orchiectomy. DHT supplements increased serum androgen levels, and some of the tear film functions and morphological features of microvilli and desmosomes were gradually close to those at baseline in the DHT injection group.

CONCLUSIONS

Persistent corneal staining, decreased tear production, short break-up time, and unhealthy corneal ultrastructure were observed in mice that received orchiectomy for at least 8 weeks. A mouse that received orchiectomy could be used as a dry eye model. Exogenous DHT supplement improved corneal epithelial ultrastructure and tear film function in this model.

Estradiol induces osteoprotegerin expression by human dental pulp cells

Estrogen deficiency is associated with increased inflammation related periapical bone resorption. The present study aimed to evaluate the effect and intracellular mechanism(s) of estrogen on osteoprotegerin (OPG) and receptor activator of nuclear factor κB ligand (RANKL) expression in human dental pulp cells (HDPs). HDPs were treated with estradiol at a concentration of 0.1-10 μM. The results showed that estradiol induced OPG expression at both the mRNA and protein levels in a dose-dependent manner. However, no influence on RANKL expression was observed. An estrogen receptor (ER) inhibitor failed to attenuate the estradiol-induced OPG expression. Furthermore, ER-α and ER-β agonists did not simulate estradiol's effects on OPG expression by HDPs. However, a significant OPG upregulation was observed in HDPs treated with an estradiol-BSA conjugate or a GPR30 agonist. An ERK inhibitor significantly enhanced estradiol-induced OPG expression, whereas a p38 inhibitor markedly attenuated this expression. In conclusion, OPG expression by HDPs may be regulated by estradiol binding a membrane receptor and the balance between the ERK and p38 signaling pathways.

Aging: a predisposition to dry eyes

Dry eye syndrome is a disease of the ocular surface and tear film that is prevalent in older adults. Even though the degree of visual acuity loss in dry eye patients is commonly mild-to-moderate, in the aging population, this minimal change in visual status can lead to a significant decrease in visual function and quality of life. A healthy ocular surface is maintained by appropriate tear production and tear drainage, and deficiencies in this delicate balance can lead to dryness. In the aging eye, risk factors such as polypharmacy, androgen deficiency, decreased blink rates, and oxidative stress can predispose the patient to developing dry eye that is frequently more severe, has higher economic costs, and leads to worse consequences to the well-being of the patient. Understanding why elderly patients are at higher risk for developing dry eyes can provide insights into the diagnosis and management of the growing number of older adults struggling with dry eye and minimize the burden of disease on our aging population.

New testing options for diagnosing and grading dry eye disease

PURPOSE

To describe new options for diagnosis and severity grading of dry eye disease.

DESIGN

Perspective on technological advancements to identify tear dysfunction and their value in diagnosing and grading dry eye disease.

METHODS

Evidence is presented on new and evolving technologies to measure tear stability, composition, and meniscus height and their role in dry eye diagnosis and therapeutic efficacy grading is assessed.

RESULTS

Evolving concepts regarding pathogenesis and new technologies to evaluate the tears and ocular surface have improved the ability to diagnose, classify, and grade the severity of dry eye disease. New technologies include noninvasive imaging of tear stability and tear meniscus height as a measure of tear volume and tear composition (osmolarity, lacrimal factors, inflammatory mediators, growth and differentiation factors). Approved tests, such as tear osmolarity and tear imaging, are being integrated into clinical practice and may eventually supplant certain traditional tests that have greater variability and less sensitivity. Other tests, such as molecular assays of tears and conjunctival cells, are currently being used in studies investigating pathogenesis and therapeutic mechanism of action. They may eventually translate to routine clinical practice.

CONCLUSIONS

New technologies have emerged that can noninvasively evaluate the tears and measure disease-associated compositional changes. These tests are being integrated into clinical practice and therapeutic trials for diagnosis, classification, and severity grading of dry eye disease.

Diagnosis of dry eye disease and emerging technologies

Dry eye is one of the most commonly encountered problems in ophthalmology. Signs can include punctate epithelial erosions, hyperemia, low tear lakes, rapid tear break-up time, and meibomian gland disease. Current methods of diagnosis include a slit-lamp examination with and without different stains, including fluorescein, rose bengal, and lissamine green. Other methods are the Schirmer test, tear function index, tear break-up time, and functional visual acuity. Emerging technologies include meniscometry, optical coherence tomography, tear film stability analysis, interferometry, tear osmolarity, the tear film normalization test, ocular surface thermography, and tear biomarkers. Patient-specific considerations involve relevant history of autoimmune disease, refractive surgery or use of oral medications, and allergies or rosacea. Other patient considerations include clinical examination for lid margin disease and presence of lagophthalmos or blink abnormalities. Given a complex presentation and a variety of signs and symptoms, it would be beneficial if there was an inexpensive, readily available, and reproducible diagnostic test for dry eye.

Emerging drugs for the treatment of dry eye disease

INTRODUCTION

Dry eye disease (DED) is a common, age-related ocular condition that in its mildest forms causes bothersome symptoms of ocular discomfort, fatigue, and visual disturbance that interfere with quality of life and in its more severe forms causes chronic pain and fluctuating vision. Though it is highly prevalent and costs billions of dollars to manage, current treatments have largely been inadequate, making it a frustrating condition, both for physicians and patients alike.

AREAS COVERED

This article will cover the recently discovered pathophysiology of DED that has prompted investigators to explore new molecules that target the core mechanisms that drive DED. These include anti-inflammatory/immune-modulatory drugs, secretagogues, lubricant, hormones, and autologous serum. Their potential mechanism of action and data from recent trials on efficacy/safety will be reviewed.

EXPERT OPINION

The emerging drugs have a vast range of putative mechanisms of action that may not only provide symptomatic relief but may potentially break the vicious cycle of DED and provide long-lasting cure. Current and future research may change our perspective on DED and redefine its treatment algorithms.