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Nutrition Research (New York, N.Y.) Dec 2023The retina, an important tissue of the eye, is essential in visual transmission and sustaining adequate eyesight. However, oxidative stress and inflammatory reactions... (Review)
Review
The retina, an important tissue of the eye, is essential in visual transmission and sustaining adequate eyesight. However, oxidative stress and inflammatory reactions can harm retinal structure and function. Recent studies have demonstrated that exposure to light can induce oxidative stress and inflammatory reactions in retinal cells, thereby facilitating the progression of retinal damage-related diseases and asthenopia. Plant bioactive compounds such as anthocyanin, curcumin, resveratrol, lutein, zeaxanthin, epigallocatechin gallate, and quercetin are effective in alleviating retinal damage and asthenopia. Their strong oxidation resistance and unique chemical structure can prevent the retina from producing reactive oxygen species and regulating eye muscle relaxation, thus alleviating retinal damage and asthenopia. Additionally, the combination of these active ingredients produces a stronger antioxidant effect. Consequently, understanding the mechanism of retinal damage caused by light and the regulation mechanism of bioactive compounds can better protect the retina and reduce asthenopia.
Topics: Humans; Asthenopia; Biological Availability; Retina; Antioxidants; Oxidative Stress; Phytochemicals
PubMed: 37980835
DOI: 10.1016/j.nutres.2023.10.003 -
Clinical Optometry 2020Accommodative insufficiency (AI), defined as the inability to stimulate accommodation in pre-presbyopic individuals, has gained much attention over recent years. Despite... (Review)
Review
PURPOSE
Accommodative insufficiency (AI), defined as the inability to stimulate accommodation in pre-presbyopic individuals, has gained much attention over recent years. Despite the enormity of the available information, there is a significant lack of clarity regarding the criteria for definition, methodology adopted for testing and diagnosis, and the varied prevalence across the globe. This review aims to gather evidence that is pertinent to the prevalence, impact and efficacy of available treatment options for AI.
METHODS
PubMed, Google Scholar and Cochrane Collaboration search engines were used with the keywords prevalence, accommodative insufficiency, symptoms, plus lens, vision therapy and treatment. Peer-reviewed articles published between 1992 and 2019 were included in the review. After reviewing the studies for study methodology and robustness, 83 articles were chosen for this literature review.
RESULTS
The prevalence of AI ranges between <1.00% and 61.6% across studies. The prevalence shows considerable variation across ethnicities and age groups. There is significant variation in the study methodology, diagnostic criteria and number of tests performed to arrive at the diagnosis. Not many studies have explored the prevalence beyond 20 years of age. The prevalence of AI is high among children with special needs. There is no high-quality evidence regarding the standard treatment protocol for AI. Both vision therapy and low plus lenses have shown efficacy in independent studies, and no studies have compared these two treatment options.
CONCLUSION
The understanding of AI prevalence is currently limited owing to the lack of a standard set of diagnostic criteria and wide variations in the study methodology. There is a lack of high-quality evidence suggesting the best possible treatment for AI. The current gaps in the literature have been identified and future scope for exploration is elucidated.
PubMed: 32982529
DOI: 10.2147/OPTO.S224216 -
International Ophthalmology Dec 2023To detect the presence of asthenopia after implantation of Implantable Collamer Lens (ICL). (Observational Study)
Observational Study
OBJECTIVE
To detect the presence of asthenopia after implantation of Implantable Collamer Lens (ICL).
METHOD
Design: prospective observational case series. Patients with myopia and/or astigmatism who underwent ICL surgeries and completed 3-month follow-up were enrolled. Asthenopia scores, amplitude of accommodation (AA), positive/negative relative accommodation (PRA/NRA), accommodative facility (AF), the ratio of accommodative convergence and accommodation (AC/A), Schirmer test, noninvasive breakup time (NBUT), and HOA were examined before surgeries and at 1 week, 1 month and 3 months postoperatively then statistically analyzed.
RESULTS
Symptoms of asthenopia were significantly decreased at 1 week after ICL surgeries than those before surgeries, but increased gradually as time went by, eventually recovered at 3 months postoperatively. AA, AF, AC/A decreased 1 week postoperatively, returned to the baseline at 1 month and were improved at 3 months after surgeries. NBUT at 1 week, 1 month and 3 months after surgeries were significantly decreased and was the lowest at 1 week postoperatively. PRA, NRA, Schiermer values and HOA had no significant change. Correlation analysis showed that the lower AF and NBUT after ICL surgeries, the more severe the asthenopia symptoms.
CONCLUSION
The symptoms of asthenopia aggravated transiently after ICL implantation surgeries, but improved gradually with time. AF and NBUT were important factors affecting the changes of asthenopia.
Topics: Humans; Lens Implantation, Intraocular; Asthenopia; Phakic Intraocular Lenses; Myopia; Accommodation, Ocular
PubMed: 37923878
DOI: 10.1007/s10792-023-02890-0 -
Journal of Clinical Medicine Nov 2022Purpose: To analyze the correlation between eye movements and asthenopia so as to explore the possibility of using eye-tracking techniques for objective assessment of...
Purpose: To analyze the correlation between eye movements and asthenopia so as to explore the possibility of using eye-tracking techniques for objective assessment of asthenopia. Methods: This prospective observational study used the computer visual syndrome questionnaire to assess the severity of asthenopia in 93 enrolled college students (age 20−30) who complained about asthenopia. Binocular accommodation and eye movements during the reading task were also examined. The correlations between questionnaire score and accommodation examination results and eye movement parameters were analyzed. Differences in eye movement parameters between the first and last reading paragraphs were compared. The trends in eye movement changes over time were observed. Results: About 81.7% of the subjects suffered from computer visual syndrome. Computer visual syndrome questionnaire total score was positively correlated with positive relative accommodation (p < 0.05). In the first reading paragraph, double vision was positively correlated with unknown saccades (all p < 0.05). Difficulty focusing at close range was positively correlated with total fixation duration, total visit duration, and reading speed (all p < 0.05). Feeling that sight was worsening was positively correlated with regressive saccades (p < 0.05). However, visual impairment symptoms were not significantly correlated with any accommodative function. In a total 20 min reading, significantly reduced eye movement parameters were: total fixation duration, fixation count, total visit duration, visit count, fixation duration mean, and reading speed (all p < 0.01). The eye movement parameters that were significantly increased were: visit duration mean and unknown saccades (all p < 0.001). Conclusion: Eye tracking could be used as an effective assessment for asthenopia. Among the various eye movement parameters, a decrease in fixation duration and counts may be one of the potential indicators related to asthenopia.
PubMed: 36498619
DOI: 10.3390/jcm11237043 -
Clinical & Experimental Optometry Nov 2019Aniseikonia is a difference in the perceived size or shape of images between eyes, and can arise from a variety of physiological, neurological, retinal, and optical... (Review)
Review
Aniseikonia is a difference in the perceived size or shape of images between eyes, and can arise from a variety of physiological, neurological, retinal, and optical causes. Aniseikonia is associated with anisometropia, as both anisometropia itself and the optical correction for anisometropia can cause aniseikonia. Image size differences above one to three per cent can be clinically symptomatic. Common symptoms include asthenopia, headache and diplopia in vertical gaze. Size differences of three and more impair binocular visual functions such as binocular summation and stereopsis. Above five per cent of aniseikonia, binocular inhibition or suppression tend to occur to prevent diplopia and confusion. Aniseikonia can be measured using a range of techniques and can be corrected or reduced by prescribing contact lenses or specially designed spectacle lenses. Subjective testing of aniseikonia is the only way to accurately measure the overall perceived amount of aniseikonia. However, currently it is not routinely assessed in most clinical settings. At least two-thirds of patients with amblyopia have anisometropia, thus we may expect aniseikonia to be common in patients with anisometropic amblyopia. However, aniseikonia may not be experienced by the patient under normal binocular viewing conditions if the image from the amblyopic eye is of poor quality or is too strongly suppressed for image size differences to be recognised. This lack of binocular simultaneous perception in amblyopia may also prevent the measurement of aniseikonia, as most common techniques require direct comparisons of images seen by each eye. Current guidelines for the treatment of amblyopia advocate full correction of anisometropia to equalise image clarity, but do not address aniseikonia. Significant image size differences between eyes may lead to suppression and abnormal binocular adaptations. It is possible that correcting anisometropia and aniseikonia simultaneously, particularly at the initial diagnosis of anisometropia, would reduce the need to develop suppression and improve treatment outcomes for anisometropic amblyopia.
Topics: Amblyopia; Aniseikonia; Anisometropia; Humans
PubMed: 30791133
DOI: 10.1111/cxo.12881 -
Kathmandu University Medical Journal... 2022Background Clinical microscopists are at a greater risk of developing binocular vision anomalies and asthenopia. Objective To assess the refractive and binocular vision...
Background Clinical microscopists are at a greater risk of developing binocular vision anomalies and asthenopia. Objective To assess the refractive and binocular vision status and to explore the association between the presence of asthenopic symptoms and microscopy work among clinical microscopists working at medical laboratory department. Method This cross-sectional study involved 37 clinical microscopists working at medical laboratory department of Dhulikhel Hospital, Nepal. The study was conducted from January to December 2013. Only those participants who had been using microscope for at least a year were enrolled in this study. Each participant underwent distance visual acuity (VA) assessment, refractions, and orthoptic evaluation, including measurement of distance and near phoria, near point of convergence (NPC), near point of accommodation (NPA), positive fusional vergence (PFV), adduction, and calculation of accommodation convergence/accommodation (AC/A) ratio. The tear test was also carried out in each subject. Information about use of glasses, microscopy work (duration, and time spent per day in microscope), and visual symptoms associated with the use of microscope such as eye strain, headache, double vision, and near vision were collected. Result The mean age of the clinical microscopists was 29 ± 5.7 years. The prevalence of refractive error was 56.76% and the mean spherical equivalent (SE) refractive error was -0.77 ± 0.86 D. Refractive error had neither correlation with microscopy work and asthenopic symptoms associated with it, and nor with binocular vision parametersNPC, AA and AC/A ratio. However, there was a positive association between asthenopic symptoms and microscopy work. There was statistically significant difference between symptomatic and asymptomatic subjects for binocular vision parameters, including NPC, AA and positive fusional vergence (PFV) for near. Conclusion Microscopy work has an impact on near binocular vision. Asthenopic symptoms bear a positive association with microscopy work. Refractive error has no significant correlation with either microscopy works or associated asthenopic symptoms.
Topics: Humans; Young Adult; Adult; Vision, Binocular; Asthenopia; Cross-Sectional Studies; Refractive Errors; Visual Acuity; Accommodation, Ocular
PubMed: 37795732
DOI: No ID Found -
Nutrients Sep 2022Digital eye strain is a complex, multifactorial condition that can be caused by excessive screen time exposure to various electronic devices such as smartphones,... (Review)
Review
Digital eye strain is a complex, multifactorial condition that can be caused by excessive screen time exposure to various electronic devices such as smartphones, tablets, e-readers, and computers. Current literature suggests oxidative damage concomitant with a chronic pro-inflammatory state represent significant etiopathogenic mechanisms. The present review aims to discuss the potential dietary role for micronutrients with nutraceutical properties to ameliorate various ocular and vision-related symptoms associated with digital eye strain. For ocular surface dysfunction, enhanced anti-inflammatory benefits with omega-3 polyunsaturated fatty acids have been well documented for treatment of dry eye disease. The anti-oxidative and immunosuppressive properties of anthocyanin phytochemicals may also confer protective effects against visually induced cognitive stress and digital asthenopia. Meanwhile, nutraceutical strategies involving xanthophyll macular carotenoids demonstrate enhanced cognitive functioning and overall visual performance that aids digital eye strain. Collectively, preliminary findings seem to offer a strong line of evidence to substantiate the need for additional randomized controlled trials aimed at treating digital eye strain with adjunctive nutraceutical strategies. Further RCT and comparisons on commercially available nutritional supplements are needed to quantify the clinical benefits.
Topics: Anthocyanins; Asthenopia; Dry Eye Syndromes; Fatty Acids, Omega-3; Humans; Micronutrients; Xanthophylls
PubMed: 36235656
DOI: 10.3390/nu14194005 -
[Zhonghua Yan Ke Za Zhi] Chinese... Apr 2021To design a valid and reliable questionnaire to determine various causes of asthenopia for use by clinicians and researchers. The items to be included in the first...
To design a valid and reliable questionnaire to determine various causes of asthenopia for use by clinicians and researchers. The items to be included in the first version questionnaire were selected based on its definition and literature review. The second version was improved from patients interviews and the Delphi method. In this phase, 17 experts, 97 patients [47 males, 50 females, age (34.42±14.62) years old] with asthenopia and 20 controls [9 males, 11 females, age (33.50±7.31) years old] were involved to generated item list. In the Validation phase, we conducted two round interview through 275 asthenopia patients [97 males,186 females,age (34.42±14.62) years old] and 49 controls [17 males,32 females,age (35.79±8.88) years old]for item reduction and questionnaire validity and reliability assessment. Exploratory factor analysis was performed to reduce items and derive the subscale that each item belongs to. Internal consistency was calculated for all resulting subscales, using Cronbach's α coefficient, spilt-half reliability and repeatability. The repeatability of the questionnaire was measured by Pearson correlation analysis. Our initial questionnaire contained 52 symptoms and 2 self-evaluation questions. After the item reduction and assessment, 19 items were selected and classified into three domains through factor analysis. Cronbach α for the three subscales of this version was between 0.79 and 0.85, while for the complete questionnaire it was 0.90, with a spilt-half reliability of 0.80. Factor analysis showed the three components had eigenvalues>3 and these explained 54.3% of the variance. The 19-item asthenopia questionnaire has acceptable psychometric properties, making it a valid and reliable tool for ophthalmologists and optometrists to evaluate asthenopia as well as to seek causes. It has the potential to be used in clinical trials and outcome research. (.
Topics: Adult; Asthenopia; Female; Humans; Male; Middle Aged; Psychometrics; Reproducibility of Results; Surveys and Questionnaires; Young Adult
PubMed: 33832053
DOI: 10.3760/cma.j.cn112142-20200701-00442 -
Journal of Family Medicine and Primary... Aug 2020Asthenopia or eye strain is one of the major medical problems that students face during their academic years.
BACKGROUND
Asthenopia or eye strain is one of the major medical problems that students face during their academic years.
OBJECTIVES
The aim of this study is to determine the prevalence of asthenopia among a sample of university students attending various majors and to identify the risk factors for its development.
METHODS
This is a cross sectional study conducted on students attending various faculties at the American University of Beirut during the spring semester of 2019. Students were asked to fill a self-administered anonymous questionnaire that inquired about demographics, use of digital devices, symptoms of asthenopia, possible risk factors and protective measures. A bivariate analysis was performed to correlate asthenopia with the different variables. A multivariate analysis was then conducted to determine the extent of contribution of the different variables to asthenopia after controlling for confounding variables.
RESULTS
The prevalence of asthenopia was found to be 67.8% with blurred vision being the most reported symptom (27.0%). A bivariate analysis was used to assess the association between asthenopia and the following variables: demographics, digital device use, reasons for using digital devices, and preventive methods. Age, being a continuous variable, was analyzed using an independent t- test. For the variables that were found to be have a p-value < 0.2, a multiple logistic regression was performed. Old age was found to be a protective factor for asthenopia, with 0.693 times reduction in asthenopia for every increase in year of age. Using the device for communication for less than four hours (=0.012), using the device for less than four hours per day (=0.000) and pattern of using the device for less than three years (=0.023) were significant in being negatively associated with asthenopia. As for preventative measures that protect users from digital eyestrain, we found that using eye drops (=0.004; OR=0.375) and taking regular breaks (=0.000; OR= 0.399) were protective factors whereas using adjustable screens was a risk factor (=0.000; OR=3.083).
CONCLUSION
Asthenopia was found to be of non-negligible prevalence among this sample of university students. The results of this study highlight the importance of establishing awareness campaigns and encourage the introduction of targeted screenings for asthenopia among college students.
PubMed: 33110788
DOI: 10.4103/jfmpc.jfmpc_340_20 -
Ophthalmic Epidemiology Aug 2023To determine the prevalence of ophthalmological findings suggesting an ocular cause for headache or occult neurological disease, among children with headache.
PURPOSE
To determine the prevalence of ophthalmological findings suggesting an ocular cause for headache or occult neurological disease, among children with headache.
METHODS
Retrospective cross-sectional study on children with headache at a tertiary outpatient ophthalmology clinic. All children underwent sensorimotor, anterior segment, and dilated fundoscopic examinations, with or without cycloplegic refraction. Prevalence of one or more new findings of ocular or occult neurological cause of headache, including glaucoma, uveitis, optic nerve elevation, or possible asthenopia from strabismus or refractive issues. Headache characteristics and associated symptoms were evaluated as risk factors for ocular findings.
RESULTS
Among 1,878 children with headache (mean age 10 yrs, range 2-18), 492 (26.1%, 95% CI 24.3-28.2%) children had one or more new ocular findings that could cause headache or indicate intracranial disease: refractive issues (342, 18.2%), strabismus (83, 4.4%), optic nerve elevation (51, 2.7%; 26 with papilledema, 25 with pseudopapilledema), uveitis (6, 0.3%), and glaucoma (2, 0.1%). Shorter headache duration was associated with ocular findings (p = .047), but headache frequency, photophobia, nausea/vomiting, and visual changes were not. In univariable analysis, visual changes (p ≤ .001), nausea/vomiting (p ≤ .002), and morning headache (p = .02) were associated with optic nerve elevation.
CONCLUSION
An ophthalmologic examination including cycloplegic refraction is indicated in children with headache, as one-quarter have a treatable ocular condition, which may be related to the headache, or sign of intracranial pathology. While nausea, visual changes, or morning headache should raise concern, coincident visual, ocular, or systemic symptoms are not reliable predictors of discovering ocular pathology in a child with headache.
Topics: Child; Humans; Child, Preschool; Adolescent; Retrospective Studies; Cross-Sectional Studies; Mydriatics; Strabismus; Refraction, Ocular; Headache; Glaucoma
PubMed: 36125107
DOI: 10.1080/09286586.2022.2125019