Prevalence of asthenopia and its risk factors in Chinese college students

Correlation between mental status and prevalence of asthenopia in Chinese college students

BACKGROUND

The purpose of this study was to identify the possible association between mental status and the risk of self-reported asthenopia among college students in China.

METHODS

Ten thousand students were randomly assessed in the study using a self-reported asthenopia questionnaire. Their demographic characteristics and mental status were recorded. Univariate analysis was performed to preliminarily select potential risk and protective factors. Then, multivariate logistic regression was used to estimate odds ratios for the selected risk factors of interest.

RESULTS

Among the 8370 students who completed the survey, the prevalence of asthenopia was 61.0%. Multivariate analysis revealed a significant relationship between asthenopia and depressive symptoms (OR 1.511 95% CI: 1.350-1.691), obsessive-compulsive symptoms (OR 1.477, 95% CI: 1.338-1.632), gender and study load. The place college students spent their off-hours (OR 0.841, 95% CI: 0.784-0.902) was found to be the strongest factor for decreasing the occurrence of asthenopia complaints.

CONCLUSION

Asthenopia appears common in Chinese college students. In addition to depressive symptoms, we should pay attention to obsessive-compulsive symptoms when considering means of preventing asthenopia. Harmonious social relationships, outdoor off-hour activities and exercising more than three times per week are crucial to relieving visual fatigue. Further study is still needed in this area.

Is there a relationship between somatic sensations, impaired vision, and cognitive performance using the factor structure of the convergence insufficiency symptoms survey questionnaire?

AIMS

This study aims to evaluate the relationship between somatic sensations, impaired vision, and cognitive performance using the factor structure convergence insufficiency symptoms survey questionnaire in university undergraduate and post-graduate students.

SETTINGS AND DESIGN

Centre-based and questionnaire-based.

SUBJECTS AND METHODS

Subjects were recruited from a university. First, an e-Survey was conducted with the help of Google form and distributed through WhatsApp and Gmail to carry out the survey. The age group of participants was ranged from 18 to 30 years. A total number of 561 responses was received during the data collection period. As per the exclusion criteria, 230 responses were excluded from the study. Out of 331 students, 154 were male while 177 were female. Out of 331 participants, 213 were undergraduates and 118 were postgraduate's students.

RESULTS

A total of 331 participants took part in the study. The minimum age was 18 years and the maximum age was 30 years. The mean age of the participants was 23.40 ± 2.42. Among all students, 23.81% had somatic sensations followed by 10.49% had impaired vision, and 16.31% had a poor cognitive function. The correlation between somatic sensations-impaired visions was a moderate positive correlation and a strong positive correlation between somatic sensations-cognitive performance and impaired vision-cognitive performance.

CONCLUSIONS

A significant relationship between somatic sensations, impaired vision, and cognitive performance was found in the study. The students had more somatic sensations than impaired vision and cognitive performance.

Prevalence and determinants of asthenopia among ophthalmologists in China: a national cross-sectional survey

Introduction

The role of ophthalmologists is defined by tasks requiring visual effort, emphasizing the importance of examining their condition within the realm of occupational visual health. Our goal was to explore the occurrence of asthenopia among Chinese ophthalmologists and identify contributing factors through the use of a reliable and validated survey instrument.

Methods

A national cross-sectional online survey was carried out in June 2017, involving 6,220 practicing ophthalmologists in China. Utilizing an 11-item Asthenopia Survey Questionnaire with established reliability and validity. Prevalence rates of asthenopia among subgroups categorized by age, gender, hospital classification, physician level, daily near vision activity duration, sleep duration, sleep quality, presbyopia status, and history of eye surgery were determined using the independent t-test, chi-square test and bonferroni test. Multiple logistic regression analysis was employed to pinpoint independent factors linked to asthenopia.

Results

Out of the 5,009 ophthalmologists who completed the survey, a 40.7% prevalence of asthenopia was identified. Multivariate analysis revealed that good sleep quality (OR: 0.24, 95%CI: 0.20-0.30), moderate sleep quality (OR: 0.47, 95%CI: 0.38-0.59), engaging in daily near vision activities for less than 7 h (OR: 0.76, 95%CI: 0.68-0.86), having daily sleep duration exceeding 7 h (OR: 0.87, 95%CI: 0.77-0.98), and working in tertiary hospitals (OR: 0.88, 95%CI: 0.78-0.99) were protective factors against asthenopia. Conversely, presbyopia was identified as a risk factor (OR: 1.33, 95%CI: 1.04-1.70). All calculated p values were below 0.05. Age, gender, physician level, and eye surgery history were not related factors.

Conclusion

Asthenopia is prevalent among Chinese ophthalmologists, with employment in tertiary hospitals providing a protective effect and presbyopia is a risk factor. Preventive strategies include improving sleep quality, restricting daily near vision activity to under 7 h, and extending daily sleep duration to over 7 h. Further investigation is needed to explore the protective implications of working in tertiary hospitals.

Assessment of precision and reliability of a novel computerized heterophoria test

Purpose

To assess the precision and reliability of a novel computerized heterophoria test (CHT).

Methods

One hundred and three subjects aged 20 to 48 (27.37 ± 5.15) were recruited from Wenzhou Medical University. All subjects with corrected spectacles were examined with CHT and a prism-neutralized objective cover test (POCT) in a randomized order. They were then re-examined with CHT within 1 week. Their heterophoria was measured at three different distances (3 m, 0.77 m and 0.4 m); the average was recorded after three consecutive measurements. Inter-examiner repeatability, intra-examiner repeatability of CHT and agreement between CHT and POCT were evaluated.

Results

There was no significant difference among repeated measurements using CHT (all p > 0.05). The difference between POCT and CHT was statistically significant at three distances (all p < 0.001). However, the mean absolute difference was 1.20^△, 1.93^△, and 2.41^△, all of which were significantly smaller than the permissible range of error (4^△) at three different distances (all p < 0.001).

Conclusion

The CHT demonstrated excellent inter- and intra-examiner repeatability, as well as good correlation with POCT. The differences between CHT and POCT were within the permissible range of error, indicating that CHT could provide a precise and reliable measurement for clinical applications.

An Explainable Student Fatigue Monitoring Module with Joint Facial Representation

Online fatigue estimation is, inevitably, in demand as fatigue can impair the health of college students and lower the quality of higher education. Therefore, it is essential to monitor college students' fatigue to diminish its adverse effects on the health and academic performance of college students. However, former studies on student fatigue monitoring are mainly survey-based with offline analysis, instead of using constant fatigue monitoring. Hence, we proposed an explainable student fatigue estimation model based on joint facial representation. This model includes two modules: a spacial-temporal symptom classification module and a data-experience joint status inferring module. The first module tracks a student's face and generates spatial-temporal features using a deep convolutional neural network (CNN) for the relevant drivers of abnormal symptom classification; the second module infers a student's status with symptom classification results with maximum a posteriori (MAP) under the data-experience joint constraints. The model was trained on the benchmark NTHU Driver Drowsiness Detection (NTHU-DDD) dataset and tested on an Online Student Fatigue Monitoring (OSFM) dataset. Our method outperformed the other methods with an accuracy rate of 94.47% under the same training-testing setting. The results were significant for real-time monitoring of students' fatigue states during online classes and could also provide practical strategies for in-person education.

Eye Habits Affect the Prevalence of Asthenopia in Patients with Myopia

Purpose

This study aims to explore the risk factors of asthenopia in the myopic population.

Methods

In this cross-sectional study, myopia patients were inquired about their eye habits and were requested to complete an asthenopia questionnaire and ocular examinations. Age, gender, occupation, anisometropia, eye care education, weekly outdoor activity time, duration of continuous near work, daily screen time, dry eye, near phoria, and binocular accommodative facility were calculated using the Student's test-test, Mann Whitney U test, and Pearson's chi-square test. Spherical equivalents and astigmatism were calculated using a generalized estimating equation. Binary logistic regression was performed on factors with a p-value <0.05.

Results

Of the 65 myopic patients, 57% showed asthenopia, 52% experienced blurry vision, 37% felt their eyes hurt or sore, and 28% felt tired when performing close work. Asthenopia patients were older than patients without asthenopia (Z = −2.887, p=0.004). Daily screen time, continuous near-work time, eye care education, and dry eye were positively correlated with asthenopia (χ² = 8.64, p=0.003; χ2 = 13.873, p < 0.001, χ2 = 9.643, p=0.002; χ2 = 7.035, p=0.008). After eliminating collinearity, eye care education and continuous near-work time were identified as independent risk factors of asthenopia, with odds ratios of 0.115 and 4.227, respectively.

Conclusion

This study shows that receiving eye care education from schools and hospitals and limiting near-work duration to less than 45 minutes per session could reduce the occurrence of asthenopia in myopic patients. This approach may be a more economical and convenient way for myopic people to relieve asthenopia.

Prevalence of Asthenopia and Its Relationship with Electronic Screen Usage During the COVID-19 Pandemic in Jazan, Saudi Arabia: A Cross-Sectional Study

Purpose

To assess the connection between the prevalence of asthenopia and the use of electronic devices in Jazan, Saudi Arabia, during the COVID-19 pandemic.

Patients and Methods

Asthenopia prevalence and its connection to electronic screens during the COVID-19 pandemic were evaluated in an analytical, cross-sectional investigation among the Jazan population. The sample population included 784 participants. Due to the COVID-19 pandemic, a pre-tested, organized, and self-administered questionnaire was used as the study method. Social media invitations were used to contact the sample group.

Results

Of the 784 participants, 587 (74.96%) had asthenopia symptoms after using digital devices at the end of the day. A total of 56.30% used digital gadgets for > 6 hours each day, whereas 55.36% spent <2 hours per day reading papers or books or writing. Daily usage of digital gadgets did not significantly differ from asthenopia (p=0.46), as well as reading papers, books, or writing and asthenopia (p=0.098). A total of 45.92% of the study population maintained digital devices/books at a distance <25 cm, which was significantly associated with symptoms of asthenopia (p=0.048). Furthermore, 90.10% of the sample population used laptops, cellphones, and iPads before going to bed or after turning off lights. A total of 63.52% preferred using devices while lying in bed. There was no positive link between asthenopia symptoms and cellphone usage at bedtime or after turning off lights (p=0.028).

Conclusion

Digital technology is used by people of all ages for a wide range of daily activities, including education, employment, business, and recreation. We concluded that this group had a high prevalence of asthenopia, especially during the COVID-19 pandemic. The high frequency of asthenopia emphasizes the significance of conducting public awareness campaigns concerning asthenopia symptoms and prevention methods.

Self-Reported Computer Vision Syndrome among Thai University Students in Virtual Classrooms during the COVID-19 Pandemic: Prevalence and Associated Factors

During the COVID-19 pandemic, computer vision syndrome (CVS) related to online classrooms were unavoidable. This cross-sectional study aimed to explore the prevalence, characteristics and associated factors of CVS. A total of 527 students who were currently studying in a virtual classroom (70.40% female, mean (standard deviation; SD) age of 20.04 (2.17) years) were included. The prevalence of CVS assessed by an online CVS-Questionnaire was 81.0% (427/527). Comparing with those in the period before the online study, an increase in screen time (interquartile range) in students with and without CVS was 3 (0−3) and 2 (1−5) h, respectively. Overall, 516 students (97.9%) experienced at least one symptom. The most frequent symptom in CVS subjects was eye pain (96.5%). The most intense symptoms were the feeling of worsening eyesight (15.9%). The factors associated with CVS were female (p < 0.001), age (p = 0.010), atopic diseases (p = 0.020), prior ocular symptoms (p < 0.001), astigmatism (p = 0.033), distance from display <20 cm (p = 0.023), presence of glare or reflection on screen (p < 0.001), low screen brightness (p = 0.045), sleep duration (p = 0.030), inadequate break time between classes (p < 0.001) and increased screen time usage during online study (p < 0.001). Recommendations to prevent CVS based on the adjustable factors might reduce the burden of online study.

Contribution of Total Screen/Online-Course Time to Asthenopia in Children During COVID-19 Pandemic via Influencing Psychological Stress

Objectives: During the coronavirus disease 2019 (COVID-19) self-quarantine period, the transition to online-course has profoundly changed the learning modes of millions of school-aged children and put them at an increased risk of asthenopia. Therefore, we aimed to determine associations of the total screen/online-course time with asthenopia prevalence among that children during the COVID-19 pandemic, and whether the associations were mediated by psychological stress.

Methods: Asthenopia was defined according to a validated computer vision syndrome questionnaire (CVS-Q). We used CVS-Q to collect the frequency and intensity of 16 asthenopia-related eye symptoms of 25,781 children. Demographic features, eye care habits, visual disorders, lifestyle, psychological and environmental factors, were also collected.

Results: The overall asthenopia prevalence was 12.1%, varying from 5.4 to 18.2% across grade/gender-classified subgroups. A 100-h increment of total screen/online-course time were associated with an increased risk of asthenopia by 9% [odds ratio (OR) = 1.09] and 11% (OR = 1.11), respectively. Mediation analysis showed that the proportions of total effects mediated by psychological stress were 23.5 and 38.1%, respectively. Age, female gender, having myopia or astigmatism, bad habits when watching screens were also risk factors. Conversely, keeping 34–65 cm between eyes and screen, increased rest time between classes, and increased eye exercise were all associated with a decreased risk.

Conclusion: Our study indicated that the influence of long total screen or online-course time on psychological stress increases asthenopia risk. The findings of this study have provided a new avenue for intervening screen-related asthenopia in addition to incorporating a reasonable schedule of online courses into educational policy.

Investigation of the Relationship Between Subjective Symptoms of Visual Fatigue and Visual Functions

Purpose

To investigate whether the severity of symptoms of visual fatigue might be associated with clinical visual measures and basic visual functions, such as accommodation, vergence, and contrast sensitivity.

Methods

In this study, 104 students were recruited (25 males, 79 females, Age 23.4 ± 2.5) for this study. Those with high myopia, strabismus, anisometropia, eye disease or history of ophthalmological surgery were excluded. The included subjects completed a questionnaire that assesses the severity of visual fatigue. Then, binocular accommodative facility, vergence facility and contrast sensitivity using a quick contrast sensitivity function approach were measured in a random sequence. Next, the correlations between each symptom of visual fatigue in the questionnaire and accommodative facility, vergence facility and contrast sensitivity were examined.

Results

Factor analysis indicated that visual fatigue, as captured by the scores of a subset of the questionnaire items, could be strongly related to binocular accommodative facility and binocular contrast sensitivity, but not to vergence facility. We also found that binocular accommodative facility and contrast sensitivity at high spatial frequencies are related.

Conclusion

Our findings suggest that visual fatigue is related to the ability of human observers to encode visual details through their binocular vision.

Factor structure of the convergence insufficiency symptom survey questionnaire

The purpose of this study is to analyze the factorial structure of the Convergence Insufficiency Symptom Survey questionnaire with 15 items, in order to identify latent dimensions that can contribute to a more focused implementation. The questionnaire was self-administered in paper by 183 university students, in the age span of 18 to 30. Both Kaiser-Meyer-Olkin measure and Bartlett's sphericity test were performed to ensure the validity of the factorization. In order to analyze the principal components, factors which obtained eigenvalues greater than 1 were chosen. The extraction of factors was performed after computing a Promax rotation and a Kaiser criterion. In each extracted factor, the internal consistency was used to prove its reliability. Bartlett's sphericity test was statistically significant (p <0.001), and the Both Kaiser-Meyer-Olkin test was 0.89, confirming the factorization of this instrument. Exploratory factor analysis followed by a Promax rotation and scree plots graphic, extracted three factors that explained 62.1% of the total variance. The composition of each factor suggests the following meanings: Factor 1 (somatic sensation) includes 8 of 15 items; Factor 2 (impaired vision) includes 3 of 15 items; Factor 3 (cognitive performance) includes 4 of 15 items. Cronbach's alpha coefficient demonstrated good internal consistency (α> 0.75) in three dimensions. The multivariate statistical analysis of the Convergence Insufficiency Symptom Survey revealed a three-factor structure, so new forms of questionnaire analysis can be designed in order to obtain gains in the management of a symptomatic patient, using 3 subscores, one for each factor, instead of a total score. The factorial structure of the questionnaire can be used with a high level of confidence in future investigations, which aim to assess which dimensions are most affected in each type of visual changes and develop more targeted therapeutic performances.

High Prevalence of Asthenopia among a Population of University Students

Purpose

To determine the prevalence of asthenopia and its associated factors in a sample of university students in Iran.

Methods

In this cross-sectional study, participants were selected using multistage cluster sampling. Presence of at least one of the 10 symptoms—foreign body sensation, diplopia, blurred vision, eye swelling, dry eye, eye pain, difficulty in sustaining visual operations, decreased visual acuity, tearing, and photophobia—was considered as asthenopia. Ocular examinations, including uncorrected/corrected visual acuity measurement, objective/subjective refraction, cover test, amplitude of accommodation (AA), and near point of convergence (NPC) were performed.

Results

Of the 1,462 students (mean age: 22.8 ± 3.1 years), 73% were women. The age- and gender-standardized prevalence was 70.9% (95% confidence interval [CI]: 68.3–73.5), 39.8% (95% CI: 36.4–43.1), and 19.7% (95% CI: 16.0–23.3) based on the presence of at least one, two, and three symptoms, respectively. The prevalence was significantly higher in females (P = 0.048), hyperopic students (P< 0.001), and astigmatic participants (P < 0.001). The mean AA and NPC were 9.7 ± 2.6 D and 10.2 ± 4.2 D (P = 0.008) and 7.0 ± 2.1 cm and 7.7 ± 3.9 cm (P< 0.001) in participants with and without asthenopia, respectively. Multiple regression model revealed age (28–29 years), astigmatism, and NPC as independent associated factors (odds ratios: 3.51, 1.61, and 0.91, respectively).

Conclusion

This study shows relatively high prevalence of asthenopia in university students. Demographic factors and visual system disorders are important risk factors and timely correction of conditions may lead to decreased asthenopia.

Video Display Operator Complaints: A 10-Year Follow-Up of Visual Fatigue and Refractive Disorders

Visual fatigue and discomfort are very common complaints for video display operators (VDTs). The aim of our study was to study work-related visual symptoms in relation to refractive disorders and psychosocial factors in 3054 public employees by way of follow-ups for 10 years with periodic medical examinations with eye evaluation in the period 2000-2009. Factors related to visual fatigue were evaluated in the follow-up using generalized equation estimation. Visual fatigue was very common in VDT operators (64.03%). During the follow-up, no relationship between visual fatigue and age, sex, seniority of work, visual acuity and refractory disorders was found. Visual fatigue was significantly associated with anxiety perception in a dose-related matter (odds ratio (OR) 7.40, confidence interval (CI) 95% 1.77-31.3), psychosocial factors (OR 1.03, CI 95% 1.01-1.07), use of lenses (OR 1.34, CI 95% 1.09-1.64) and time of VDT usage (OR 1.27, CI 95% 1.04-1.53). This study confirmed that visual fatigue is common in VDT users and is related to anxiety perception, time of VDT usage, use of lenses and stress. No relationship was found between visual fatigue and refractory disorders or visual acuity.

Accommodative asthenopia among Romanian computer-using medical students-A neglected occupational disease

Computers have become to play an important role in people's lives throughout the world thus increasing the number of patients with ocular complaints. Also known as computer vision syndrome, accommodative asthenopia might be considered as a neglected occupational condition, but there is no consensus regarding diagnostic criteria, which leads to under-recognition and under-reporting. The aim of the study was to investigate the prevalence, early symptoms and specific preventive measures of accommodative asthenopia among computer-using medical students (n = 420), in a cross-sectional study. The most common early symptoms were: tired eyes/eye strain (86.1%), burning eyes (46.8%), migraines/headaches (46.8%), red-swollen eyes (43%), photophobia (41.8%), temporary blurred vision (35.4%), and eyelid spasms (32.9%). Our study identifies the most frequent early symptoms of accommodative asthenopia as a possible occupational disease, which might serve as a fundament for a future consensus strategy.

Fruit and vegetable consumption and its relation to risk of asthenopia among Chinese college students

AIM

To investigate the associations between fruit and vegetable consumption and risk of asthenopia among Chinese college students.

METHODS

A total of 1022 students were selected from five universities by a multi-stage stratified cluster sampling method. They were surveyed via a self-administered questionnaire including socio-demographic features, dietary and lifestyle habits, eye-related symptoms, eye care habits and history of diseases. Ascertainment of asthenopia was based on participants' subjectively reported symptoms. The associations between fruit and vegetable intake with asthenopia risk were assessed using multivariate logistic regression analysis.

RESULTS

There were no significant associations between total fruit and vegetable, total vegetable, or fruit and the risk of asthenopia. Higher intake of dark-green leafy vegetable was likely to be inversely associated with asthenopia risk [odd ratio (OR): 0.60; 95%CI: 0.37-0.97; P_trend=0.21] after controlling for nondietary and dietary risk factors. Stratified analysis showed that the inverse association between dark-green leafy vegetable intake and asthenopia risk was limited to participants with suboptimal eyesight (OR: 0.45; 95%CI: 0.25-0.82; P_trend=0.05), wearing glasses (OR: 0.35; 95%CI: 0.17-0.72; P_trend=0.03) or using computer ≥3h/d (OR: 0.48; 95%CI: 0.25-0.93; P_trend=0.08).

CONCLUSION

A higher consumption of dark-green leafy vegetable is associated with a lower asthenopia risk among college students with suboptimal eyesight and poor eye care habits.

Objective Evaluation of Visual Fatigue Using Binocular Fusion Maintenance

Purpose

In this study, we investigated whether an individual's visual fatigue can be evaluated objectively and quantitatively from their ability to maintain binocular fusion.

Methods

Binocular fusion maintenance (BFM) was measured using a custom-made binocular open-view Shack-Hartmann wavefront aberrometer equipped with liquid crystal shutters, wherein eye movements and wavefront aberrations were measured simultaneously. Transmittance in the liquid crystal shutter in front of the subject's nondominant eye was reduced linearly, and BFM was determined from the transmittance at the point when binocular fusion was broken and vergence eye movement was induced. In total, 40 healthy subjects underwent the BFM test and completed a questionnaire regarding subjective symptoms before and after a visual task lasting 30 minutes.

Results

BFM was significantly reduced after the visual task (P < 0.001) and was negatively correlated with the total subjective eye symptom score (adjusted R² = 0.752, P < 0.001). Furthermore, the diagnostic accuracy for visual fatigue was significantly higher in BFM than in the conventional test results (aggregated fusional vergence range, near point of convergence, and the high-frequency component of accommodative microfluctuations; P = 0.007).

Conclusions

These results suggest that BFM can be used as an indicator for evaluating visual fatigue.

Translational Relevance

BFM can be used to evaluate the visual fatigue caused by the new visual devices, such as head-mount display, objectively.

Symptomatic accommodative and binocular dysfunctions from the use of flat-panel displays

AIM

To determine the presence of symptomatic accommodative and non-strabismic binocular dysfunctions (A_NSBD) in a non-presbyopic population of video display unit (VDU) users with flat-panel displays.

METHODS

One hundred and one VDU users, aged between 20 to 34y, initially participated in the study. This study excluded contact-lens wearers and subjects who had undergone refractive surgery or had any systemic or ocular disease. First, subjects were asked about the type and nature of eye symptoms they experienced during VDU use. Then, a thorough eye examination excluded those subjects with a significant uncorrected refractive error or other problem, such as ocular motility disorders, vertical deviation, strabismus and eye diseases. Finally, the remaining participants underwent an exhaustive assessment of their accommodative and binocular vision status.

RESULTS

Eighty-nine VDU users (46 females and 43 males) were included in this study. They used flat-panel displays for an average of 5±1.9h a day. Twenty subjects presented A_NSBD (22.5%). Convergence excess was the most frequent non-strabismic binocular dysfunction (9 subjects), followed by fusional vergence dysfunction (3 subjects) and convergence insufficiency (2 subjects). Within the accommodative dysfunctions, accommodative excess was the most common (4 subjects), followed by accommodative insufficiency (2 subjects). Moderate to severe eye symptoms were found in 13 subjects with A_NSBD.

CONCLUSION

Significant eye symptoms in VDU users with accommodative and/or non-strabismic binocular dysfunctions often occur and should not be underestimated; therefore, an appropriate evaluation of accommodative and binocular vision status is more important for this population.

Visual Fatigue Induced by Viewing a Tablet Computer with a High-resolution Display

Purpose

In the present study, the visual discomfort induced by smart mobile devices was assessed in normal and healthy adults.

Methods

Fifty-nine volunteers (age, 38.16 ± 10.23 years; male : female = 19 : 40) were exposed to tablet computer screen stimuli (iPad Air, Apple Inc.) for 1 hour. Participants watched a movie or played a computer game on the tablet computer. Visual fatigue and discomfort were assessed using an asthenopia questionnaire, tear film break-up time, and total ocular wavefront aberration before and after viewing smart mobile devices.

Results

Based on the questionnaire, viewing smart mobile devices for 1 hour significantly increased mean total asthenopia score from 19.59 ± 8.58 to 22.68 ± 9.39 (p < 0.001). Specifically, the scores for five items (tired eyes, sore/aching eyes, irritated eyes, watery eyes, and hot/burning eye) were significantly increased by viewing smart mobile devices. Tear film break-up time significantly decreased from 5.09 ± 1.52 seconds to 4.63 ± 1.34 seconds (p = 0.003). However, total ocular wavefront aberration was unchanged.

Conclusions

Visual fatigue and discomfort were significantly induced by viewing smart mobile devices, even though the devices were equipped with state-of-the-art display technology.

Warming infusion improves perioperative outcomes of elderly patients who underwent bilateral hip replacement

BACKGROUND

This prospective, randomized, and controlled study was performed to determine the benefits of prewarmed infusion in elderly patients who underwent bilateral hip replacement.

METHODS

Between September 2015 and April 2016, elderly patients who underwent bilateral hips replacement that met the inclusion and exclusion criteria were included in this study. After inclusion, patients were randomized into one of the study groups: in the control group, patients received an infusion of fluid kept at room temperature (22-23°C); in the warming infusion group, patients received an infusion of fluid warmed using an infusion fluid heating apparatus (35°C). Postoperative outcomes, including recovery time, length of hospital stay, visual analogue scale (VAS) score, and postoperative complications rate of patients from both groups, were compared.

RESULTS

A total of 64 patients were included in our study (71.2 ± 7.6 years, 53.1% males), with 32 patients in the control group and 32 patients in warming infusion group. No significant difference was found in terms of demographic data and intraoperative blood transfusion rate between 2 groups (P > 0.05). Patients receiving a prewarmed infusion had a significantly shorter time to spontaneous breath, eye opening, consciousness recovery, and extubation than the control group (P < 0.05). In addition, significant differences were found in Steward score and VAS score between 2 groups (P < 0.05). Moreover, warming infusion group also showed an obviously decreased incidence of shivering and postoperative cognitive dysfunction (P < 0.05).

CONCLUSION

A prewarmed infusion could reduce the incidence of perioperative hypothermia and improve outcomes in the elderly during bilateral hip replacement.

Main visual symptoms associated to refractive errors and spectacle need in a Brazilian population

AIM

To determine the main visual symptoms in a Brazilian population sample, associated to refractive errors (REs) and spectacle need to suggest priorities in preventive programs.

METHODS

A cross-sectional study was conducted in nine counties of the southeast region of Brazil, using a systematic sampling of households, between March 2004 and July 2005. The population was defined as individuals aged between 1 and 96y, inhabitants of 3600 residences to be evaluated and 3012 households were included, corresponding to 8010 subjects considered for participation in the survey, of whom 7654 underwent ophthalmic examinations. The individuals were evaluated according their demographic data, eye complaints and eye examination including the RE and the need to prescribe spectacles according to age. Statistical analysis was performed using SPSS software package and descriptive analysis using 95% confidence intervals (P<0.05).

RESULTS

The main symptom detected was asthenopia, most frequent in the 2^nd and 3^rd decades of life, with a significant decline after the 4^th decade. Astigmatism was the RE most associated with asthenopia. Reduced near vision sight was more frequent in those ≥40y with a progressive decline thereafter. Spectacles were most frequently required in subjects of ≥40 years of age.

CONCLUSION

The main symptom related to the vision was asthenopia and was associated to astigmatism. The greatest need for spectacles prescription occurred after 40's, mainly to correct near vision. Subjects of ≥40 years old were determined to be at high risk of uncorrected REs. These observations can guide intervention programs for the Brazilian population.

The effect of Vaccinium uliginosum extract on tablet computer-induced asthenopia: randomized placebo-controlled study

Background

To investigate the alleviation effect of Vaccinium uliginosum extract (DA9301) on tablet computer-induced asthenopia.

Methods

This was a randomized, placebo-controlled, double-blind and parallel study (Trial registration number: 2013–95). A total 60 volunteers were randomized into DA9301 (n = 30) and control (n = 30) groups. The DA9301 group received DA9301 oral pill (1000 mg/day) for 4 weeks and the control group received placebo. Asthenopia was evaluated by administering a questionnaire containing 10 questions (responses were scored on a scales of 0–6; total score: 60) regarding ocular symptoms before (baseline) and 4 weeks after receiving pills (DA9301 or placebo). The participants completed the questionnaire before and after tablet computer (iPad Air, Apple Inc.) watching at each visit. The change in total asthenopia score (TAS) was calculated and compared between the groups

Results

TAS increased significantly after tablet computer watching at baseline in DA9301 group. (from 20.35 to 23.88; p = 0.031) However, after receiving DA9301 for 4 weeks, TAS remained stable after tablet computer watching. In the control group, TAS changes induced by tablet computer watching were not significant both at baseline and at 4 weeks after receiving placebo. Further analysis revealed the scores for “tired eyes” (p = 0.001), “sore/aching eyes” (p = 0.038), “irritated eyes” (p = 0.010), “watery eyes” (p = 0.005), “dry eyes” (p = 0.003), “eye strain” (p = 0.006), “blurred vision” (p = 0.034), and “visual discomfort” (p = 0.018) significantly improved in the DA9301 group.

Conclusions

We found that oral intake of DA9301 (1000 mg/day for 4 weeks) was effective in alleviating asthenopia symptoms induced by tablet computer watching.

Trial registration

The study is registered at www.clinicaltrials.gov (registration number: NCT02641470, date of registration December 30, 2015).

Visual and ocular effects from the use of flat-panel displays

AIM

To evaluate the prevalence of eye symptoms in a non-presbyopic population of video display unit (VDU) users with flat-panel displays.

METHODS

One hundred and sixteen VDU users with flat-panel display from an urban population participated in the study; their ages ranging from 20 to 34y. There were 60 females and 56 males. An eye examination to rule out the presence of significant uncorrected refractive errors, general binocular dysfunctions and eye conditions was carried out. In order to determine and quantify the type and nature of eye symptoms, participants were asked to answer written questionnaire and the results were grouped by gender, age and number of hours a day spent using a VDU.

RESULTS

Seventy-two percent of participants reported eye symptoms related to VDU use. Eye symptoms from moderate-to-severe were found in 23% of participants. The main symptom was moderate-to-severe tired eyes (14%); followed by sensitivity to bright lights (12%), blurred vision at far distances (10%), eyestrain or dry eye or irritated or burning eyes (9%), difficulty in refocusing from one distance to another or headache (8%) and blurred vision at near or intermediate distances (<4%). Eye symptoms were greater among females (P=0.005) and increased with VDU use, markedly above 6h spent using a VDU in a typical day (P=0.01).

CONCLUSION

Significant eye symptoms relate to VDU use often occur and should not be underestimated. The increasing use of electronic devices with flat-panel display should prompt users to take appropriate measures to prevent or to relieve the eye symptoms arising from their use.