Normal Acuity Research Articles

The Effects of Excessive Use of Computer Screen on Visual Acuity among Non-academic University Staff

Background: The increasing prevalence of computer vision syndrome (CVS) necessitates a thorough understanding of its impact on visual health among users. This study aimed to investigate the adverse effects of long-term computer usage on the visual acuity of non-academic staff at the University of Port Harcourt, Nigeria. Methods: This cross-sectional study involved 321 non-academic staff members aged 18-45 years with at least two years of computer usage experience. The participants were randomly selected and completed a structured questionnaire assessing demographic details, computer usage habits, and visual health status. Visual acuity was measured using the Snellen eye chart, and the data were analysed using SPSS version 25, applying descriptive statistics and chi-square tests for significance. Results: Among the 159 computer users, 32.7% reported using screens for more than six hours daily. Common symptoms included eye strain (17.6%), blurred vision (14.7%), and headaches (13.2%). Visual acuity assessments indicated that 66.9% of computer users had normal vision in the left eye, whereas 82.6% of computer users exhibited abnormal visual acuity compared with non-users (χ2 = 29.89, p = 0.00). A significant association was found between increased screen time and reduced normal visual acuity, with 27.3% of users with over five years of screen time reporting normal vision. Conclusion: This study highlighted the adverse effects of prolonged computer usage on visual acuity among non-academic staff, emphasizing the need for awareness and preventive measures to mitigate the risk of CVS in this population.

Quantifying the Functional Relationship Between Visual Acuity and Contrast Sensitivity Function.

Studies have reported that individuals with certain ocular disorders may have significant decreases in contrast sensitivity function (CSF) despite having normal or near normal visual acuity (VA). This study seeks to elucidate this phenomenon by investigating the relationship between VA and CSF. We analyzed data from 14 eyes tested with Electronic Early Treatment Diabetic Retinopathy and quantitative CSF under four Bangerter foil conditions (n = 56). From the CSF data, we estimated peak gain, peak frequency, and contrast sensitivity acuity (CSA). We explored the correlations between VA and various CSF parameters and evaluated five predictive models of VA using CSA alone and in combination with additional CSF parameters through ridge regression. We found that similar VA scores can correspond with markedly different CSFs and observed significant correlations among all CSF parameters and between VA and each CSF parameter (all P < 0.001). The most effective predictive model, incorporating CSA and peak gain, explained 90.97% of the variance with a root mean squared error of 0.0676 logMAR, which is comparable with the average standard deviation of the VA scores (0.0627 logMAR) and accounted for 38.6% of the residual variance not explained by the CSA-alone model. This study offers the first empirical inference of the quantitative relationship between VA and CSF, suggesting that various CSF parameter combinations can yield identical VA. This might help to explain why some clinical populations with normal or near-normal VA exhibit significant CSF deficits and calls for further research in different clinical settings.

Understanding contrast perception in amblyopia: a psychophysical analysis of the ON and OFF visual pathways.

The study aimed to explore potential discrepancies in contrast sensitivity in the ON and OFF visual pathways among individuals with amblyopia compared to controls. Eleven adult amblyopes (26.2 ± 4.4 [SD] years old) and 10 controls (24.6 ± 0.8 years old) with normal or corrected to normal visual acuity (logMAR VA ≤ 0) participated in this study. Using the quick contrast sensitivity function (qCSF) algorithm, we measured balanced CSF which would stimulate the ON and OFF pathways unselectively, and CSFs for increments and decrements that would selectively stimulate the ON and OFF visual pathways. Contrast sensitivity and area under log contrast sensitivity function were extracted for statistical analysis. For the balanced CSF, we found significant interocular differences in sensitivity and area under log contrast sensitivity function in both amblyopes [F(1,10) = 74.992, p < 0.001] and controls [F(1,9) = 35.6, p < 0.001], while such differences were more pronounced in amblyopes than in controls. For increment and decrement CSFs, we found that the increment sensitivity (p = 0.038) and area under log contrast sensitivity function (p = 0.001) were significantly lower than the decrement in the amblyopic eye. Such differences between increment and decrement CSFs were not observed in the fellow eye of the amblyopes or in the controls. There is a subtle difference in the contrast sensitivity of the amblyopic eye when exposed to stimulation in the ON and OFF pathways.

Imprint of preterm birth with very low birth weight on optic disc OCT in adulthood-A two-country birth cohort study.

To determine the pattern, degree and prevalence of optic disc optical coherence tomography (OCT) alterations in adults born preterm with very low birth weight (VLBW; birth weight < 1500 g). Optic disc OCT was assessed in 98 VLBW participants and 139 term-born controls from birth cohorts in Finland and Norway at the mean age of 36 years. The participants had not been treated for retinopathy of prematurity and had no diagnosed brain abnormality. OCT assessment included parameters for optic disc size, neural rim and peripapillary retinal nerve fibre layer thickness (pRNFLT), and for the foveal developmental stage. Background data, visual acuity, refractive error and intraocular pressure were recorded. In the VLBW group, optic disc neural rim and pRNFLT were significantly decreased, most frequently in the nasal and inferior sectors. In 40% (95% CI: 33-47) of the VLBW eyes, nerve fibre thickness of at least one optic disc sector was below the fifth percentile of the control group, including 9% (95% CI: 6-14) subgroup falling below the first percentile, that is, clinically below normal limits. VLBW participants with nerve fibre thickness below the fifth percentile did not differ by perinatal data or foveal developmental stage from the other VLBW participants. All participants had normal visual acuity. A moderate decrease of the optic disc neural rim and pRNFLT is frequently seen in clinically healthy adults born preterm with VLBW. Awareness of the VLBW-related optic disc nerve fibre shallowness especially in the inferior and nasal sectors is important while evaluating acquired optic disc pathology in adulthood.

Auditory Memory and Visual Memory in Typically Developing Children: Modality Dependence/ Independence.

The study aimed to determine whether there was a difference or an association between auditory memory and visual memory in typically developing children. Eighteen children, aged 8 to 12 years, with normal hearing and visual acuity, were evaluated using the Children's Memory Scale (CMS) to determine their auditory and visual memory performance. Using the core subtest battery of the CMS, auditory/verbal (immediate and delayed), visual/nonverbal (immediate and delayed), and general memory index scores were assessed. No significant difference was found between auditory/verbal memory and visual/nonverbal memory scores for both immediate and delayed recall. Likewise, no correlation between auditory/verbal memory and visual/nonverbal memory scores was found. However, there was a significant correlation between immediate and delayed recall scores within each modality. The non-significant difference between the two modalities for both immediate and delayed recall gives the impression that memory is modality independent. However, the lack of any correlation between the two suggests there was no association between them. The absence of a significant difference between modalities can be attributed to the auditory and visual test material used in CMS not being analogous. It can thus be inferred that the auditory and visual modalities are independent. While the visual material evaluates simultaneous/concurrent perception, the auditory material assesses sequential perception.

Integration of auditory and visual cues in spatial navigation under normal and impaired viewing conditions.

Auditory landmarks can contribute to spatial updating during navigation with vision. Whereas large inter-individual differences have been identified in how navigators combine auditory and visual landmarks, it is still unclear under what circumstances audition is used. Further, whether or not individuals optimally combine auditory cues with visual cues to decrease the amount of perceptual uncertainty, or variability, has not been well-documented. Here, we test audiovisual integration during spatial updating in a virtual navigation task. In Experiment 1, 24 individuals with normal sensory acuity completed a triangular homing task with either visual landmarks, auditory landmarks, or both. In addition, participants experienced a fourth condition with a covert spatial conflict where auditory landmarks were rotated relative to visual landmarks. Participants generally relied more on visual landmarks than auditory landmarks and were no more accurate with multisensory cues than with vision alone. In Experiment 2, a new group of 24 individuals completed the same task, but with simulated low vision in the form of a blur filter to increase visual uncertainty. Again, participants relied more on visual landmarks than auditory ones and no multisensory benefit occurred. Participants navigating with blur did not rely more on their hearing compared with the group that navigated with normal vision. These results support previous research showing that one sensory modality at a time may be sufficient for spatial updating, even under impaired viewing conditions. Future research could investigate task- and participant-specific factors that lead to different strategies of multisensory cue combination with auditory and visual cues.

The Short- and Long-Term Perceptual Learning of Clinical Dynamic Visual Acuity Test.

The purpose of this study was to investigate the short- and long-term learning effect of dynamic visual acuity (DVA) tests. Participants between 18 and 30years with corrected to normal visual acuity were enrolled in this study. Three repeated sessions were performed, with 15 minutes and 15 days' intervals between sessions. Each session included 9 DVA tests of horizontal, vertical, and diagonal motions of E optotypes at 20, 40, and 80degrees per second (dps). The short- and long-term learning effects were analyzed from repeated DVA tests. Of the 58 enrolled participants, the mean age was 23.1 ± 2.1years. DVA significantly varied among motion types and velocities (P < 0.05, respectively). There was a significant short-term learning effect for 20 (P = 0.004), 40 (P < 0.001), and 80 (P = 0.014) dps DVA test of horizontal motion, 40dps DVA test of vertical (P = 0.003), and diagonal motion (P = 0.036). The long-term learning effect was detected in the 40dps diagonal motion DVA test (P = 0.015). The short- and long-term learning effects were positively associated with initial DVA in most combinations of motion type and velocity tests (P < 0.05, respectively). The short- (P = 0.031) and long-term (P = 0.024) learning effect of 80dps horizontal motion DVA test was greater in male than female participants. There is a significant short-term learning effect in the DVA test of various motion types, but the long-term learning effect was rarely observed, and it is greater in participants with worse initial DVA.

Lipemia retinalis following FLAG-Ida protocol in an 11-year-old patient with acute myeloid leukemia.

We report a case of early-onset lipemia retinalis secondary to the FLAG-Ida protocol in the treatment of acute myeloid leukemia (AML) in an 11-year-old girl. An 11-year-old patient, diagnosed with AML at four months old, experienced a relapse and was treated with the FLAG-Ida protocol (fludarabine, idarubicin, granulocyte-colony stimulating factor, and high-dose cytarabine). Prior to allogeneic stem cell transplantation, she underwent a pre-transplantation eye examination. The patient exhibited normal visual acuity in both eyes. Fundus examination revealed cream-white retinal vessels and a salmon-pink retina, indicative of grade 3 lipemia retinalis. Laboratory tests, normal before treatment initiation, showed significantly elevated serum cholesterol (727.6 mg/dL) and triglyceride (6015.6 mg/dL) levels post-treatment. After receiving fenofibrate, these levels decreased markedly, and the retinal vessels normalized on follow-up fundus examination. Lipemia retinalis, characterized by creamy-white retinal vessels resulting from hypertriglyceridemia, can develop as a secondary condition to chemotherapy. Early detection and treatment of hyperlipidemia are crucial to prevent severe ocular and systemic complications. This case highlights the importance of monitoring lipid levels and conducting thorough ophthalmologic examinations in patients undergoing chemotherapy.

Visual Performance of School-age Children Wearing Dual-Focus Soft Contact Lenses: A Randomized Controlled Trial

To investigate the effect of wearing dual-focus soft contact lenses (DFSCL) on the visual performance of school-age children. In this randomized controlled clinical trial, 64 children aged 8 to 12 years with spherical equivalent refraction between -0.75 D and -4.00 D were recruited in our hospital in October 2022. Using the envelope method, the subjects were evenly and randomly assigned to the control group wearing single vision spectacles (SVS) or the intervention group wearing MiSight dual-focus soft contact lenses (DFSCL) from CooperVision. Follow-up examinations were conducted once every 3 months. The corrected visual acuity, contrast sensitivity function (CSF), and the scores for National Eye Institute Refractive Error Quality of Life Instrument-42 (NEI-RQL-42) were compared between the control and intervention groups. By December 2023, a total of 58 subjects completed follow-up (30 in the SVS group and 28 in the DFSCL group). No significant difference in corrected visual acuity was observed between subjects wearing DFSCL and those wearing SVS. The CSF of the DFSCL group was comparable to that of the SVS group across the spatial frequencies of 3, 6, 12, and 18 cpd (P>0.05). According to the results of the NEI-RQL-42 survey at the 6-month follow-up, the score for ocular discomfort symptoms was 89±14 in the SVS group and 79±16 in the DFSCL group (P=0.008), reflecting that the DFSCL group had a 12.66% higher level of discomfort. For appearance, the score was 70±32 in the SVS group and 92±22 in the DFSCL group (P=0.002), showing a 31.43% improvement in the DFSCL group. In addition to providing the normal visual acuity and CSF, wearing MiSight DFSCL also leads to better satisfaction with the appearance.

Automated visual acuity estimation by optokinetic nystagmus using a stepped sweep stimulus.

To describe an automatic system for objective measurement of visual acuity (VA) using optokinetic nystagmus (OKN). This pilot study tested the system's sensitivity and specificity for detecting reduced VA in healthy adults by comparing VA-OKN to VA with an Early Treatment of Diabetic Retinopathy Study (ETDRS) chart (VA-ETDRS). Adult participants (age 30 ± 12 years) with either reduced VA (n = 11, VA-ETDRS > 0.20 logMAR) or normal VA (n = 12, VA-ETDRS ≤ 0.20 logMAR) completed monocular VA-OKN measurements in each eye. The VA-OKN stimulus was an array of drifting (5°/s) vanishing discs presented in descending/ascending size order (0.00-1.00 logMAR in 0.10 steps). The stimulus was stepped every 2 s, and 10 sweeps were shown per eye (five ascending and five descending). Eye-tracking data determined when OKN activity ceased (descending sweep) or began (ascending sweep), which was used to determine VA-OKN for each sweep. The estimates were averaged across sweeps to produce an automated VA-OKN. The automated sweeps were then provided in randomised order to a reviewer blinded to the VA-ETDRS findings who determined a final VA-OKN for an eye. A single randomly selected eye from each observer was used for analysis. The sensitivity and specificity of VA-OKN using the same 0.20 logMAR threshold as VA-ETDRS was 100%. Comparisons between the VA-OKN and VA-ETDRS measures were made for participants in the reduced VA group. There was no significant difference between VA-OKN and VA-ETDRS (p = 0.55) and the two measures produced comparable values (r2 = 0.84, 95% limits of agreement = 0.19 logMAR, intra-class correlation coefficient = 0.90 [95% CI:0.68-0.97]). Visual acuity using optokinetic nystagmus correctly identified a VA deficit in adults and for those with a VA deficit, VA-OKN was strongly correlated with the gold-standard clinical measure of VA. OKN is a promising method which has the potential for use in cognitively impaired adults and pre-verbal children.

Impact of macular scotoma and tubular vision on oculomotor behavior and performance in visuospatial comparison tasks.

Our aim in this study was to understand how we perform visuospatial comparison tasks by analyzing ocular behavior and to examine how restrictions in macular or peripheral vision disturb ocular behavior and task performance. Two groups of 18 healthy participants with normal or corrected visual acuity performed visuospatial comparison tasks (computerized version of the elementary visuospatial perception [EVSP] test) (Pisella et al., 2013) with a gaze-contingent mask simulating either tubular vision (first group) or macular scotoma (second group). After these simulations of pathological conditions, all participants also performed the EVSP test in full view, enabling direct comparison of their oculomotor behavior and performance. In terms of oculomotor behavior, compared with the full view condition, alternation saccades between the two objects to compare were less numerous in the absence of peripheral vision, whereas the number of within-object exploration saccades decreased in the absence of macular vision. The absence of peripheral vision did not affect accuracy except for midline judgments, but the absence of central vision impaired accuracy across all visuospatial subtests. Besides confirming the crucial role of the macula for visuospatial comparison tasks, these experiments provided important insights into how sensory disorder modifies oculomotor behavior with or without consequences on performance accuracy.

Ocular dominance and its association with retinal thickness profile - A cross-sectional study.

The retinal thickness profile is essential for detecting ocular diseases like glaucoma and other optic neuropathies. The retinal nerve fiber layer (RNFL) thickness is affected by age, ethnicity, axial length, optic disc area, and inter-eye differences. Ocular dominance has a strong functional correlation with cerebral cortical activity. However, its relationship with RNFL thickness profile is yet to be fully established. A cross-sectional study was conducted in 136 healthy adults to study the association between ocular dominance and RNFL parameters measured by Spectral domain optical coherence tomography (SD-OCT) and to study the association of ocular dominance with other parameters such as handedness, intraocular pressure, average axial length, average keratometry, and refractive error. Sighting ocular dominance was detected using the Miles test, and sensory ocular dominance was detected using the fogging test. Visual acuity and refraction assessment were done, and the patients underwent ocular biometry using the Lenstar 900 machine to measure the axial length and keratometry. The RNFL thickness was measured using the Cirrus HD optical coherence tomographer. One hundred and thirty-two (97.06%) individuals were right-handed, four (2.94%) were left-handed, 108 (79.41%) participants were right eye dominant, and 28 (20.59%) were left eye dominant. There was 100% agreement between sighting and sensory ocular dominance. The average RNFL thickness and other measured ocular parameters were comparable in the dominant and nondominant eyes. Regardless of dominance, the left eyes in the study cohort had a greater statistically significant difference in superior RNFL thickness (P < 0.05), which correlated with increased central macular thickness. Ocular dominance occurred mostly in the right eye. The RNFL thickness profile is not associated with ocular dominance in emmetropic and mild myopic individuals with normal best corrected visual acuity.

Visual recovery after oral high-dose methylprednisolone in acute inflammatory optic neuropathy.

High doses of venous corticosteroids are currently the only validated treatment for the management of optic neuritis (ON). The objective is to assess the changes in visual function parameters after oral high-dose methylprednisolone in patients with ON. A retrospective analysis of patients with acute ON was performed. Patients received 1 g per day of oral methylprednisolone for 3 to 5 days. Visual function was measured using the ETDRS test for visual acuity, 30-2 automated visual field test, contrast sensitivity test, and color vision test before treatment, 4 days, 2 weeks, 1 month and 3 months, and 6 months following treatment. To assess anatomical changes, optical coherence tomography of the ganglion cells was performed at various timepoints. Between September 2014 and September 2016, a total of 29 patients were included in the study. More than 80% of patients had recovered normal visual acuity after 3 and 6months. This recovery of all parameters of visual function was observed as early as 4days but occurred predominantly within 15days after the initiation of treatment. We observed a thinning of the ganglion cell layer during the follow-up, which mainly occurs within one month. The P100 wave of visually evoked potentials was discernible in all patients at 6months. During the 6years of follow-up, 2 patients had experienced a relapse of ON. No serious adverse effects were observed. This study demonstrated a rapid recovery of all visual function parameters after oral high-dose methylprednisolone ON with no serious adverse effects.

Multiple Evanescent White Dot Syndrome following COVID-19 Vaccination: Two Case Reports

Purpose: We present two cases of multiple evanescent white dot syndrome (MEWDS) following COVID-19 vaccination.Case summary: We present two cases of visual field defects following BNT162b2 (Pfizer-BioNTech, Kronach, Germany) COVID-19 vaccination. A 14-year-old male experienced reduced visual acuity in the temporal field of his left eye after his second dose. Similarly, a 38-year-old woman experienced decreased visual acuity in her right eye after her first dose. Notably, neither patient had pre-existing medical conditions or exhibited COVID-19 symptoms following vaccination. Funduscopic examination revealed multifocal peripapillary hyperreflective lesions in both cases. Visual field defects and hyperreflective lesions spontaneously resolved within 6 weeks, with normal visual acuity and fundus findings at the 7-month follow-up.Conclusions: The recent COVID-19 pandemic has led to a significant increase in vaccination rates. Notably, MEWDS demonstrated a significant association with previous vaccines, including influenza and hepatitis, and the cases describe herein also suggest a potential association between BNT162b2 vaccination and MEWDS.

Ocular findings in Jansen metaphyseal chondrodysplasia.

Jansen metaphyseal chondrodysplasia (JMC) is an ultra-rare disorder caused by germline heterozygous PTHR1 variants resulting in constitutive activation of parathyroid hormone type 1 receptor. A description of ocular manifestations of the disease is lacking. Six patients with JMC underwent a detailed ophthalmic evaluation, spectral-domain optical coherence tomography (OCT), visual field testing, and craniofacial CT scans. Five of 6 patients had good visual acuity. All patients had widely spaced eyes; 5/6 had downslanted palpebral fissures. One patient had proptosis, and another had bilateral ptosis. Two patients had incomplete closure of the eyelids (lagophthalmos), one had a history of progressive right facial nerve palsy with profuse epiphora, while the second had advanced optic nerve atrophy with corresponding retinal nerve fiber layer (RNFL) thinning on OCT and significant bilateral optic canal narrowing on CT scan. Additionally, this patient also had central visual field defects and abnormal color vision. A third patient had normal visual acuity, subtle temporal pallor of the optic nerve head, normal average RNFL, but decreased temporal RNFL and retinal ganglion cell layer analysis (GCA) on OCT. GCA was decreased in 4/6 patients indicating a subclinical optic nerve atrophic process. None of the patients had glaucoma or high myopia. These data represent the first comprehensive report of ophthalmic findings in JMC. Patients with JMC have significant eye findings associated with optic canal narrowing due to extensive skull base dysplastic bone overgrowth that appear to be more prevalent and pronounced with age. Progressive optic neuropathy from optic canal narrowing may be a feature of JMC, and OCT GCA can serve as a useful biomarker for progression in the setting of optic canal narrowing. We suggest that patients with JMC should undergo regular ophthalmic examination including color vision, OCT, visual field testing, orbital, and craniofacial imaging.

Contrast Sensitivity and Low Contrast Visual Acuity in Children With Normal Visual Acuity

To measure and report the distribution of distance and near contrast sensitivity (CS) and low contrast visual acuity (LCVA) at 5% and 2.5% contrast in children aged 5-15 years with normal visual acuity (VA). Prospective, cross-sectional study. Schools in Southern India. One thousand fifty-two children aged 5 to 15 years (mean age 10.61 ± 2.85 years) with a presenting visual acuity of 0.00 logMAR or better in both eyes and a stereo acuity of 40 seconds of arc or better were recruited from nine schools. Repeatability of contrast sensitivity and low contrast visual acuities were tested in 246 children. Pelli-Robson charts were used to measure the distance and near contrast sensitivity at 1 m and 40 cm, respectively. The low contrast visual acuity was recorded at 5% and 2.5% contrast using LEA Symbols at 3 m. Overall, the mean ± SD, (95% CI) monocular distance and near CS were 1.75 ± 0.11 (1.76-1.75) logCS and 1.72 ± 0.10 (1.73-1.71) logCS, respectively. The mean LCVA at 5% and 2.5% contrasts were 0.20 ± 0.10 (0.21-0.20) logMAR and 0.39 ± 0.11 (0.40-0.39) logMAR, respectively. Distance and near CS gradually improved till the ages of 11 and 13, respectively, and then plateaued. Similarly, LCVA at 5% and 2.5% contrasts gradually improved till age ten before plateauing. The Coefficient of Repeatability (CoR) for CS was ±0.02 logCS for distance, ±0.05 logCS for near, and ±0.01 logMAR for both LCVA contrasts. The study provides age-specific normative values for distance and near CS, and LCVA in a cohort of children aged 5-15 years. These results are important to understand the impact of ocular conditions on CS in children and have utility in clinical evaluations.

Dental Occlusion as A Health Risk for Visual Acuity in Relation to Salivary Transforming Growth Factor Beta-1 ( TGF-Β1) Among Students Aged 8-10 Years

Background: Correct mouth function is one of the functional matrices that contribute to the growth of the maxilla, which is connected to the growth of orbit, and vice versa. Objective: to ascertain how dental malocclusion affects the visual acuity-related salivary transforming growth factor beta-1 (TGF-β1). Patients and Methods: This is a cross-sectional study on 653 students, 8–10 years of age from elementary schools in the governorate of Al-Diwaniyah during the period from 1st of November 2022 to 30th March 2023. Using the Snellen E chart and Angle's classification to identify malocclusion, they were subjected to visual-capacity testing for refractive disorders. Sub-samples were selected from the normal and visually impaired groups for salivary transforming growth factor beta-1 salivary analysis measurement. Results: Only 70 out of 653 students were found to have reduced visual acuity. When compared to students with normal visual acuity, they had significantly higher levels of salivary transforming growth factor beta-1. Those with reduced visual acuity were found to have a much higher occurrence of dental malocclusion utilizing molar's relation of Angle's categorization. Conclusion: The students with impaired visual acuity were more likely to have dental malocclusions and increased levels of TGF-β1.

Prevalence and Pattern of Ocular Diseases among Rural Dwellers in Affa, Enugu State

Background: The prevalence and pattern of different ocular diseases among rural dwellers vary in different parts of the world. It is usually influenced by a numerous factor, including but not limited to utilization of eye care services, socio-economic status, and level of education. Aim: To identify the most prevalent eye diseases and their pattern of occurrence, among rural dwellers in South East Nigeria, with a view to influence targeted health policies and subsequently, targeted interventions to improve eye health in the region. Methods: The study was a cross sectional study involving patients willing to participate in the study during a one-day free eye outreach organized by the Ophthalmology department, ESUTH Parklane at Affa Community in Udi Local Government Area of Enugu state. A preliminary visit was made one week prior to the health outreach, by some members of the outreach team to mobilize the community, seek their consent and fix a date through their leaders. On the day for the outreach, the objective of the eye screening was explained to the participants in both English and their local language. Subsequently, informed consent was obtained and each subject registered and the bio-data documented. Registered participant had their unaided and aided Visual Acuity (VA) of each eye determined. Then, the anterior and posterior segment was examined. Data collected were recorded using a proforma and later inputted into a computer, cleaned and analysed using SPSS version 21. Results were presented in tables and represented in frequencies percentages. Association between variables were done using t-test and p- value of &lt;0.05 was considered significant. Results: One hundred and sixty-eight participants were screened during the outreach programme/study with mean age of 40+0.5years. There were more females 116 (69.1%) than males 52 (30.9%), giving a female to male ratio of 2:1 and they are predominantly Christians and farmers. The common ocular problems among the participants include cataract 53 (22.6%), refractive error 37 (15.8%), Pterygium 35 (14.9%). Cataract was the most common eye disease among the outreach participants and responsible for 22.6% of all ocular problems. Normal visual acuity was found more in participants &lt; 50 years of age, mild visual impairment occurred more in participants 51-70 years while moderate visual impairment to blindness were seen more in patients &gt;70 years. Conclusion: In this study, the commonest ocular problems among the participants include Cataract, Refractive error, and Pterygium which are reversible causes of visual impairment and blindness. Therefore, health policies and advocacies should be directed towards reducing the burden of these reversible causes of visual impairment and blindness among the rural dwellers which constitute greater proportion of our population.

Unveiling Visual Acuity in 58,712 Four-Year-Olds: Standardized Assessment Defined Normative Visual Acuity Threshold.

The purpose was to define the threshold of normal visual acuity (VA), mean monocular and binocular VA, and interocular difference in the uniform cohort of healthy four-year-old children. All the children were recruited from the Croatian National Registry of Early Amblyopia Detection database. LEA Symbols® inline optotypes were used for VA testing at near and distance, binocularly and monocularly. The pass cut-off level was set to ≤0.1 logMAR. The final sample consisted of 58,712 four-year-old children. In total, 83.78% of the children had unremarkable results, and 16.22% of the children were referred to examination. Of those, 92% of the children were referred due to binocular, and 8% of the children due to monocular causes. The children referred due to binocular causes demonstrated a VA of 0.3 ± 0.24, while the children referred due to monocular causes 0.6 ± 0.21. The ROC curve analysis defined the uniform cut-off value for a normative VA of 0.78. We analyzed the largest uniform cohort of 58,712 children, and have determined normative data for binocular and monocular VA tested with gold standard logMAR chart in four-year-old children. The results presented here established no reasoning to further utilize historical protocols in testing VA in preschool children aged ≥ 4 years.

Eyes on CVI: Eye movements unveil distinct visual search patterns in Cerebral Visual Impairment compared to ADHD, dyslexia, and neurotypical children

Visual search problems are often reported in children with Cerebral Visual Impairment (CVI). To tackle the clinical challenge of objectively differentiating CVI from other neurodevelopmental disorders, we developed a novel test battery. Visual search tasks were coupled with verbal and gaze-based measurements. Two search tasks were performed by children with CVI (n: 22; mean age (SD): 9.63 (.46) years) ADHD (n: 32; mean age (SD): 10.51 (.25) years), dyslexia (n: 28; mean age (SD): 10.29 (.20) years) and neurotypical development (n: 44; mean age (SD): 9.30 (.30) years). Children with CVI had more impaired search performance compared to all other groups, especially in crowded and unstructured displays and even when they had normal visual acuity. In-depth gaze-based analyses revealed that this group searched in overall larger areas and needed more time to recognize a target, particularly after their initial fixation on the target. Our gaze-based approach to visual search offers new insights into the distinct search patterns and behaviours of children with CVI. Their tendency to overlook targets whilst fixating on it, point towards higher-order visual function (HOVF) deficits. The novel method is feasible, valid, and promising for clinical differential-diagnostic evaluation between CVI, ADHD and dyslexia, and for informing individualized training.