Visual Test Research Articles

Hardy-Rand-Rittler colour vision testing in cone and cone-rod dystrophies: correlation with structural and functional outcome measures.

To determine how Hardy-Rand-Rittler (HRR) colour vision testing correlates with visual functional and structural assessments in Cone and Cone-Rod Dystrophy. Thirty-four Cone and 69 Cone-Rod Dystrophy patients diagnosed by electroretinography (ERG) at the Save Sight Institute in Sydney were included in a retrospective analysis. Each patient's HRR colour vision test scores were compared with markers of cone and rod system function including visual acuity (VA), ERG responses, changes on Spectral Domain Optical Coherence Tomography (OCT) and Fundus Autofluorescence. The number of plates identified on HRR testing correlated with logMAR best-corrected distance VA; r(101) = -0.49, p < 0.0001. HRR scores correlated with markers of cone and macula function including OCT Ellipsoid Zone Gap Width, Central Macular and Outer Nuclear Layer Thickness, Full Field ERG 30 Hz flicker amplitudes, light adapted 3.0 b-wave amplitudes and Pattern ERG 15- and 30-degree p50 amplitudes. HRR colour vision testing correlates with structural and functional measures in Cone and Cone-Rod Dystrophy. HRR colour vision testing provides a simple clinic-based option to monitor disease changes in Cone and Cone-Rod Dystrophy patients, especially when ERG testing is not available.

Impact of driver licensing renewal policies on older driver crash involvement and injury rates in 13 states, 2000–2019

BackgroundMotor vehicle crashes are the second leading cause of injury death among adults aged 65 and older in the U.S., second only to falls. A common state-level approach to mitigating older adult crash risk is the implementation of driver license renewal policies which vary largely between states and data on their effectiveness in preventing crashes and injuries are limited. To fill this gap, the aim of this study is to examine the association between state driver license renewal policies and older driver crash and injury rates.MethodsHistorical crash data, license renewal policy data, and other relevant policy and demographic data were gathered from 13 U.S. states (CO, IL, IA, KS, MN, MO, NE, ND, OH, SD, UT, WI, WY) for years 2000 through 2019, inclusive. Main exposures included six license renewal policies: renewal period, in-person renewal frequency, vision testing, knowledge testing, on-road drive testing, and mandatory physician reporting. The primary outcomes were crash and injury rates per 100,000 population.ResultsThe study population included 19,010,179 crash-involved drivers aged 40 and older. State policies became less restrictive in many states over the study period, even for drivers aged 75 and older, resulting in longer times between renewals and fewer in-person renewal requirements. Loosening of in-person renewal from every time to less than every time was associated with increased crash rates, among drivers aged 65 to 74 (RRcrash = 1.08, 95% CI: 1.01–1.16). A longer duration between in-person renewals was associated with increased injury rates among drivers 75 and older (RRinjury = 1.18, 95% CI: 1.00–1.39).ConclusionsGenerally, state policies became less restrictive and resulted in longer required intervals between license renewal. Loosening of driver license renewal policies was associated with increased crash and injury rates. However, safety benefits of restrictive older driver licensing policies should be carefully weighed against costs to older adult well-being and quality of life following licensure loss. Additional methods to assess fitness to drive are necessary to identify the mechanisms behind the increased rates.

Effect of comorbid allergic diseases on attention-deficit hyperactivity disorder symptoms and sleep: A cross-sectional study.

Recent studies have shown a close relationship between attention-deficit hyperactivity disorder (ADHD) and allergic diseases in children. Regrettably, few studies have investigated the effect of comorbid allergies on ADHD symptoms and sleep, in particular, it is unclear whether comorbid allergic conditions further exacerbate sleep problems in children with ADHD. To investigate the effect of comorbid allergic on symptoms and sleep in children with ADHD. This was a cross-sectional study, 222 ADHD children (aged 6-14 years) were enrolled in, of whom 93 had allergic diseases and 129 without allergic diseases. Collected all ADHD symptom severity and functional impairment scales, including: Swanson, Nolan and Pelham (SNAP) scale, Integrated Visual and Auditory Continuous Performance Test (IVA-CPT), Conners Parents Symptom questionnaire (PSQ) and Weiss Functional Impairment Rating Scale-Parent Form (WFIRS-P). Every guardian of children diagnosed with ADHD is required to complete the Children's Sleep Habits Questionnaire (CSHQ). Compared to ADHD children without allergic diseases, we observed significantly higher hyperactivity and impulsivity scores on the SNAP-IV, higher hyperactivity index and impulsivity index on the PSQ, and higher risky activities on the WFIRS-P in ADHD children with comorbid allergic diseases (all p < 0.05). CSHQ total score and sleep disordered breathing were particularly prominent in ADHD children with comorbid allergic diseases (all p < 0.05), and changes in CSHQ correlate with ADHD symptoms and functional impairment. Further analyses revealed that ADHD symptoms and sleep did not worsen with increasing number of comorbid allergic diseases (all p > 0.05). The primary influence on ADHD symptoms and sleep was the type of allergic diseases, where food allergies predominantly influence ADHD symptoms, including attention deficit disorder and hyperactivity disorder (all p < 0.05); allergic rhinitis notably impacts parasomnias, sleep disordered breathing (all p < 0.05); and allergic asthma significantly affects sleep anxiety, daytime sleepiness, and sleep disordered breathing in children with ADHD (all p < 0.05). The presence of comorbid allergic diseases affects both the hyperactivity and impulsivity symptoms of ADHD and sleep disordered breathing, predominantly influenced by the type of the allergic diseases.

Voxel-based lesion symptom mapping localizes residual visual function in hemianopia.

Damage to the primary visual cortex (V1) results in visual field deficits on the contralateral side of the world corresponding to the damaged region. Patients with such loss nonetheless show varying residual vision within this apparently blind region, with the neural mechanisms underlying this ability obscured by small study populations. We identified lesions on structural scans from 39 patients (12 female) with hemianopia and occipital lobe damage. We estimated the proportion of damage throughout visual cortex, and correlated this with performance in up to three different tests of residual vision in the blind field. We then performed voxel-based lesion symptom mapping (VLSM) to determine the precise neural regions associated with residual vision. V1 damage did not show a relationship with residual vision measured with any task, although the extent of damage to V4 and hMT+/V5 both correlated with the ability to detect contrast-modulated stimuli. Indeed, damage to hMT+/V5 severely impacted performance across all three tasks, particularly motion detection. Although hMT+/V5 appeared necessary for residual vision, some patients with intact hMT+/V5 had no residual vision, indicating this area alone was not sufficient. VLSM revealed that damage to the optic radiation laterally was most highly associated with poor residual vision. Thus, VLSM indicates that hMT+/V5 and the optic radiation specifically are critical for residual vision in hemianopia.Significance Statement Visual loss is extremely common after acquired brain injury, but is notoriously difficult to treat. Residual vision, or 'blindsight' represents a potential target for visual retraining and plasticity. In the largest single method study in blindsight, we apply the technique of voxel-based lesion symptom mapping for the first time. We show that extrastriate cortex is important for residual vision, but its involvement in lesions cannot explain all behavioural results. Instead, a region of optic radiation close to the visual motion area and lateral occipital cortex is most highly associated with residual vision in hemianopia. This represents a potential target for hemianopia recovery training, and may help us understand why some patients benefit from extensive visual retraining while others do not.

Assessment of Ecological State of a River by the Visual Test Method (by Example of the Vorskla River within the Sumy Region Limits)

The article deals with assessment of the ecological state of the Vorskla River within the Sumy region limits using the visual test methodology. The purpose was to adapt the test methodology for assessment of the ecological state of a river at the key sites and the certain area, and development of the water-protection measures. According to the test methodology, the ecological state of the Vorskla River at key points and within the studied section "Klimentovo - Buimerivka" was determined mainly as "good" and "still good", at three points - as "moderate", and ecological state of the mouth areas of the tributaries was assessed as "moderate" (Sosonka, Gusynka, Oleshnia rivers) and "poor" (Okhtyrka River). It was proposed to delineate the water protection zones and coastal protection zones as natural biofilters, introduction of strict penalties for violation of their integrity and pollution, prevention of construction in the coastal protection zones, and facilitation of their rehabilitation.

COMPARATIVE EXPERIMENTAL INVESTIGATION ON VISCOSITY AND STABILITY OF W/EG-BASED NON-NEWTONIAN HYBRID NANOFLUIDS

This research explores the stability and rheological characteristics of hybrid nanofluids made from water-ethylene glycol (W/EG) and incorporating nanoparticles such as SiC, Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;, and multi-walled carbon nanotubes (MWCNT). The preparation involved a two-step method, and the nanoparticles were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Stability assessment showed that Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;-MWCNT hybrid nanofluids are optically more stable than SiC-MWCNT as W/EG-based Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;-MWCNT hybrid nanofluids took longer to sediment. Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;-MWCNT hybrid nanofluids exhibited superior stability in visual tests over a period of 19-21 days while SiC-MWCNT nanofluid took 12-14 days to sediment. The rheological analysis revealed that higher particle concentrations resulted in increased viscosity, with SiC-MWCNT and Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;-MWCNT hybrid nanofluids showing viscosity increases of 3.56 and 3.98 times, respectively, in comparison to the base fluid. Conversely, raising the temperature from 25&amp;deg;C to 55&amp;deg;C led to a decrease in shear stress, with reductions of 72.8&amp;#37; and 64.8&amp;#37; observed for SiC-MWCNT and Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt;-MWCNT hybrid nanofluids, respectively. Furthermore, the viscosity versus shear rate trends indicated a pseudoplastic or shear-thinning nature for both hybrid nanofluids with particle volume fraction above or equal to 0.1&amp;#37;.

Safety and efficacy of omaveloxolone v/s placebo for the treatment of Friedreich's ataxia in patients aged more than 16 years: a systematic review

Abstract Background Friedreich’s ataxia (FA) is a rare genetic disorder caused by silencing of the frataxin gene (FXN), which leads to multiorgan damage. Nrf2 is a regulator of FXN, which is a modulator of oxidative stress in animals and humans. Omaveloxolone (Omav) is an Nrf2 activator and has been reported to have antioxidative potential in various disease conditions. The present review was conducted to determine the use of Omav, the only FDA-approved treatment for FA. Methods Three electronic databases, Cochrane, PubMed and Google Scholar, were searched with terms such as ‘Omaveloxolone’, ‘Friedreich ataxia’, ‘genetic diseases’, ‘autosomal recessive’, and ‘rare disorders’ using various advanced search filters. Articles were screened, extracted, and assessed for quality, and a qualitative synthesis of the data was performed. The study protocol was registered in PROSPERO (CRD42024531449). Results A total of 201 records were found, with very few published research articles on the topic. Only two randomized clinical trials published in a series of three research articles were included in the current systematic review. Peak load exercise and modified Friedreich’s Ataxia Rating Scale (mFARS) values were considered the major outcome measures for determining the efficacy of 150 mg Omav capsules/day in FA. Exploratory outcome measures, such as low-contrast letter visual acuity test, exercise test, T25-FW, 9-HPT, health-related quality of life, and biochemical tests, were also assessed along with adverse events in all the studies. Conclusion Although, the quality of the articles demonstrated low bias. However, the short duration, small sample size, and missing data, including the values of different measures of mFARS scores in patients, limit the generalizability of the results. Further studies with longer durations and in severe patients with foot deformities are needed to clearly define the efficacy of Omav in FA and to determine the optimal drug for FA patients in India.

Qualitative Assessment of a Construction Building

A construction building's structural integrity, material quality, workmanship, and conformity to design specifications were all assessed qualitatively. Potential problems like cracks, corrosion, or subpar construction techniques were found during the examination through visual inspections, material testing, and documentation analysis. Guidelines for upkeep, fixes, or structural improvements were offered to guarantee the building's longevity, security, and adherence to rules. The evaluation sought to improve the building's durability, functionality, and occupant safety while correcting any flaws to preserve structural integrity.

Morbidity Profile of Workers in a Sponge Iron Industry in Goa: A Retrospective Record-based Study

Introduction The Sponge iron industries are categorized as red industries (i.e. highly polluted industries) with the major pollutants including particulate matter and gaseous pollutants, the toxic effects of which are often rapid. Prolonged exposure to such pollutants leads to obstructive lung diseases such as asthma or chronic obstructive respiratory disease. The current study aims to assess the morbidities prevalent among the workers in the Sponge iron industry in Goa and help them minimize those with suitable measures. Objective To study the morbidity profile of workers in a Sponge iron industry in Goa. Materials and Methods A retrospective record-based study was conducted on 217 workers. Selected health parameters were studied: socio-demographic details, anthropometry, blood pressure, serum Creatinine, Total cholesterol, vision tests, ECG, Spirometry, urine microscopy, and audiometry readings. Results Among the 217 workers that were studied, 8% had Hypertension, 40% workers had a refractive error, 31% had Dyslipidemia, 14.7% had mild restriction, 0.9% had moderate restriction, and 1.3% had a severe restriction in Spirometry testing, 10.1% had elevated Creatinine, 2.7% had mild to moderate hearing loss, 0.9% had changes in ECG and was referred to do echo. Conclusion The study revealed that the conditions of employment had caused numerous comorbidities among the sponge iron industry workers, several of which had spirometry restrictions suggesting pulmonary changes, which may lead to eventual respiratory deterioration and the advent of diseases such as COPD. The study revealed issues about overall health parameters, including but not limited to other intricate issues. Consequently, further tests will have to be conducted along with the use of protective equipment to reduce and limit the effects of such occupational outcomes.

Parental Compliance with Preschool Vision Screening Test

Objective: To assess the barriers to parental compliance with preschool vision screening tests and the recommended follow-up eye care. Methods: This prospective study included children aged 3–6 years attending 46 preschools. Parents were asked for consent for their children to participate in a vision screening test. Parents whose child did not participate due to lack of parental consent and parents whose child failed the screening test were contacted by telephone and given a standardized questionnaire to identify potential barriers to compliance. Results: A total of 1511 children (mean age 4.76 years ± 0.76, 51.3% boys) were eligible for vision screening. Consent was given by the parents of 1295 children (85.7%). Lack of consent in children who had never been examined by an ophthalmologist was primarily due to unawareness of the screening test or other logistical reasons (117 cases, 92.1%). Of the children screened, 140 (11.1%) failed the test and 80.0% of their parents adhered to the recommended follow-up eye care. Parents who followed the screening vision test recommendations were more likely to be native language speakers (82.8% vs. 58.8% mothers and 88.9% vs. 60.0% fathers; p = 0.049 and 0.015, respectively). There was a higher chance of at least one parent being native-born if recommendations were followed (90.6% vs. 58.8%, p = 0.004). All other factors tested were insignificant. Conclusions: Parental consent and cooperation with vision screening test and its recommendations were high. Migrant families are more likely to face challenges in following vision screening test recommendations, underscoring the need for tailored approaches for specific populations.

A Case of Myelin Oligodendrocyte Glycoprotein Antibody-Positive Optic Neuritis

Purpose: To report a case of optic neuritis associated with myelin oligodendrocyte glycoprotein (MOG) antibodies, treated with intravenous methylprednisolone pulse therapy.Case summary: A 40-year-old male patient with no underlying disease presented to clinic with sudden onset of bilateral blurry vision that began three days ago. He experienced severe headache and had history of bilateral refractive surgery. Best-corrected visual acuity measured right 0.06 and left 0.04. Relative afferent pupillary defect test was unremarkable, while Ishihara color vision test revealed inability to read any numbers in both eyes, except control plates. Although there were no limitations in extraocular movements, the patient reported pain in both eyes for all gaze movements. Widefield photograph and retinal nerve fiber layer image confirmed swelling of optic nerve head in both eyes. He was treated with high-dose intravenous methylprednisolone (1 g/day for 3 days). Magnetic resonance imaging demonstrated enhancement of the optic nerve sheaths in both eyes, and serum testing indicated positivity for MOG IgG antibodies. Three weeks later, visual acuity in both eyes improved to 1.0, and the color vision test showed correct identification of all 17 plates. Optic nerve head swelling in both eyes had resolved. However, optic neuritis recurred at 4, 6 weeks, and 3 months after the initial treatment, with each episode managed by high-dose intravenous methylprednisolone.Conclusions: This case shows early diagnosis and treatment of MOG antibody-associated optic neuritis can lead to improved visual outcomes. Appropriate serum testing for the diagnosis may be effective in patients with MOG antibody-associated optic neuritis.

The Prevalence of Accommodative and Binocular Dysfunctions in Children with Reading Difficulties

Uncorrected refractive error and unsatisfactory performance on several clinical accommodation and binocular vision tests are more common in children who struggle with reading. The aim of the current study is to explore the prevalence of accommodative and binocular dysfunctions in children with and without reading difficulties. Reading performance was assessed with the Acadience Reading (formerly DIBELS Next) test adjusted and validated for the Latvian language. Children with (N = 39) and without (N = 43) reading difficulties underwent thorough assessment of their subjective refraction, as well as binocular and accommodation functions. The results demonstrate no difference in the prevalence of complaints between children with and without reading difficulties (26% and 23%, respectively). However, children with reading difficulties more frequently present with significant uncorrected refractive errors and/or accommodative and binocular dysfunctions than children without reading difficulties (69% and 47%, respectively). According to the findings, even in cases where a child does not exhibit any ocular or visual complaints, a comprehensive visual function evaluation should be required for any child who struggles with reading.

Effectiveness of Low-Dose Tamoxifen for Managing Ocular Manifestations in Breast Cancer Patients

Background: Breast cancer remains one of the most common malignancies worldwide, with hormonal therapies like tamoxifen significantly improving survival rates in hormone receptor-positive cases. However, tamoxifen’s systemic effects can lead to adverse outcomes, including ocular manifestations such as cataracts, retinopathy, and optic neuritis. These complications, although rare, may impact quality of life, prompting a focus on low-dose tamoxifen to mitigate risks while preserving efficacy. Objective: This study evaluates the ocular outcomes of low-dose tamoxifen in breast cancer patients, aiming to explore its safety and implications for long-term therapy. Methods: A longitudinal study was conducted at Dhaka Medical College Hospital between October 2019 and July 2020. Sixty breast cancer patients treated with low-dose tamoxifen for more than two years were evaluated through detailed ophthalmic examinations, including visual acuity tests, slit lamp biomicroscopy, color fundus photography (CFP), and optical coherence tomography (OCT). Data were analyzed using SPSS software. Results: Among the participants, 11.1% (n=5) exhibited ocular manifestations, including cataracts (6.7%), retinitis (2.2%), and optic neuritis (2.2%). These complications were associated with extended tamoxifen therapy (27–33 months). The findings suggest a correlation between prolonged tamoxifen use and ocular toxicity, although the prevalence was relatively low. Conclusion: Low-dose tamoxifen was associated with minimal ocular side effects, supporting its viability as a safer alternative for long-term therapy in breast cancer patients. Comprehensive ophthalmic evaluation before and during treatment is recommended to ensure early detection and management of potential complications.

Validation of a screening test based on symbols visual search to detect visuo-attentionnal reading difficulties.

Visuo-attentional dyslexia has been associated with impaired simultaneous visual processing of multiple items made of separable features (i.e. symbols). We designed a visual search screening test, consisting to find the (unique) black circle among circles of various colours versus among circles combined with a bar of various length and location. We evaluated its reliability and its validity to detect visuo-attentional deficit prone to affect reading. RESULTS OF STUDY 1: Assessment of 2015 children between 3 and 11 years old established that the screening test was feasible from kindergarten, and that our index contrasting visual search performance for symbols relative to colours (the Temporal Gap) decreased with age. Satisfactory test-retest reliability of the standardised index (independent from age) was found on a sample of 69 individuals. RESULTS OF STUDY 2: Reading speed and inaccuracy assessed for 769 4th and 5th grades children were significantly correlated to the Temporal Gap. A Temporal Gap above 75th centile predicted reading efficiency deficit above 95th percentile with 63 % sensitivity and 71 % specificity. Our screening test can be used in clinic to detect whether a child with developmental dyslexia presents visuo-attentional fragility prone to contribute to the reading difficulties. Its validity as early predictor of a risk to develop visuo-attentional dyslexia needs further investigation.

Facial Affect Recognition and Executive Function Abnormalities in ADHD Subjects: An ERP Study.

Attention-deficit/hyperactivity disorder (ADHD) affects approximately 12% of children worldwide. With a 50% chance of persistence into adulthood and associations with impairments in various domains, including social and emotional ones, early diagnosis is crucial. The exact neural substrates of ADHD are still unclear. This study aimed to reassess the behavioral and neural metrics of executive functions and neural substrates of facial affect recognition. A total of 117 ADHD patients and 183 healthy controls were evaluated by two Go/NoGo tasks: the classic visual continuous performance test and the emotional continuous performance test, which requires facial affect encoding. Group differences between ADHD subjects and healthy controls were assessed using analysis of covariance (ANCOVA), with age and sex included as covariates. Dependent variables comprised behavioral (number of omission and commission errors, reaction time, and reaction time variability) and neurophysiological measures (event-related potentials [ERPs]). As the main result, we identified significant differences between ADHD patients and healthy controls in all behavioral metrics, one neural marker of action inhibition (P3d) and the facial processing marker (N170). The differences were moderate-to-large when expressed as effect size measures in behavioral variables and small-to-moderate for neurophysiological variables. The small-to-moderate effect sizes obtained from the neurophysiological measures suggest that ERPs are insufficient as sole markers for effectively screening emotion and face processing abnormalities in ADHD.

User-Centred Design and Development of a Smartphone Application (OverSight) for Digital Phenotyping in Ophthalmology.

Visual impairment can significantly impact an individual's daily activities. Patients require regular monitoring, typically occurring within hospital eye services. Capacity constraints have necessitated innovative solutions to improve patient care. Existing digital solutions rely on task-based digital home monitoring such as visual acuity testing. These require active involvement from patients and do not typically offer an indication of quality of life. Digital phenotyping refers to the use of personal digital devices to quantify passive behaviour for detecting clinically significant changes in vision and act as biomarkers for disease. Its uniqueness lies in the ability to detect changes passively. The objective was to co-design an accessible smartphone app (OverSight) for the purposes of digital phenotyping in people with sight impairment. Development of OverSight included stakeholder consultations following principles of user-centred design. Apple iOS software frameworks (HealthKit, ResearchKit, and SensorKit) and a SwiftUI developer toolkit were used to enable the collection of active and passive data streams. Accessibility and usability were assessed using the System Usability Scale (SUS) and feedback following a 3-month pilot study. Consultations with patients informed the design of OverSight, including preferred survey scheduling and the relevancy of patient support resources. Twenty visually impaired participants (mean age 42 ± 19 years) were recruited to the pilot study. The average score on the SUS was 76.8 (±8.9), indicating good usability. There was a statistically significant moderate negative correlation between SUS scores and visual acuity in both the better (r = -0.494; p ≤ 0.001) and worse eye (r = -0.421; p ≤ 0.001). OverSight offers promising potential for collecting patient-generated health data for the purposes of digital phenotyping in patients with eye disease. Through further testing and validation, this novel approach to patient care may ultimately provide opportunities for remote monitoring in ophthalmology.

A brief effective screening protocol for identifying cataract patients with binocular vision anomalies

BackgroundTo compare the effectiveness of a brief binocular vision screening protocol to a comprehensive examination for detecting binocular vision anomalies before and after cataract surgery.MethodsA comprehensive binocular vision test battery as a gold standard were administered on recruited patients before the first surgery and at the third visit after surgery on the second eye. A receiver operating characteristic (ROC) curve was plotted to illustrate the diagnostic ability of each test. In addition, a univariate logistic regression analysis was performed to further determine the contribution of each preoperative test to the prediction of pre- and post-surgical binocular vision anomalies.ResultsSignificant differences were shown for the difference in phoria from distance to near measured by the cover test (Area Under Curve [AUC] = 0.96, P < 0.01), step vergence testing of positive fusional vergence at distance (AUC = 0.71, P < 0.01) and near (AUC = 0.77, P < 0.01). The other tests did not show statistically significant differences. The ROC curve generated by combining the difference in distance and near phoria with positive fusional vergence at both distance and near demonstrated a more robust measure of diagnostic accuracy. (AUC = 0.98, P < 0.01).ConclusionDistance and near phoria difference measured by cover test has similar effectiveness as a comprehensive binocular vision testing protocol for the diagnosis of binocular vision anomalies. Distance and near positive fusional vergence measured by step vergence testing also have significant predictive value. A combination of the two tests is an outstanding screening protocol for binocular vision anomalies before cataract surgery.Trial registrationThe study was registered at ClinicalTrials.gov (NCT03592615, Date of registration: July 19, 2018).

Ocular Morbidity among Orphans and Vulnerable Children Living in Shelters in Ibadan Metropolis

Background: Globally, orphans and vulnerable children (OVC) represent a significant population at risk of poor health as well as a high risk of developing ocular disorders. These ocular disorders could lead to childhood visual impairment or blindness if left undetected or untreated. This study therefore focuses on ocular morbidity among OVC living in shelter facilities to provide relevant data for planning eye care interventions. Methods: A descriptive, cross-sectional study was conducted among OVC ages 5–16 years living within shelter facilities in Ibadan, Oyo State. Sociodemographic characteristics were obtained. Ocular examinations, including visual acuity measurements, colour vision test, Hirschberg test, anterior and posterior segments assessment, and cycloplegic refraction were conducted. Descriptive and inferential analysis was done with IBM SPSS Statistics version 24. All analyses were at 5% level of statistical significance. Results: A total of 497 eligible OVC participated in the study. The mean age was 11 ± 3.4 years, and 263 (52.9%) were males. The prevalence of ocular morbidity was 18.1%. The most common types of ocular morbidity were refractive errors 47 (9.5%) and allergic conjunctivitis 18 (3.6%), with more females affected by both conditions, 28 (59%) and 11 (61%), respectively. Ocular morbidity was most common (28.3%) among the 14–16 years age group (P = 0.001). Conclusion: Refractive errors and allergic conjunctivitis, which are treatable ocular conditions, were the most common ocular morbidities among these children. Regular eye screening as well as the provision of quality and affordable eye care services is advocated for this vulnerable population of children.

Green Recycling for Polypropylene Components by Material Extrusion.

High volumetric shrinkage and rheological behavior of polypropylene (PP) are the main problems that make material extrusion (MEX) uncommon for this material. The complexity is raised when recycled materials are used. This research covered different aspects of the MEX process of virgin and recycled PP, from the analysis of rough materials to the mechanical evaluation of the final products. Two types of virgin PP (one in pellet and the other in filament form) and one recycled PP were analyzed. Thermal characterization and rheological analysis of these materials were initially employed to understand the peculiar properties of all investigated PP and set filament extrusion. The 3D parts were then printed using processed filaments to check fabrication quality through visual analysis and mechanical tests. A well-structured approach was proposed to encompass the limitations of PP 3D printing by accurately evaluating the influence of the material properties on the final part performance. The results revealed that the dimensional and mechanical performances of the recycled PP were comparable with the virgin filament commonly employed in MEX, making it particularly suitable for this application.

Experimental Study on the Output Characteristics of a Novel Intensifier Controlled by an Electromagnetic Valve

The application of ultra-high-pressure (UHP) water jets for rock slotting in the bottom hole has been recognized as a highly effective approach to enhance rock-breaking efficiency. However, the current downhole intensifiers are confronted with various limitations, including the short duration of UHP pulse water jet output and challenges in attaining both controllable and adjustable output frequencies, consequently leading to compromised slotting efficiency. In this study, a novel intensifier controlled by an electromagnetic valve was designed, and a visual test platform was constructed to investigate the output pressure characteristics and their influencing factors. The output characteristics of the intensifier consist of a mixed pulse jet composed of high-pressure and low-pressure jets, resulting in a square wave-like output waveform with an adjustable frequency. The output pressure characteristics of the intensifier are primarily influenced by the input pressure and the switching time of the electromagnetic valve, assuming that the structural parameters are constant. Increasing the input pressure raises the peak pressure, thereby enhancing the slotting capability of the jet stream. Aligning the switching time of the electromagnetic valve with the rotation period of the drill bit improves the slotting efficiency. In the lab tests, the output pressure of the intensifier was successfully increased to 118.2 MPa, with a sustained duration of a high-pressure jet segment for 2.1 s. These research findings offer a new method for enhancing drilling efficiency in deep hard rock formations.