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Saudi Journal of Ophthalmology :... 2023The aim of this study is to investigate the association between body mass index (BMI) and visual efficiency skills of university students.
PURPOSE
The aim of this study is to investigate the association between body mass index (BMI) and visual efficiency skills of university students.
METHODS
This study adopted an analytical and descriptive methodology whereby a comprehensive screening of 385 university students was conducted. Ultimately, 116 subjects were selected to ensure judicious distribution of subjects across the four categories of BMI. These 116 subjects were subjected to visual efficiency testing parameters, as referenced from "Clinical Management of Binocular Vision," by Scheiman and Wick.
RESULTS
BMI and visual efficiency anomalies were observed to be correlated with statistical significance to each other as indicated by a = 0.018 and = 15.22. It was also observed that the obese category exhibited the highest prevalence of accommodation and vergence anomalies, followed by the underweight category, as discerned from a detailed analysis of subjects classified according to the BMI categories. These findings imply a noteworthy and potentially deleterious impact of BMI on the visual system and underscore the importance of regular screening for visual efficiency skills in individuals across various BMI categories.
CONCLUSION
This study established a compelling association between BMI and visual efficiency skills anomalies. Consistent with prior research, the findings of this study suggest that individual with higher BMI is more prone to experiencing such anomalies.
PubMed: 38074302
DOI: 10.4103/sjopt.sjopt_95_23 -
Scientific Reports Dec 2023Quantifying eye movement is important for diagnosing various neurological and ocular diseases as well as AR/VR displays. We developed a simple setup for real-time...
Quantifying eye movement is important for diagnosing various neurological and ocular diseases as well as AR/VR displays. We developed a simple setup for real-time dynamic gaze tracking and accommodation measurements based on Purkinje reflections, which are the reflections from front and back surfaces of the cornea and the eye lens. We used an accurate eye model in ZEMAX to simulate the Purkinje reflection positions at different focus distances of the eye, which matched the experimental data. A neural network was trained to simultaneously predict vergence and accommodation using data collected from 9 subjects. We demonstrated that the use of Purkinje reflection coordinates in machine learning resulted in precise estimation. The proposed system accurately predicted the accommodation with an accuracy better than 0.22 D using subject's own data and 0.40 D using other subjects' data with two-point calibration in tests performed with 9 subjects in our setup.
Topics: Humans; Accommodation, Ocular; Lens, Crystalline; Eye Movements; Cornea; Machine Learning
PubMed: 38062067
DOI: 10.1038/s41598-023-47572-0 -
Contact Lens & Anterior Eye : the... Feb 2024Soft contact lenses have been developed and licensed for reducing myopia progression. These lenses have different designs, such as extended depth of focus (EDOF) and... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Soft contact lenses have been developed and licensed for reducing myopia progression. These lenses have different designs, such as extended depth of focus (EDOF) and dual focus (DF). In this prospective, double-masked, cross-over study, different lens designs were investigated to see whether these had impact on accommodative microfluctuations and eye movements during reading.
METHODS
Participants were fitted with three lenses in a randomised order; a single vision (SV) design (Omafilcon A2; Proclear), a DF design (Omafilcon A2; MiSight), and an EDOF lens design (Etafilcon A; NaturalVue),. Accommodative microfluctuations were measured at 25 cm for at least 60s in each lens, using a Shin-Nippon SRW-5000 autorefractor adapted to continuously record accommodation at 22Hz. Eye movement data was collected with the Thomson Clinical Eye Tracker incorporating a Tobii Eye bar. Eye movements include fixations per row, fixations per minute, mean regressions per row, total number of regressions, and total rightward saccades. Accommodation data was analysed using power spectrum analysis. Differences between the lenses were compared using a related sample two-way Friedman test.
RESULTS
Twenty-three participants (18-29 years) were recruited to take part. The average mean spherical error was -2.65D ± 1.42DS, with an average age of 23.4 ± 3.5 years. No significant difference for accommodative microfluctuations was found. Significant differences were found for fixations per row (P = 0.03), fixations per minute (P = 0.008), mean regressions per row (P = 0.002), and total number of regressions (P = 0.002), but not total rightward saccades (P = 0.10). Post-hoc analysis indicated the EDOF lens results were significantly different from the other lenses, with more regressive eye movements observed.
CONCLUSIONS
Regressive saccades appear to increase when wearing EDOF lens designs, which may impact visual comfort. Further studies in children, over a longer period of adaptation are necessary to assess the potential impact of this finding on daily reading activities in children.
Topics: Child; Humans; Young Adult; Adult; Eye Movements; Reading; Cross-Over Studies; Prospective Studies; Accommodation, Ocular; Myopia; Contact Lenses, Hydrophilic
PubMed: 38057197
DOI: 10.1016/j.clae.2023.102095 -
Clinical Ophthalmology (Auckland, N.Z.) 2023To investigate the visual acuity and satisfaction of patients after Zhang & Zheng's corneal laser-enhanced accommodation refraction Q (ZZ-CLEAR-Q) surgery utilizing... (Clinical Trial)
Clinical Trial
PURPOSE
To investigate the visual acuity and satisfaction of patients after Zhang & Zheng's corneal laser-enhanced accommodation refraction Q (ZZ-CLEAR-Q) surgery utilizing differential modulation of binocular longitudinal spherical aberration and determine its clinical significance.
PATIENTS AND METHODS
This prospective observational study enrolled a consecutive cohort of patients with presbyopia who underwent ZZ-CLEAR-Q surgery between December 2020 and January 2023. The study assessed visual acuity, distance-corrected defocus curve, satisfaction, Q factor, manifest spherical equivalent, and primary spherical aberration, among others, at 3 months postoperatively. Additionally, the study conducted a binocular comparison to analyze the clinical significance of setting the different longitudinal spherical aberrations.
RESULTS
A total of 232 eyes of 116 patients were included. The binocular uncorrected distance visual acuity was 20/20 for all patients. At 3 months postoperatively, the binocular uncorrected near visual acuity was Jaeger 1 for 96% of the patients and Jaeger 2 for 100% of the patients. Furthermore, 93.1% of the patients expressed satisfaction. The monocular distance-corrected defocus curve revealed that the dominant eyes had significantly better visual acuity at 0 D (P<0.001), while the non-dominant eyes had significantly better visual acuity across various defocus levels except 0 and -0.50 D (All P<0.05). At 3 months, there were no significant differences between the expected and achieved manifest spherical equivalents, corneal Q factor values, and ocular primary spherical aberration values of both groups.
CONCLUSION
Patients with presbyopia who underwent ZZ-CLEAR-Q surgery were likely to achieve normal uncorrected visual acuity and be satisfied. The increased depth of field has clinical significance for assisting near vision.
PubMed: 38026604
DOI: 10.2147/OPTH.S437324 -
Germs Dec 2022Botulinum toxin, the strongest known neurotoxin, is the cause of a rare fatal neuroparalytic disease characterized by the so-called "four Ds": diplopia, dysarthria,...
INTRODUCTION
Botulinum toxin, the strongest known neurotoxin, is the cause of a rare fatal neuroparalytic disease characterized by the so-called "four Ds": diplopia, dysarthria, dysphagia, dry mouth. If left untreated, botulism may cause paralysis of the respiratory muscles, impairing the respiratory function which can ultimately lead to death.
CASE REPORT
We describe the cases of two patients who presented, two years apart, with similar ocular symptoms such as blurred vision due to accommodation palsy, diplopia, accompanied by xerostomia and swallowing disorders, which were further confirmed as botulism. Both cases had a similar clinical presentation of the intoxication and a positive response to treatment with botulinum antitoxin, while only the first case had a laboratory confirmation of the disease.
CONCLUSIONS
The key to diagnose botulism correctly is based on high clinical suspicion and requires a medical multidisciplinary approach and urgent specific treatment. Ophthalmology specialists must be aware of the disease, especially in cases in which ophthalmic manifestation appear at the onset.
PubMed: 38021184
DOI: 10.18683/germs.2022.1359 -
Journal of Clinical Medicine Nov 2023Tinnitus assessment and outcome measurement are complex, as tinnitus is a purely subjective phenomenon. Instruments used for the outcome measurement of tinnitus in the... (Review)
Review
OBJECTIVE
Tinnitus assessment and outcome measurement are complex, as tinnitus is a purely subjective phenomenon. Instruments used for the outcome measurement of tinnitus in the context of clinical trials include self-report questionnaires, visual analogue or numeric rating scales and psychoacoustic measurements of tinnitus loudness. For the evaluation of therapeutic interventions, it is critical to know which changes in outcome measurement instruments can be considered as clinically relevant. For this purpose, the concept of the minimal clinically important difference (MCID) has been introduced.
STUDY DESIGN
Here we performed a literature research in PubMed in order to identify for which tinnitus outcome measurements MCID criteria have been estimated and which of these estimates fulfil the current methodological standards and can thus be considered as established.
RESULTS
For most, but not all tinnitus outcome instruments, MCID calculations have been performed. The MCIDs for the Tinnitus Handicap Inventory (THI), the Tinnitus Questionnaire (TQ), the Tinnitus Functional Index (TFI) and visual analogue scales (VAS) vary considerably across studies. Psychoacoustic assessments of tinnitus such as loudness matching have not shown sufficient reliability and validity for the use as an outcome measurement.
CONCLUSION
Future research should aim at the confirmation of the available estimates in large samples involving various therapeutic interventions and under the consideration of time intervals and baseline values. As a rule of thumb, an improvement of about 15% can be considered clinically meaningful, analogous to what has been seen in other entirely subjective pathologies like chronic pain.
PubMed: 38002730
DOI: 10.3390/jcm12227117 -
Indian Journal of Ophthalmology Dec 2023This study aimed to determine the effect of the blue light (BL) filter on the different tasks performed on a laptop on a daily basis.
PURPOSE
This study aimed to determine the effect of the blue light (BL) filter on the different tasks performed on a laptop on a daily basis.
METHODS
Forty subjects were required to perform a 45-minute task on the laptop screen with or without the BL filter on two different days. In the first task, subjects were made to watch a video. In the second task, subjects were made to read a passage from the laptop for 3 minutes, and reading speed was calculated. In the third task, subjects were made to enter the data on the laptop. The time taken to fill in the data was recorded. After the completion of the task, questionnaires were administered. Pre- and post-task accommodative tests were performed.
RESULTS
Forty emmetropes with a mean age of 21 ± 2 were recruited. In visual performance, the subjective response showed a significant difference in visual fatigue level with and without the filter. A statistically significant difference was seen in reading speed and data entry during task performance with and without the filter. Pre- and post-task accommodative parameters showed variable responses.
CONCLUSION
This study showed that the use of a BL filter improves task performance, but subjectively, people experienced more visual fatigue while using the filter.
Topics: Humans; Young Adult; Adult; Task Performance and Analysis; Asthenopia; Light; Accommodation, Ocular; Microcomputers
PubMed: 37991308
DOI: 10.4103/IJO.IJO_534_23 -
Investigative Ophthalmology & Visual... Nov 2023Uncorrected hyperopic children must overcome an apparent conflict between accommodation and vergence demands to focus and align their retinal images. This study tested...
PURPOSE
Uncorrected hyperopic children must overcome an apparent conflict between accommodation and vergence demands to focus and align their retinal images. This study tested hypotheses about simultaneous accommodation and vergence performance of young hyperopes to gain insight into ocular motor strategies used to maintain eye alignment.
METHODS
Simultaneous eccentric photorefraction and Purkinje image tracking were used to assess accommodative and vergence responses of 26 adult emmetropes (AE) and 94 children (0-13 years) viewing cartoons. Children were habitually uncorrected (CU) (spherical equivalent refractive error [SE] -0.5 to +4 D), corrected and aligned (CCA), or corrected with a history of refractive esotropia (CCS). Accommodative and vergence accuracy, dissociated heterophoria, and vergence/accommodation ratios in the absence of retinal disparity cues were measured for 33- and 80-cm viewing distances.
RESULTS
In binocular viewing, median accommodative lags for 33 cm were 1.0 D (AE), 1.33 D (CU), 1.25 D (CCA), and 1.0 D (CCS). Median exophorias at 80 and 33 cm were 1.2 and 4.5 pd (AE), 0.8 and 2.5 pd (CU), and 0 and 1.2 pd (CCA), respectively. Without disparity cues, most response vergence/accommodation ratios were between 1 and 2 meter angle/D (∼5-10 pd/D) (69% of AE, 44% of CU, 60% of CCA, and 50% of CCS).
CONCLUSIONS
Despite apparent conflict in motor coupling, uncorrected hyperopes were typically exophoric and achieved adultlike accuracy of both vergence and accommodation simultaneously, indicating ability to compensate for conflicting demands rather than bias to accurate vergence while tolerating inaccurate accommodation. Large lags and esophoria are therefore atypical. This analysis provides normative guidelines for clinicians and a deeper mechanistic understanding of how hyperopes avoid strabismus.
Topics: Adult; Child; Humans; Strabismus; Esotropia; Exotropia; Accommodation, Ocular; Cues; Hyperopia
PubMed: 37962529
DOI: 10.1167/iovs.64.14.17 -
Case Reports in Ophthalmology 2023Acute acquired comitant esotropia (AACE) is an acquired strabismus with uncrossed sudden-onset diplopia due to esodeviation, comitant esotropia without accommodation...
INTRODUCTION
Acute acquired comitant esotropia (AACE) is an acquired strabismus with uncrossed sudden-onset diplopia due to esodeviation, comitant esotropia without accommodation factor, or paretic eye movement. The diagnosis of AACE entails differentiation from incomitant esotropia caused by abnormalities in the central nervous system. We present 2 pediatric patients with AACE as the first symptom of brainstem tumor.
CASE PRESENTATION
The 2 patients were aware of their diplopia and had no other neurological abnormalities. There were no special findings in the anterior segment, ocular media, or fundus. Esotropia with a difference of no more than 10Δ between distant and near fixations was observed. Eye movements were normal, and Hess red-green test under prism neutralization did not reveal abduction restriction. The presumed cause of AACE in both patients was excessive use of digital displays, and brain magnetic resonance imaging (MRI) was performed to confirm the absence of neurological abnormality. Using MRI, a definitive diagnosis of AACE was made based on comitant esotropia associated with diffuse median glioma and medullary pilocytic astrocytoma without abducens nerve palsy.
CONCLUSION
Although the incidence of AACE caused by brainstem tumors may be low, it is necessary to perform head imaging to confirm etiology. Furthermore, Hess red-green test under prism neutralization is considered important for the differentiation of abducens nerve palsy.
PubMed: 37946847
DOI: 10.1159/000534709 -
Scientific Reports Nov 2023This study investigated the influence of large-diameter multifocal contact lenses on the ocular surface, visual quality, and visual function for presbyopic adults with... (Randomized Controlled Trial)
Randomized Controlled Trial
This study investigated the influence of large-diameter multifocal contact lenses on the ocular surface, visual quality, and visual function for presbyopic adults with dry eye syndromes. The study enrolled 40-55-year-old adults with presbyopia and dry eye syndromes (DES). The subjects were randomly assigned to three groups wearing different designs of contact lenses (Proclear, SMR, and Optimum) for 6-8 h a day for two weeks. Ocular surface health, tear quality, visual quality, and visual function were measured before and after lens wear. No significant difference was observed across all three groups for the amount of conjunctival redness, blink frequency (lens on), and stereopsis vision before and after wearing. Although there seemed to be a significant declining trend for corneal staining and limbal redness, non-invasive tear break-up time (TBUT), and lipid layer thickness while lens wear, the measured values were all within the normal range. Vice-versa after lens removal, results also showed significant improvement on lipid layer thickness, blink frequency (lens off), and contact TBUT. A significant improvement was observed in the modulation transfer function (MTF) of the total area ratio after wearing contact lenses. In contrast, the MTF of the high-order aberration area ratio resulting from lens wear was lower than that of the baseline measurement. There are also significant improvements observed for SMR and Optimum regarding near visual acuity, near point of accommodation, and the subjective questionnaire (OSDI and VBP) scores. Although it is difficult to avoid a specific negative impact on the ocular surface and tear film, visual function and visual quality can still be positively improved, especially shown on larger diameter and distance-center designed multifocal contact lenses.
Topics: Humans; Adult; Middle Aged; Vision, Ocular; Contact Lenses; Dry Eye Syndromes; Presbyopia; Lipids; Tears
PubMed: 37945680
DOI: 10.1038/s41598-023-46732-6