Dry Eye Disease: A Review of Epidemiology in Taiwan, and its Clinical Treatment and Merits

Recent updates on ocular disease management with ophthalmic ointments

Ophthalmic diseases can result in permanent vision loss and blindness. Convenient topical and systemic treatments are preferred to address these sight-threatening conditions. However, the unique anatomy of the eye presents challenges for drug delivery. Various ophthalmic ointment formulations have been developed to enhance bioavailability in the eye to prolong residence time and improve corneal permeability. This article explores a wide range of ocular diseases affecting individuals globally and how ointments are used to manage them. From eye to ocular barriers, this review focuses on published scientific research and formulation strategies for severe ocular complications using conventional topical ointments. Additionally, it delves through patented technologies and marketed formulations supporting the use of ointments in ocular drug delivery.

Predicting Risks of Dry Eye Disease Development Using a Genome-Wide Polygenic Risk Score Model

Purpose

The purpose of this study was to conduct a large-scale genome-wide association study (GWAS) and construct a polygenic risk score (PRS) for risk stratification in patients with dry eye disease (DED) using the Taiwan Biobank (TWB) databases.

Methods

This retrospective case-control study involved 40,112 subjects of Han Chinese ancestry, sourced from the publicly available TWB. Cases were patients with DED (n = 14,185), and controls were individuals without DED (n = 25,927). The patients with DED were further divided into 8072 young (<60 years old) and 6113 old participants (≥60 years old). Using PLINK (version 1.9) software, quality control was carried out, followed by logistic regression analysis with adjustments for sex, age, body mass index, depression, and manic episodes as covariates. We also built PRS prediction models using the standard clumping and thresholding method and evaluated their performance (area under the curve [AUC]) through five-fold cross-validation.

Results

Eleven independent risk loci were identified for these patients with DED at the genome-wide significance levels, including DNAJB6, MAML3, LINC02267, DCHS1, SIRPB3P, HULC, MUC16, GAS2L3, and ZFPM2. Among these, MUC16 encodes mucin family protein. The PRS model incorporated 932 and 740 genetic loci for young and old populations, respectively. A higher PRS score indicated a greater DED risk, with the top 5% of PRS individuals having a 10-fold higher risk. After integrating these covariates into the PRS model, the area under the receiver operating curve (AUROC) increased from 0.509 and 0.537 to 0.600 and 0.648 for young and old populations, respectively, demonstrating the genetic-environmental interaction.

Conclusions

Our study prompts potential candidates for the mechanism of DED and paves the way for more personalized medication in the future.

Translational Relevance

Our study identified genes related to DED and constructed a PRS model to improve DED prediction.

Inflammatory bowel disease and the associated risk of dry eye and ocular surface injury: a nationwide matched cohort study

BACKGROUND

Inflammatory bowel disease (IBD) is associated with lacrimal gland dysfunction and ocular inflammation. The objective of this research was to elucidate the temporal relationships between IBD, dry eye disease (DED), and corneal surface damage.

METHODS

In a matched nationwide cohort study, we evaluated the risk of DED and corneal surface damage associated with IBD. Multivariable Cox proportional hazards regression analyses were implemented to estimate the risk of ocular complications.

RESULTS

A total of 54,293 matched pairs were included for analyses. The median follow-up time was 8.3 years (interquartile range: 5.5 - 10.5). The period incidence of DED was 8.18 and 5.42 per 1000 person-years in the IBD and non-IBD groups, respectively. After adjusting for confounders, statistically significant associations were found between IBD and DED [adjusted hazard ratio (aHR): 1.43, 95% confidence interval (CI): 1.35 - 1.51, p < 0.0001], Sjögren's syndrome-related (aHR: 1.67, 95% CI:1.46 - 1.90, p < 0.0001) and non-Sjögren's syndrome-related subtypes (aHR: 1.38, 95% CI: 1.30 - 1.46, p < 0.0001). Furthermore, increased risks of corneal surface damage (aHR: 1.13, 95% CI: 1.03 - 1.24, p = 0.0094) among the patients with IBD were observed when compared with the controls. Other independent factors associated with corneal surface damage were age (aHR: 1.003), sex (male vs. female, aHR: 0.85), and monthly insurance premium (501-800 vs. 0-500 U.S. dollars, aHR: 1.45; ≥ 801 vs. 0-500 U.S. dollars, aHR: 1.32).

CONCLUSIONS

Our results suggested that IBD was an independent risk factor for DED and ocular surface damage. Clinical strategies are needed to prevent visual impairment or losses in these susceptible patients.

Klotho Null Mutation Indirectly Leads to Age-Related Lacrimal Gland Degeneration in Mutant Mice

The Klotho null mutation is known to lead to accelerated aging in many organs, but its effects on tear secretion and lacrimal gland (LG) senescence have not been addressed. This study investigated whether the Klotho null mutation would lead to a dry eye status and the outcome of LG without Klotho function. The Klotho (-/-) mutant mice showed reduced LG size and tear volume on the 8th week, as compared to their littermates (+/+, +/-). Hematoxylin-Eosin and Masson's trichrome staining were performed to determine morphological changes and collagen deposition. Traits of LG aging, including acinar atrophy, thickened capsules, and more collagen depositions, were observed. Immunohistochemical detections for Klotho, α-SMA, MDA, 8-OHdG, vasoactive intestinal polypeptide (VIP), tyrosine hydroxylase (TH), MMP-2, MMP-9, and FGF-23 were performed and compared among the three genotypes (+/+, +/-, -/-) at 6 and 8 weeks of age for mechanism analyses. Unexpectedly, the Klotho protein was not detected in the LG of all the three genotypes, indicating indirect effects from the Klotho null mutation. Further analyses showed abundant MDA and 8-OHdG detected in the Klotho (-/-) LG on the 8th week, indicating elevated oxidative stress. In addition, both sympathetic and parasympathetic neural transducing activities, as represented by TH and VIP expression, respectively, and α-SMA were increased in LGs with Klotho mutations. Furthermore, MMP-2 and MMP-9 expression were elevated, with FGF-23 expression being decreased on the 8th week in the Klotho (-/-) LG. In conclusion, characteristics of age-related LG degeneration were found in the Klotho null mutant mice. These traits support the use of Klotho mutant mice as a model of age-related dry eye disease.

Systemic Lupus Erythematosus and Risk of Dry Eye Disease and Corneal Surface Damage: A Population-Based Cohort Study

Systemic lupus erythematosus (SLE) potentially involves multiple parts of the ocular system, including the lacrimal glands and the cornea. The present study sought to assess the risk of aqueous-deficient dry eye disease (DED) and corneal surface damage in patients with SLE. We conducted a population-based cohort study using Taiwan's National Health Insurance research database to compare the risks of DED and corneal surface damage between subjects with and without SLE. Proportional hazard regression analyses were used to calculate the adjusted hazard ratio (aHR) and 95% confidence interval (CI) for the study outcomes. The propensity score matching procedure generated 5083 matched pairs with 78,817 person-years of follow-up for analyses. The incidence of DED was 31.90 and 7.66 per 1000 person-years in patients with and without SLE, respectively. After adjusting for covariates, SLE was significantly associated with DED (aHR: 3.30, 95% CI: 2.88-3.78, p < 0.0001) and secondary Sjögren's syndrome (aHR: 9.03, 95% CI: 6.86-11.88, p < 0.0001). Subgroup analyses demonstrated that the increased risk of DED was augmented among patients with age < 65 years and female sex. In addition, patients with SLE had a higher risk of corneal surface damage (aHR: 1.81, 95% CI: 1.35-2.41, p < 0.0001) compared to control subjects, including recurrent corneal erosion (aHR: 2.98, 95% CI: 1.63-5.46, p = 0.0004) and corneal scar (aHR: 2.23, 95% CI: 1.08-4.61, p = 0.0302). In this 12-year nationwide cohort study, we found that SLE was associated with increased risks of DED and corneal surface damage. Regular ophthalmology surveillance should be considered to prevent sight-threatening sequelae among patients with SLE.

The Relationship Between Caffeine Intake and Dry Eye Disease

PURPOSE

The aim of this study was to determine the association between caffeine intake and dry eye disease (DED) in the large, population-based LifeLines cohort in the Netherlands.

METHODS

DED was cross-sectionally assessed in 85,302 participants (59% female participants) using the Women's Health Study dry eye questionnaire. Dietary caffeine was calculated from the intake of coffee, tea, cola, and energy drinks. Logistic regression was used to investigate the relationship between DED and caffeine, correcting for demographic variables, smoking status, alcohol intake, and 48 comorbidities of DED.

RESULTS

The mean (SD; range) age of participants was 50.7 years (12.4; 18-96), and 50,339 (59%) were female. The mean (SD) caffeine intake was 285 (182) mg/d. After correcting for demographics, body mass index, smoking status, and alcohol intake, higher caffeine intake was associated with a decreased risk of Women's Health Study-defined DED [odds ratio (OR) 0.971 per 100 mg/d, 95% CI, 0.956-0.986, P < 0.0005]. When additionally adjusting for medical comorbidities, no significant effect was observed (OR 0.985, 95% CI, 0.969-1.001, P = 0.06). Caffeine's effect on DED was similar in male and female participants and independent of sleep quality and stress at work. Decaffeinated coffee intake was significantly associated with an increased risk of DED, when adjusted for caffeinated coffee, demographics, alcohol intake, smoking status, and comorbidities (OR 1.046 per cup/d, 95% CI, 1.010-1.084, P = 0.01). None of the beverages were significantly associated with the risk of DED, when correcting for intake of the other caffeinated beverages, demographics, smoking status, alcohol intake, and all comorbidities.

CONCLUSIONS

Dietary caffeine intake does not seem to be a risk factor for DED in the general population.

Rheumatoid Arthritis Associated with Dry Eye Disease and Corneal Surface Damage: A Nationwide Matched Cohort Study

Rheumatoid arthritis is potentially connected to ocular disorders, such as corneal inflammation and lacrimal gland destruction. This study aimed to evaluate the risk of dry eye disease (DED) and corneal surface damage among patients with rheumatoid arthritis. In a nationwide cohort study, we utilized Taiwan’s National Health Insurance research database and conducted propensity score matching to compare the risks of DED and corneal surface damage between patients with and without rheumatoid arthritis. Proportional hazards regression analyses were used to calculate the adjusted hazard ratio (aHR) and 95% confidence interval (CI) for the outcomes of interest. The matching procedure generated 33,398 matched pairs with 501,377 person-years of follow-up for analyses. The incidence of DED was 23.14 and 10.25 per 1000 person-years in patients with and without rheumatoid arthritis, respectively. After adjusting for covariates, rheumatoid arthritis was significantly associated with DED (aHR: 2.03, 95% CI: 1.93−2.13, p < 0.0001). The association was generally consistent across the subgroups of age, sex, use of systemic corticosteroids, and different comorbidity levels. In addition, patients with rheumatoid arthritis had a higher risk of corneal surface damage (aHR: 1.36, 95% CI: 1.21−1.51, p < 0.0001) compared to control subjects. Other independent factors for corneal surface damage were age and sleeping disorders. Rheumatoid arthritis was associated with an increased risk of DED and corneal surface damage. Ophthalmological surveillance is required to prevent vision-threatening complications in this susceptible population.

Lifestyle and Symptom Risk Factors for Dry Eye Disease in Asian Gout Population: A Population-Based Case-Control Study

We aim to investigate the lifestyle and symptom factors related to dry eye disease (DED) presence in patients with persistent gout using the Taiwan Biobank (TWB) database. A retrospective case-control study was conducted, and patients with a history of gout longer than 10 years were enrolled in the persistent-gout group. Each persistent-gout patient was age- and sex-matched to two non-gout individuals who served as the control group, and we included a total of 973 and 1946 patients in the persistent-gout group and non-gout groups. The main outcome of our study is the presence of DED and the distribution of several lifestyle and symptom risk factors of DED in persistent-gout and non-gout individuals. Logistic regression considering the age and sex and interaction test was applied to estimate the correlation of each lifestyle and symptom risk factor to DED in the two groups. A total of 95 and 140 DED events were found in the persistent-gout and non-gout groups, with a significantly higher percentage in the persistent-gout population (aOR: 1.167, 95% CI: 1.073-3.855, p = 0.0415). The visual display terminal (VDT) user (p = 0.0026) and persistent alcohol drinking (p = 0.0384) were associated with DED more often in the persistent-gout population than the non-gout population. Moreover, the percentages of DED in the patients with gout intervals of 10-20 years and more than 20 years were statistically insignificant (aOR: 1.042, 95% CI: 0.886-1.910, p = 0.5279). In conclusion, VDT usage and persistent alcohol drinking are prominent lifestyle and symptom risk factors for DED occurrence in patients who have experienced gout for more than 10 years.

Neurostimulation for dry eye disease

PURPOSE OF REVIEW

To review the neuroanatomy and physiology of the basal and reflex tearing and present the available and developing therapies using the concept of neurostimulation in dry eye disease (DED).

RECENT FINDINGS

The most prevalent current DED treatments seek to supplement low tear volume and tear components or reduce inflammation. Neurostimulation is a unique approach gaining momentum in recent years, geared toward increasing the production of all basal tear components by stimulating the nerves responsible for producing the various tear components. The neuroanatomy of the lacrimal unit provides several possible access points to stimulate tear production through two arms of the sensory trigeminal nerves. Modes of stimulation include chemical or energy in electrical or magnetic form. Research thus far has shown that neurostimulation can achieve lacrimal, goblet cell, and meibomian gland stimulation. Subjectively it improves symptoms of DED. Clinically, neurostimulation has improved the signs and symptoms of DED by increasing basal tear production and tear volume.

SUMMARY

Neurostimulation using electrical, mechanical, or chemical means is a novel concept to increase tear production and was demonstrated to be an effective, safe, and well-tolerated method for managing DED.

Effectiveness of acupuncture at acupoint BL1 (Jingming) in comparison with artificial tears for moderate to severe dry eye disease: a randomized controlled trial

BACKGROUND

The global incidence of dry eye disease (DED) is very high. DED seriously affects the quality of life of patients; however, the current curative effect of medicine for moderate to severe DED is poor. This randomized clinical trial was planned to investigate the effect of acupuncture compared with artificial tears (AT) on moderate to severe DED.

METHODS

A randomized clinical trial was performed at 2 hospitals in China. 120 DED patients were randomly equally divided into an acupuncture and an artificial tear group. Either acupuncture or artificial tears was performed for an 8-week period, and a 24-week follow-up was performed. The primary outcome measure was the Schirmer-I test (SIT) change from baseline. The secondary outcome measures included the numerical rating scale (NRS) change from baseline for improvement in ocular symptoms, the ocular surface disease index (OSDI), the tear-film break-up time (TBUT), corneal fluorescein staining (CFS), and acupuncture acceptability. Adverse events also were monitored and documented.

RESULTS

For the primary outcome, the mean changes from baseline in the SIT values were significantly different between the acupuncture (5.75 [2.53-9.75]) and AT (0.52 [- 1.18-2.46]) groups at week 8 with a between difference of 5.23 (P < 0.05). Between-group differences of 8.49 in OSDI score change from baseline differed significantly at week 8 (P < 0.05). However, between-group differences of the changes in the average symptom NRS score, TBUT, and CFS did not differ significantly at week 8. Five cases experienced acupuncture-related adverse events.

CONCLUSIONS

This randomized clinical trial found that acupuncture at BL1 significantly promoted tear secretion. Acupuncture showed greater benefits than AT for moderate to severe DED. However, the study findings warrant verification.

TRIAL REGISTRATION

Registration number: ChiCTR1800015831. Name of trial registry: Efficacy and safety of acupuncture in the treatment of moderate to severe dry eye disease: a randomized controlled trial. Registered on 23 April 2018 ( https://clinicaltrials.gov/ ).

Derivative Three-Dimensional Synchronous Fluorescence Analysis of Tear Fluid and Their Processing for the Diagnosis of Glaucoma

Background: Sensitive and rapid diagnosis of the early stages of glaucoma from tear fluid is a great challenge for researchers. Methods: Tear fluid was analyzed using three-dimensional synchronous fluorescence spectroscopy (3D-SFS). Our previously published results briefly describe the main methods which applied the second derivative to a selected synchronous spectrum Δλ = 110 nm in distinguishing between healthy subjects (CTRL) and patients with glaucoma (POAG). Results: In this paper, a novel strategy was used to evaluate three-dimensional spectra from the tear fluid database of our patients. A series of synchronous excitation spectra were processed as a front view and presented as a single curve showcasing the overall fluorescence profile of the tear fluid. The second derivative spectrum provides two parameters that can enhance the distinction between CTRL and POAG tear fluid. Conclusions: Combining different types of 3D-SFS data can offer interesting and useful diagnostic tools and it can be used as input for machine learning and process automation.

Experience of Dry Eye Patients With Anxiety and Depression: A Qualitative Study

Purpose

Anxiety and depression are important risk factors for dry eye disease (DED). The aims of this research are to identify the cause of anxiety and depression in DED patients and explore their strategies in coping with DED.

Methods

This is a qualitative study based on semi-structured interviews, and the interviews records were analyzed through inductive thematic analysis. Participants were recruited from a large university affiliated hospital in the north of China, including 47 participants affected by depression and anxiety.

Results

Analysis revealed the causes of anxiety and depression in DED patients could be divided into three major themes and nine subthemes: (1) From hospital: including difficulties in diagnosing and seeking medical advice, neglect or lack of attention from clinicians, low treatment satisfaction and complex comorbidities; (2) From daily life: including life satisfaction and well-being, changes in lifestyle pattern and changes in workstyle pattern; (3) From society: including burden of disease and reduction of social interaction. Most DED Patients with anxiety and depression were more likely to face the condition as well as receive treatments negatively, while the others tended to seek treatments unduly and blindly.

Conclusion

This investigation offers new insights into the understanding difficulties in DED patients with anxiety and depression, and provides valuable guidance for supporting them to reduce depression and anxiety as well as improve prognosis.

Alleviation of dry eye syndrome with one dose of antioxidant, anti-inflammatory, and mucoadhesive lysine-carbonized nanogels

Most dry eye syndromes (DES) are caused by oxidative stress and an overactive inflammatory response, leading to tear deficiency and excessive tear evaporation. Conventional eye drops for DES treatment require high doses and frequent administration due to their insufficient precorneal residence time. To overcome these problems, in this study, we have developed carbonized nanogels (CNGs) via the straightforward pyrolysis of lysine hydrochloride (Lys) to provide a long-lasting eye drop formulation for topical DES therapy. This methodology thermally converts Lys-into nitrogen-doped crosslinked polymers with embedded nanographitic structures, which enable efficient free radical scavenging. The cationic and crosslinked polymeric features of the Lys-CNGs also prolong the precorneal retention time and improve ocular bioavailability. These Lys-CNGs exhibit high biocompatibility with corneal epithelial cells both in vitro and in vivo, indicating their safety as eye drops. In a DES rabbit model, a single dose of Lys-CNGs (50 µg mL^-1) can effectively alleviate the signs of DES within 4 days, whereas multiple treatments of 10-fold higher concentration of cyclosporine A are needed to achieve similar therapeutic effects (one dose every 12 h; 500 µg mL^-1). The topical administration of Lys-CNGs enable a reduced therapeutic dose and extended dosing interval, thereby demonstrating a superior therapeutic efficacy compared to the commercial cyclosporine A eye drops. These Lys-CNGs, which exhibit significant free radical scavenging, anti-inflammatory activity, high biocompatibility, and a remarkable ocular bioadhesive property, hold great potential as a long-lasting eye drop formulation for the treatment of dry eye disease. STATEMENT OF SIGNIFICANCE: Multifunctional nanobiomaterial-based eye drops can render an ideal pharmaceutical formulation for the treatment of a variety of ocular surface diseases. To our knowledge, this is the first report describing the development of carbonized nanogels as topically administered therapeutics for alleviating dry eye syndrome (DES). We present evidence that the thermal transformation of lysine hydrochloride into carbonized nanogels (Lys-CNGs) endows superior antioxidant, anti-inflammatory, and bioadhesive properties. While a single dose of Lys-CNGs (50 µg mL^-1) is sufficient to relieve the symptoms of DES for 4 days, multiple treatments of 10-fold higher concentration of commercially available cyclosporine eye drops are needed to achieve similar therapeutic outcomes (one dose every 12 h; 500 µg mL^-1), suggesting an effective and long-lasting ocular carbonized nanomedicine.

Fungi of the human eye: Culture to mycobiome

The focus of the current review is multi-fold and compares the diversity and abundance of fungi on the ocular surface by the conventional culture-based method with the more sensitive, high throughput, culture-independent NGS method. The aim is to highlight the existence of a core ocular mycobiome and explore the transition of the ocular fungal microbiota from the normal eye to the diseased eye. PubMed, Google Scholar and Medline were used to search for publications and reviews related to cultivable fungi and the mycobiome of the normal and diseased eye. The conventional cultivable approach and the NGS approach confirm that the eye has its own mycobiome and several confounding factors (age, gender, ethnicity etc.) influence the mycobiome. Further, dysbiosis in the mycobiome appears to be associated with ocular diseases and thus impacts the health of the human eye. Considering that the mycobiome of the eye is influenced by several confounding factors and also varies with respect to the disease status of the eye there is a need to extensively explore the mycobiome under different physiological conditions, different ethnicities, geographical regions etc. Such studies would unravel the diversity and abundance of the mycobiomes and contribute to our understanding of ocular health. Research focused on ocular mycobiomes may eventually help to build a targeted and individualized treatment.

Low ambient temperature correlates with the severity of dry eye symptoms

PURPOSE:

The symptoms of dry eye disease (DED) are influenced by environmental factors, but the effect of ambient temperature is less certain. Our purpose was to investigate the relationship between the severity of DED symptoms and the ambient temperature.

MATERIALS AND METHODS:

This retrospective study reviewed the symptom scores, including ocular surface disease index (OSDI) and standardized patient evaluation of eye dryness (SPEED), as well as tear film parameters of first-time DED patients between June 2018 and June 2019. The contribution of tear film parameters and environmental factors, including ambient temperature, humidity, wind speed, and the concentration of air pollutants, to the severity of dry eye symptoms was evaluated by univariate and multivariate linear regression analyses.

RESULTS:

There were 351 patients included aged 52.8 ± 13.6 years, and 257 (73.2%) were female. The average tear film break-up time, Schirmer test value, and lipid layer thickness were 2.6 ± 0.7 s, 5.5 ± 4.3 mm, and 64.1 ± 6.0 μm, respectively. The average OSDI and SPEED were 41.8 ± 19.8 and 12.1 ± 5.1, respectively. In winter, the patients reported higher OSDI and SPEED. Both scores were significantly correlated with low ambient temperature. Regression analysis showed that low ambient temperature and Schirmer test value contributed to higher OSDI, while low ambient temperature and younger age contributed to higher SPEED.

CONCLUSION:

Low ambient temperature plays a significant role in DED symptom severity.

Tear function in patients with diabetes mellitus: A systematic review and meta-analysis

PURPOSE

To examine tear function in patients with diabetes mellitus (DM).

DESIGN

Systematic review and meta-analysis.

METHOD

We searched Embase and PubMed from database inception to March 16, 2022. We included observational studies that compared tear function between patients with and without DM. Tear function was measured using invasive tear breakup time (ITBUT) and Schirmer's 1 test. Pooled results are presented as standard mean difference (SMD) with 95% confidence interval (CI) based on random-effects models.

RESULTS

We included 59 studies (7,234 eyes) comparing the tear function between patients with and without DM. This meta-analysis indicated that patients with DM had worse tear function than those without DM (ITBUT: SMD: -0.98, 95% CI: -1.27 to -0.69; Schirmer's 1 test: SMD: -0.45, 95% CI: -0.64 to -0.26), and the results remained consistent in patients with different types of DM (e.g., type 1 DM and type 2 DM) and from different ethnic backgrounds (e.g., Asian vs. non-Asian). Patients with DM under poor glycemic control had worse tear function than those of the non-DM group (ITBUT: SMD: -1.26, 95% CI: -1.86 to -0.66; Schirmer's 1 test: SMD: -0.25, 95% CI: -0.48 to -0.02), whereas there were no significant differences in tear function between patients with DM under optimal glycemic control and non-DM groups.

CONCLUSIONS

We found that patients with type 1 or type 2 DM had significantly reduced tear function. The level of tear function could be determined by glycemic control, and therefore, our findings suggest that glycemic control in patients with DM is critical for maintaining tear function.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero, identifier CRD42021250498.

Retrospective evaluation of the curative effect of traditional Chinese medicine on dry eye disease

Dry eye disease (DED) is a multifactorial illness with an increasingly high global prevalence and multiple risk factors that widely influences patients’ daily lives. It is essential to identify treatments with few or no side effects for patients with DED. We have reviewed studies published from 2001 to 2020 that investigated traditional Chinese medicine (TCM) and integrated Chinese and Western medicine for DED treatment. Current Chinese medicines used in DED therapy were categorized into four types, namely anti-oxidants, anti-inflammatory agents, hormone-like agents, and cell-repairing agents. Compound herbs, including Chi-Ju-Di-Huang-Wan and Qiming granule, can effectively alleviate dry eye symptoms. Moreover, patients with DED who were treated with Western medicine combined with TCM experienced significantly magnified therapeutic effects and reasonable costs of treatment. In conclusion, TCM can be a promising approach for treating DED, and combined treatment with TCM and Western drugs may represent a new strategy for improving the curative effect.

Protective effects of low-molecular-weight components of adipose stem cell-derived conditioned medium on dry eye syndrome in mice

The present study demonstrated the protective effects of low-molecular-weight adipose-derived stem cell-conditioned medium (LADSC-CM) in a mouse model of dry eye syndrome. Mice subjected to desiccating stress and benzalkonium chloride had decreased tear secretion, impaired corneal epithelial tight junction with microvilli, and decreased conjunctival goblet cells. Topical application of adipose-derived stem cell-conditioned medium (ADSC-CM) stimulated lacrimal tear secretion, preserved tight junction and microvilli of the corneal epithelium, and increased the density of goblet cells and MUC16 expression in the conjunctiva. The low-molecular-weight fractions (< 10 kDa and < 3 kDa) of ADSC-CM (LADSC-CM) provided better protections than the > 10 kDa or > 3 kDa fractions of ADSC-CM. In the in vitro study, desiccation for 10 min or hyperosmolarity (490 osmols) for 24 h caused decreased viability of human corneal epithelial cells, which were reversed by LADSC-CM. The active ingredients in the LADSC-CM were lipophobic and stable after heating and lyophilization. Our study demonstrated that LADSC-CM had beneficial effects on experimental dry eye. It is worthy of further exploration for the active ingredient(s) and the mechanism.

Laser Acupuncture Improves Tear Film Stability in Patients with Dry Eye Disease: A Two-Center Randomized-Controlled Trial

Objectives: To investigate the efficacy of laser acupuncture (LA) therapy in patients with dry eye disease (DED). Design: A two-center randomized controlled trial. Settings/Location: The Department of Ophthalmology, Chinese Medicine at the Kaohsiung Chang Gung Memorial Hospital, and the Sunming Eye Clinic in South Taiwan. Subjects: Fifty-nine participants ages 20 to 65 years were enrolled and randomly assigned to the experimental group (LA plus conventional treatment) or the sham control group (LA without laser output plus conventional treatment). Interventions: Subjects underwent LA treatment three times a week for 12 weeks. The subjects in the experimental group sequentially received 0.375 J of energy at each of the following acupoints: BL2, TE23, ST2, LI4, ST36, and GB37. Subjects in the control group received a sham LA treatment, without any laser output. Outcome Measures: The primary outcome measure was ocular surface disease index (OSDI). The secondary outcome measures included tear film breakup time (TFBUT), Schirmer-I test finding, and visual analog scale (VAS) score. Results: At 4 and 12 weeks after the first visit, the experimental group showed significant improvement of dry eye symptoms as measured by OSDI, TFBUT, Shirmer-I test, and VAS. Compared with the control group, the OSDI (7.23, p = 0.001) and TFBUT (-1.78, p = 0.001) significantly improved in the experimental group at 12 weeks of treatment. Conclusions: LA improved the symptoms and tear stability related to DED in conjunction with conventional treatment. The authors suggest that LA be considered a complementary therapy for DED when conventional treatment does not provide satisfactory effects. Trial Registration: ClinicalTrials.gov Identifier NCT03204903.

The Risks of Corneal Surface Damage in Aqueous-Deficient Dry Eye Disease: A 17-Year Population-Based Study in Taiwan

PURPOSE

To investigate the epidemiologic characteristics and risk of corneal surface damage in patients with aqueous-deficient dry eye disease (DED) in Taiwan.

DESIGN

Retrospective, population-based cohort study.

METHODS

We used claims data in the Taiwan National Health Insurance Research Database from 1997 to 2013 of patients with DED, defined according to diagnoses, drug codes, and clinical follow-up. A comparison cohort without DED was selected through propensity score matching. The main outcome measures were corneal surface damage, including corneal erosion, corneal ulcers, or corneal scars.

RESULTS

Patients with DED had a significantly higher rate of corneal surface damage (hazard ratio [HR]: 2.70; 95% confidence interval [CI] 2.38-3.06, P < .001), especially higher in patients aged <18 years (HR 6.66; 95% CI 3.58-12.41) than in older patients and in women (HR 2.98; 95% CI 2.57-3.46) than in men (HR 2.22; 95% CI 1.78-2.77), compared to those in the non-DED cohort. DED with diabetes mellitus (P = .002), rheumatoid arthritis (P = .029), or systemic lupus erythematosus (P = .005) was positively associated with corneal surface damage. The overall prevalence of DED was 7.85%, higher among women (10.49%) than men (4.92%), and increased with age (0.53%, 3.94%, 10.08%, and 20.72% for ages <18, 18-39, 40-64, and >65 years, respectively). The prevalence increased gradually during the study period.

CONCLUSIONS

The younger age group (<18 years) had the highest risk of corneal surface damage in aqueous-deficient DED. Other predisposing factors included female sex, diabetes, and autoimmune diseases. To improve clinical care, special attention is required for patients with DED with these risk factors.

Exposure to Ambient NO2 Increases the Risk of Dry Eye Syndrome in Females: An 11-Year Population-Based Study

Previous studies have indicated that women suffer from dry eye syndrome (DES) more significantly than men. Therefore, we specifically explore the associations between air pollutant levels and the risks of DES for women. The study obtained 27,605 participants from the 29 recruitment centers of the Taiwan Biobank, which was established in October 2012. A large scale cross-sectional study involving DES sufferers and age- and education-matched control groups without DES was designed. Based on the municipality of residence, the predicted concentration levels of various air pollutants, including PM_2.5, sulfur dioxide (SO₂), ozone (O₃), and nitrogen dioxide (NO₂) were estimated by using hybrid kriging/LUR model. Multiple logistic regressions were applied to estimate the prevalence ratios (PR) of DES and 95% confidence interval. Hormone supplementations, DBP, allergies, and arthritis were considered as important comorbidities for increased PR risk of DES. In addition, with each standard deviation (SD) increment of PM_2.5 and temperature, women had significant increases in PRs of DES of 1.09- and 1.07-fold, respectively; conversely, each SD increment of relative humidity (RH) had a protective effect against the risk of DES. After considering hormone supplementation, arthritis, and allergy, the SD increment of NO₂ and temperature were associated with the PRs of DES. In conclusion, significant associations of ambient NO₂ concentration, RH and temperature with DES indicated the importance of increased environmental protection in the female population. Female exposure to high levels of NO₂ when receiving hormone supplementation, or suffering with allergies or arthritis, had significantly increased risk of DES.

Altered ocular surface immune cell profile in patients with dry eye disease

PURPOSE

Aberrant inflammation and immune dysregulation are known pathogenic contributors in dry eye disease (DED). Aim of the study was to determine the proportions of immune cell subsets on the ocular surface (OS) of DED patients.

METHODS

15 healthy controls (22 eyes) and 48 DED subjects (36 eyes with evaporative DED - EDED; 60 eyes with aqueous deficient DED - ADED) were included in the study. Tear break up time (TBUT), Schirmer's test 1 (ST1), corneal staining (CS) and ocular surface disease index (OSDI) scoring were recorded. OS wash was used to collect immune cells on the OS of study subjects. The cells immunophenotyped using flow cytometry include leukocytes, neutrophils, macrophages, natural killer-NK cells and T cell subsets (CD4; CD8; double positive-DP; gamma delta-γδ and NK T cells).

RESULTS

Significantly higher proportions of leukocytes, neutrophils, CD4 T cells, CD8 T cells, DP T cells and CD4/CD8 T cells ratio were observed in EDED and/or ADED patients. Significantly higher proportions of neutrophils and lower proportions of NK cells were observed in ADED subjects with corneal staining compared to those without and controls. Neutrophils/NK cells ratio was significantly higher in EDED and ADED subjects compared to controls. Correlation analysis revealed pathological relationships between proportions of leukocytes, neutrophils, CD4 T cells and Neutrophil/NK cells ratio with DED clinical parameters.

CONCLUSION

OS immune cell subset proportion changes in DED patients were associated with DED types and severity. The data suggests the potential for a new generation of therapies targeting immune cells on the ocular surface.

Modifiable lifestyle risk factors for dry eye disease

PURPOSE

To examine the association between modifiable lifestyle factors and dry eye disease.

METHODS

Three hundred and twenty-two community residents (186 females, 136 males; mean ± SD age, 41 ± 22 years) with no major systemic or ophthalmic conditions (other than dry eye disease) were recruited in a cross-sectional study. A lifestyle factor questionnaire was administered, 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 TFOS DEWS II reports.

RESULTS

A total of 111 (34 %) participants fulfilled the TFOS DEWS II diagnostic criteria for dry eye disease. Multivariate regression analysis demonstrated that advancing age, female sex, East Asian ethnicity, and increased digital screen exposure time were positive risk factors for dry eye disease (all p < 0.05), while increased caffeine consumption was a protective factor (p = 0.04).

CONCLUSIONS

Increased digital screen exposure time and reduced caffeine consumption were modifiable lifestyle factors associated with higher odds of dry eye disease. These findings might contribute to informing the design of future prospective research investigating the efficacy of preventative intervention and risk factor modification strategies.

Tear Proteomics Study of Dry Eye Disease: Which Eye Do You Adopt as the Representative Eye for the Study?

Most studies about dry eye disease (DED) chose unilateral eye for investigation and drew conclusions based on monocular results, whereas most studies involving tear proteomics were based on the results of pooling tears from a group of DED patients. Patients with DED were consecutively enrolled for binocular clinical tests, tear biochemical markers of DED, and tear proteome. We found that bilateral eyes of DED patients may have similar but different ocular surface performance and tear proteome. Most ocular surface homeostatic markers and tear biomarkers were not significantly different in the bilateral eyes of DED subjects, and most clinical parameters and tear biomarkers were correlated significantly between bilateral eyes. However, discrepant binocular presentation in the markers of ocular surface homeostasis and the associations with tear proteins suggested that one eye’s performance cannot represent that of the other eye or both eyes. Therefore, in studies for elucidating tear film homeostasis of DED, we may lose some important messages hidden in the fellow eye if we collected clinical and proteomic data only from a unilateral eye. For mechanistic studies, it is recommended that researchers collect tear samples from the eye with more severe DED under sensitive criteria for identifying the more severe eye and evaluating the tear biochemical and proteomic markers with binocular concordance drawn in prior binocular studies.

The efficacy and safety of acupuncture or combined with western medicine for dry eye: A protocol for systematic review and meta-analysis

BACKGROUND

As a traditional Chinese medicine external treatment method, acupuncture is characterized by simple operation, significant treatment effect and few side effects. Dry eye, also known as conjunctival xerosis, refers to pathological changes in tissues of ocular surface caused by abnormal tear quality and quantity or dynamics due to various reasons, which can cause red and swollen eyes, congestion, and severe cases may result in lesions of the conjunctiva. Clinical practice shows that acupuncture has a certain therapeutic effect on dry eye, but there is a lack of medical evidence. The objective of the research carried out in this program is to evaluate the effectiveness and safety of acupuncture combined with western medicine in the treatment of dry eye.

METHODS

Computer retrieval English database (PubMed, Embase, Web of Science, the Cochrane Library) and Chinese database (CNKI, WF, VIP, CBMDISC), moreover manual retrieval of clinical research on the treatment of dry eyes by acupuncture in combination with western medicine from Baidu academic and Google Academic from database building to May 2020, the quality included in the study was evaluated and data extraction was completed by 2 independent researchers. RevMan5.3 software was utilized for meta-analysis to the included literature.

RESULTS

In this study, the effectiveness and safety of acupuncture combined with western medicine in the treatment of dry eye were evaluated by several indicators, such as the score of the ocular surface disease index, the amount of tear secretion and the tear film rupture time.

CONCLUSIONS

This study will provide reliable evidence for the clinical application of acupuncture combined with western medicine in the treatment of dry eyes.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/5DJ9W.

Ocular conditions and dry eye due to traditional and new forms of smoking: A review

Addiction to cigarette smoking has high prevalence rates recorded worldwide. Smoking has been linked to several life-threatening systemic conditions such as cancer, heart attack and stroke, in addition to a range of ocular pathologies. In recent years, electronic cigarettes (EC) have emerged as alternatives to smoking. ECs are nicotine delivery devices which produce an aerosol by heating, rather than combusting, a liquid which contains nicotine, flavours and preservatives. This review focuses on the association of traditional and new forms of smoking with dry eye disease, contact lens wear and four other common ocular diseases: cataract, age-related macular degeneration, glaucoma and Graves' ophthalmopathy. It is concluded that smoking and vaping appear as a risk factor for the aforementioned ocular conditions. An evidence-based, clear link between cigarette smoking, or EC vaping and ocular problems is yet to be discovered.