Lacrimal hypofunction as a new mechanism of dry eye in visual display terminal users

Effectiveness of an Acupuncture Steam-Warming Eye Mask on Dry Eye Disease in Visual Display Terminal Users: A Prospective Randomized Controlled Trial

We aim to evaluate the effectiveness of an acupuncture steam-warming eye mask (ASEM) on dry eye disease (DED) in visual display terminal (VDT) users. This prospective randomized clinical trial included VDT users with DED-related features who were randomly assigned to the ASEM group (ASEM for 2 weeks, 20 participants) or the steam-warming eye mask (SEM) group (SEM for 2 weeks, 20 participants). The tear film break-up time (TBUT), Schirmer test, tear meniscus height, ocular surface staining scores, eyelid and meibomian gland exam, subjective symptoms, and quality of life (QoL) scores before and after treatment were collected. A generalized linear mixed model was applied to compare the improvement of symptoms and signs between the two groups. After the 2-week treatment, all the subjective symptoms and questionnaire scores in the ASEM group improved significantly (all p < 0.05), whereas the feelings of relaxation, comfortable, and refreshment did not change in the SEM group (both p > 0.05). The TBUT, tear meniscus height, and meibum quality in the lower eyelid were significantly better in the ASEM group than the SEM group (all p < 0.05), whereas no significant changes were observed in the Schirmer test and ocular surface staining scores. Compared with the SEM group, the ASEM group experienced a stronger feeling of refreshment (p = 0.013), lower sensation of ocular discharge (p = 0.031), higher TBUT (p = 0.045), better meibomian gland expressibility of both eyelids (both p < 0.05), and better meibum quality of both eyelids (both p < 0.05), even after adjustments for age and sex. In conclusion, comparing with SEM, ASEM can improve some subjective DED symptoms, tear film stability, and meibum status in VDT users.

Dry eye in primary care: the relationship between digital display device usage and dry eye syndrome (DES) in medical students

OBJECTIVE

As digital display devices become more and more indispensable, associated health problems have started to increase. We aimed to investigate the frequency and relationship of digital display device usage behaviours and dry eye syndrome (DES) in medical students.

METHODS

An observational, cross-sectional study was conducted on medical school students who voluntarily participated in our study online, about the duration and variety of their digital screen use, usage patterns, and protective measures, together with the Ocular Surface Disease Index (OSDI) questionnaire. Where necessary, the Schirmer-I, tear break-up time, and fluorescein staining tests were carried out.

RESULTS

Of the 255 participants, 75.3% (n = 192) were female, 63.1% (n = 161) had no refractive vision defects, and 45.9% used smartphones for more than 5 h a day. According to the OSDI scores for DES screening, only 36.1% of the participants were normal, 17.3% had mild DES, 20.4% had moderate DES, and 26.3% had severe DES. A positive correlation was found between digital display usage time in hours per day and a high OSDI score. As the distance between the eye and the screen decreased, the DES score increased, which is significant for computer, e-book, and tablet use (P < 0.005). The DES rate of the 25 participants who underwent further evaluation was 40% for the tear break-up time test and 52% for the fluorescein staining test.

CONCLUSION

The high prevalence of DES due to digital screen use among medical school students highlights the importance of DES screening as a preventive measure in family medicine.

Tear Film Dynamics in Visual Display Terminal Users: A Review of Impact on Goblet Cells, Lacrimal and Meibomian Gland Function

PURPOSE

The prevalence of dry eye disease (DED) is rising among visual display terminal (VDT) users, a trend that correlates with the growing use of digital devices. The prevalence of VDT-associated DED is reported based on dry eye questionnaires; however, VDT's impact on tear film parameters is less understood.

METHODS

A review of published literature on both the alterations in tear film observed in VDT users and the impact of various interventions on their tear film.

RESULTS

Most studies show reduction in tear stability as well as reduction in the blink rate. The role of lacrimal gland hypofunction in visual display terminal (VDT) users is a subject of ongoing debate. Schirmer test values typically exceed the 10 mm threshold, suggesting normal tear production, and tear osmolarity remains within normal ranges but VDT users consistently present with lower Schirmer values compared to non-VDT users. The effects on Meibomian glands and mucin levels need more research as the numbers studied are small. Very few studies have analysed mucin levels in VDT users with reports of normal or reduced values. Even asymptomatic users can have tear film instability; hence, the diagnostic criteria need to be formulated and validated. Different interventions such as neurostimulation, blink improving apps, eyelid warming devices, moist goggles, and lubricants have been explored in VDT users but without a control arm and in asymptomatic VDT users in most studies.

CONCLUSION

The alterations have been observed on aqueous, lipid and mucin components of the tear film, although the extent of the impact is variable across studies. There is urgent need of well-designed studies for studying the tear film changes and management options for the upcoming lifestyle epidemic in VDT users.

Determining the effect of climate and profession on dry eye disease: A prevalence study among young males in north, north-west and central India

Background

Ocular tear film and the ocular surface together represent a dynamic playground of various protective factors against environmental influencers. Surrounding environment and geoclimatic milieu are the pertinent and continuous influencing factors. Prevalence study of Dry eye disease (DED) in various climatic conditions and professions provides an insight into this peculiar aspect of DED and human geography.

Methods

This was a hospital based, cross-sectional, comparative, analytical observational study. 1840 young soldiers between 25 and 45 years of age were studied. Divided in five climate groups based on Köppen-Geiger climate classification system the subjects were sub-grouped into professions exposed to known aggravating environmental factors. The ocular surface was examined for signs and symptoms of DED and its prevalence and risk ratio for different climates and professions were calculated.

Results

Highest prevalence of DED was found in cold desert climate and among visual display unit (VDU) users. Least prevalence was seen in highland type of climate and among people involved in professional exposed to high temperature. Prevalence of DED based upon the signs and ocular surface disease index (OSDI) was calculated and stratified with risk ratio for climatic conditions and professions.

Conclusion

Different climatic conditions and professions had different prevalence of signs, symptoms of OSD and DED which indicated its influence on prevalence of the disease.

Tear film changes in symptomatic versus asymptomatic video display terminal users following computer challenge test

PURPOSE

To assess the real-time changes in the tear film and ocular surface of symptomatic video display terminal (VDT) versus asymptomatic users.

METHODS

A total of 35 symptomatic (29 ± 5.6 years; Group 1, mild dry eye disease) and 35 asymptomatic (24.1 ± 4.6 years; Group 2) VDT users with a mean OSDI of 28 ± 11 and 0.86 ± 2.1, respectively, had tear film examination (Oculus Keratograph 5 M and Tearlab Osmolarity System) at baseline and after 1 h of watching a movie on the laptop inside a controlled environment chamber along with blink rate calculation.

RESULTS

The mean VDT use was 11.4 ± 3.2 h/day in Group 1 and 2.3 ± 2.3 h/day in Group 2. In Group 1, the mean pre- and post-VDT task values for NIBUT and bulbar congestion were 10.7 ± 3.7s and 6.7 ± 3.1s (P = 0.007), and 0.8 ± 0.4 and 1.1 ± 0.5 (P = 0.01), respectively. There were no significant changes in tear meniscus height (P = 0.77), Schirmer I (P =0.14), corneal staining score (P = 1.0), and tear osmolarity (P > 0.05). Group 2 showed insignificant change in all parameters. Only 16.2% individuals in Group 1 met modified TFOS-DEWS II diagnostic criteria at baseline that increased to 67.6% following VDT task. The blink rate reduced significantly during the last 15 min (6.8 ± 3.4 vs. 9.3 ± 4.5; P = 0.006) compared to the first 15 min of the task in Group 1, whereas no significant change occurred in Group 2.

CONCLUSION

Tear film instability and increased bulbar congestion are observed in symptomatic VDT users after computer work despite baseline stable tear film. The changes are significantly altered in symptomatic VDT users compared to asymptomatic users.

Dry Eyes among Visual Display Terminal Users Visiting the Outpatient Department of Ophthalmology of a Tertiary Care Centre

Introduction

Visual display terminal usage has increased substantially in recent years across all age groups and is considered one of the major risk factors for dry eye disease. Early assesment of dry eyes and prevention is important. The aim of this study is to find the prevalence of dry eyes among visual display terminal users visiting the Outpatient Department of Ophthalmology of a tertiary care centre.

Methods

A descriptive cross-sectional study was conducted among patients visiting the Department of Ophthalmology in a tertiary care centre after receiving ethical approval from the Institutional Review Committee. Data was collected from 1 October 2021 to 31 March 2022. Convenience sampling method was used. The point estimate was calculated at a 90% Confidence Interval.

Results

Among 94 visual display terminal users, the prevalence of dry eyes was 55 (58.51%) (50.18-66.84, 90% Confidence Interval).

Conclusions

The prevalence of dry eyes among visual display terminal users visiting the Outpatient Department of Ophthalmology was similar to other studies done in similar settings.

Keywords

dry eyes; health; prevalence.

Review of genes potentially related to hyposecretion in male non-obese diabetic (NOD) mice, a Sjögren's syndrome model

BACKGROUND

Sjögren's syndrome (SS) is known to cause dry eyes and mouth due to inflammation of the lacrimal and salivary glands. However, some reports imply that other factors trigger dry eyes and mouth. We previously investigated various factors using RNA-sequencing analysis of lacrimal glands from male non-obese diabetic (NOD) mice, an SS model. In this review, we described (1) the exocrine features of male and female NOD mice, (2) the up- and down-regulated genes in the lacrimal glands of male NOD mice as revealed by our RNA-sequencing data, and (3) comparisons between these genes and data in the Salivary Gland Gene Expression Atlas.

HIGHLIGHTS

Male NOD mice exhibit a steady worsening of lacrimal hyposecretion and dacryoadenitis, whereas females exhibit a complex pathophysiological condition that includes diabetic disease, salivary hyposecretion, and sialadenitis. Ctss, an up-regulated gene, is a potential inducer of lacrimal hyposecretion and is also expressed in salivary glands. Two other up-regulated genes, Ccl5 and Cxcl13, may worsen the inflammation of SS in both the lacrimal and salivary glands. The genes Esp23, Obp1a, and Spc25 were detected as down-regulated, but judging the relationship between these genes and hyposecretion is difficult as only limited information is available. Another down-regulated gene, Arg1, is involved in lacrimal hyposecretion, and it also has the potential to cause salivary hyposecretion in NOD mice.

CONCLUSION

In NOD mice, males may be better than females at evaluating the pathophysiology of SS. Some regulated genes revealed by our RNA-sequencing data might be potential therapeutic targets for SS.

TFOS Lifestyle: Impact of the digital environment on the ocular surface

Eye strain when performing tasks reliant on a digital environment can cause discomfort, affecting productivity and quality of life. Digital eye strain (the preferred terminology) was defined as "the development or exacerbation of recurrent ocular symptoms and/or signs related specifically to digital device screen viewing". Digital eye strain prevalence of up to 97% has been reported, due to no previously agreed definition/diagnostic criteria and limitations of current questionnaires which fail to differentiate such symptoms from those arising from non-digital tasks. Objective signs such as blink rate or critical flicker frequency changes are not 'diagnostic' of digital eye strain nor validated as sensitive. The mechanisms attributed to ocular surface disease exacerbation are mainly reduced blink rate and completeness, partial/uncorrected refractive error and/or underlying binocular vision anomalies, together with the cognitive demand of the task and differences in position, size, brightness and glare compared to an equivalent non-digital task. In general, interventions are not well established; patients experiencing digital eye strain should be provided with a full refractive correction for the appropriate working distances. Improving blinking, optimizing the work environment and encouraging regular breaks may help. Based on current, best evidence, blue-light blocking interventions do not appear to be an effective management strategy. More and larger clinical trials are needed to assess artificial tear effectiveness for relieving digital eye strain, particularly comparing different constituents; a systematic review within the report identified use of secretagogues and warm compress/humidity goggles/ambient humidifiers as promising strategies, along with nutritional supplementation (such as omega-3 fatty acid supplementation and berry extracts).

Heterochronic Parabiosis Causes Dacryoadenitis in Young Lacrimal Glands

Aging is associated with inflammation and oxidative stress in the lacrimal gland (LG). We investigated if heterochronic parabiosis of mice could modulate age-related LG alterations. In both males and females, there were significant increases in total immune infiltration in isochronic aged LGs compared to that in isochronic young LGs. Male heterochronic young LGs were significantly more infiltrated compared to male isochronic young LGs. While both females and males had significant increases in inflammatory and B-cell-related transcripts in isochronic and heterochronic aged LGs compared to levels isochronic and heterochronic young LGs, females had a greater fold expression of some of these transcripts than males. Through flow cytometry, specific subsets of B cells were increased in the male heterochronic aged LGs compared to those in male isochronic aged LGs. Our results indicate that serum soluble factors from young mice were not enough to reverse inflammation and infiltrating immune cells in aged tissues and that there were specific sex-related differences in parabiosis treatment. This suggests that age-related changes in the LG microenvironment/architecture participate in perpetuating inflammation, which is not reversible by exposure to youthful systemic factors. In contrast, male young heterochronic LGs were significantly worse than their isochronic counterparts, suggesting that aged soluble factors can enhance inflammation in the young host. Therapies that aim at improving cellular health may have a stronger impact on improving inflammation and cellular inflammation in LGs than parabiosis.

Assessment of risk factors on eye dryness in young adults using visual display device in both contact lens wearers and non-wearers

PURPOSE

Researchers are interested in examining the impact of visual display devices (VDDs) on the development of dry eye illness because their use is becoming more common among college students. The goal of this study was to see if there was a link between certain risk factors and the development of eye dryness in VDDs using young adults who wore contact lenses and those who did not.

METHODS

The self-administrated survey was hosted in Google Forms, sent via e-mail to the participants. It consisted of two parts of assessing different risk factors (i.e., environmental conditions, angle of gaze, and years of VDD use) with contact lens use and Ocular Surface Disease Index (OSDI) questionnaire. The OSDI scores of the entire sample who suffer from dry eye and the subgroup using contact lenses were calculated. The relationship between different risk factors with the OSDI scores was also assessed.

RESULTS

A total of 274 young adults from college students and academic staff (216 female, 58 male) were suffering from eye dryness. Eighty-eight of the 274 participants wore contact lenses. The mean OSDI scores of the 274 young adults were 32.92. Mean OSDI scores in contact lens wearers and non-wearers were 34.36 and 32.24, respectively (p < 0.01). There was a statistically significant relationship between OSDI score and indoor environmental conditions in computer using VDD group. Using a computer in a dark environment and above the line of sight resulted in a higher OSDI scores. Females who wore contact lenses while using a computer for more than three years had significantly higher OSDI scores than non-wearer females. Tablet type VDD use increased the mean ODSI scores of the contact lens wearers significantly.

CONCLUSIONS

Dry eye symptoms were shown to be increased in the contact lens wearer group with the increased duration of computer VDD use, decreased indoor environmental brightness conditions, and above the line of sight.

Review on the possible pathophysiological mechanisms underlying visual display terminal-associated dry eye disease

BACKGROUND

Visual display terminal (VDT) use is a key risk factor for dry eye disease (DED). Visual display terminal (VDT) use reduces the blink rate and increases the number of incomplete blinks. However, the exact mechanisms causing DED development from VDT use have yet to be clearly described.

PURPOSE

The purpose of the study was to conduct a review on pathophysiological mechanisms promoting VDT-associated DED.

METHODS

A PubMed search of the literature investigating the relationship between dry eye and VDT was performed, and relevance to pathophysiology of DED was evaluated.

FINDINGS

Fifty-five articles met the inclusion criteria. Several pathophysiological mechanisms were examined, and multiple hypotheses were extracted from the articles. Visual display terminal (VDT) use causes DED mainly through impaired blinking patterns. Changes in parasympathetic signalling and increased exposure to blue light, which could disrupt ocular homeostasis, were proposed in some studies but lack sufficient scientific support. Together, these changes may lead to a reduced function of the tear film, lacrimal gland, goblet cells and meibomian glands, all contributing to DED development.

CONCLUSION

Visual display terminal (VDT) use appears to induce DED through both direct and indirect routes. Decreased blink rates and increased incomplete blinks increase the exposed ocular evaporative area and inhibit lipid distribution from meibomian glands. Although not adequately investigated, changes in parasympathetic signalling may impair lacrimal gland and goblet cell function, promoting tear film instability. More studies are needed to better target and improve the treatment and prevention of VDT-associated DED.

Review on the possible pathophysiological mechanisms underlying visual display terminal-associated dry eye disease

BACKGROUND

Visual display terminal (VDT) use is a key risk factor for dry eye disease (DED). Visual display terminal (VDT) use reduces the blink rate and increases the number of incomplete blinks. However, the exact mechanisms causing DED development from VDT use have yet to be clearly described.

PURPOSE

The purpose of the study was to conduct a review on pathophysiological mechanisms promoting VDT-associated DED.

METHODS

A PubMed search of the literature investigating the relationship between dry eye and VDT was performed, and relevance to pathophysiology of DED was evaluated.

FINDINGS

Fifty-five articles met the inclusion criteria. Several pathophysiological mechanisms were examined, and multiple hypotheses were extracted from the articles. Visual display terminal (VDT) use causes DED mainly through impaired blinking patterns. Changes in parasympathetic signalling and increased exposure to blue light, which could disrupt ocular homeostasis, were proposed in some studies but lack sufficient scientific support. Together, these changes may lead to a reduced function of the tear film, lacrimal gland, goblet cells and meibomian glands, all contributing to DED development.

CONCLUSION

Visual display terminal (VDT) use appears to induce DED through both direct and indirect routes. Decreased blink rates and increased incomplete blinks increase the exposed ocular evaporative area and inhibit lipid distribution from meibomian glands. Although not adequately investigated, changes in parasympathetic signalling may impair lacrimal gland and goblet cell function, promoting tear film instability. More studies are needed to better target and improve the treatment and prevention of VDT-associated DED.

Current approaches for the regeneration and reconstruction of ocular surface in dry eye

Significant research revealed the preocular tear film composition and regulations that remain vital for maintaining Ocular surface functional integrity. Inflammation triggered by many factors is the hallmark of Ocular surface disorders or dry eyes syndrome (DES). The tear deficiencies may lead to ocular surface desiccation, corneal ulceration and/or perforation, higher rates of infectious disease, and the risk of severe visual impairment and blindness. Clinical management remains largely supportive, palliative, and frequent, lifelong use of different lubricating agents. However, few advancements such as punctal plugs, non-steroidal anti-inflammatory drugs, and salivary gland autografts are of limited use. Cell-based therapies, tissue engineering, and regenerative medicine, have recently evolved as long-term cures for many diseases, including ophthalmic diseases. The present article focuses on the different regenerative medicine and reconstruction/bioengineered lacrimal gland formation strategies reported so far, along with their limiting factors and feasibility as an effective cure in future.

The association between visual display terminal use and dry eye: a review

BACKGROUND

Dry eye disease (DED) is a multifactorial disease of the tear film and ocular surface. It causes ocular symptoms, reduced quality of life and a considerable economic burden on society. Prolonged use of visual display terminals (VDTs) has been suggested as an important risk factor for DED.

PURPOSE

This review aims to study the association between DED and VDT use with an emphasis on the prevalence of DED among VDT users and harmful daily duration of VDT use.

METHODS

A PubMed search was conducted and yielded 57 relevant articles based on a set of inclusion and exclusion criteria. The studies were subclassified according to study design.

RESULTS

The far majority of the studies showed an association between VDT use and DED or DED-related signs and symptoms. The prevalence of definite or probable DED in VDT and office workers ranged from 26% to 70%, with as few as 1-2 hr of VDT exposure per day being associated with DED.

CONCLUSION

VDT use is strongly associated with DED. VDT-associated DED is prevalent, but the exact prevalence needs to be further elucidated using standardized DED diagnosis criteria. Furthermore, a safe lower limit of daily VDT use has yet to be established. More research is needed on the effect of digitalization and digital transformation, which are particularly high during the time of the COVID-19 pandemic.

Prevalence of dry eye disease among Chinese high school students during the COVID-19 outbreak

Purpose

The study aimed to investigate the prevalence of dry eye disease (DED) and relevant risk factors among Chinese high school students during the COVID-19 outbreak.

Methods

A cross-sectional study was conducted from November to December 2020, and 4825 high school students from nine high schools in Shanghai were recruited. All students completed ocular surface disease index (OSDI) and perceived stress scale (PSS) questionnaires and answered other questions designed to ascertain information on the risk factors related to DED. DED was diagnosed when OSDI scores were greater than or equal to 13. The prevalence of symptomatic DED was determined. A T-test, Kruskal-Wallis test, Chi-square test, and logistic regression analysis were used to examine the possible risk factors.

Results

The prevalence of symptomatic DED among Chinese high school students was 70.5%. In univariate analysis, higher PSS scores (P<0.001), prolonged video display terminal (VDT) use (P<0.001), wearing contact lenses (P=0.001), poor sleep quality (P<0.001), and being female (P<0.001) were significantly correlated with dry eyes. In multivariate logistic regression analysis, higher PSS scores (P<0.001, OR=1.20), prolonged VDT use (P<0.001, OR=1.07), poor sleep quality (P<0.001, OR=1.84), and being female (P=0.001, OR=1.25) were significant risk factors associated with DED.

Conclusions

Due to the epidemic, most Chinese high school students are in a high-risk environment in which they are more likely to suffer from DED, such as long online courses and heavy stress from school. Relevant preventive measures that may have a positive impact on public health and quality of life for high school students should be brought to the forefront.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02408-9.

Immediate Ocular Changes After Light-Emitting Diode Displays Exposure-A Preliminary Study

Purpose

Computer vision syndrome (CVS) is one of the most frequently encountered problems among video display terminals (VDT) users, but little is known regarding the short-term effect after exposure to light-emitting diodes (LED). The purpose of this study was to determine if short-term exposure to LED leads to changes in corrected distance visual acuity (CDVA), lipid layer thickness (LLT), blink rates, partial blink ratio, and computer vision syndrome questionnaire (CVS-Q) score.

Design

Prospective, cross-sectional study.

Methods

In this study, participants were recruited at the National Cheng-Kung University Hospital, a tertiary referral center in southern Taiwan, for examination. Participants were asked to complete the CVS-Q and undergo a series of ocular examinations, including CDVA, LLT, blink rates and partial blink ratio before and after watching an LED display for 15 min. Main Outcome Measures were changes in CDVA, LLT, blink rates, partial blink ratio, and CVS-Q measurements.

Results

In total, 120 eyes from 60 participants (mean age: 35.7 ± 9.4 years) were included; 31 participants were men (51.7%), and 29 were women (48.3%). The CDVA, LLT, blink rates, and partial blink ratio did not change after watching the LED display. The CVS-Q score significantly improved after short-term LED exposure (P < 0.001). A subgroup analysis of subjects with a baseline LLT of <60 nm or ≥60 nm determined that LLT significantly decreased in individuals with a baseline LLT of ≥60 nm (P = 0.016).

Conclusion

Short-term use of LED displays reduced LLT in individuals with a baseline LLT of ≥60 nm, despite the visual symptoms of CVS improved subjectively. Therefore, digital device users should be aware of the potential negative effects of LED exposure on the eyes.

Mean Tear-Film Lipid Layer Thickness and Video Display Terminal Time as Risk Factors for Abnormal Blinking in Children

Objective: To explore the risk factors for abnormal blinking in children and the role of the tear-film lipid layer thickness (LLT) as a function of duration of video display terminal (VDT) use in children. Methods: Children attending the Optometry Clinic of Xinhua Hospital affiliated with Shanghai Jiao Tong University were recruited for the study between June 2019 and June 2020. Time spent viewing a VDT (VDTt) over the previous 6 months was recorded. Incomplete blinking (IB) and blinking rate were measured over a 10 s period using the Lipiview^® interferometer (Tear Science, Morrisville, NC, USA), and participants were allocated into groups with normal blinking (NBG, blink rate < 20 blinks/min) and abnormal blinking (ABG, blink rate ≥ 20 blinks/min). T-test, chi-square test and Mann-Whitney U-test were used to compare the differences in tear film (TF) stability indexes and meibomian gland function indexes between the two groups. Binary logistic analysis was used to analyze the risk factors for abnormal blinking and protective factors related to children's use of VDT, and receiver operating characteristic (ROC) curve analysis was also conducted. Results: A total of 167 children were included, with no statistically significant differences in age or sex between the two groups. According to the t-test, VDTt was significantly higher in ABG than NBG, while TF stability indices including tear break up time, LLT and the height of the tear meniscus, were significantly higher in NBG than ABG (P < 0.001). The results also showed better meibomian gland function in NBG than ABG (P < 0.05). Binary logistic analysis showed that VDTt is an important risk factor for abnormal blinking, and the average of LLT (AVG) was found to be an important protective factor for children using a VDT for long periods, with a cut-off value of 1.5 h and 57.5 nm, respectively. ROC curve analysis showed that the area under the curve value of VDTt and AVG was 0.833 and 0.969, respectively (P < 0.001). Conclusion: In children, VDTt is an important risk factor for abnormal blinking, and the AVG is an important protective factor for children using VDT for long periods.

The Prevalence and Risk Factors for Symptomatic Dry Eye in Adults in Riyadh, Saudi Arabia

Objectives:

The objective of this study is to estimate the prevalence of symptomatic suspected dry eye, diagnosed dry eye syndrome (DES), and associated risk factors; in Riyadh, Saudi Arabia.

Methods:

A cross-sectional study of 654 participants was employed using a self-administered semi-structured questionnaire that included demographic characteristics like age, gender, and risk factors (smoking, using contact lenses, chronic comorbidities, etc.).

Results:

There were 266 (40.7%) previously diagnosed DES participants and 388 (59.3%) non-diagnosed DES, of which 497 were female and 157 were male. Females had a significantly higher rate of diagnosed DES than males (p<0.001), with a significant increase in the rate of DES diagnosis with age (p<0.001). There was also a significant increase in DES in participants with diabetes mellitus, allergic eye, thyroid eye, and skin diseases, as well as having undergone laser surgery or using contact lenses. There was no significant increase in DES in cases of smoking, daily use of electronic devices, or duration of sleep.

Conclusion:

The prevalence of dry eye among adults in Riyadh was 46.6%, with the most important risk factors being female gender, increasing age, Lasik refractive surgery, skin disease around the eye, and thyroid eye disease.

Effect of Blue Light Filters on Tear and Contrast Sensitivity in Individuals Using Electronic Devices

OBJECTIVES

To investigate the effect of contact lenses with blue light filters on contrast sensitivity and any alteration in tear quantity and quality.

METHODS

This prospective longitudinal pilot study required three visits by each participant. Monocular visual acuity, contrast sensitivity, phenol red thread test, and tear breakup time were measured at each visit.

RESULTS

There were significant differences in logarithmic contrast sensitivity between the groups. The breakup time (BUT) was significantly lower after using video display terminals than before (P<0.05). No differences in BUT were found between groups video display terminals and contact lenses having the blue filter (P>0.05). However, higher mean values were observed in the group after video display terminal use with contact lenses having the blue filter than that with standard contact lenses (P>0.05 in both groups). Furthermore, the mean value of phenol red thread test on the group after video display terminal use with contact lenses having the blue filter was lower than the group before its use (P>0.05).

CONCLUSION

The results establish a possible relationship between tear stability, improved contrast sensitivity, and the use of a blue filter in contact lenses.

Animal models of dry eye disease: Useful, varied and evolving (Review)

Dry eye disease (DED), which is a prevalent disease that still lacks successful treatment options, remains a major challenge in ophthalmology. Multiple animal models of DED have been used to decipher its pathophysiology and to develop novel treatments. These models use mice, rats, rabbits, cats, dogs and non-human primates. Each model assesses aspects of DED by focusing on elements of the lacrimal functional unit, which controls the homeostasis of the tear film. The present review outlines representative DED animal models and assesses their contribution to the study of DED. Murine models are the most extensively used, followed by rabbit models; the latter offer the advantage of larger eyes, a favorable biochemical profile for drug studies, experimental ease and relatively low cost, contrasting with non-human primates, which, although closer to humans, are not as accessible and are expensive. No comprehensive ‘ideal’ animal model encompassing all aspects of human DED exists nor is it feasible. Investigators often choose an animal model based on their experimental needs and the following four features of a given model: The size of the eye, its biochemical composition, the available research reagents and cost. As research efforts in DED expand, more refined animal models are needed to supplement the enormous contribution made to date by existing models.

The Relationship Between Dry Eye Disease and Digital Screen Use

Dry eye disease is characterized by tear film instability that can result in ocular surface damage. Patients with dry eye disease may experience ocular pain/discomfort and visual disturbances that may negatively impact quality of life. Increased use of digital screens for work, communication, and entertainment, especially during times of pandemic, may contribute to dry eye. Extensive cross-sectional studies have shown that digital screen use duration is associated with an increased risk of severe symptoms and clinical diagnosis of dry eye disease in adults. Smartphone use duration has also been found to be greater in school-age children with dry eye disease than in those without dry eye disease. A commonly accepted hypothesis for the relationship between digital screen use and dry eye disease is that digital screen use changes blinking dynamics, leading to ocular dryness. This review describes evidence that digital screen use is associated with dry eye disease, that digital device use alters blinking dynamics, and that dry eye affects mental health and work productivity in digital screen users. Helpful prevention and management strategies for dry eye disease exist for those who use digital screens.

Clinical Performance of Samfilcon A Contact Lenses in Intensive Digital Device Users: A Multicenter, Prospective Clinical Study

Introduction

To evaluate patient satisfaction with samfilcon A contact lenses (CLs) in intensive digital device users with myopia and to compare patient satisfaction with samfilcon A lenses to prior experience with senofilcon A or lotrafilcon B CLs.

Methods

This was a comparative, prospective, national study conducted at 14 centers in Turkey. Subjects were adults aged 18 and 45 years with myopia (range −0.25 D to −6.00 D) who spend a minimum of 3 hours viewing digital devices (e.g., computer, smartphone). A subgroup of patients were habitual lens wearers (senofilcon A or lotrafilcon B lens wear for at least 6 months prior to enrollment). The primary assessment was patient satisfaction with samfilcon A lenses (0–100 Likert scale). Secondary assessments included patient satisfaction with samfilcon A lenses compared to patients’ habitual lenses, investigator satisfaction with samfilcon A lenses and investigator-evaluated slit lamp examination findings.

Results

Samfilcon A lenses were given high overall ratings from both patients and investigators, with a low incidence of ocular symptoms. Overall, patients were highly satisfied with samfilcon A lenses for comfort, vision and overall performance, and stated that they would consider wearing these lenses in the future. Among habitual senofilcon A or lotrafilcon B lens wearers, samfilcon A lenses were rated significantly better than the habitual lenses in regard to comfort, vision and overall performance. Investigator assessments were also highly favorable, both at initial fit and after 4 weeks of follow-up, with no significant findings noted on slit lamp examination.

Conclusion

Samfilcon A lenses were rated highly by investigators in regard to fit, handling and slit lamp findings, and by novice and habitual lens wearers in regard to comfort, vision and overall performance. These results support the use of samfilcon A lenses among digital device users who seek day-long comfort and good visual acuity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-021-00389-4.

Impact of the use of digital devices on eyes during the lockdown period of COVID-19 pandemic

Purpose:

The purpose of this study is to observe pattern of digital device use and the various ocular, visual and systemic symptoms associated with them during the lockdown period of the novel coronavirus disease (COVID-19) pandemic.

Methods:

Two hundred and thirty-three volunteers were included in web-based open e-survey. The survey was designed on the ‘Survey Monkey’ website and distributed through social media platform. The information was collected regarding hours and numbers of digital devices along with numbers of digital activities carried out during the pandemic. A pretested symptom questionnaire was also included regarding ocular, visual and systemic symptoms before and during lockdown. The statistical analysis was carried out using Statistical Package of Social Science software.

Results:

During the pandemic, most of the respondents were engaged in more than two digital activities (73.81%) over more than two digital devices (48.50%) for more than six days (65.66%). Maximum respondents were mobile users (97.85%) spending major time on social media (89.70%). Symptoms including watering eyes (P = 0.000), dry eyes (P = 0.000), shoulder pain (P = 0.020), back pain (P = 0.003) and headache (P = 0.043) showed positive correlation with hours of digital device use per day during lockdown, while itching eyes (P = 0.036) and pain behind eyes (P = 0.025) were the major symptoms in those engaged in a greater number of digital activities. Moreover, red eyes (P = 0.040) were more prominent in respondents using multiple devices for a greater number of hours.

Conclusion:

A big jump in digital activities on multiple digital devices was seen during lockdown which are more prone to ocular symptoms. Acceleration of ocular and systemic symptoms was particular with rise in time spending on digital devices.

Prevalence and risk factors of dry eye disease in young and middle-aged office employee: a Xi'an Study

AIM

To estimate the prevalence of and risk factors for dry eye disease (DED) in young and middle-aged office employee in Xi'an.

METHODS

This cross-sectional study of the prevalence of and risk factors for DED investigated 486 young and middle-aged Chinese office employee in Xi'an. DED symptoms and potential risk factors were assessed using the ocular surface disease index combined with a risk factors questionnaire, and tear function was evaluated using the tear film break-up time and Schirmer's test. Possible risk factors for DED were estimated by binary Logistic regression analysis.

RESULTS

DED was diagnosed in 100 females and 96 males, giving a prevalence of 40.3% [95% confidence interval (CI)=36.0%-44.7%]. The multivariate binary Logistic regression model indicated that the possible risk factors for DED were being female (OR=1.592, 95%CI=1.034-2.451, P=0.035), being aged ≥40y (OR=1.593, 95%CI=1.034-2.454, P=0.035), using a VDT daily for >6h (OR=1.990, 95%CI=1.334-2.971, P=0.001), the presence of central air conditioning (OR=1.548, 95%CI=1.053-2.276, P=0.026), and self-reported dryness of the mouth and nose (OR=1.589, 95%CI=1.071-2.357, P=0.021).

CONCLUSION

There is a high prevalence of clinically diagnosed DED in young and middle-aged video display terminal (VDT) users. Interventions against the modifiable risk factors should be taken to prevent the occurrence and development of DED in this population.

Screen time duration and timing: effects on obesity, physical activity, dry eyes, and learning ability in elementary school children

Background

As internet use becomes more widespread, the screen time (ST) of elementary school students increases yearly. It is known that longer durations of ST can affect obesity, physical activity, dry eye disease, and learning ability. However, the effects of ST just before bedtime have not been clarified. Therefore, we examined ST duration and timing effects on elementary school children.

Methods

We conducted a survey of 7419 elementary school students in Tokyo, Japan using a questionnaire on food education. ST duration and timing (just before bedtime) served as the explanatory variables, and the relationship between obesity, physical activity, dry eyes, and learning ability was analyzed using logistic regression analysis. Gender, school year, height, and weight were considered confounding factors. First, we examined whether ST duration and timing were related to each objective variable, using a univariate model to examine all variables. Thereafter, we performed multivariate logistic regression analyses for all variables showing a significant difference in the univariate models.

Results

A significant association was observed between ST duration and obesity, physical activity, and academic performance, indicating that a longer ST duration may lead to obesity, decreased physical activity, and decreased academic performance. ST timing was associated with obesity, dry eyes, and academic performance, and ST immediately before bedtime contributed to obesity, dry eyes, and reduced academic performance. Furthermore, the results of investigating the combined effect of ST duration and timing (immediately before bedtime) on these factors revealed that ST timing has a greater effect on dry eyes, and ST duration has a greater effect on academic performance.

Conclusion

Our findings indicate that ST in school children is related to obesity, physical activity, dry eyes, and learning ability, and they suggest that not only the duration but also the timing of ST is important.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10484-7.

Dry Eye Disease Association with Computer Exposure Time Among Subjects with Computer Vision Syndrome

Purpose

To assess the time of exposure to the computer and dry eye disease (DED) in subjects with computer vision syndrome (CVS).

Methods

A cross-sectional study was conducted in office workers, computer users of both sexes, with an age range of 18–45 years without comorbidities; we included 108 subjects divided into 3 groups according to the time of computer exposure in hours per day (H/D): <4 (n = 23), 4 −7.9 (n = 49), >8 (n = 39). A specific questionnaire was applied to them on the exposure time and the type of visual display terminal (VDT) used, as well as the computer vision symptoms scale (CVSS17). DED was diagnosed with the Ocular Surface Disease Index (OSDI). Ocular surface damage and signs of DED were evaluated with the tear rupture time test (TBUT), the integrity of the ocular surface by ocular surface staining (OSS) and the production of the aqueous basal tear film using the Schirmer test.

Results

Average computer exposure time, measured differently, was positively correlated with DED development. The computer exposure time measured in hours per year and TBUT showed a significant negative correlation (p <0.001) (rho −0.463). Years of computer exposure and staining of the ocular surface showed a significant positive correlation (p <0 0.001; rho 0.404). The accumulated exposure time was negatively correlated with TBUT (p <0.001; rho −0.376) and positively with OSS (p <0.001; rho 0.433). Schirmer test did not correlate with computer exposure time.

Conclusion

The prolonged time of exposure to the computer in subjects with CVS was significantly correlated with the DED tests, in the different ways of measuring it; but not with the Schirmer test.

The Effects of Chewing Gum in Preventing Eyestrain

Purpose

To investigate the effects of chewing gum and tablet candy to reduce eyestrain in healthy individuals.

Materials and Methods

A double-blinded crossover trial was conducted. Forty-six healthy individuals (23 men, 23 women) between 20 and 59 years old, feeling eyestrain, were enrolled. Each 10-year age group included 12 individuals except the 30s group, which included 10 individuals. A visual task was performed on reading material displayed on a computer screen at a fixed distance for 60 min. Gum or tablet candy of two pieces were chewed for two 15-min periods starting 15 and 45 min after starting to read. Subjects chewed gum on Day 1 and tablet candy on Day 2, and vice versa. Primary outcome is as follows: subjective eye fatigue (eye tiredness, eye heaviness, blurred vision, double vision, and eye dryness) using a visual analog scale (VAS). Secondary outcomes are as follows: subjective accommodation from near and far points of accommodation measured with a D'ACOMO, spherical equivalent refraction, and eye dryness by analyzing ring break-up time (RBUT) measured with the RT-7000 Auto Ref-Topographer.

Results

The VAS scores of subjective eye fatigue were not significantly changed between chewing gum and tablet candy (P = 0.397 − P = 0.909). Those scores of eye tiredness and eye heaviness were significantly longer before and after the visual task with tablet candy (P = 0.013 and P = 0.025, respectively) but not with chewing gum. The changes of subjective accommodation were significantly lower after the visual task between chewing gum and candy (P = 0.043). There were significant differences among each age group (20 s vs. 30 s, P = 0.594; 20 s vs. 40 s, P = 0.002; 20 s vs. 50 s, P = 0.002). After reading, the changes of spherical equivalent refraction did not indicate a shift toward myopia (P = 0.267). In the RBUT, there were no significant differences between the samples (P = 0.680).

Conclusions

Chewing gum helps improve the ability of the eye to focus, especially in young adults.

Use of digital displays and ocular surface alterations: A review

Digital display use has been accepted to be implicated as a contributing factor for dry eye disease (DED). Abnormal blinking during computer operation, including a reduced blink rate and an incomplete eyelid closure, increased palpebral fissure as consequence of high visualization angles, and meibomian gland dysfunction associated to long-term display use, are behind the increased prevalence of dry eye signs and symptoms found in digital display users. Previous research reveals significant reductions in tear volume and stability, alterations in tear film composition, including increased osmolarity, inflammatory cytokines, oxidative stress markers and reduced mucin secretion, eyelid abnormalities and ocular surface damage, encompassing corneal and conjunctival staining and bulbar redness, as a direct consequence of digital display use. In this regard, individual differences in the way that the various digital displays are typically set up and used may account for differences in their effects on induced dryness signs and symptoms. Furthermore, factors such as the use of contact lenses or inappropriate working environments, usually accompanying the use of displays, may significantly increase the prevalence and the severity of induced dry eye. Other factors, such as old age and female gender are also relevant in the appearance of associated alterations. Finally, clinicians should adopt a treatment strategy based on a multidirectional approach, with various treatments being applied in conjunction.

Effect of warming eyelids on tear film stability and quality of life in visual display terminal users: a randomized controlled trial

We aimed to evaluate the effect of warming eyelids on tear-film stability and quality of life (QoL) in video display terminal (VDT) users. A prospective study was conducted and 45 volunteers with ocular symptoms and tear-film instability associated with VDT use were randomly allocated into the study (n = 22) or control groups (n = 23). Subjects in the study group used eyelid warming steamer (EWS) for 2 weeks and tear fluorescein breakup time (TBUT) after single and 2-week EWS treatment, Schirmer I test, ocular surface staining scores, meibomian gland assessment, severity of dry eye disease (DED) and QoL scores after 2-week EWS treatment were analysed. The TBUT improved after both single and 2-week EWS treatment (P = 0.023 and 0.027, respectively) in the study group. The ocular surface staining scores were significantly decreased only in the study group (P = 0.038). About 60% DED patients in the study group shifted towards non-DED and the pattern of distribution was significantly different compared to baseline (P < 0.001). The QoL scores significantly improved in the study group (P = 0.002) with a negative correlation with TBUT. In conclusion, in VDT users with short TBUT, eyelid warming steamer is effective in improving tear-film stability and QoL.

A New Perspective on Dry Eye Classification: Proposal by the Asia Dry Eye Society

The 2017 consensus report of the Asia Dry Eye Society (ADES) on the definition and diagnosis of dry eyes described dry eye disease as "Dry eye is a multifactorial disease characterized by unstable tear film causing a variety of symptoms and/or visual impairment, potentially accompanied by ocular surface damage." The report emphasized the instability of tear film and the importance of visual dysfunction in association with dry eyes, highlighting the importance of the evaluation of tear film stability. This report also discussed the concept of tear film-oriented therapy, which stemmed from the definition, and which is centered on provision of insufficient components in each tear film layer and ocular surface epithelium. The current ADES report proposes a simple classification of dry eyes based on the concept of tear film-oriented diagnosis and suggests that there are three types of dry eye: aqueous-deficient, decreased wettability, and increased evaporation. It is suggested that these three types respectively coincide with the problems of each layer: aqueous, membrane-associated mucins, and lipid/secretory mucin. Although each component cannot be quantitatively evaluated with the current technology, a practical diagnosis based on the patterns of fluorescein breakup is recommended. The Asia Dry Eye Society classification report suggests that for a practical use of the definition, diagnostic criteria and classification system should be integrated and be simple to use. The classification system proposed by ADES is a straightforward tool and simple to use, only through use of fluorescein, which is available even to non-dry eye specialists, and which is believed to contribute to an effective diagnosis and treatment of dry eyes.

Arginase 1 is involved in lacrimal hyposecretion in male NOD mice, a model of Sjögren's syndrome, regardless of dacryoadenitis status

Key points

Few reports have explored the possibility of involvement of non‐inflammatory factors in lacrimal hyposecretion in Sjögren's syndrome (SS).

RNA‐sequencing analysis revealed that only four genes, including arginase 1, were downregulated in the lacrimal gland of SS model male mice (NOD mice) after onset of lacrimal hyposecretion and dacryoadenitis.

Even in non‐dacryoadenitis‐type NOD mice, tear secretion and arginase 1 expression remained low.

An arginase 1 inhibitor reduced tear secretion and partially reduced saliva secretion in BALB/c mice.

The results indicate that a non‐inflammatory factor, arginase 1, is involved in lacrimal hyposecretion in male NOD mice, regardless of dacryoadenitis status.

Abstract

Lacrimal fluid (tears) is important for preservation of the ocular surface, and thus lacrimal hyposecretion in Sjögren's syndrome (SS) leads to reduced quality of life. However, the cause(s) of lacrimal hyposecretion remains unknown, even though many studies have been conducted from the perspective of inflammation. Here, we hypothesized that a non‐inflammatory factor induces lacrimal hyposecretion in SS pathology, and to elucidate such a factor, we conducted transcriptome analysis of the lacrimal glands in male non‐obese diabetic (NOD) mice as an SS model. The NOD mice showed inflammatory cell infiltration and decreased pilocarpine‐induced tear secretion at and after 6 weeks of age compared to age‐matched BALB/c mice. RNA‐sequencing analysis revealed that only four genes, including arginase 1, were downregulated, whereas many genes relating to inflammation were upregulated, in the lacrimal glands of male NOD mice after onset of lacrimal hyposecretion and dacryoadenitis (lacrimal gland inflammation). Changes in the level of arginase 1 expression were confirmed by real‐time RT‐PCR and western blot analysis. Furthermore, non‐dacryoadenitis‐type NOD mice were used to investigate the relationships among arginase 1 expression, lacrimal hyposecretion and dacryoadenitis. Interestingly, these NOD mice retained the phenotype of dacryoadenitis with regard to tear secretion and arginase 1 expression level. An arginase 1 inhibitor reduced tear secretion and partially reduced saliva secretion in BALB/c mice. In conclusion, a non‐inflammatory factor, arginase 1, is involved in lacrimal hyposecretion in male NOD mice, regardless of dacryoadenitis status. These results shed light on the pathophysiological role of arginase 1 in SS (dry eye).

Few reports have explored the possibility of involvement of non‐inflammatory factors in lacrimal hyposecretion in Sjögren's syndrome (SS).

RNA‐sequencing analysis revealed that only four genes, including arginase 1, were downregulated in the lacrimal gland of SS model male mice (NOD mice) after onset of lacrimal hyposecretion and dacryoadenitis.

Even in non‐dacryoadenitis‐type NOD mice, tear secretion and arginase 1 expression remained low.

An arginase 1 inhibitor reduced tear secretion and partially reduced saliva secretion in BALB/c mice.

The results indicate that a non‐inflammatory factor, arginase 1, is involved in lacrimal hyposecretion in male NOD mice, regardless of dacryoadenitis status.

The Effects of High Molecular Weight Hyaluronic Acid Eye Drop Application in Environmental Dry Eye Stress Model Mice

Hyaluronic acid (HA) ophthalmic solution is widely used in dry eye treatment worldwide. However, there are no reports comparing the dry eye treatment effects of high molecular weight HA with low molecular weight HA. Sixty eight-week-old C57BL/6 mice were assigned to the following 6 groups and exposed to environmental dry eye stress (EDES) that mimics office work environment: 1) 0.1% low molecular weight HA (LMWHA) eye drops, 2) 0.3% LMWHA eye drops, 3) 3% diquafosol sodium (DQ) eye drops, 4) 0.15% high molecular weight HA (HMWHA) eye drops, 5) no treatment with exposure to EDES (EDES+/Treatment-), and 6) no treatment without exposure to EDES (EDES-/Treatment-). After EDES, the HMWHA group had significantly longer break-up time (BUT) than the 0.1%, 0.3% LMWHA groups and the DQ group. After EDES, the HMWHA group had significantly lower lissamine green staining scores than the LMWHA and DQ groups. Subepithelial presumed dendritic cell density in the HMWHA group was significantly lower than the EDES+/Treatment- group. After EDES exposure, Conjunctival Muc5AC mRNA expression in the HMWHA group was significantly higher than the 0.1 and 0.3% LMWHA groups. Ophthalmic HMWHA solution may have a better dry eye treatment effect than LMWHA or DQ solution, owing to its anti-inflammatory effect.

Loss of Concentration May Occur by Blink Inhibition in DED Simulation Models

Purpose: Patients with dry eye disease (DED) often suffer productivity loss and distress due to bothersome symptoms. The aim of this study was to objectively quantify and compare productivity-related emotional states obtained from brain waveforms in natural and simulated DED conditions. Method: 25 healthy adults (6 females and 19 males; mean age ± standard deviation, 22.6 ± 8.3 years) were recruited for the study, which included an electroencephalogram (EEG), measurements of interblinking time, and questionnaires. DED was simulated by suppressing blinking, while spontaneous blinking served as a control. Elements of concentration, stress, and alertness were extracted from the raw EEG waveforms and the values were compared during spontaneous and suppressed blinking. The relation with DED-related parameters was then explored. Written informed consent was obtained from all participants. Results: All participants successfully completed the experimental protocol. Concentration significantly decreased during suppressed blinking in 20 participants (80%), when compared with spontaneous blinking, whereas there were no or small differences in stress or alertness between spontaneous and suppressed blinking. The change in concentration was correlated with interblinking time (β = −0.515, p = 0.011). Conclusion: Loss of concentration was successfully captured in an objective manner using the EEG. The present study may enable us to understand how concentration is affected during blink suppression, which may happen in office work, particularly during computer tasks. Further study using detailed ocular evaluation is warranted to explore the effect of different interventions.

Acupoint selection for the treatment of dry eye: A systematic review and meta-analysis of randomized controlled trials

The effectiveness of acupuncture in the treatment of dry eye has been confirmed, but the association between acupoint selection and therapeutic effect has remained to be elucidated. In the present study, a systematic review and meta-analysis were performed to evaluate the effect of periocular acupoints and periocular acupoints plus body acupoints compared with AT for the treatment of dry eye disease (DED). The PubMed, Cochrane Library, Embase, Ovid, China National Knowledge Infrastructure and Chonqing VIP Information, Co., Ltd. databases were searched with entries until 10 July 2018 considered. Only randomized controlled trials (RCTs) were included. Meta-analyses were performed to compare the effects of acupuncture with those of conventional treatment (including AT or other non-acupuncture therapies). The primary outcomes, including tear break-up time (BUT), Schirmer's I test (SIT) result and Symptom scores were analyzed. Subgroup analysis was performed for periocular acupoints only and periocular acupoints plus body acupoints. A total of 12 studies comprising 900 participants were included. In the primary meta-analysis, a significant improvement in the BUT [n=1,209, weighted mean difference (WMD)=1.01, 95% CI: 0.56-1.84, P<0.00001], SIT result (n=1,107, WMD=1.98, 95% CI: 0.44-3.34, P<0.00001) and Symptom scores (n=402, WMD=-1.02, 95% CI: -1.33 to -0.72, P<0.00001) was obtained to evaluate the clinical efficacy of acupuncture and AT. Furthermore, periocular acupoints plus body acupoints were more effective in the treatment of DED. However, the total sample size of subjects with only periocular acupoints in the treatment of DED was too small to get any firm conclusions. Further large RCTs are warranted.

Identification of Lacrimal Gland Postganglionic Innervation and Its Regulation of Tear Secretion

Tear fluid secreted from the exocrine lacrimal gland (LG) has an essential role in maintaining a homeostatic environment for a healthy ocular surface. Tear secretion is regulated by the sympathetic and parasympathetic components of the autonomic nervous system, although the contribution of each component is not fully understood. To investigate LG innervation, we identified sympathetic and parasympathetic postganglionic nerves, specifically innervating the mouse LG, by injecting a retrograde neuronal tracer into the LG. Interruption of neural stimuli to the LG by the denervation of these postganglionic nerves immediately and chronically decreased tear secretion, leading to LG atrophy along with destruction of the lobular structure. This investigation also found that parasympathetic, but not sympathetic, innervation was involved in these alterations.

The Effects of Rebamipide 2% Ophthalmic Solution Application on Murine Subbasal Corneal Nerves After Environmental Dry Eye Stress

Rebamipide ophthalmic solution is a mucin secretagogue which is an important therapeutic agent in the treatment of dry eye. It has been noted that dry eye in office workers is associated with a decrease in secretory mucin. This study aimed to evaluate the effects of 2% rebamipide ophthalmic solution in mice subjected to environmental dry eye stress (EDES), which mimics the conditions of office workers. Thirty eyes from thirty BALB/c mice (eight-week-old males) were divided into three treatment groups: artificial tear (vehicle), 2% rebamipide ophthalmic solution, and 0.1% hyaluronic acid (HA) ophthalmic solution. After four days of pretreatment, mice were exposed to EDES for three days. The corneal subbasal nerve and inflammatory cells were then examined using in vivo confocal microscopy. Following EDES exposure, the lissamine green staining score was significantly lower and corneal sensitivity was more preserved in the 2% rebamipide group than in the HA group. In addition, the subbasal nerve fiber density was significantly higher and the DC density was significantly lower in the 2% rebamipide group than in the HA group. Overall, the topical rebamipide ophthalmic solution showed more favorable therapeutic effects when compared to the HA ophthalmic solution in a mouse model of EDES, likely owing to its anti-inflammatory and neuroprotective effects.

Correlation between handheld digital device use and asthenopia in Chinese college students: a Shanghai study

PURPOSE

The purpose of this study was to investigate the use of handheld digital devices and the prevalence of self-reported asthenopia among college students in China and their potential relationship.

METHODS

Five thousand students were randomly assessed using a self-reported asthenopia questionnaire. The students' demographic characteristics and habits regarding digital device use were recorded. Univariate analysis was performed to select potential risk factors, and multivariate logistic regression was used to estimate the odds ratios for the selected risk factors of interest.

RESULTS

Among the 4786 students who completed the survey, the prevalence of asthenopia was 53.3%. Multivariate analysis revealed significant relationships between asthenopia and each of the following: level of digital reliance (OR 1.350, 95%CI: 1.230-1.481), workload, time spent on computer per day, sex and time spent on handheld digital devices in bed and at desk. Aerobic exercise duration (OR 0.912, 95%CI: 0.839-0.990) was found to be strong predictor of less asthenopia complaints.

CONCLUSION

Asthenopia appears to be common among college students in China. Preventative measures against asthenopia include limiting the amount of time spent using digital devices in bed (<0.5 h), adopting a posture of lying on one's back while doing so and engaging in aerobic exercise for more than one hour per day. Furthermore, studies on this topic are needed.

Enriched environment alleviates stress-induced dry-eye through the BDNF axis

The number of patients with dry eye disease (DED) is increasing, and DED has become an urgent public health problem. A comorbidity of mental disorders has been reported in DED patients. We hypothesized that physical and psychological stressors impair tear secretion. To examine the relationship between stress loading and decreased tear secretion, we established a stress-induced DED mouse model, which permitted us to address the underlying mechanism of pathogenesis and resilience. Enriched environment (EE) was an effective intervention to prevent and alleviate stress-induced decreased tear secretion. Because stress loading resulted in decreased brain-derived neurotrophic factor (BDNF) expression while EE resulted in increased expression, we focused on the role of BDNF in tear secretion. Using two distinct Bdnf gene knockdown mice, we evaluated whether BDNF was a deterministic factor in regulating tear secretion in healthy and stressed conditions. Bdnf knockdown mice showed decreased basal tear secretion and loss of stress tolerance by EE for tear secretion. These results suggest that BDNF expression is related to tear secretion and to the pathology of DED.

Effects of long-term computer use on eye dryness

OBJECTIVE:

To evaluate the effects of long-term computer use on tear production and evaporation.

METHODS:

In this study, 30 eyes of 30 people using computer for 8 hours a day were taken as the study group. In the control group, 30 eyes of 30 healthy individuals who did not spend 1 hour using computer on a daily basis were evaluated. The cases were examined at 8 am and 5 pm. The Schirmer test, tear break-up time (TBUT), and ocular surface disease index (OSDI) were evaluated.

RESULTS:

There was no significant difference between the groups in terms of age and gender. The Schirmer test results, which measure the parameters of tear production, were 16.80±2.04 and 15.50±2.06 mm (p>0.05) in the study group, and 17.28±1.52 and 17.16±2.53 in the control group. The TBUT measurements were 9.15±2.93 and 6.80±1.11 sec in the study group. It was observed that the evening TBUT decreased (p<0.05). The TBUT measurements were 15.80±3.15 sec and 15.20±1.92 sec (p>0.05) in the control group. The OSDI scores were 26.7±3.36 and 28.3±1.19 in the study group, and 25.0±4.48 and 27.3±2.27 in the control group.

CONCLUSION:

As a result, it was found that a long-term computer use did not change the Schirmer test results significantly, but there were statistically significant changes in the tear break-up time (TBUT) results of the evaporative type eye dryness. According the our study results, long-term computer usage may cause an evaporative-type dry eye disease.

A new dry eye mouse model produced by exorbital and intraorbital lacrimal gland excision

Chronic dry eye is an increasingly prevalent condition worldwide, with resulting loss of visual function and quality of life. Relevant, repeatable, and stable animal models of dry eye are still needed. We have developed an improved surgical mouse model for dry eye based on severe aqueous fluid deficiency, by excising both the exorbital and intraorbital lacrimal glands (ELG and ILG, respectively) of mice. After ELG plus ILG excision, dry eye symptoms were evaluated using fluorescein infiltration observation, tear production measurement, and histological evaluation of ocular surface. Tear production in the model mice was significantly decreased compared with the controls. The corneal fluorescein infiltration score of the model mice was also significantly increased compared with the controls. Histological examination revealed significant severe inflammatory changes in the cornea, conjunctiva or meibomian glands of the model mice after surgery. In the observation of LysM-eGFP^(+/−) mice tissues, postsurgical infiltration of green fluorescent neutrophils was observed in the ocular surface tissues. We theorize that the inflammatory changes on the ocular surface of this model were induced secondarily by persistent severe tear reduction. The mouse model will be useful for investigations of both pathophysiology as well as new therapies for tear-volume-reduction type dry eye.

Restoration of Tear Secretion in a Murine Dry Eye Model by Oral Administration of Palmitoleic Acid

Sea buckthorn (Hippophae rhamnoides)-derived products have traditionally been used as food and medicinal ingredients in Eastern countries. The purpose of this study was to investigate the effect of oral intake of sea buckthorn oil products on tear secretion using a murine dry eye model. Orally administered sea buckthorn pulp oil (not seed oil) restored aqueous tear secretion to its normal value under a dry eye condition. Palmitoleate (C16:1), a fatty acid present in sea buckthorn pulp oil, preserved tear secretion and suppressed inflammatory cytokines in the lacrimal gland to the same extent as that by pulp oil. These results suggest that an oral intake of sea buckthorn pulp oil has a potency to preserve tear secretion capacity in the dry eye state and palmitoleate, its main constituent fatty acid, is an active component of the oil. This effect may enable a potent diet-based treatment for the prevention of dry eye.

External eye symptoms in indoor environments

Eye irritation, for example dry or irritated eyes, is generally among top three reported symptoms in office-like environments, in particular among workplaces with cognitive demanding visual display unit (VDU) work. The symptoms are especially among middle and advanced ages and particularly among women more than men. The symptoms are also among the most commonly reported complaints in the eye clinic. To be in a position to interpret the high prevalence of eye symptoms, a multidisciplinary and integrated approach is necessary that involves the external eye physiology (separate from internal eye effects), eye diseases (evaporative dry eye (DE), aqueous-deficient DE, and gland dysfunctions), and risk factors that aggravate the stability of precorneal tear film (PTF) resulting in hyperosmolarity and initiation of inflammatory reactions. Indoor environmental, occupational and personal risk factors may aggravate the PTF stability; factors such as age, contact lenses, cosmetics, diet, draft, gender, low humidity and high temperature, medication, outdoor and combustion pollutants, and VDU work. Psychological stressors may further influence the reporting behavior of eye symptoms. The impact of the risk factors may occur in a combined and exacerbating manner.

Clinical Evaluation of a Royal Jelly Supplementation for the Restoration of Dry Eye: A Prospective Randomized Double Blind Placebo Controlled Study and an Experimental Mouse Model

Background

Dry eye is a multifactorial disease characterized by ocular discomfort and visual impairment. Lacrimal gland function has been shown to decrease with aging, a known potent risk factor for dry eye. We have previously found that orally administrated royal jelly (RJ) restored tear secretion in a rat model of dry eye.

Methods and Findings

We examined the effects of RJ oral administration on dry eye in this prospective, randomized, double-blind, placebo-controlled study. Forty-three Japanese patients aged 20–60 years with subjective dry eye symptoms were randomized to an RJ group (1200 mg/tablet, six tablets daily) or a placebo group for 8 weeks. Keratoconjunctival epithelial damage, tear film break-up time, tear secretion volume, meibum grade, biochemical data, and subjective dry eye symptoms based on a questionnaire were investigated at baseline, and at 4 and 8 weeks after intervention. Adverse events were reported via medical interviews. In the RJ group, tear volume significantly increased after intervention (p = 0.0009). In particular, patients with a baseline Schirmer value of ≤10 mm showed a significant increase compared with baseline volume (p = 0.0005) and volume in the placebo group (p = 0.0051). No adverse events were reported. We also investigated the effect of RJ (300 mg/kg per day) administration using a mouse model of dry eye. Orally repeated administration of RJ preserved tear secretion, potentially through direct activation of the secretory function of the lacrimal glands.

Conclusion

Our results suggest that RJ improves tear volume in patients with dry eye.

Trial Registration

Registered NO. the University Hospital Medical Information Network in Japan (UMIN000014446)