Use of digital displays and ocular surface alterations: A review

Prevalence of Computer Vision Syndrome and Its Risk Factors in a Spanish University Population

OBJECTIVES

To determine the prevalence of digital eye strain or computer vision syndrome (CVS) and its risk factors in a university population (University of Valladolid, Spain).

METHODS

An anonymous cross-sectional online survey was conducted in a university population [staff (lecturers and administrative employees) and students (undergraduate, master's, and PhD)], including two validated questionnaires (Ocular Surface Disease Index [OSDI] and the 17-item Computer-Vision Symptom Scale questionnaire [CVSS17]) and questions about sociodemographic data and visual display terminal use. The prevalence and risk factors for CVS (CVSS17≥29) (multivariate logistic regression model) were calculated.

RESULTS

One thousand nine participants responded to the survey (35.2±15.2 years; 64.1% women). The mean OSDI and CVSS17 questionnaire scores were 18.9±15.6 and 31.5±6.4, respectively, and 35.4% of the respondents had dry eye symptoms (OSDI>22). The total prevalence of CVS was 65.4% (95% CI 62.1-68.3). Undergraduate students showed the highest CVS prevalence (72.6%; P <0.01), which was significant. In addition, women, participants younger than 36 years old, contact lens wearers, and subjects with dry eye symptoms reported a statistically higher CVSS17 score ( P ≤0.01). In the multivariate model, significant factors associated with the presence of CVS ( P ≤0.03) were female sex (OR=2.10; 95% CI 1.54-2.88), dry eye symptoms (OSDI>22) (OR=16.98; 95% CI 10.36-27.84), VTD use ≥6 hr daily (OR=1.96; 95% CI 1.09-3.52), and being an undergraduate student (OR=2.23; 95% CI 1.54-3.24).

CONCLUSION

A high prevalence (65.4%) of CVS was found among the Spanish university population, with the undergraduate student group having the highest prevalence (72.6%). Female sex, more than 6 hr/day of visual display terminal use, being an undergraduate student, and dry eye symptoms significantly increased the risk of CVS in the university population.

Single-cell landscape reveals the epithelial cell-centric pro-inflammatory immune microenvironment in dry eye development

Dry eye disease (DED) is a prevalent chronic eye disease characterized by an aberrant inflammatory response in ocular surface mucosa. The immunological alterations underlying DED remain largely unknown. In this study, we employed single-cell transcriptome sequencing of conjunctival tissue from environment-induced DED mice to investigate multicellular ecosystem and functional changes at different DED stages. Our results revealed an epithelial subtype with fibroblastic characteristics and pro-inflammatory effects emerging in the acute phase of DED. We also found that T helper (Th)1, Th17, and regulatory T cells (Treg) were the dominant clusters of differentiation (CD)4+ T-cell types involved in regulating immune responses and identified three distinct macrophage subtypes, with the CD72+CD11c+ subtype enhancing chronic inflammation. Furthermore, bulk transcriptome analysis of video display terminal-induced DED consistently suggested the presence of the pro-inflammatory epithelial subtype in human conjunctiva. Our findings have uncovered a DED-associated pro-inflammatory microenvironment in the conjunctiva, centered around epithelial cells, involving interactions with macrophages and CD4+ T cells, which deepens our understanding of ocular surface mucosal immune responses during DED progression.

Ocular surface changes following computer use in post-LASIK patients

PURPOSE

To assess the impact of computer use on the ocular surface of individuals after laser in situ keratomileusis (LASIK).

METHODS

The dry eye symptoms and ocular surface of 18 post-LASIK young individuals and 18 controls were evaluated before and after performing a 30-min task on a computer without (Visit 1) and with (Visit 2) initial instillation of artificial tears. Symptoms were assessed using the Ocular Surface Disease Index (OSDI), Symptom Assessment in Dry Eye questionnaire version two (SANDE II) and Computer Vision Syndrome Questionnaire (CVS-Q). The ocular surface was assessed by measuring corneal higher order aberrations, tear meniscus height (TMH), conjunctival redness, blink rate and incomplete blinking, lipid layer thickness (LLT) and non-invasive keratograph break-up time (NIKBUT).

RESULTS

SANDE II scores were >0 after the computer task in both groups (p ≤ 0.01). SANDE II and CVS-Q scores did not differ between LASIK and controls (p ≥ 0.43). Greater bulbar-temporal conjunctival redness, TMH and LLT and shorter NIKBUT were found after computer use in the LASIK group (p ≤ 0.04), whereas no changes were observed in the controls (p ≥ 0.20). Lower SANDE II and CVS-Q scores were reported at Visit 2 compared with Visit 1 in both groups (p ≤ 0.01). Likewise, no worsening of dry eye signs was observed at Visit 2 (p ≥ 0.11).

CONCLUSIONS

Ocular symptoms reported during computer use were comparable between the groups. However, a worsening of dry eye signs was mostly observed in post-LASIK individuals. The instillation of artificial tears was effective in preventing the effects of computer use on the ocular surface in post-LASIK patients.

Comparing the impact of three-dimensional digital visualization technology versus traditional microscopy on microsurgeons in microsurgery: a prospective self-controlled study

BACKGROUND

Emerging three-dimensional digital visualization technology (DVT) provides more advantages than traditional microscopy in microsurgery; however, its impact on microsurgeons' visual and nervous systems and delicate microsurgery is still unclear, which hinders the wider implementation of DVT in digital visualization for microsurgery.

METHODS AND MATERIAL

Forty-two microsurgeons from the Zhongshan Ophthalmic Center were enrolled in this prospective self-controlled study. Each microsurgeon consecutively performed 30 min conjunctival sutures using a three-dimensional digital display and a microscope, respectively. Visual function, autonomic nerve activity, and subjective symptoms were evaluated before and immediately after the operation. Visual functions, including accommodative lag, accommodative amplitude, near point of convergence and contrast sensitivity function (CSF), were measured by an expert optometrist. Heart rate variability was recorded by a wearable device for monitoring autonomic nervous activity. Subjective symptoms were evaluated by questionnaires. Microsurgical performance was assessed by the video-based Objective Structured Assessment of Technical Skill (OSATS) tool.

RESULTS

Accommodative lag decreased from 0.63 (0.18) diopters (D) to 0.55 (0.16) D ( P =0.014), area under the log contrast sensitivity function increased from 1.49 (0.15) to 1.52 (0.14) ( P =0.037), and heart rate variability decreased from 36.00 (13.54) milliseconds (ms) to 32.26 (12.35) ms ( P =0.004) after using the DVT, but the changes showed no differences compared to traditional microscopy ( P >0.05). No statistical significance was observed for global OSATS scores between the two rounds of operations [mean difference, 0.05 (95% CI: -1.17 to 1.08) points; P =0.95]. Subjective symptoms were quite mild after using both techniques.

CONCLUSIONS

The impact of DVT-based procedures on microsurgeons includes enhanced accommodation and sympathetic activity, but the changes and surgical performance are not significantly different from those of microscopy-based microsurgery. Our findings indicate that short-term use of DVT is reliable for microsurgery and the long-term effect of using DVT deserve more consideration.

Nicotinamide mononucleotide, a potential future treatment in ocular diseases

PURPOSE

The burden of ocular diseases has been gradually increasing worldwide. Various factors are suggested for the development and progression of ocular diseases, such as ocular inflammation, oxidative stress, and complex metabolic dysregulation. Thus, managing ocular diseases requires the modulation of pathologic signaling pathways through many mechanisms. Nicotinamide mononucleotide (NMN) is a bioactive molecule naturally found in life forms. NMN is a direct precursor of the important molecule nicotinamide adenine dinucleotide (NAD+), an essential co-enzyme required for enormous cellular functions in most life forms. While the recent experimental evidence of NMN treatment in various metabolic diseases has been well-reviewed, NMN treatment in ocular diseases has not been comprehensively summarized yet. In this regard, we aimed to focus on the therapeutic roles of NMN treatment in various ocular diseases with recent advances.

METHODS

How we came to our current opinion with a recent summary was described based on our own recent reports as well as a search of the related literature.

RESULTS

We found that NMN treatment might be available for the prevention of and protection from various experimental ocular diseases, as NMN treatment modulated ocular inflammation, oxidative stress, and complex metabolic dysregulation in murine models for eye diseases such as ischemic retinopathy, corneal defect, glaucoma, and age-related macular degeneration.

CONCLUSION

Our current review suggests and discusses new modes of actions of NMN for the prevention of and protection from various ocular diseases and can urge future research to obtain more solid evidence on a potential future NMN treatment in ocular diseases at the preclinical stages.

Prevalence of dry eye during the COVID-19 pandemic: A systematic review and meta-analysis

OBJECTIVE

During the COVID-19 pandemic, many people devoted longer time to screen viewing due to the need for study, work, and online social activities, instead of outdoor activities, which may have led to an increase in dry eye symptoms. This study aimed to evaluate the prevalence of dry eye during the COVID-19 pandemic.

METHODS

PubMed, Cochrane Library, Embase, and Web of Science were searched from January 1, 2020 to October 20, 2022. Cross-sectional surveys on dry eye prevalence conducted after January 1, 2020 were included. Two review authors independently performed data extraction and assessed study quality. The random-effects model was used to analyze the prevalence of dry eye, and the odds ratio was used to assess the strength of the association between variables. Subgroup analysis was performed to detect heterogeneity, the leave-one-out method for sensitivity analysis, and the Egger test for publication bias.

RESULTS

A total of eleven studies with 15692 individuals met the eligibility criteria. The prevalence of dry eye during the COVID-19 pandemic was 61.0% (95%CI: 51.8%-70.2%) globally and 56.7% (95%CI: 45.3%-68.1%) in Asia. The prevalence of dry eye had significant differences in sex and visual display time, with higher prevalence among females and visual display time of more than 4 hours per day. Subgroup analysis was performed based on diagnostic tools, study population, and average age. A significant difference was found in diagnostic tools, but no significant change in heterogeneity (P<0.05). The leave-one-out method showed stable results, and the Egger test identified no significant publication bias.

CONCLUSION

The prevalence of dry eye during the COVID-19 pandemic is significantly higher than before, and a higher prevalence is found among females and those having a visual display time of more than 4 hours per day.

Awareness About Dry Eye Symptoms and Risk Factors Among Eastern Province Population in Saudi Arabia

Background Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS), is a common cause of patient's visits to the ophthalmologist. It is characterized by a defect in the tear film homeostasis, symptoms of ocular discomfort, and visual disturbance. Also, it increases the risk of ocular surface damage if complicated by tear film hyperosmolarity and ocular surface inflammation. The present study aims to measure awareness about dry eye disease and the risk factors among the Eastern region population in Saudi Arabia via an online questionnaire. Methods This is a cross-sectional community-based study conducted in Saudi Arabia that assessed knowledge and awareness of dry eye among the eastern province population using a self-administered online questionnaire. The minimum sample size was 385 adults. Statistical analysis was performed using SPSS software, version 21.0 (IBM Corp., Armonk, NY), and participants' overall awareness level was evaluated based on correct answers. Results In this study, a total of 522 participants fulfilling the inclusion criteria completed the study questionnaire. Participants ranged from 18 to 65 years, with a mean age of 27.2 ± 14.6 years old. Females represented a higher percentage of the sample, 341 (65.3%). Public awareness regarding dry eye diseases in the Eastern region, Saudi Arabia of 149 participants (28.5%) is overall a good awareness level while 373 (71.5%) of them had poor awareness. Conclusion Participants showed unsatisfactory results in awareness of risk factors of dry eye symptoms, where the most reported causes were prolonged concentration while using electronic devices, climatic factors, and lacrimal gland disorders.

Design and Usability Study of a Point of Care mHealth App for Early Dry Eye Screening and Detection

Significantly increased eye blink rate and partial blinks have been well documented in patients with dry eye disease (DED), a multifactorial eye disorder with few effective methods for clinical diagnosis. In this study, a point of care mHealth App named "EyeScore" was developed, utilizing blink rate and patterns as early clinical biomarkers for DED. EyeScore utilizes an iPhone for a 1-min in-app recording of eyelid movements. The use of facial landmarks, eye aspect ratio (EAR) and derivatives enabled a comprehensive analysis of video frames for the determination of eye blink rate and partial blink counts. Smartphone videos from ten DED patients and ten non-DED controls were analyzed to optimize EAR-based thresholds, with eye blink and partial blink results in excellent agreement with manual counts. Importantly, a clinically relevant algorithm for the calculation of "eye healthiness score" was created, which took into consideration eye blink rate, partial blink counts as well as other demographic and clinical risk factors for DED. This 10-point score can be conveniently measured anytime with non-invasive manners and successfully led to the identification of three individuals with DED conditions from ten non-DED controls. Thus, EyeScore can be validated as a valuable mHealth App for early DED screening, detection and treatment monitoring.

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.

Visual Quality, Motility Behavior, and Retinal Changes Associated with Reading Tasks Performed on Electronic Devices

BACKGROUND

The purpose of this study was to objectively evaluate visual discomfort using an eye tracker and aberrometer after a 21-min reading session on an iPad and an Ebook. Additionally, retinal changes were analyzed using optical coherence tomography (OCT).

METHODS

A total of 31 young subjects (24 ± 4 years) participated in this study. They read for 21 min on an Ebook and for another 21 min on an iPad under controlled lighting conditions while their eye movements were monitored using an eye tracker. Aberrometry and retinal OCT measurements were taken before and after each reading session. Parameters such as pupil diameter, fixations, saccades, blinks, total aberration, high-order aberration, low-order aberration, and central and peripheral retinal thickness in the nine early treatment diabetic retinopathy study (ETDRS) areas were measured for each reading situation. Statistical analysis was performed on the collected data.

RESULTS

No statistically significant differences (p > 0.05) between the two devices were observed in terms of the different types of eye movements or the changes in retinal thickness. However, the aberrometric analysis showed variations in post-reading situations depending on the device used.

CONCLUSION

Reading speed and visual discomfort resulting from electronic device usage can be objectively assessed using an eye tracker and aberrometer. Additionally, changes found in central and peripheral retinal thickness between the two devices and the baseline measurements were not significant and remained relatively stable.

TFOS Lifestyle: Impact of contact lenses on the ocular surface

Several lifestyle choices made by contact lens wearers can have adverse consequences on ocular health. These include being non-adherent to contact lens care, sleeping in lenses, ill-advised purchasing options, not seeing an eyecare professional for regular aftercare visits, wearing lenses when feeling unwell, wearing lenses too soon after various forms of ophthalmic surgery, and wearing lenses when engaged in risky behaviors (e.g., when using tobacco, alcohol or recreational drugs). Those with a pre-existing compromised ocular surface may find that contact lens wear exacerbates ocular disease morbidity. Conversely, contact lenses may have various therapeutic benefits. The coronavirus disease-2019 (COVID-19) pandemic impinged upon the lifestyle of contact lens wearers, introducing challenges such as mask-associated dry eye, contact lens discomfort with increased use of digital devices, inadvertent exposure to hand sanitizers, and reduced use of lenses. Wearing contact lenses in challenging environments, such as in the presence of dust and noxious chemicals, or where there is the possibility of ocular trauma (e.g., sport or working with tools) can be problematic, although in some instances lenses can be protective. Contact lenses can be worn for sport, theatre, at high altitude, driving at night, in the military and in space, and special considerations are required when prescribing in such situations to ensure successful outcomes. A systematic review and meta-analysis, incorporated within the review, identified that the influence of lifestyle factors on soft contact lens dropout remains poorly understood, and is an area in need of further research. Overall, this report investigated lifestyle-related choices made by clinicians and contact lens wearers and discovered that when appropriate lifestyle choices are made, contact lens wear can enhance the quality of life of wearers.

Visual complaints during the COVID-19 pandemic in Spain and Portugal

PURPOSE

This study reports visual health during the COVID-19 pandemic in 2021 in Spain and Portugal, focusing on eye complaints and population habits.

MATERIAL AND METHODS

Cross-sectional survey through an online email invitation to patients attending ophthalmology clinics in Spain and Portugal from September to November 2021. Around 3833 participants offered valid anonymous responses in a questionnaire.

RESULTS

Sixty percent of respondents identified significant discomfort related to dry eye symptoms for increased screen time and lens fogging using facemasks. 81.6% of the participants used digital devices for more than 3 h per day and 40% for more than 8 h. In addition, 44% of participants referred to worsening near vision. The most frequent ametropias were myopia (40.2%) and astigmatism (36.7%). Parents considered eyesight the most important aspect of their children (87.2%).

CONCLUSIONS

The results show the challenges for eye practices during the initial COVID-19 pandemic. Focusing on signs and symptoms that lead to ophthalmologic conditions is an essential concern, especially in our digital society highly dependent on vision. At the same time, the excessive use of digital devices during this pandemic has aggravated dry eye and myopia.

Lutein fortification of wheat bread with marigold powder: impact on rheology, water dynamics, and structure

BACKGROUND

Demands for foods conducive to eye health have been on the increase in the global healthcare sector. Marigold powder as a major source of lutein was utilized to produce lutein-fortified breads for ocular health. The physicochemical characteristics of the doughs and breads were investigated in terms of rheology, water mobility, and protein secondary structures.

RESULTS

The incorporation of marigold powder decreased the water absorption of doughs without significantly altering thermomechanical properties. With a range of fortification levels (1-3%), marigold powder led to decreased storage and loss modulus of doughs by weakening their gluten network, which was supported by their T₂ relaxation times. The resistance of the doughs weakened with increasing levels of marigold powder, while their extensibilities significantly incremented. Fourier transform infrared spectral deconvolution revealed the changes in wheat protein structures upon marigold powder incorporation, in which the proportion of β-turn increased at the expense of β-sheet ratio. The breads with marigold powder displayed increased specific volume from 4.034 to 4.368 mL g^-1 , accompanied by softer textures. The baking process led to heat-induced losses in lutein concentration of less than 10% within the crumb and approximately 30% in the crust.

CONCLUSION

The use of marigold powder induced changes in protein secondary structure and extensional features of doughs, contributing to increased loaf volume and softer texture. Overall, this study provides fundamental information on the rheological and structural effects of marigold powder in a wheat bread system, consequently encouraging the food industry to utilize marigold power as a functional food ingredient. © 2023 Society of Chemical Industry.

The effects of breaks on digital eye strain, dry eye and binocular vision: Testing the 20-20-20 rule

PURPOSE

To evaluate the benefits on the eyes of taking breaks based on the 20-20-20 rule.

METHODS

Bespoke computer software using the laptop webcam to assess user breaks, eye gaze and blinking, and emitting personalized reminders of breaks based on the 20-20-20 rule, was downloaded onto the laptops of 29 symptomatic computer users. Digital eye strain (DES), binocular vision and dry eye were assessed before and after two weeks of using the reminders and one week after the discontinuation of the strategy. Binocular measurements included visual acuity, accommodative posture, stereopsis, fixation disparity, ocular alignment, accommodative facility, positive/negative vergences and near point of convergence. Symptoms were evaluated using the computer vision syndrome questionnaire, ocular surface disease index (OSDI), and symptom assessment in dry eye questionnaire (SANDE) versions one and two. Dry eye signs were assessed by measuring tear meniscus height, conjunctival redness, blink rate and incomplete blinking, lipid layer thickness, non-invasive keratograph break-up time, corneal and conjunctival staining and lid wiper epitheliopathy.

RESULTS

A decrease in the duration of computer work and the duration of breaks, along with an increase in the number of breaks taken per day was observed as a result of the 20-20-20 rule reminders (p ≤ 0.015). No changes on any binocular parameter were observed after the management period (p ≥ 0.051), except for an increase in accommodative facility (p = 0.010). Dry eye symptoms and DES decreased with the rule reminders (p ≤ 0.045), although this improvement was not maintained one week after discontinuation (p > 0.05). No changes on any ocular surface and tear film parameter were observed with the rule reminders (p ≥ 0.089).

CONCLUSIONS

The 20-20-20 rule is an effective strategy for reducing DES and dry eye symptoms, although 2 weeks was not enough to considerably improve binocular vision or dry eye signs.

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).

Dry Eye Disease Associated with Meibomian Gland Dysfunction: Focus on Tear Film Characteristics and the Therapeutic Landscape

Meibomian gland dysfunction (MGD) is highly prevalent and is the leading cause of evaporative dry eye disease (DED). MGD is characterized by a reduction in meibum secretion and/or a change in meibum composition that results in the disruption of the tear film lipid layer and an increase in the tear film evaporation rate. Excessive evaporation causes tear film instability, desiccation, tear hyperosmolarity, inflammation, and apoptosis of ocular surface cells, resulting in a continuous cycle of DED. The primary treatment goal for DED associated with MGD is to restore the tear film lipid layer and decrease evaporation, thereby reducing ocular signs and symptoms. The management of MGD includes home care options (eyelid hygiene, warming eye masks, ocular lubricants) and office-based treatments (manual expression, microblepharoexfoliation, thermal pulsation, intense pulsed light, intraductal probing). Topical ophthalmic prescription medications attempt to alter various factors that may contribute to DED (e.g., inflammation, bacterial growth, inadequate tear production). In this review, clinical evidence regarding available treatments and emerging therapies from randomized studies in patients with DED associated with MGD is summarized. Although some treatment modalities have been evaluated specifically for DED patients with MGD, large-scale randomized controlled trials are needed to confirm efficacy and safety in this patient population. Currently, there are no approved prescription pharmacologic treatments specifically indicated for DED associated with MGD, and those medications approved for the treatment of DED do not target the key driver of the disease (i.e., excessive evaporation). NOV03 (perfluorohexyloctane; under review with the US Food and Drug Administration) is the most advanced emerging therapy for DED associated with MGD and has demonstrated statistically significant improvements in both signs and symptoms in randomized controlled trials. Development of novel pharmacotherapies will improve therapeutic options and allow for a more individualized approach for patients with DED associated with MGD.

Spotlight on Digital Eye Strain

Digital Eye Strain (DES) is a clinical syndrome manifested with visual disturbances and/or ophthalmic dysfunction related to the usage of screen-enabled digital equipment. This term is gradually replacing the older term computer vision syndrome (CVS) that focused on the same symptoms found on personal computer users. DES is encountered more frequently during the past years due to the explosive increase in the usage of digital devices and subsequent increase in time in front of any screens. It presents with a series of atypical symptoms and signs stemming from asthenopia, dry eye syndrome, preexisting untreated vision issues and poor screen ergonomics. This review summarizes research data to date to determine whether the concept of DES has been conclusively defined and demarcated as a separate entity and if sufficient guidance is offered on professionals and the lay public. The maturity of the field, grouping of symptoms, examination techniques, treatment and prevention modalities are summarily presented.

Blink Rate Measured In Situ Decreases While Reading From Printed Text or Digital Devices, Regardless of Task Duration, Difficulty, or Viewing Distance

Purpose

To compare blinking measured in situ during various tasks and examine relationships with ocular surface symptoms. The day-to-day repeatability of the blink rate and interblink interval was assessed.

Methods

Twenty-four students (28.6 ± 6.3 years; 8 male and 16 female) completed six reading tasks (printed text, laptop, TV, smartphone, smartphone at 50% brightness, smartphone with complex text), and two nonreading tasks (conversation, walking) in a randomized cross-over study. Ocular surface symptoms and clinical signs were assessed. The blink rate and interblink interval were measured using a wearable eye tracking headset. Blink parameters were compared across tasks and time (linear mixed model and post hoc comparisons with Bonferroni correction). Associations between blinking, symptoms, ocular surface, and clinical signs were assessed (Spearman's correlation). The smartphone reading task was completed twice to determine the coefficient of repeatability.

Results

The blink rate was lower (mean 10.7 ± 9.7 blinks/min) and the interblink interval longer (mean 9.6 ± 8.7 seconds) during all reading tasks compared with conversation (mean 32.4 ± 12.4 blinks/min; 1.5 ± 0.6 seconds) and walking (mean 31.3 ± 15.5 blinks/min; 1.9 ± 1.3s) (P < 0.001). There were no significant differences in blink parameters between any of the reading tasks or between conversation and walking. Changes in blinking occurred within 1 minute of starting the task. No associations were evident between blink rate or interblink interval and ocular surface symptoms or signs. The coefficient of repeatability was ±12.4 blinks/min for blink rate and ±18.8 seconds for interblink interval.

Conclusions

Spontaneous blinking can be measured reliably in situ. The blink rate was decreased and the interblink interval increased during reading compared with conversation and walking. Changes in blinking were immediate, sustained, and not associated with ocular surface symptoms or signs.

Retinal protective effect of curcumin metabolite hexahydrocurcumin against blue light-induced RPE damage

BACKGROUND

Age-related macular degeneration (AMD) is a disease of retinal pigment epithelium (RPE) cells. We have previously demonstrated that blue light can damage RPE cells and their underlying mechanisms. We found that hexahydrocurcumin (HHC), a metabolite of curcumin, had better retinal protection than curcumin. However, the involved mechanisms remain unclear.

METHODS

By exposing ARPE-19 human RPE cells and mouse primary RPE cells to blue light, the intracellular mechanisms of HHC in cells were investigated, including the proliferation of RPE cells and the effects of HHC on activating intracellular protective mechanisms and related factors. Next-generation sequencing (NGS) RNA sequencing revealed the underlying mechanisms involved in the induction and regulation of HHC treatment following blue light exposure.

RESULTS

HHC promoted autophagy by enhancing autophagic flux, reduced oxidative stress and endoplasmic reticulum (ER) stress, and effectively reversed blue light-induced cell death. RNA sequencing-based bioinformatics approaches comprehensively analyze HHC-mediated cellular processes.

CONCLUSION

Our findings elucidate the mechanisms of HHC against blue light damage in RPE cells and are beneficial for the development of natural metabolite-based preventive drugs or functional foods.

Improving Visual Comfort during Computer Gaming with Preservative-Free Hyaluronic Acid Artificial Tears Added to Ergophthalmological Measures

Digital asthenopia (DA) or Computer Vision Syndrome can occur after prolonged use of digital devices and is usually managed with ergophthalmological measures and the use of artificial tears. This prospective, controlled study evaluated the use of hyaluronic acid artificial tears on the signs and symptoms of DA in participants of a videogame convention. Subjects (n = 56) were randomized into a control group (CG, n = 26), which followed ergophthalmological measures, and a study group (SG, n = 30), which followed ergophthalmological measures and instilled 1 drop of artificial tears with hyaluronic acid 0.15% four times a day. Subjects were evaluated before and after playing for three consecutive days for eye dryness (SPEED questionnaire), conjunctival hyperemia, corneal fluorescein staining, conjunctival lissamine green staining, tear breakup time, Schirmer I test, near convergence and accommodation, and using questionnaires for DA symptoms. After 3 days of intense videogaming, the SPEED score of CG increased significantly (p = 0.0320), while for the SG it was unchanged. Similarly, the CG presented significant increases in ocular fatigue (p = 0.0173) and dryness (p = 0.0463), while these parameters decreased significantly in the SG (p = 0.0149 and p = 0.00427, respectively). This study confirms the protective effect of hyaluronic acid artificial tears against DA symptoms associated with prolonged visual display terminal use.

Prevalence and risk factors of computer vision syndrome-assessed in office workers by a validated questionnaire

Background

Computer vision syndrome (CVS) is a common occupational health problem, but its clinical definition, prevalence and risk factors are not well defined. In general, non-validated diagnostic instruments have been used to assess its prevalence. For this reason, the aim of this study is to estimate the prevalence and potential risk factors for CVS using a validated questionnaire.

Methods

A cross-sectional study (n = 238) was carried out in Italian office workers using digital devices. All participants responded to an anamnesis, a digital exposure questionnaire, and the validated Italian version of the Computer Vision Syndrome Questionnaire. A battery of 3 ocular surface and tear ophthalmic tests (break-up time, BUT), Schirmer II and corneal staining) was performed.

Results

The mean age (±SD) was 45.55 (11.02) years, 64.3% were female. 71.4% wore glasses to work, whose design was monofocal (for distance) in 47.6%, monofocal (for near) in 26.5%, general progressive in 16.5% and occupational progressive in 8.8% of cases. 35.7% used digital devices >6 hours/day in the workplace. The prevalence of CVS was 67.2%. In the multivariate model, female sex (aOR: 3.17; 95% CI [1.75-5.73]), the use of digital devices >6 hours/day at workplace (aOR: 2.07; 95% CI [1.09-3.95]) and the use of optical correction at work (aOR: 2.69; 95% CI [1.43-5.08]) significantly increased the odds of CVS. Association was observed between presenting CVS and having abnormal BUT (χ2 = 0.017).

Conclusions

The prevalence of CVS in Italian office workers, especially among females, was high. Intensive use of digital devices at work (>6 hours/day) and the use of optical correction at work significantly increased the odds of CVS. There is an association between poor tear stability and CVS. Further research is needed on the influence of wearing optical correction on CVS. The use of a validated questionnaire in health surveillance of digital workers is strongly recommended.

Assessment of condition-induced changes on the ocular surface using novel methods to assess the tear film dynamics and the lipid layer

OBJECTIVES

To assess the effects of different condition-induced changes on current and novel ocular surface metrics.

METHODS

Eighty-four healthy volunteers (22.4 ± 2.6 years) participated in this study. The ocular surface and tear film response to (1) computer use, (2) contact lens insertion and (3) tear film instillation during computer use with contact lenses were assessed. Current metrics included the ocular surface disease (OSDI) questionnaire, 5-item dry eye questionnaire (DEQ-5), bulbar redness, tear meniscus height (TMH) and non-invasive keratograph break-up time (NIKBUT). Novel metrics included the lipid layer thickness obtained from the intensity of the reflected Placido disk and the speed of tear film particles post-blink.

RESULTS

Higher dry eye symptoms, TMH and bulbar redness, and lower values in metrics related to the intensity of the Placido disk pattern and to particle speed were found after the computer reading task (p < 0.036). When a contact lens was fitted, lower TMH, NIKBUT and particle speed metrics were obtained (p < 0.044). Mixed ANOVA revealed that artificial tears significantly ameliorated the effect of computer reading on OSDI, DEQ-5, NIKBUT, metrics related to the intensity of the Placido disk pattern and metrics related to particle speed (p < 0.033).

CONCLUSIONS

Computer use and contact lens wear worsened dry eye signs and symptoms, but artificial tears ameliorated this effect. Newly developed methods can serve as a tool to detect changes in the tear film triggered by different ocular surface-disturbing conditions.

Concurrent Rising of Dry Eye and Eye Strain Symptoms Among University Students During the COVID-19 Pandemic Era: A Cross-Sectional Study

PURPOSE

Students spend extended hours using electronic devices due to online teaching. Digital eye strain (DES) and dry eye disease (DED) symptoms are both associated with prolonged screen exposure time and may co-occur. This study aimed to evaluate the correlation between DES and DED symptoms and determine the prevalence of DED according to the severity of DES.

PATIENTS AND METHODS

This cross-sectional study was conducted among international students in Chinese universities. The survey was built using Wenjuan Mini Program and distributed using the WeChat platform. The questionnaire assessed participants' screen exposure, the 20-20-20 rule, ED practices, and DED awareness. Computer Vision Syndrome Questionnaire (CVS-Q) and Dry Eye Questionnaire (DEQ-5) were used to diagnose DES and DED symptoms, respectively.

RESULTS

498 students completed the survey, but 452 were considered for the study. Predictors of DES and DED symptoms were conjunctivitis, eye allergy, glares, tired eye, neck pain, back pain, PhD students, and daily spending > 9h on screen (P < 0.05 for all). We observed that an increase in DES scores also exponentially increases DED scores. Among students diagnosed with DES symptoms, 26.5% had mild to moderate DED symptoms, and 8.2% had severe DED symptoms. In contrast, only 8.4% and 0.9% of those with asymptomatic DES had mild to moderate and severe DED symptoms, respectively (P < 0.000). A strong and significant positive correlation (r = 0.695, P < 0.000) between DES and DED scores was found.

CONCLUSION

We found an extremely high prevalence of DES and DED symptoms compared to the previous studies with a similar population group. We believe that the prevalence of DED may be underestimated in the young population. Training about proper ED practices is mandatory to prevent these deleterious ocular surface conditions.

Dry Eye-Related Risk Factors for Digital Eye Strain

OBJECTIVES

To evaluate dry eye-related lifestyle and demographic factors associated with digital eye strain (DES).

METHODS

An anonymous online survey was conducted in 851 university students. Participants were classified into DES (computer vision syndrome questionnaire [CVS-Q]≥6) or non-DES (CVS-Q<6). Respondents completed three dry eye questionnaires (Ocular Surface Disease Index [OSDI]; 5-item Dry Eye Questionnaire [DEQ-5]; 8-item Contact Lens Dry Eye Questionnaire) and were surveyed on dry eye risk factors contemplated by the Tear Film and Ocular Surface Society Dry Eye Workshop II.

RESULTS

Six hundred twenty-eight participants were classified into the group with DES and 222 into the group without DES. Participants with DES slept fewer hours, spent more hours indoors with air conditioning, drank more caffeinated beverages, used the computer for longer periods, reported poorer health quality, and obtained a higher score in all questionnaires (P<0.025). A higher proportion of the participants were female, had several health disorders, and took several medications associated with dry eye (P<0.029). Multivariate logistic regression analysis revealed that stress (P=0.035), contact lens wear (P=0.011), hours of computer use per day (P=0.010), migraine headaches (P=0.013), and a higher OSDI (P<0.001) and DEQ-5 score (P<0.001) were associated with DES.

CONCLUSIONS

Several dry eye-related risk factors and health conditions are associated with suffering from DES. Clinicians should acknowledge the relevance of triaging questions and dry eye disease risk factors when dealing with patients who view screens for extended periods.

Determining the Best Management Strategy for Preventing Short-Term Effects of Digital Display Use on Dry Eyes

OBJECTIVES

To assess and compare the effectiveness of four main management strategies for preventing short-term effects of digital display use on dry eye signs and symptoms.

METHODS

The ocular surface, tear film, and visual fatigue of 47 healthy individuals were assessed before and after reading on a laptop computer for 20 min under five different experimental conditions: control, instillation of artificial tears, taking a brief break, using a blue light screen filter, and blink control. Measurements included the Ocular Surface Disease Index (OSDI) Questionnaire, 5-item Dry Eye Questionnaire (DEQ-5), tear meniscus height (TMH), noninvasive keratograph break-up time (NIKBUT), bulbar conjunctival redness, and pupil size.

RESULTS

Worse results were obtained after the control and blue light filter conditions in all variables (P≤0.037). A higher post-task DEQ-5 score (P=0.013) and TMH (P<0.0005) were obtained when taking a brief break compared with pretask, although the increase in symptoms was significantly smaller than that observed in the nonmanagement control condition (P≤0.036). Similarly, a smaller increase in OSDI and DEQ-5 was obtained with the use of artificial tears and blink control in comparison with the control condition (P≤0.008), whereas a greater increase in DEQ-5 and decrease in NIKBUT was obtained for the blue light filter condition in comparison with the instillation of artificial tears (P=0.017) or blink control (P=0.008), respectively. Finally, a significantly lower post-task pupil size was obtained for all the conditions (P≤0.027).

CONCLUSIONS

The instillation of artificial tears and blink control were the best management strategies for preventing short-term effects of digital display use on dry eyes. Conversely, using a blue light filter did not offer any benefits.

A new antioxidant made from a pterostilbene functionalized graphene nanocomposite as an efficient treatment for dry eye disease

Dry eye disease is a common condition that affects the eyes. It is caused by problems with the tear film and the tear dynamics. Dry eye can be caused by an increase in the amount of reactive oxygen species (ROS) in the corneal epithelium. The treatment for dry eye typically focuses on relieving the uncomfortable symptoms by using eye drops such as artificial tears, antibiotics, and by using anti-inflammatory/immunosuppressive agents such as cyclosporine, and lifitegrast. However, the recovery of patients with dry eye can take several years particularly if the symptoms are severe. This is because the present treatment approaches for dry eye are not based on its cause, e.g., the oxidative stress arising from the rapid increase in ROS. This work describes a new type of antioxidant made from pterostilbene (PS) and carboxyl-chitosan modified graphene (CG). The use of a hydrophilic two-dimensional CG nanosheet to improve the properties of PS is reported. Superior enhanced properties including better cellular permeability, long sustained release period (over 30 h), and antioxidant properties, were realized by using PS-CG. A hyperosmotic (HS) damaged human corneal epithelial cell (HCEC) model was used for antioxidant tests. This model has an intracellular ROS level 4 times more than that of a control group. The ROS content was declined efficiently to the same amount as normal cells in the PS-CG treated HS group. There was a significant decline in the content of lactate dehydrogenase (LDH) and the apoptosis rate of HCEC in the PS-CG treated HS group when compared to that seen in the HS model. Real-time polymerase chain reaction (PCR) and western blots (WB) were used to understand the antioxidant mechanism of PS-CG. The results showed that the antioxidant was working by activating the Keap1-Nrf2-ARE signalling pathway. In vivo testing testing using a dry eye mouse model suggested that the PS-CG acted as an efficient antioxidant. More tear production and healthier corneal and conjunctival epithelial cells were achieved when PC-CG was applied to this model. The use of PS-CG could be a new strategy for treating dry eye and other ocular diseases caused by ROS.

Smartphone gaming induces dry eye symptoms and reduces blinking in school-aged children

Purpose

Smartphone use by children is rising rapidly, but its ocular surface impact is unknown. This study examined the effect of smartphone use on blinking, symptoms, and tear function in children.

Methods

Prospective intervention study where 36 children aged 6–15years (14 M:22 F) played games on a smartphone continuously for one hour. Symptoms (SANDE, IOSS, NRS) and tear film (lipid layer thickness, tear secretion, stability) were assessed before and after gaming. Blink rate and interblink interval were measured in situ using an eye tracking headset, before (during conversation) and continuously throughout gaming. Symptoms and tear film changes were examined using paired t-tests. Changes in blinking throughout one hour were examined using repeated measures ANOVA, post-hoc comparisons with Bonferroni correction. Associations examined using Pearson bivariate correlation. Significance level was 0.05.

Results

Symptoms worsened following one hour smartphone gaming (SANDE + 8.2units, p = 0.01; IOSS + 1.3units, p < 0.001; NRS-average +6.3units, p = 0.03; NRS-comfort +7.6units, p = 0.04; NRS-tiredness +10.1units, p = 0.01), but tear film remained unchanged. Blink rate reduced from 20.8 blinks/min to 8.9 blinks/min (p < 0.001) and interblink interval increased from 2.9 s to 8.7 s (p = 0.002) within the first minute of gaming relative to baseline conversation, and this effect remained unchanged throughout one hour of gaming.

Conclusions

Smartphone use in children results in dry eye symptoms and immediate and sustained slowing of blinking, with no change in tear function evident up to one hour. Given the ubiquitous use of smartphones by children, future work should examine whether effects reported herein persist or get worse over a longer term causing cumulative damage to the ocular surface.

Digital display use and contact lens wear: Effects on dry eye signs and symptoms

PURPOSE

To assess the potential additive effects of short-term display use and contact lens (CL) wear on the ocular surface and tear film.

METHODS

Thirty-four healthy volunteers (20.87 ± 2.33 years old) participated in this study. Participants' dry eye symptoms, ocular surface, tear film and pupil size were assessed before and after executing a 20-min reading task on a computer and a smartphone with and without CL wear, or with CL wear and artificial tear instillation. Measurements included the Ocular Surface Disease Index (OSDI) questionnaire; 5-item Dry Eye Questionnaire (DEQ-5); tear meniscus height (TMH); noninvasive keratograph break-up time (NIKBUT); bulbar conjunctival redness (BR) and pupil size.

RESULTS

Higher symptoms were reported after reading on both displays with and without CLs (p ≤ 0.001) for short periods. BR was higher and NIKBUT shorter after reading on the computer regardless of wearing CLs (p ≤ 0.02 and p ≤ 0.02, respectively), while TMH increased for all conditions (p ≤ 0.02) except for CL computer reading (p = 0.23). Reading with CLs did not lead to greater signs of dry eye (BR, NIKBUT) and symptoms compared with reading unaided (p > 0.05), although a smaller increase in TMH was observed when reading on the computer with CLs (p = 0.005). Artificial tear instillation during CL wear led to a smaller increase in symptoms (p ≤ 0.02), a smaller increase in BR (p ≤ 0.04) and a decrease in NIKBUT (p = 0.02) compared to reading without correction.

CONCLUSIONS

Disposable CL wear had no additive effects on signs and symptoms of dry eye when using digital devices for short periods. The instillation of artificial tears is an effective strategy for reducing the impact of display use in CL wearers.

Ocular surface predisposing factors for digital display-induced dry eye

CLINICAL RELEVANCE

The use of digital displays is recognised as a consistent risk factor for dry eye disease.

BACKGROUND

To identify ocular parameters contributing to the impact of computer use on dry eye.

METHODS

The ocular surface of 82 undergraduate students with a mean age of 22.8 ± 2.1 years was assessed at baseline and after reading on a computer for 30 minutes. Measurements included the ocular surface disease index (OSDI) questionnaire, 5-item dry eye questionnaire (DEQ-5), tear meniscus height, non-invasive keratograph break-up time (NIKBUT), conjunctival bulbar redness, meibomian gland dropout percentage, spontaneous blink rate and percentage of incomplete blinks. Multiple linear regressions and generalised linear mixed models were conducted to explore the associations between baseline parameters and pre-task - post-task differences and to predict the impact of computer use, respectively.

RESULTS

Greater dry eye symptoms (p < 0.0005), higher tear meniscus height and conjunctival bulbar redness (p < 0.0005 and p = 0.012, respectively) and shorter NIKBUT (p = 0.03) were obtained after reading on the computer for 30 minutes. The baseline score obtained with the OSDI and DEQ-5 was positively associated with the increase in symptoms with computer use (p < 0.0005), while the change in conjunctival redness and pre-task NIKBUT were associated with the change in NIKBUT (p ≤ 0.005). No ocular surface parameter revealed an association with tear meniscus height changes. Having a positive OSDI score at baseline increased the odds of painful and sore eyes (p = 0.012), while a higher pre-task NIKBUT increased the odds of a reduction in tear stability (p = 0.038).

CONCLUSIONS

Participants with greater dry eye symptoms were more likely to experience a greater increase in symptomatology with computer operation, while the participants with longer NIKBUT and greater conjunctival redness were more likely to suffer a greater reduction in tear stability.

Is dry eye disease the same in young and old patients? A narrative review of the literature

Advanced age is one of the most evident risk factors for dry eye disease (DED), with male/female sex, chronic drug consumption, and prolonged device use. This article aims to review the literature about the changes of the ocular surface associated with DED in the elderly and patients < 40 years. The pathophysiologic changes of the ocular surface responsible for eye dryness are linked with inflammation and neurosensory abnormalities and may occur with a different feature in young patients compared with elders. Peculiar treatment strategies may be needed for young and older subjects with DED.

Benefits and Safety of Astaxanthin in the Treatment of Mild-To-Moderate Dry Eye Disease

Objectives: To evaluate the effect of astaxanthin in the treatment of mild-to-moderate dry eye disease (DED) in middle-aged and elderly patients.

Methods: 120 eyes of 60 middle-aged and elderly patients with mild-to-moderate DED were enrolled in this prospective, one-group, quasi-experimental study. Six milligram Astaxanthin tablets (Weihong Haematococcus Pluvialis Astaxanthin, Hangzhou Xinwei Low Carbon Technology R&D Co., Ltd., China) were administered orally, twice daily for 30 ± 2 days. History of eye diseases, treatment, systemic disease, and medication before the test were recorded. In addition, the ocular surface disease index (OSDI) questionnaire, non-invasive tear break-up time (NIBUT), fluorescein break-up time (FBUT), corneal fluorescein staining (CFS) score, eyelid margin signs, meibomian gland (MG) expressibility, meibum quality, meibomian gland dropout (MGDR), Schirmer I test (SIt), tear meniscus height (TMH), bulbar conjunctiva congestion degree, blink frequency, incomplete blink rate, and thickness of tear film lipid layer were collected before treatment, 2 weeks after the initiation of treatment, and at the end of treatment. Visual acuity (VA), intraocular pressure (IOP), anterior segment, fundus, discomfort symptoms and other adverse reactions were also monitored throughout the study to assess the safety.

Results: OSDI score, NIBUT, BUT, CFS score, eyelid margin signs, MG expressibility, meibum quality, and blink frequency improved significantly to varying degrees after treatment compared with those before the treatment (P < 0.05), while TMH, SIt, conjunctival congestion, the thickness of tear film lipid layer, MGDR, incomplete blink rate, VA and IOP did not differ (P > 0.05).

Conclusions: Oral administration of astaxanthin improves the symptoms and signs of middle-aged and elderly patients with mild-to-moderate DED.

Comparison of the influence of light between circularly polarized and linearly polarized smartphones on dry eye symptoms and asthenopia

This paper aims to investigate the efficacy of circularly polarized light smartphones in affecting dry eye symptoms and asthenopia through a comparison with linearly polarized smartphones. One hundred twenty participants were randomly divided into four groups. Dry eye and asthenopia symptoms were evaluated using the Ocular Surface Disease Index (OSDI), Computer Vision Syndrome Scale 17 (CVSS17), Convergence Insufficiency Symptom Survey (CISS), and visual analogue scale (VAS). Objective ocular examinations were assessed by confusion flicker frequency (CFF), tear meniscus height (TMH), noninvasive break‐up time (NIBUT), conjunctiva redness, fluorescein tear break‐up time (FTBUT), corneal fluorescein staining, and the Schirmer I test. Tests were performed before and after a reading task. Subjective evaluations including the OSDI, CVSS17, and CISS were all significantly increased after reading on a linearly polarized smartphone, whereas no change was observed in the circular polarization groups in both light and dark environments. A significantly enlarged VAS was shown in all of the four groups, but a significant increase in ΔVAS only appeared in the linear polarization groups. There were significant decreases in TMH, NIBUT, conjunctiva redness, FTBUT, and CFF after reading on a linearly polarized smartphone but the circularly polarized smartphone had lesser effects on these parameters. Our study indicated that reading on linearly polarized smartphones may cause dry eye disorder, asthenopia, and ocular discomforts, whereas circularly polarized smartphones appears to minimize these adverse effects on eye dryness and visual fatigue in light and dark environments.

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.

Extended screen time and dry eye in youth

PURPOSE

Extended screen time amongst youth is a pervasive global phenomenon, with wide-ranging implications for health and quality of life. Dry eye disease is increasingly reported as emerging in paediatric populations and is associated with modified blinking behaviour during extended screen time. This study sought to evaluate spontaneous blink rates, dry eye symptomology and screen use habits of young extended screen time users.

METHODS

Attendees of a gaming convention in Auckland, NZ, completed a self-directed iPad-based survey on personal screen use habits and ocular symptoms using the 5-item Dry Eye Questionnaire (DEQ-5) and the Symptom Assessment in Dry Eye (SANDE) questionnaire. Blink rate was covertly and concomitantly recorded using the front-facing iPad camera and quantified by automated software. A validated, self-assessment blink test was administered as a proxy for tear film stability measurements.

RESULTS

A total of 456 respondents (mean age ± SD: 24 ± 10 years, range: 13 - 75, 38% female) reported an average weekly screen time of 43.7 ± 24.4 h. DEQ-5 and SANDE scores were 10 ± 3 and 34 ± 19; 90% of respondents qualified as symptomatic for dry eye disease (DEQ-5 ≥ 6). Blink test results suggested a tear film stability < 10 s in 24% of cases. Poorer symptomology correlated with increased screen use, elevated blink rates and reduced proxy tear film stability (r = 0.15 to 0.22, all p < 0.01).

CONCLUSION

Extended screen time in a young population was associated with blinking behaviour and symptomology consistent with patients with dry eye. Implementing routine clinical screening, educational interventions, and developing official guidance on safe screen use may help prevent an accelerated degradation of ocular surface health and quality of life in young people.

Blinking kinematics characterization during digital displays use

Purpose

This study aimed to assess the differences in blinking kinematics while reading on different digital displays and a control condition.

Methods

Thirty-two young healthy individuals were included in this prospective clinical study. The blinks of subjects were recorded for 150 s while reading on a laptop computer, tablet, e-reader, and smartphone and a control condition. Blinks were recorded using an eye-tracking device and were analyzed by means of image analysis to obtain a non-invasive detailed description of the blink movement.

Results

Blink rate decreased when reading on all displays compared to the control (p < 0.0005), although no differences were obtained amongst displays (p > 0.05). The percentage of incomplete blinks was higher with the computer compared to the control (p = 0.043), and lower with the smartphone compared to the rest of the conditions (p ≤ 0.015). Blink amplitude was smaller when reading from handheld devices compared to the control (p < 0.0005) and the computer (p ≤ 0.048). Closing and opening blink durations remained unvaried amongst conditions (p > 0.05), while opening and closing speeds were greater for the control and the computer compared to the handheld displays (p < 0.0005). Finally, contact and total blink durations were shorter during computer reading compared to the control (p = 0.004 and p = 0.017, respectively).

Conclusion

Blinking kinematics vary considerably amongst displays and with respect to baseline, with these differences being probably attributed to differences in the way the displays are set up and the cognitive demand of the task.

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.

Online Vs In-person Education: Evaluating the Potential Influence of Teaching Modality on Dry Eye Symptoms and Risk Factors During the COVID-19 Pandemic

OBJECTIVES

To assess the potential effects of switching to online lecture format on dry eye symptoms and dry eye disease (DED) risk factors.

METHODS

An anonymous cross-sectional online survey was conducted in 812 university students (mean age, 21.5±4.0 years). Participants were classified according to the number of hours the participants took online lectures into online students or in-person students. Respondents completed a total of three DED questionnaires (Ocular Surface Disease Index [OSDI]; 5-item Dry Eye Questionnaire; 8-item Contact Lens Dry Eye Questionnaire) and were surveyed on dry eye risk factors contemplated by the Tear Film and Ocular Surface Society Dry Eye Workshop II in addition to other factors potentially linked to dry eye.

RESULTS

Five hundred twenty-three subjects (64.4%) were classified into the online group and 289 (35.6%) into the in-person group. No statistically significant age (P=0.266) or sex (P=0.423) differences were found between groups. Students taking online lectures used the computer more, spent less time outdoors, practised more exercise, wore a face mask for less time, experienced fewer allergies and fewer psoriasis episodes, and obtained a higher OSDI score (P<0.029 for all). Multivariate logistic regression analysis revealed that the hours of online lectures taken per week was independently associated with having a positive OSDI score (P=0.022).

CONCLUSIONS

Taking online lectures is independently associated with having dry eye symptoms. Despite a lower prevalence of DED risk factors, a higher computer use is probably behind the greater ocular dryness reported by online students.

Prevalence of Self-Reported Symptoms of Computer Vision Syndrome and Associated Risk Factors among School Students in China during the COVID-19 Pandemic

PURPOSE

To determine the prevalence and risk factors of self-reported symptoms of Computer Vision Syndrome (CVS) in school students during COVID-19 pandemic.

METHODS

In this cross-sectional study in Nanjing, China, students (grades 1-12) from six randomly selected schools self-administered the online survey questionnaire about hours on electronic devices, outdoor activities, frequency and intensity of 17 CVS symptoms during virtual learning period of COVID-19 pandemic.

RESULTS

Among 2363 invited students, 2005 (84.8%) completed the survey. Mean (SD) age was 12 (3.0) years, 51% were male, 53% wore glasses, 56% did not know the 20-20-20 rule (take a 20 second break every 20 min of close work and gaze at objects at least 20 feet away) and 6.5% knew but never followed the 20-20-20 rule. Mean (SD) hours/day was 4.6 (3.4) for screen time and 1.2 (1.0) for outdoor activities. Total of 1543 (77.0%) students reported at least one CVS symptom (median = 4) with eye dryness and itching the most common (48%). In multivariable analysis, CVS score 4 or more was independently associated with older age (adjusted odds ratio (aOR) = 1.05 for per-year increase, p = 0.02), children with myopia not wearing glasses (aOR = 2.12, p = 0.0003), astigmatism (aOR = 1.37, p = 0.04), other ocular diseases (aOR = 1.59, p = 0.005), not complying 20-20-20 rule (aOR = 2.13, p = 0.04), more screen time (aOR = 1.53 for >6 vs. ≤2 hours, p = 0.0001) and less outdoor activities (aOR = 1.37 for ≤0.6 vs. ≥1.9 hours, p = 0.005).

CONCLUSIONS

During COVID-19 pandemic, self-reported CVS symptoms occurred in more than three-quarters of students. Besides pre-existing ocular diseases, children with myopia not wearing glasses, excessive time on screens, non-compliance of the 20-20-20 rule and reduced outdoor activities were associated with higher risk of CVS.

Assessment of dry eye symptoms among university students during the COVID-19 pandemic

CLINICAL RELEVANCE

The synchronous hybrid learning environment is associated with increased time spent by students working with VDT and increased prevalence of dry eye symptoms in a university-based population.

BACKGROUND

To assess the prevalence of dry eye symptoms using the ocular surface disease index (OSDI) questionnaire in university students and to identify whether factors such as the synchronous hybrid learning environment as a preventive measure of COVID-19, video display terminal use, gender or contact lens wear influence dry eye symptomatology.

METHODS

This study was performed using a web-based questionnaire that was distributed to university students to assess questions related to class attendance, to the use of video display terminals, the need for optical correction and, finally, the OSDI questionnaire.

RESULTS

A total of 676 university students with an average age of 20.7 ± 2.9 years completed the questionnaire, of which 72.6% (491) were females and 27.4% (185) were males. Only 10.2% of the participants attended face to face classes. Of the participants, 35.5% were contact lens wearers. The mean OSDI score of the study population was 27.68 ± 20.09 and the prevalence of symptomatic dry eye disease (OSDI score above 22) was 51.8%. Female gender (X²(3) = 38.605, p < 0.001), online class attendance (X²(1) = 20.31; p < 0.001), increased hours of online class attendance (X²(2) = 26.84, p < 0.001) and contact lens wear (X²(2) = 15.264, p < 0.05) were associated with a higher incidence of symptomatic dry eye disease.

CONCLUSION

The synchronous hybrid learning environment increases the time students spend working with video display terminals and the prevalence of dry eye symptoms. Female gender and contact lens wear were also associated with a higher prevalence of dry eye symptoms. It should not be ignored that dry eye could also affect academic performance.

Nicotinamide Mononucleotide Alleviates Hyperosmolarity-Induced IL-17a Secretion and Macrophage Activation in Corneal Epithelial Cells/Macrophage Co-Culture System

Background

Hyperosmosis stress (HS) was a key pathological factor in the development of dry eye disease (DED). Nicotinamide mononucleotide (NMN) demonstrated protective effects in the corneal damage, however, its role in the HS-induced DED remained unclear.

Methods

A NaCl based HS in-vitro model (500 mOsm) was generated and used in a co-culture system including corneal epithelial cells (CEC) and macrophage cell line RAW264.7. The effect of NMN on NAD+ metabolism and the expression of HS biomarker, tonicity-responsive element binding protein (TonEBP), was studied in the CEC. The cellular activity, including cell viability, apoptosis status and lactate dehydrogenase (LDH) release through trypan blue staining, flow cytometry and LDH assay, respectively. The mitochondrial membrane potential (MMP) assay would be conducted using the JC1 kit. The expression of IL-17a were detected using RT-PCR, ELISA and Western blot. After co-culture with the CEC in different group for 24 h, the phagocytosis ability and macrophage polarization were assessed in RAW264.7 cells co-cultured with CEC with or without HS or NMN treatment. Besides, the involvement of Notch pathway in the RAW264.7 would be analyzed. The potential involvement of Sirtuin 1 (SIRT1) and IL-17a in the crosstalk between CEC and macrophage was studied with SIRT1 inhibitor EX 527 and anti-IL-17a monoclonal antibody, respectively.

Results

NMN treatment increased NAD+ concentration and thus improved cell viability, reduced apoptotic rate and decreased the LDH release in HS-treated CEC. Besides, NMN alleviated HS-induced MMP, intracellular ROS and LDH release. Besides, it was confirmed NMN improve SIRT1 function and decreased the HS related IL-17a expression in CEC and then alleviated macrophage phagocytosis ability and M1 polarization based on a CEC-macrophage co-culture system. Moreover, NMN treatment of CEC in the CEC could moderate the subsequent macrophage activation through Notch pathway. SIRT1 activation and IL-17a inhibition was regarded as key progress in the function of NMN based on the application of EX 527 and anti-IL-17a antibody in the CEC-macrophage co-culture system.

Conclusion

The findings demonstrated that NMN could alleviated HS-induced DED status through regulating the CEC/macrophage interaction. Our data pointed to the role of SIRT1, IL-17a and Notch pathway in the function of NMN and then provided updated knowledge of potential NMN application in the management of DED.