Early screening for amblyogenic risk factors lowers the prevalence and severity of amblyopia

Comparison of photorefraction by Plusoptix A12 and cycloplegic autorefraction in children

BACKGROUND

Plusoptix photoscreeners are capable of measuring refractive errors of children from 1 meter distance, without cyloplegia. We aimed to compare refractive data obtained from the newest version of Plusoptix (model 12) with cycloplegic autorefraction.

METHODS

We examined 111 consecutive children aged 3-7 years first by Plusoptix A12C under manifest condition and subsequently for cycloplegic refraction by Topcon KR-1 tabletop autorefractometer. Sphere, spherical equivalent, cylinder and axis of astigmatism measured by the two methods were analyzed to determine correlation, agreement and differences.

RESULTS

Binocular examination of 111 children aged 4.86±1.27 years revealed good agreement between refractive data obtained by Plusoptix and cycloautorefraction, according to Bland-Altman plots. Significant (p < 0.001) and strong correlation was found between all refractive measurements (Pearson's r value of 0.707 for sphere, 0.756 for pherical equivalent, and 0.863 for cylinder). Plusoptix mean sphere, spherical equivalent and cylinder were 1.22, 0.56, and -1.32 D, respectively. Corresponding values for cycloautorefraction were 1.63, 1.00, and -1.26 D. The difference between axis of cylinder measured by the two methods was < 10° in 144 eyes (64.9%).

CONCLUSIONS

Considering the significant agreement and correlation between Plusoptix photoscreener and cycloplegic autorefraction, the need for cycloplegic drops in refractive examination of children may be obviated. The mean difference between cylinder measurements are considerably trivial (0.06 D), but sphere is approximately 0.4 D underestimated by Plusoptix compared to cycloautorefraction, on average.

Pre-Cycloplegic Exam Benefit of Photoscreening and Accommodation-Relaxing Skiascopy

Background

Seeking a quick way to estimate refractions for challenging pediatric patients, we studied two non-contact methods with particular attention to accuracy and level of stress in uncovering cycloplegic hyperopia.

Methods

Newly referred and follow-up pediatric eye patients had timed school bus accommodation-relaxing skiascopy (SBARS) and Plusoptix A12 (Px) photoscreener testing before cyclopentolate 1% confirmatory examinations. The ABCD ellipsoid univariate method based on relative blur and vector components was used to compare dry sphero-cylinder refraction estimates with cycloplegic. Receiver operating characteristic (ROC) curves were used to determine screening value.

Results

Three compared refractions were attempted in 191 racially diverse children of whom 100 were age 0.2-3.9 years and 91 were 4 to 14 years. Plusoptix failed to yield a result in 21 and an additional 21 were interpreted as an excess sphere. Median spherical equivalent did not differ between Px and SBARS for 149 with Px readings but in hyperopic patients, Plusoptix uncovered 27% less hyperopia. The ellipsoid for SBARS of 0.8 was better than 2.4 for Plusoptix (Mann-Whitney p<0.001). Plusoptix was fastest (3-15 seconds) followed by SBARS (15-30 seconds) compared to 30-45 minutes for cycloplegic exam.

Conclusion

Non-contact quick refractive methods enhanced confirmatory cycloplegic pediatric exam in high-risk pediatric patients.

A population-level post-screening treatment cost framework to help inform vision screening choices for children under the age of seven

PURPOSE/BACKGROUND

Visual acuity (VA) screening in children primarily detects low VA and amblyopia between 3 and 6 years of age. Photoscreening is a low-cost, lower-expertise alternative which can be carried out on younger children and looks instead for refractive amblyopia risk factors so that early glasses may prevent or mitigate the conditions. The long-term benefits and costs of providing many children with glasses in an attempt to avoid development of amblyopia for some of them needs clarification. This paper presents a framework for modeling potential post-referral costs of different screening models once referred children reach specialist services.

METHODS

The EUSCREEN Screening Cost-Effectiveness Model was used together with published literature to estimate referral rates and case mix of referrals from different screening modalities (photoscreening and VA screening at 2, 3-4 years and 4-5 years). UK 2019-20 published National Health Service (NHS) costings were used across all scenarios to model the comparative post-referral costs to the point of discharge from specialist services. Potential costs were compared between a) orthoptist, b) state funded ophthalmologist and c) private ophthalmologist care.

RESULTS

Earlier VA screening and photoscreening yield higher numbers of referrals because of lower sensitivity and specificity for disease, and a different case mix, compared to later VA screening. Photoscreening referrals are a mixture of reduced VA caused by amblyopia and refractive error, and children with amblyopia risk factors, most of which are treated with glasses. Costs relate mainly to the secondary care providers and the number of visits per child. Treatment by an ophthalmologist of a referral at 2 years of age can be more than x10 more expensive than an orthoptist service receiving referrals at 5 years, but outcomes can still be good from referrals aged 5.

CONCLUSIONS

All children should be screened for amblyopia and low vision before the age of 6. Very early detection of amblyopia refractive risk factors may prevent or mitigate amblyopia for some affected children, but population-level outcomes from a single high-quality VA screening at 4-5 years can also be very good. Total patient-journey costs incurred by earlier detection and treatment are much higher than if screening is carried out later because younger children need more professional input before discharge, so early screening is less cost-effective in the long term. Population coverage, local healthcare models, local case-mix, public health awareness, training, data monitoring and audit are critical factors to consider when planning, evaluating, or changing any screening programme.

Impact of COVID-19 pandemic control measures on amblyopia treatment: a retrospective study of records from a tertiary eye hospital in China

OBJECTIVES

Amblyopia is the most common cause of unilateral visual impairment in children and requires long-term treatment. This study aimed to quantify the impact of pandemic control measures on amblyopia management.

DESIGN AND SETTING

This was a retrospective cohort study of data from a large amblyopia management database at a major tertiary eye care centre in China.

PARTICIPANTS

Outpatients with amblyopia who visited the hospital from 1 June 2019, through 28 February 2022.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the number of first and follow-up in-person visits to the hospital for amblyopia treatment. Secondary outcomes included the time interval between consecutive visits and improvement of vision (visual acuity, contrast sensitivity and stereopsis). Patient records were grouped into prepandemic and during pandemic periods.

RESULTS

A total of 10 060 face-to-face visits for 5361 patients (median age 6.7 years, IQR 5.4, 8.9) that spanned two lockdown periods were included in the analysis, of which 28% were follow-up visits. Pandemic control measures caused a sharp decline in the number of outpatient visits (3% and 30% of prepandemic levels in the months directly after the start of the first (2020) and second (2021) periods of pandemic control measures, respectively). However, these drops were followed by pronounced rebounds in visits that exceeded prepandemic levels by 51.1% and 108.5%, respectively. The interval between consecutive visits increased significantly during the pandemic from a median (IQR) of 120 (112, 127) days in 2019 to 197 (179, 224) in 2020 (p<0.001) and 189 (182, 221) in 2021 (p<0.001). There were no significant differences in the improvement of visual function or treatment compliance between the prepandemic and postpandemic groups.

CONCLUSIONS

The number of amblyopia patient hospital visits spiked well above prepandemic levels following lockdown periods. This pattern of patient behaviour can inform planning for amblyopia treatment services during and after public health-related disruptions.

Pediatric and School-Age Vision Screening in the United States: Rationale, Components, and Future Directions

Pediatric vision screening detects children at risk for visual conditions with the goal of connecting those in need with an eye care provider for evaluation and treatment. The primary aim for vision screening in younger children is the detection of those at risk for amblyopia, which can result in irreversible vision loss if left untreated. In older children, screening goals broaden to include the detection of risk for uncorrected refractive error. In the United States, professional organization guidelines and state-mandated requirements for vision screening vary widely across both the timing and components of screening. In this article, we describe the goals and components of pediatric vision screenings, current challenges, novel approaches to providing follow-up services through school-based vision programs, and future directions.

Agreement between Lea Symbols and Patti Pics visual acuity in children and adults

BACKGROUND

Patti Pics (PP) and Lea Symbols (LS) are commonly used by eye care practitioners worldwide. Although the relationship between the two tests is fairly well understood, the availability of different chart designs (single optotypes, multiple optotypes, multiple optotypes with crowding box) merits futher understanding. The purpose of this study is to explore the agreement between the acuity measures obtained with Patti Pics and Lea Symbols in children and adults and compare their performance with the Sloan Letter (SL) chart in adults.

METHODS

Monocular visual acuity was obtained from ninety-three 3 to 5-year-old children using Patti Pics and Lea Symbols. Acuities were also obtained from 113 adults using the same tests under identical conditions. Acuity results obtained with the pediatric tests were compared with the gold-standard Sloan Letter chart in adults. The Bland-Altman method was implemented to compare the level of agreement between tests.

RESULTS

Patti Pics yielded worse visual acuity than the Lea Symbols by approximately half a logMAR line in both children (mean difference: -0.07 ± 0.07 logMAR, p <0.01) and adults (Mean difference: -0.05 ± 0.06 logMAR, p <0.01). The 95% limits of agreement between Lea Symbol acuity and Patti pics acuity in children was ± 0.14 logMAR. Mean difference between the Sloan Letter chart and Lea Symbols acuity was not statistically significant (p = 0.08) in adults but the difference was statistically significant between PP and SL (p<0.001). The 95% limits of agreement between LS and SL and between PP and SL was ± 0.19 logMAR and ± 0.22 logMAR, respectively.

CONCLUSION

Patti Pics consistently underestimated visual acuity as compared to Lea Symbols both in children and adults although the differences were not clinically significant. The LS and PP did not yield clinically significant differences in acuities when compared with Sloan letters in adults.

Reaching Target Communities in a Community Preschool Vision Screening Program

PURPOSE

To develop a method to identify preschools with the greatest need for vision screening, correlations between socioeconomic status, preschool capacity, and rates of pediatric vision screenings performed by a community vision screening program were investigated. Geoinformatics mapping software was used to visually display the areas of greatest need.

METHODS

Vision screening data from a community vision screening program, child care facility data from California Department of Social Services, and income data from the U.S. Census Bureau through ArcGIS software (Esri) were collected. When possible, data were consolidated at the ZIP code level. Kolmogorov-Smirnov analysis was used to determine correlations between data elements. Licensed child care facilities were scored on a scale (from 1 to 5) based on the socioeconomic status of the ZIP code and the facility capacity. The scoring system prioritized larger facilities in lower income communities to most efficiently use vision screening program resources.

RESULTS

There was a positive correlation between the capacity of the child care facility and the median household income (P = .005). Second, we found a positive correlation between child care capacity and the median household income (P = .005). Licensed child care facilities were mapped and colored using GIS software according to their cumulative score.

CONCLUSIONS

Challenges to vision screening in under-served communities include the lack of child care facilities and smaller facility size. The use of a scoring system and mapping software can direct vision screening programs to reach a greater number of children with the most efficient use of resources. [J Pediatr Ophthalmol Strabismus. 2022;59(6):375-379.].

Towards a national pre-school vision screening programme

The aim of the study is to examine common approaches to pre-school vision screening, including the current New South Wales model which is known as Statewide Eyesight Preschooler Screening (StEPS) to determine whether the criteria set by the World Health Organization are fulfilled by StEPS, and therefore, whether there is sufficient justification to deploy a similar model nationally. A literature review was conducted to answer four key questions related to vision screening. The authors sought to review (i) the justification for vision screening of a pre-school population; (ii) the principles and best approaches to vision screening such as how, where and who should conduct vision screening; (iii) the conditions that are targeted in vision screening; and (iv) the acceptable pass/fail vision screening criteria. The StEPS vision screening model is an accurate, reliable and economical way of screening for reduced vision at a time when neural plasticity allows improvement in vision following intervention. It fulfils World Health Organization criteria for a successful screening programme. StEPS has very high participation rates compared to other screening methods in Australia due to its unique model whereby screeners utilise early childhood settings to recruit and screen 4-year-old children. Due consideration should be given to deploying the StEPS vision screening model nationally.

The Impact of Early Photoscreening on Medium-term Visual Acuity: A Population-Based Study

PURPOSE

To analyze the outcomes of an early ophthalmological intervention in children included in the pilot project of the "Rastreio de Saúde Visual Infantil" (RSVI) visual screening program in Portugal.

METHODS

This was a retrospective analysis of the medical records of all children included in the RSVI from April 1, 2016 to December 31, 2016, and who were referred to an ophthalmology appointment. Data of refractive errors, anisometropia, amblyopia, instituted treatments, and visual acuity at the end of the ophthalmological intervention were collected.

RESULTS

Two hundred sixty-seven (18.2%) 2-year-old children from the Centro Hospitalar Universitário do Porto reference area had a positive screening result and were subsequently referred to an ophthalmology appointment. Glasses were prescribed to 31.1% of the patients who attended. Presumed amblyopia was diagnosed in 2.5% and occlusion was prescribed. At the end of a median follow-up of 3 years, of those who wore glasses without occlusion, 94.3% had a visual acuity of 20/25 or better in both eyes with an asymmetry of two lines or less between eyes. Of the 4 children who wore glasses with occlusion, 3 of them had a visual acuity of 20/25 or better in both eyes with an asymmetry of two lines or less between eyes.

CONCLUSIONS

This study demonstrates the effectiveness of an early intervention in the prevention and treatment of amblyopia, because after a median follow-up of 3 years after treatment none of the referred children met criteria for amblyopia and 94.3% of the referred children who had an intervention had a normal visual acuity. [J Pediatr Ophthalmol Strabismus. 20XX;X(X):XX-XX.].

Binocular versus standard occlusion or blurring treatment for unilateral amblyopia in children aged three to eight years

BACKGROUND

Current treatments for amblyopia, typically patching or pharmacological blurring, have limited success. Less than two-thirds of children achieve good acuity of 0.20 logMAR in the amblyopic eye, with limited improvement of stereopsis, and poor adherence to treatment. A new approach, based on presentation of movies or computer games separately to each eye, may yield better results and improve adherence. These treatments aim to balance the input of visual information from each eye to the brain.  OBJECTIVES: To determine whether binocular treatments in children, aged three to eight years, with unilateral amblyopia result in better visual outcomes than conventional patching or pharmacological blurring treatment.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register), MEDLINE, Embase, ISRCTN, ClinicalTrials.gov, and the WHO ICTRP to 19 November 2020, with no language restrictions.

SELECTION CRITERIA

Two review authors independently screened the results of the search for relevant studies. We included randomised controlled trials (RCTs) that enrolled children between the ages of three and eight years old with unilateral amblyopia. Amblyopia was classed as present when the best-corrected visual acuity (BCVA) was worse than 0.200 logMAR in the amblyopic eye, with BCVA 0.200 logMAR or better in the fellow eye, in the presence of an amblyogenic risk factor, such as anisometropia, strabismus, or both. To be eligible, children needed to have undergone cycloplegic refraction and  ophthalmic examination, including fundal examination and optical treatment, if indicated, with stable BCVA in the amblyopic eye despite good adherence with wearing glasses. We included any type of binocular viewing intervention, on any device (e.g. computer monitors viewed with liquid-crystal display shutter glasses; hand-held screens, including mobile phones with lenticular prism overlay; or virtual reality displays). Control groups received standard amblyopia treatment, which could include patching or pharmacological blurring of the better-seeing eye. We included full-time (all waking hours) and part-time (between 1 and 12 hours a day) patching regimens. We excluded children who had received any treatment other than optical treatment; and studies with less than 8-week follow-up.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. The primary outcome of the review was the change from baseline of distance BCVA in the amblyopic eye after 16 (± 2) weeks of treatment, measured in logMAR units on an age-appropriate acuity test.

MAIN RESULTS

We identified one eligible RCT of conventional patching treatment versus novel binocular treatment, and analysed a subset of 68 children who fulfilled the age criterion of this review. We obtained data for the mean change in amblyopic eye visual acuity, adverse events (diplopia), and adherence to prescribed treatment at 8- and 16-week follow-up intervals, though no data were available for change in BCVA after 52 weeks. Risk of bias for the included study was considered to be low. The certainty of evidence for the visual acuity outcomes at 8 and 16 weeks of treatment and adherence to the study intervention was rated moderate using the GRADE criteria, downgrading by one level due to imprecision. The certainty of evidence was downgraded by two levels and rated low for the proportion of participants reporting adverse events due to the sample size.  Acuity improved in the amblyopic eye in both the binocular and patching groups following 16 weeks of treatment (improvement of -0.21 logMAR in the binocular group and -0.24 logMAR in the patching group, mean difference (MD) 0.03 logMAR (95% confidence interval (CI) -0.10 to 0.04; 63 children). This difference was non-significant and the improvements in both the binocular and patching groups are also considered clinically similar. Following 8 weeks of treatment, acuity improved in both the binocular and patching groups (improvement of -0.18 logMAR in the patching group compared to -0.16 logMAR improvement in the binocular-treatment group) (MD 0.02, 95% CI -0.04 to 0.08). Again this difference was statistically non-significant, and the differences observed between the patching and binocular groups are also clinically non-significant. No adverse event of permanent diplopia was reported. Adherence was higher in the patching group (47% of participants in the iPad group achieved over 75% compliance compared with 90% of the patching group).  Data were not available for changes in stereopsis nor for contrast sensitivity following treatment.

AUTHORS' CONCLUSIONS

Currently, there is only one RCT that offers evidence of the safety and effectiveness of binocular treatment. The authors are moderately confident that after 16 weeks of treatment, the gain in amblyopic eye acuity with binocular treatment is likely comparable to that of conventional patching treatment. However, due to the limited sample size and lack of long term (52 week) follow-up data, it is not yet possible to draw robust conclusions regarding the overall safety and sustained effectiveness of binocular treatment. Further research, using acknowledged methods of visual acuity and stereoacuity assessment with known reproducibility, is required to inform decisions about the implementation of binocular treatments for amblyopia in clinical practice, and should incorporate longer term follow-up to establish the effectiveness of binocular treatment. Randomised controlled trials should also include outcomes reported by users, adherence to prescribed treatment, and recurrence of amblyopia after cessation of treatment.

The UCI EyeMobile Preschool Vision Screening Program: Refractive Error and Amblyopia Results from the 2019-2020 School Year

Purpose

To introduce the University of California Irvine (UCI) EyeMobile for Children preschool vision screening program and describe the ophthalmic examination results of children who failed screening with the PlusoptiX S12C photoscreener during one school year.

Patients and Methods

Children aged 30-72 months were screened with the PlusoptiX using ROC mode 3 during the 2019-2020 school year. Children who failed screening were referred for comprehensive eye examination on the EyeMobile mobile clinic. Presence of amblyopia risk factors (ARFs), amblyopia, and refractive error was determined via retrospective review of records. Amblyopia was defined as unilateral if there was ≥ 2-line interocular difference in the best-corrected visual acuity (BCVA) and as bilateral if BCVA was < 20/50 for children < 4 years old and < 20/40 for children ≥ 4 years old. ARFs were defined using 2021 American Association for Pediatric Ophthalmology and Strabismus (AAPOS) instrument-based screening guidelines.

Results

5226 children were screened during the study period. Of the 546 children who failed screening, 350 (64%) obtained consent and were examined. Mean age of examined children was 4.45 years. Amblyopia was found in 8% of examined children, with unilateral amblyopia seen in 79% of amblyopic subjects. Glasses were prescribed to 246 (70.3%) children. Of the 240 children who received cycloplegic examinations, 43% had hyperopia and 30% had myopia. The positive predictive value (PPV) of the PlusoptiX screening for ARFs in children who received cycloplegic examinations was 70.4%.

Conclusion

A significant proportion of Orange County preschoolers with refractive errors and amblyopia have unmet refractive correction needs. The PlusoptiX S12C photoscreener is an adequate screening device for the UCI EyeMobile for Children program, although modification of device referral criteria may lead to increased PPV. Further research is necessary to understand and overcome the barriers to childhood vision care in our community.

The Global Prevalence of Amblyopia in Children: A Systematic Review and Meta-Analysis

Epidemiological data about the prevalence of amblyopia around the world vary widely among regions and periods. This meta-analysis aimed to determine the global prevalence of amblyopia in children. PubMed, Embase, and the Cochrane Library were searched for prevalence studies published up to 5 November 2021. The outcome was the prevalence of amblyopia, analyzed as pooled estimates with 95% confidence intervals (CI). A total of 97 studies were included, including 4,645,274 children and 7,706 patients with amblyopia. The overall worldwide pooled prevalence of amblyopia was 1.36% (95%CI: 1.27-1.46%). The prevalence of amblyopia was higher in males (1.40%, 95%CI: 1.10-1.70%) than in females (1.24%, 95%CI: 0.94-1.54%) (OR = 0.885, 95%CI: 0.795-0.985, P = 0.025). The results of the meta-regression analysis showed that there were no significant associations between the prevalence of amblyopia and geographical area, publication year, age, sample size, and whether it was carried out in a developed or developing country (all P > 0.05). Begg's test (P = 0.065) and Egger's test (P < 0.001) showed that there was a significant publication bias in the prevalence of amblyopia. In conclusion, amblyopia is a significant vision problem worldwide, and public health strategies of early screening, treatment, and management are important.

COVID-19 outbreak and increased risk of amblyopia and epidemic myopia: Insights from EUROCOVCAT group

The most common cause of vision impairment in children is amblyopia. It is defined as impaired visual acuity in one or both eyes that is present with no demonstrable abnormality of the visual pathway and is not immediately resolved by wearing glasses. After the World Health Organization (WHO) recognized COVID-19 as a global pandemic on March 11, 2020, widespread changes and restrictions to social and sanitary practices have presented significant issues in access to eye care during the COVID-19 pandemic. A reduction of more than 80% in pediatric eye care volume up to its total cessation has been observed in different departments. In this scenario, reduced or absent eyesight, due to delay in timely treatment of amblyopic conditions, could create major, long-lasting effects on all aspects of life, including daily personal activities, interacting with the community, school and work opportunities and the ability to access public services. Processes coming out of lockdown should be gradually easing restrictions giving priority to ophthalmology and eye care facilities so that amblyopia does not remain unattended and irreversible as in adults due to lack of timely treatments. If not reversible, this process could lead to a dramatic increase in disability and unsustainable social costs for many governments.

Evaluation of the PlusoptiX photoscreener in the examination of children with intellectual disabilities

PURPOSE:

This study aimed to determine whether the plusoptiX vision screener (PVS) can be used to detect amblyogenic risk factors (ARFs) as defined by the American Association for Paediatric Ophthalmology and Strabismus Vision Screening Committee guidelines (2013) for automated vision screening devices.

METHODS:

In this cross-sectional study, children attending a special needs school underwent screening with the PVS and complete ophthalmologic examinations. Ophthalmologic examinations were used as the gold standard to compute the prevalence, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and testability.

RESULTS:

Forty-four children with special needs (mean age, 8.5 years; range, 4–18 years) were included. The PVS recommended referral of 31 cases (referral rate 70%). Thirty-nine of the 44 children (89%) met the referral-positive threshold for strabismus, reduced vision and/or amblyogenic factors on examination. The plusoptiX had a sensitivity of 40% (confidence interval [CI] 7%–83%), specificity of 78% (CI 55%–85%), PPV of 15% (CI 3%–46%), and NPV of 90.3% (CI 73%–97%). The PVS underestimated refractive errors by 0.67 to 0.71 D in the right (P < 0.001) and left eyes (P = 0.002). Testability was relatively low, with the PVS at 75% compared to the gold standard examination at 100%.

CONCLUSION:

We found that although the plusoptiX photoscreener might be a useful tool in pediatric vision screening, it might not perform as well in children with intellectual disabilities. Utilization of the PVS as a single screening device may fail to identify a considerable proportion of young children with ARFs or amblyopia.

Application of deep learning and image processing analysis of photographs for amblyopia screening

Purpose

Photo screeners and autorefractors have been used to screen children for amblyopia risk factors (ARF) but are limited by cost and efficacy. We looked for a deep learning and image processing analysis-based system to screen for ARF.

Methods

An android smartphone was used to capture images using a specially coded application that modified the camera setting. An algorithm was developed to process images taken in different light conditions in an automated manner to predict the presence of ARF. Deep learning and image processing models were used to segment images of the face. Light settings and distances were tested to obtain the necessary features. Deep learning was thereafter used to formulate normalized risks using sigmoidal models for each ARF creating a risk dashboard. The model was tested on 54 young adults and results statistically analyzed.

Results

A combination of low-light and ambient-light images was needed for screening for exclusive ARF. The algorithm had an F-Score of 73.2% with an accuracy of 79.6%, a sensitivity of 88.2%, and a specificity of 75.6% in detecting the ARF.

Conclusion

Deep-learning and image-processing analysis of photographs acquired from a smartphone are useful in screening for ARF in children and young adults for a referral to doctors for further diagnosis and treatment.

Comparative evaluation of qualitative performance of technical human resource in school eye health program

Purpose

To measure sensitivity and specificity of vision screeners in identifying children with visual impairment and positive signs and symptoms and assess association of effectiveness with individual characteristics of screeners and type of schools screened.

Methods

A total of 1096 children from age 5 to 15 years of age were screened. A total of 396 children were screened from a municipal school, 200 children from a government-aided school, and 500 children from a private school were screened. Four persons with basic 12th standard science qualification willing to be a part of school eye health program were selected who carried out screening in school children after receiving appropriate training.

Results

The two vision screeners who had a background of conducting community eye health programs and worked in eye hospital had 100% sensitivity and specificity for presenting visual acuity, squint detection, and blurring. The screening by these screeners was done in private and semi-private schools, respectively. The other two screeners with no such background conducting screening in government schools had 60% and 75% sensitivity in detecting presenting visual acuity, respectively.

Conclusion

People with a background of organizing community eye health programs and those working in eye hospitals are the best candidates for being trained as new cadre of vision screeners with best results being obtained in private and government-aided schools.

Amblyopia treatment: an evidence‐based approach to maximising treatment outcome

The basis of treatment for amblyopia (poor vision due to abnormal visual experience early in life) for 250 years has been patching of the unaffected eye for extended times to ensure a period of use of the affected eye. Over the last decade randomised controlled treatment trials have provided some evidence on how to tailor amblyopia therapy more precisely to achieve the best visual outcome with the least negative impact on the patient and the family. This review highlights the expansion of knowledge regarding treatment for amblyopia and aims to provide optometrists with a summary of research evidence to enable them to better treat amblyopia. Treatment for amblyopia is effective, as it reduces overall prevalence and severity of visual loss in this population. Correction of refractive error alone significantly improves visual acuity, sometimes to the point where further amblyopia treatment is not required. Atropine penalisation and patch occlusion are effective in treating amblyopia. Lesser amounts of occlusion or penalisation have been found to be just as effective as greater amounts. Recent evidence has highlighted that occlusion or penalisation in amblyopia treatment can create negative changes in behaviour in children and impact on family life. These complications should be considered when prescribing treatment because they can negatively affect compliance. Studies investigating the maximum age at which treatment of amblyopia can still be effective and the importance of near activities during occlusion are ongoing.

Amblyopia: prevalence, natural history, functional effects and treatment

Amblyopia, defined as poor vision due to abnormal visual experience early in life, affects approximately three per cent of the population and carries a projected lifetime risk of visual loss of at least 1.2 per cent. The presence of amblyopia or its risk factors, mainly strabismus or refractive error, have been primary conditions targeted in childhood vision screenings. Continued support for such screenings requires evidence-based understanding of the prevalence and natural history of amblyopia and its predisposing conditions, and proof that treatment is effective in the long term with minimal negative impact on the patient and family. This review summarises recent research relevant to the clinical understanding of amblyopia, including prevalence data, risk factors, the functional impact of amblyopia and optimum treatment regimes and their justification from a vision and life skills perspective. Collectively, these studies indicate that treatment for amblyopia is effective in reducing the overall prevalence and severity of visual loss from amblyopia. Correction of refractive error alone has been shown to significantly reduce amblyopia and less frequent occlusion can be just as effective as more extensive occlusion. Occlusion or penalisation in amblyopia treatment can create negative changes in behaviour in children and impact on family life, and these factors should be considered in prescribing treatment, particularly because of their influence on compliance. Ongoing treatment trials are being undertaken to determine both the maximum age at which treatment of amblyopia can still be effective and the importance of near activities during occlusion. This review highlights the expansion of current knowledge regarding amblyopia and its treatment to help clinicians provide the best level of care for their amblyopic patients that current knowledge allows.

Utilizing minicomputer technology for low-cost photorefraction: a feasibility study

Eccentric photorefraction is an objective technique to determine the refractive errors of the eye. To address the rise in prevalence of visual impairment, especially in rural areas, a minicomputer-based low-cost infrared photorefractor was developed using off-the-shelf hardware components. Clinical validation revealed that the developed infrared photorefractor demonstrated a linear working range between +4.0 D and -6.0 D at 50 cm. Further, measurement of astigmatism from human eye showed absolute error for cylinder of 0.3 D and high correlation for axis assessment. To conclude, feasibility was shown for a low-cost, portable and low-power driven stand-alone device to objectively determine refractive errors, showing potential for screening applications. The developed photorefractor creates a new avenue for telemedicine for ophthalmic measurements.

Prevalence of Amblyopia After Photoscreening

PURPOSE

To assess the prevalence of amblyopia in a population of adolescents screened for amblyogenic risk factors at preschool age.

METHODS

Data were retrospectively collected from the preschool screening for amblyogenic risk factors routinely performed in the authors' hospital. A stratified random sampling was used. A school from the region was randomly selected and then two grades were randomly selected. All classes from these grades were evaluated and only children who were previously screened for amblyogenic risk factors were included. Ophthalmological examination included best visual acuity (distance and near, Early Treatment of Diabetic Retinopathy Study scale and Jaeger eye chart) and stereopsis (Randot Stereo Test; Stereo Optical Company, Inc). Sample size was estimated as more than 283 participants. Pertinent data were extracted for analysis.

RESULTS

A total of 520 children were recruited, and 299 met the inclusion criteria. Fifteen percent of children (n = 46) had results at the screening that prompted a further ophthalmological evaluation and 9% of children (n = 26) had meaningful refractive errors or strabismus. Overall amblyopia prevalence was 1.00%. One of the 3 children who developed amblyopia had microstrabismus, and the remaining 2 children had a previous positive screening result but missed the follow-up evaluations. At the follow-up evaluation, 79.3% (n = 237) of children were not wearing glasses.

CONCLUSIONS

A structured screening may allow the early detection of amblyogenic factors and prevent further vision deterioration in children, thus improving their long-term quality of life. The prevalence of amblyopia in this study was lower than that recently stated for Europe. [J Pediatr Ophthalmol Strabismus. 2020;57(6):372-377.].

Longitudinal Analysis of Refractive Errors in Premature Children during the First Three Years of Life

PURPOSE

To examine the longitudinal behavior of refractive errors in both retinopathy of prematurity (ROP) and non-ROP screened premature children during the first three years of life.

METHODS

This retrospective cohort included premature children (less than 37 weeks gestational age) born between 10/2011 and 8/2013 with ≥ two cycloplegic refractions. Cycloplegic refractions were converted into power vectors: M (spherical equivalent), J₀ [positive for with-the-rule (WTR) and negative for against-the-rule (ATR) astigmatism], and J ₄₅ (oblique astigmatism). Each power vector component was fitted by multilevel mixed-effects linear regression models; the mean change over time was analyzed.

RESULTS

Mean J₀ was 0.59 (95% CI 0.53-0.66) at six months and 0.29 (95% CI 0.19-0.39) at 18 months; afterward, the change was <0.1 per year. J₀ decreased -0.32 (0.64 diopters) over three years. When analyzed in one-year increments, the mean change in J₀ and M was lowest at 24 months. M decreased 1.13 diopters over three years.

CONCLUSION

WTR astigmatism and spherical equivalent decreased over the first three years of life. WTR astigmatism accounted for the majority of amblyopogenic refractive errors. The change in J₀ leveled after 18 months and the lowest rate of change was at 24 months in J₀ and M, thus it may be appropriate to screen this high-risk population around 18-24 months.

Comparison of refractive value and pupil size under monocular and binocular conditions between the Spot Vision Screener and binocular open-field autorefractor

We determined the repeatability-reproducibility of refraction values and pupil size measured using the Spot Vision Screener and compare the obtained values with those measured using the binocular open-field autorefractor Grand Seiko WAM 5500 in healthy adults. This cross-sectional study included 22 eyes of 22 healthy adults with emmetropia to myopia. For each participant, spherical equivalent value, cylindrical value, and pupil size were measured in the right eye using the Spot Vision Screener and Grand Seiko autorefractor devices by two different orthoptists under two conditions: monocular and binocular (three consecutive refraction measurements). Repeatability-reproducibility of values measured using both devices were evaluated using intra-class correlation coefficients (ICCs). The mean spherical equivalent value measured using the Spot Vision Screener was -2.79D in the monocular condition and -2.69D in binocular condition, which showed a small significant difference to those measured using the Grand Seiko autorefractor (-2.98D and -2.93D, respectively). The mean cylindrical value measured using the Spot Vision Screener was -0.59D in the monocular condition and -0.52D in the binocular condition, which showed a small significant difference compared with those measured using the Grand Seiko autorefractor in the binocular condition (-0.70D and -0.75D, respectively). Correlation coefficients of the spherical equivalent values, cylindrical values, and pupil sizes measured using both devices were R=0.959 (P<0.001), R=0.243 (P=0.260) and R=0.917 (P<0.001), respectively, in the monocular condition and R=0.962 (P<0.001), R=0.444 (P=0.040), and R=0.832 (P<0.001), respectively, in the binocular condition. ICC values of spherical equivalent value in intra-rater or inter-rater were more than 0.99 in both devices and conditions. ICC values of cylindrical values under the binocular condition in the Spot Vision Screener were 0.636 in intra-rater and 0.574 in inter-rater, which were lower than those of the Grand Seiko autorefractor (0.874 and 0.839, respectively). ICC values of pupil sizes under the binocular condition in the Spot Vision Screener were 0.871 in intra-rater and 0.760 in inter-rater, which were lower than those of the Grand Seiko autorefractor (0.967 and 0.943, respectively). The refractive value and pupil size obtained using the Spot Vision Screener showed high repeatability and reproducibility and were similar to the values obtained using the Grand Seiko autorefractor. Thus, the Spot Vision Screener, an automated vision screener, is a reliable portable refractor and pupillometry device for measuring refractive errors in clinical settings.

Evidence-Based Clinical Practice Guideline: Comprehensive Pediatric Eye and Vision Examination

Republished with written permission granted from the American Optometric Association, October 2, 2020.

Prevalence and pattern of amblyopia in a rural hospital in Ghana

Amblyopia is a developmental ocular disease of childhood-onset which may lead to persistent sequelae into adulthood. Early detection and management of amblyopia usually result in an improved visual outcome. The purpose of this study was to determine the prevalence and pattern of amblyopia in a rural hospital in Ghana. Clinical records of patients seen (from January 2014 to December 2018) at Westphalian Medical Center, Oyoko, Ashanti Region, Ghana, were reviewed retrospectively. Unilateral amblyopia was defined as a two-line interocular difference or more in visual acuity. Bilateral amblyopia was defined as best-corrected visual acuity (BCVA) of Snellen 6/12 or worse in both eyes, with evidence of bilateral ametropia or obstruction of the visual pathway. Following a review of 12,602 patient records, 258 cases of amblyopia were identified. The mean (±SD) presenting age of amblyopic patients was 24.3 ± 16.1 years, with a male-to-female ratio of 1:1.1. The period prevalence of amblyopia was 2.04%. The period prevalence of unilateral and bilateral amblyopia was 1.38% and 0.66%, respectively. The most prevalent form of amblyopia was refractive with a cumulative prevalence of 1.42%. Strabismic and stimulus deprivation amblyopia accounted for 0.36% and 0.21% of all amblyopic cases, respectively. A major cause of amblyopia in this population was refractive error, hence the use of spectacle correction for its initial management. Repeated assessment after an appropriate period of refractive adaptation would elucidate the proportion of amblyopias needing additional treatment modalities. Vision screening for early detection of amblyopia in childhood with accessible and effective management of amblyopia (including refractive correction and occlusion treatment) is necessary to reduce the impact of amblyopia in Ghana.

Current Management of Childhood Amblyopia

Amblyopia is defined as the reduction of best-corrected visual acuity of one or both eyes caused by conditions that affect normal visual development. The basic strategy to treat amblyopia is to obtain a clear retinal image in each eye and correct ocular dominance through forced use of the amblyopic eye. Treatment modalities include correcting any underlying organic disease, prescribing appropriate optical correction, and providing occlusion/penalization therapy for the non-amblyopic eye. Given the success of amblyopia treatment declines with increasing age, the detection and management of amblyopia should begin as early as possible during the sensitive period for visual development. Proper management of amblyopia during childhood can reduce the overall prevalence and severity of visual loss. This study aims to provide an update for the management of childhood amblyopia to provide better visual outcomes.

Fifteen-minute consultation: Managing a child with a new-onset squint

OBJECTIVE

To provide a systematic approach to the child with a new squint.

METHOD

Review of the current available literature.

CONCLUSION

Squint is a common presentation in the paediatric population. Although the parents' primary concern may be cosmetic, a new squint in childhood may be the first sign of a serious or life-threatening ocular or neurological pathology. Thorough assessment and timely referral are essential.

Assessment of availability, awareness and perception of stakeholders regarding preschool vision screening in Kumasi, Ghana: An exploratory study

BACKGROUND

Regardless of the importance of preschool vision screening (PSVS), there is limited data on the current state of these programs in Africa (particularly Ghana). This study sought to investigate the level of awareness and perception of stakeholders regarding PSVS, its availability and related policies/programmes in the Kumasi Metropolis, Ghana.

METHODS

This descriptive cross-sectional study included 100 systematically sampled preschools in the metropolis (using probability proportional-to-size method); 72 private schools and 28 public schools. Convenience sampling was used to recruit stakeholders of preschools (teachers, head teachers, proprietors, administrators, directors, and educationists), and were interviewed using a well-structured questionnaire. Questionnaires were administered to all eligible respondents who were present at the time of data collection.

RESULTS

A total of 344 respondents participated in the study; 123 (35.8%) males and 221 (64.2%) females. The overall mean age of respondents was 37.63 ±12.20 years (18-71 years). Of the respondents, 215 (62.5%), 94 (27.3%), and 35 (10.2%) were enrolled from private schools, public schools, and Metropolitan Education Directorate, respectively. 73.8% of respondents reported the absence of routine PSVS in schools whereas 90.1% reported no written policies for PSVS in schools. Only 63.6% of respondents were aware of PSVS whereas more than half (59.6%) of all respondents perceived PSVS to be very important for preschoolers. Private school ownership was significantly associated with availability of PSVS whereas age, teachers, private school ownership, and preschool experience > 10 years were significantly associated with awareness of PSVS (P < 0.05). However, there was no significant association between sociodemographic factors and perception of PSVS.

CONCLUSION

PSVS is largely unavailable in most Ghanaian schools. Majority of stakeholders were aware of PSVS and agreed to its implementation and incorporation into schools' health programmes. There is the need to implement a national programme/policy on preschool vision screening in Ghana.

Refinement strategies in photoscreening for the detection of amblyopia risk factors in 12-to-24-month-old children

PURPOSE

To establish an appropriate clinical protocol for early photoscreening in 12-to-24-month-old children at pediatric well-baby clinics.

METHODS

This prospective study included a total of 277 children aged 12-24 months who visited a pediatric well-baby clinic. All participants underwent: 1) inquiry of medical history; 2) photoscreening with PlusoptiX A12; and 3) comprehensive ophthalmologic examinations. The optimal referral cut-off point for PlusoptiX was determined by receiver operating characteristic analyses. A high-risk subgroup was defined as having a birth weight <3000 g or a history of major systemic diseases, based on the results of multivariable risk factor analysis from children's medical history. A strategy of selective photoscreening focusing on the high-risk subgroup was evaluated. The main outcome measures included sensitivity, specificity, and positive and negative predictive values.

RESULTS

The prevalence of amblyopia risk factors in our study population was 12.3%. A total of 172 children (62.1%) were assigned to the high-risk subgroup. Compared with the nonselective photoscreening of all 277 children, selective photoscreening of the high-risk children yielded a higher positive predictive value (59.6% vs. 46.7%, p = 0.001) while showing no difference in sensitivity (82.3% vs. 85.3%, p = 0.32), specificity (92.2% vs, 86.4%, p = 0.05), and negative predictive value (97.4% vs. 97.6%, p = 0.50).

CONCLUSION

At pediatric well-baby clinics, selective photoscreening among 12-to-24-month-old children with a birth weight <3000 g or a history of major systemic diseases helped reducing the number of children need to be screened and conserving medical resources yet identifying children at risk for timely eye care.

Evaluation of the Spot Vision Screener in comparison with the orthoptic examination in visual screening in 3-5 year-old schoolchildren

PURPOSE

To evaluate the Spot Vision Screener (SVS) compared with the orthoptic examination for detection of amblyopia risk factors in preschools.

METHODS

This prospective study included children with a visual screening organized by the department of "le" (PMI) in Côte d'Or (Burgundy, France), between June 2017 and April 2018. All children were evaluated with the SVS followed by a clinical orthoptic examination. Results with the SVS were compared with those obtained by clinical orthoptic examination.

RESULTS

A total of 1236 subjects were included in the study from 100 preschools. The mean age of the children was 3.6±0.7 years, and 627 were female (50.7%). The orthoptic examination detected 308 (24.9%) children with subnormal visual acuity for age in one eye or both. In children with a history of prematurity, the orthoptic examination was more frequently abnormal (P=0.002), which was not seen with the SVS (P=0.050). The SVS screened 20 (1.6%) children with strabismus, while 40 (3.2%) were detected by orthoptic examination. At the end of the screening, the SVS detected 182 (14.7%) suspect patients while 311 (25.1%) suspect patients were detected after the orthoptic examination. Comparing SVS with orthoptic examination, agreement was fair (κ=0.4).

CONCLUSION

The SVS can be a useful device for visual screening, but agreement with the orthoptic examination was only fair. The Spot vision screener should be used in conjunction with a clinical orthoptic examination.

Simplified updates on the pathophysiology and recent developments in the treatment of amblyopia: A review

Amblyopia is the most common cause of monocular visual impairment affecting 2-5% of the general population. Amblyopia is a developmental cortical disorder of the visual pathway essentially due to abnormal visual stimulus, reaching the binocular cortical cells, which may be multivariate. Ganglion cells are of two types: parvocellular (P cells) and magnocellular (M cells); they are the first step where the light energy is converted in to neural impulse. P cells are involved in fine visual acuity, fine stereopsis, and color vision and M cells are involved in gross stereopsis and movement recognition. Strabismus, refractive error, cataract, and ptosis, occurring during critical period are highly amblyogenic. The critical period extends from birth to 7--8 years. The earlier the clinically significant refractive error and strabismus are detected and treated, the greater the likelihood of preventing amblyopia. Treatment for amblyopia in children includes: optical correction of significant refractive errors, patching, pharmacological treatment, and alternative therapies which include: vision therapy, binocular therapy, and liquid crystal display eyeglasses are newer treatment modalities for amblyopia. Age of starting the treatment is not predictive of outcome, instituting treatment on detection and early detection plays a role in achieving better outcomes. This review aims to give a simplified update on amblyopia, which will be of use to a clinician, in understanding the pathophysiology of the complex condition. We also share the cortical aspects of amblyopia and give recent developments in the treatment of amblyopia.

To assess the accuracy of Plusoptix S12-C photoscreener in detecting amblyogenic risk factors in children aged 6 months to 6 years in remote areas of South India

Purpose:

To assess the screening accuracy of a novel fourth generation, handheld Plusoptix S12 C photo screener in detecting amblyogenic risk factors in children aged 6 months to 6 years in remote areas of South India.

Methods:

In this cross sectional study, 381 children aged 6 months to 6 years were screened by a trained fieldworker in Anganwadis and schools using the Plusoptix photoscreener. This was followed by complete ophthalmic evaluation including retinoscopy, subjective refraction, and strabismus evaluation by an optometrist and an orthoptist. All children further underwent complete ocular examination by the senior pediatric ophthalmologist for validation of the results.

Results:

A total of 367 children were included in the study. The sensitivity and specificity of the photo screener were found to be 86.76% and 82.27%, respectively. Positive Predictive Value, Negative Predictive Value, and Receiver Operative Characteristics were 52.67%, 96.47%, and 83.11%, respectively. In subgroup younger than 3 years, sensitivity and specificity was 89.19% and 81.18%, respectively. Myopic astigmatism was the most common amblyogenic risk factor in our study group.

Conclusion:

In India, with a lack of adequate healthcare professionals and poor health-seeking behavior; photo screeners can play an important role. We recommend the use of photo screeners for screening children as young as 6 months, especially in remote low-resource settings. This will help in expanding reliable eye care services to previously underserved areas.

Diagnostic test accuracy of Spot and Plusoptix photoscreeners in detecting amblyogenic risk factors in children: a systemic review and meta-analysis

PURPOSE

Amblyopia is a permanent visual impairment developed in early childhood. Recently, instrument-based photoscreeners have been widely used for vision screening to detect amblyopia risk factors, which is key for the prevention and treatment of amblyopia. This meta-analysis aims to evaluate the diagnostic test accuracy of Spot and Plusoptix photoscreeners in detecting risk factors for amblyopia in children.

METHODS

An electronic literature search was performed in October 2018 using the MEDLINE, Embase, and Web of Science databases. Twenty-one publications with a total of 5022 subjects were included. Subjects given a comprehensive examination were considered to have amblyopia or amblyogenic risk factors based on the American Association for Pediatric Ophthalmology and Strabismus (AAPOS) referral criteria guidelines.

RESULTS

The overall sensitivity for Spot and Plusoptix was 87.7% and 89.4%, respectively (p = 0.38); the specificity was 78.0% and 89.9%, respectively (p = 0.90). For subjects under 7 years old (preschool children), the overall sensitivity for Spot and Plusoptix was 91.7% and 90.2%, respectively (p = 0.81); the specificity was 82.6% and 93.0%, respectively (p = 0.46).

CONCLUSION

Both Spot and Plusoptix photoscreeners demonstrated good sensitivity and specificity in detecting amblyopia risk factors in children, especially at preschool ages. There was no significant difference in diagnostic test accuracy between them.

Guide de pratique clinique fondé sur des données probantes pour l'examen périodique de la vue chez les enfants de 0 à 5 ans au Canada

CONTEXTE

Étant donné que les maladies oculaires avant l'âge de 5 ans sont courantes, une certaine forme de dépistage des troubles de la vision devrait être effectuée chez les enfants avant qu'ils ne fréquentent l'école primaire. Cependant, l'absence de recommandations nationales cohérentes crée de la confusion chez les patients, les professionnels des soins oculovisuels et les gouvernements. MéTHODES: L'objectif de ce document est de fournir des recommandations quant aux types d'examens oculaires à pratiquer chez les enfants en bonne santé de 0 à 5 ans ainsi que sur le moment et la périodicité de tels examens. Une recension des écrits a produit 403 articles. Un comité d'experts multidisciplinaire (composé de deux optométristes, d'un ophtalmologiste effectuant des examens complets de la vue, d'un ophtalmologiste pratiquant en pédiatrie, d'un médecin de famille et d'un pédiatre) a établi de façon indépendante les articles jugés essentiels à la question clinique. Les articles se prêtant à un classement [n = 16] ont ensuite été soumis à une évaluation critique indépendante par un groupe externe, lequel a fourni un profil « GRADE » des articles à utiliser et leur a attribué une cote.

RECOMMANDATIONS

En plus du dépistage de routine effectué par les professionnels de première ligne, un examen complet de la vue mené par un professionnel possédant l'expertise nécessaire à la détection des facteurs de risque de l'amblyopie (comme un ophtalmologiste ou un optométriste) est requis durant la petite enfance. Les conclusions confirment l'importance de la détection précoce de l'amblyopie avant 36 mois et au plus tard 48 mois par le dépistage assorti d'au moins un examen complet de la vue avant l'âge de 5 ans.

CONCLUSIONS

Le dépistage de la vue effectué chez les bébés et les enfants par les fournisseurs de soins de première ligne au cours des consultations de routine et des vaccinations périodiques est un élément essentiel de la détection des maladies oculaires. Toutefois, le potentiel de détection précoce est limité et un examen oculovisuel complet est également recommandé avant que l'enfant n'entre à l'école. Si l'amblyopie, le strabisme ou une autre pathologie oculaire est détecté ou soupçonné, et que le problème dépasse le champ de compétences du professionnel qui examine le patient, celui-ci peut être dirigé vers le spécialiste approprié, ce qui permet d'amorcer le traitement en temps opportun.

Evidence-based clinical practice guidelines for the periodic eye examination in children aged 0-5 years in Canada

BACKGROUND

As eye disease before age 5 years is common, some form of vision screening should be performed on children before attending primary school. However, the lack of consistent national recommendations creates confusion for patients, eye care professionals, and governments alike.

METHODS

The objective of this document is to provide guidance on the recommended timing, intervals, and types of ocular assessments for healthy children aged 0-5 years. A literature search yielded 403 articles. A multidisciplinary expert committee (comprising 2 optometrists, a comprehensive ophthalmologist, a pediatric ophthalmologist, a family physician, and a pediatrician) independently determined those articles deemed to be key to the clinical question. Articles that were gradable (n = 16) were then submitted for independent critical appraisal by an external review group, which provided a Grading of Recommendations Assessment, Development and Evaluation profile of the reviewed articles to use for assigning a grade of evidence.

RECOMMENDATIONS

In addition to routine screening by a primary health care professional, a comprehensive eye examination by an individual with the expertise to detect risk factors for amblyopia-such as an ophthalmologist or optometrist-is required in early childhood. The findings support the importance of early detection of amblyopia before 36 months and no later than 48 months of age via screening with at least 1 comprehensive eye examination before age 5 years.

CONCLUSIONS

Vision screening performed by primary health care providers during routine well-baby/child visits and scheduled vaccinations is an essential part of the detection of ocular disease. However, this early detection potential is limited, and a full oculovisual assessment is also recommended before the child entering the school system. If amblyopia, strabismus, or other eye pathology is detected or suspected that is beyond the scope of the eye care professional examining the patient, a referral to the appropriate specialist can be made, allowing treatment to be initiated in a timely fashion.

Choosing appropriate tools and referral criteria for vision screening of children aged 4-5 years in Canada: a quantitative analysis

OBJECTIVES

To assess the diagnostic accuracy of five vision screening tools used in a school setting using sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV).

DESIGN

We compared the results of the five best evidence-based screening tools available in 2014 to the results of a comprehensive eye exam with cycloplegic refraction by a licenced optometrist. Screening included Cambridge Crowded Acuity Cards, Plusoptix S12 and Spot photoscreeners, Preschool Randot Stereoacuity Test and the Pediatric Vision Scanner (PVS). Referral criteria followed AAPOS (2013) guidelines and published norms.

SETTING

A large school in Toronto, Canada, with 25 split classrooms of junior kindergarten (JK: 4 year olds) and senior kindergarten (SK: 5 year olds) children.

PARTICIPANTS

Over 2 years, 1132 eligible children were enrolled at the school. After obtaining parental consent, 832 children were screened. Subsequently, 709 children had complete screening and optometry exam data.

MAIN OUTCOME MEASURES

The presence/absence of a visual problem based on optometrist's assessment: amblyopia, amblyopia risk factors (reduced stereoacuity, strabismus and clinically significant refractive errors) and any other ocular problem (eg, nystagmus).

RESULTS

Overall, 26.5% of the screened children had a visual problem, including 5.9% with amblyopia. Using all five tools, screening sensitivity=84% (95% CI 78 to 89), specificity=49% (95% CI 44 to 53), PPV=37% (95% CI 33 to 42), and NPV=90% (95% CI 86 to 93). The odds of having a correct screening result in SK (mean age=68.2 months) was 1.5 times those in JK (mean age=55.6 months; 95% CI 1.1 to 2.1), with sensitivity improved to 89% (95% CI 80 to 96) and specificity improved to 57% (95% CI 50 to 64) among SK children.

CONCLUSIONS

A school-based screening programme correctly identified 84% of those kindergarten children who were found to have a visual problem by a cyclopleged optometry exam. Additional analyses revealed how accuracy varies with different combinations of screening tools and referral criteria.

Prevalence of vision impairment and refractive error in school learners in Calabar, Nigeria

Background: Uncorrected refractive error could negatively affect learning and academic performance, there is still inadequate information for planning school health.Aim: To determine the proportion of students with vision impairment because of uncorrected refractive error, and prevalent types among learners aged 10–18 years.Setting: The study site included two of 18 local government areas of the Cross River State in Nigeria, with 23 public and mission secondary schools.Methods: A two-stage cluster sampling method was used to enrol 4241 study participants from eight selected secondary schools.Results: The prevalence of vision impairment (presenting visual acuity worse than 6/12) was 7.9% (95% confidence interval [CI]: 7.17% – 8.6%). The prevalence of vision impairment because of refractive error was 7.2% (95% CI: 6.41% – 7.96%) in the better eye. Astigmatism was the predominant type of refractive error with a prevalence of 4.2% (95% CI: 3.6% – 4.8%), followed by myopia (1.72%; 95% CI: 1.3% – 2.1%) and hyperopia (1.3%; 95% CI: 0.9% – 1.6%). There were statistically significant differences in proportions of female participants who presented with myopic astigmatism (30.8%; p 0.012). Statistically significant difference in proportions was found in older (33.3%; p 0.0004) and male (29.6%; p 0.0003) participants who presented with hyperopic astigmatism compared to younger and female participants, respectively. Myopia accounted for 4.8% (95% CI: 4.2% – 5.5%) and was significantly higher in female participants (5.5%; p 0.033).Conclusion: Refractive error was the major cause of vision impairment and myopic astigmatism was the predominant type of refractive error among secondary school children in Calabar.

Evidence-based preschool-age vision screening: health policy considerations

Background

There are many causes of visual impairment, and even blindness, which are treatable or at least preventable. Two such conditions are strabismus (crossed-eye, squint) and refractive error (visual image not focused on the most sensitive part of the retina). If these are not detected and corrected at an early age, they can lead to an irreversible impairment known as amblyopia (lazy eye). Pediatric vision screening and subsequent treatment for amblyopia and amblyogenic risk factors are thus key to preventing vision loss. Furthermore, vision screening can detect moderate to high hyperopia, which has been found to be associated with poor school readiness.

Evidence-based recommendations call for screening children at 3–5 years of age; they are old enough to cooperate, but still within the window of effective intervention. However, these recommendations have yet to be universally implemented as the standard of care.

Methods

This paper integrates a review of the literature and the international experience of preschool vision screening with the findings from a preliminary feasibility study of expanded screening in Israel to formulate a discussion of the current health policy challenge in Israel and the options for addressing it. The advantages and disadvantages of various venues for vision screening are discussed.

Findings

Screening by optometrists in Mother and Child Health Centers, as implemented in a recent pilot project in the Jerusalem District, would allow the most comprehensive testing. Photo-screening in preschools would reach the most children, but at the cost of missing hyperopia (farsightedness). Either approach would probably constitute improvements over the current situation. The relative strengths of the two approaches depends in part on the ability to purchase automatic screening equipment (and the efficacy of that equipment) vs. the ongoing cost of paying trained personnel.

Conclusions

Further research should be conducted in Israel to determine the prevalence of refractive errors, so that best practices can be established for Israel’s population and social needs. In the interim, the Ministry of Health should promptly implement the inclusion of preschool visions screening for children in the approved “basket of services” covered by the National Health Insurance Laws, using photo-screening, including collection of the clinical data.

Electronic supplementary material

The online version of this article (10.1186/s13584-019-0339-z) contains supplementary material, which is available to authorized users.

The Effects of Anisometropic Amblyopia on the FNS and TNO Stereotest Thresholds in Four- to Eight-Year-Olds

Purpose

To investigate the relationship between stereoacuity and factors associated with anisometropic amblyopia in children aged 4-8 years.

Methods

44 participants had their stereoacuity thresholds measured using the Frisby Near Stereotest (FNS) and the TNO Randot Stereotest (TNO). Participants were divided into anisometropic amblyopes and controls (normal uniocular visual acuity (VA) with or without glasses). FNS and TNO stereoacuity thresholds were compared based on different factors, which included interocular acuity difference (IAD), VA levels, and the degree of anisometropia.

Results

All 44 participants achieved better stereoacuity with the FNS compared to the TNO (p = 0.045). The control group performed significantly better on the FNS (p = 0.012) and the TNO (p = 0.009) when compared with anisometropic amblyopes. The only statistically significant correlation was found between stereoacuity - as measured with FNS - and IAD (p = 0.009). However, the TNO showed a correlation in the presence of poor VA, larger IADs and a high degree of anisometropia.

Conclusions

Stereoacuity thresholds are significantly affected by poor VA, large IAD and high degrees of spherical anisometropia when trying to distinguish the resolution of a target with the TNO yet the same factors do not appear to affect ability to distinguish the disparity of a target with the FNS. Controls also performed worse on the TNO.

Development and Preliminary Evaluation of a Smartphone App for Measuring Eye Alignment

Purpose

We evaluate a smartphone application (app) performing an automated photographic Hirschberg test for measurement of eye deviations.

Methods

Three evaluation studies were conducted to measure eye deviations in the horizontal direction. First, gaze angles were measured with respect to the ground truth in nonstrabismic subjects (n = 25) as they fixated monocularly on targets of known eccentricity covering an angular range of approximately ±13°. Second, phoria measurements with the app at near fixation (distance = 40 cm) were compared with the modified Thorington (MT) test in normally-sighted subjects (n = 14). Third, eye deviations using the app were compared to a cover test with prism neutralization (CTPN; n = 66) and Synoptophore (n = 34) in strabismic subjects. Regression analyses were used to compare the app and clinical measurements of the magnitude and direction of eye deviations (prism diopters, Δ).

Results

The gaze angles measured by the app closely followed the ground truth (slope = 1.007, R² = 0.97, P < 0.001), with a root mean squared error (RMSE) of 2.4Δ. Phoria measurements with the app were consistent with MT (slope = 0.94, R² = 0.97, P < 0.001, RMSE = 1.7Δ). Overall, the strabismus measurements with the app were higher than with Synoptophore (slope = 1.15, R² = 0.91, P < 0.001), but consistent with CTPN (slope = 0.95, R² = 0.95, P < 0.001). After correction of CTPN values for near fixation, the consistency of the app measurements with CTPN was improved further (slope = 1.01).

Conclusions

The app measurements of manifest and latent eye deviations were consistent with the comparator clinical methods.

Translational Relevance

A smartphone app for measurement of eye alignment can be a convenient clinical tool and has potential to be beneficial in telemedicine.

Preschool Vision Screening: Where We Have Been and Where We Are Going

PURPOSE

To discuss the evolution of instrument-based screening to detect amblyopia and its risk factors, and to summarize the importance of preschool vision screening.

DESIGN

Expert commentary.

METHODS

Author experiences were supplemented by a review and interpretation of pertinent medical literature.

RESULTS

Amblyopia remains a public health problem, as it is a common cause of monocular visual impairment. As a disease, amblyopia detection is best obtained by appropriate vision screening rather than by yearly mandated comprehensive eye examinations for all children; the US Preventative Services Task Force (USPSTF) recently reaffirmed their recommendations for vision screening in preschool children. Vision screening devices have evolved over the past 4 decades ranging from photoscreeners that use instantaneously developing film, to autorefractors that detect amblyopia risk factors, to nerve fiber layer scanners that detect the microtropia that nearly always accompanies amblyopia. When it is detected early, effective treatment for amblyopia can be initiated.

CONCLUSIONS

Amblyopia is a reversible cause of vision loss in children. Vision screening devices and screening programs have been extensively studied-experts and literature agree: vision screening devices and programs are cost-effective, are efficient, and are effective methods for amblyopia detection. The authors support the regular use of instrument-based vision screening in the medical home for all children until they reach a developmental stage where they can participate reliably in optotype-based vision screening.

Primary Care Implementation of Instrument-Based Vision Screening for Young Children

Vision screening for young children can detect conditions that may lead to amblyopia and vision loss if left untreated. Portable vision screening devices with high levels of precision are now available, but their effectiveness in busy primary care settings is unknown. We analyzed the effect of deploying instrument screening devices (SPOT Vision Screener, Welch-Allyn) in 19 pediatric practices. At baseline, using chart-based screening, 65.3% of 3- to 5-year-old children completed screening. A significant increase was observed starting 3 weeks after delivery of devices, and a stable level was reached 12 weeks after implementation, with 86.5% of children completing vision screening ( P = .007 by interrupted time series analysis). Improvement was greatest among 3-year-olds (44.0%-79.8%) but was also seen among 4-year-olds (70.9%-88.4%) and 5-year-olds (80.3%-90.8%). The deployment of vision screening devices in primary care practices substantially improved completed screening among preschool-aged children.

Global and regional estimates of prevalence of amblyopia: A systematic review and meta-analysis

Background: Amblyopia is one of the most important causes of vision impairment in the world, especially in children. Although its prevalence varies in different parts of the world, no study has evaluated its prevalence in different geographical regions comprehensively. The aim of the present study was to provide global and regional estimates of the prevalence of amblyopia in different age groups via a systematic search.Methods: In this study, international databases, including Embase, Scopus, PubMed, Web of Science, and other relevant databases, were searched systematically to find articles on the prevalence of amblyopia in different age groups published in English. The prevalence and 95% CI were calculated using binomial distribution. The Cochran's Q-test and I² statistic were applied to assess heterogeneity, a random-effects model was used to estimate the pooled prevalence, and a meta-regression method was utilized to investigate the factors affecting heterogeneity between studies.Results: Of 1252 studies, 73 studies were included in the analysis (sample volume: 530,252). Most of these studies (n = 25) were conducted in the WHO-Western Pacific Regional Office. The pooled prevalence estimate of amblyopia was 1.75% (95% CI: 1.62-1.88), with the highest estimate in European Regional Office (3.67%, 95% CI: 2.89-4.45) and the lowest in African Regional Office (0.51%, 95% CI: 0.24-0.78). The most common cause of amblyopia was anisometropia (61.64%). The I² heterogeneity was 98% (p < 0.001). According to the results of univariate meta-regression, the variables of WHO region (b: 0.566, p < 0.001), sample size (b: -0.284 × 10^-4, p: 0.025), and criteria for definition of amblyopia (b: -0.292, p: 0.010) had a significant effect on heterogeneity between studies, while age group, publication date, and cause of amblyopia had no significant effect on heterogeneity.Conclusion: The prevalence of amblyopia varies in different parts of the world, with the highest prevalence in European countries. Geographical location and criteria for definition of amblyopia are among factors contributing to the difference across the world. The results of this study can help stakeholders to design health programs, especially health interventions and amblyopia screening programs.

Critical Assessment of an Ocular Photoscreener

PURPOSE

To determine the accuracy of the PlusoptiX A12 photoscreener (PlusoptiX, Inc., Atlanta, GA) in detecting amblyopia or ambylogenic risk factors in pediatric patients in Nebraska.

METHODS

Using the PlusoptiX A12 photoscreener, data were collected from pediatric patients seen at a single pediatric ophthalmology practice. Each patient was screened using the device and also received a comprehensive ophthalmic examination. The results of the PlusoptiX A12 photoscreener were compared to the gold standard, comprehensive ophthalmic examination findings. The assessment of amblyopia or amblyogenic risk factors in the patients was based on the updated American Association for Pediatric Ophthalmology and Strabismus (AAPOS) referral criteria guidelines.

RESULTS

Data were collected from 219 consecutive pediatric patients (438 eyes) during the 3-month study period. Among the patients, 87 (40%) children were determined to have amblyopia or ambylogenic risk factors after the comprehensive pediatric ophthalmology examination based on the AAPOS guidelines. The PlusoptiX A12 photoscreener was found to have a sensitivity of 93.02%, specificity of 84.96%, false-positive rate of 9.13%, false-negative rate of 2.74%, positive predictive value of 80.00%, and negative predictive value of 94.96%.

CONCLUSIONS

The PlusoptiX A12 photoscreener is viable and comparable to various commercially available devices in the detection of refractive amblyogenic risk factors based on the Nebraska pediatric patient population. Future studies may show increased sensitivity by combining the use of the PlusoptiX A12 photoscreener with an alternate cover test. [J Pediatr Ophthalmol Strabismus. 2018;55(3):194-199.].

Evaluation of visual function in preschool-age children using a vision screening protocol

Purpose

To evaluate the relationship between uncorrected visual acuity and refraction and binocular function using a vision screening protocol.

Methods

In total, 760 children (3–6 years old) who were enrolled in 4 nursery schools in Otawara, Japan, were recruited; a total of 1,520 eyes were examined. We assessed uncorrected near visual acuity, manifest refraction, stereopsis, and eye position. Subjects were divided into 4 subgroups according to the lowest uncorrected near visual acuity value compared between the 2 eyes: group 1 (visual acuity [VA] ≤0.00 [logarithm of the minimum angle of resolution]), group 2 (VA 0.15–0.05), group 3 (VA 0.52–0.22), and group 4 (VA >0.52). These parameters were compared among the groups.

Results

The sample number of each of the 4 sub-groups was as follows: group 1, 608; group 2, 114; group 3, 27; and group 4, 11. The median spherical equivalent values were −1.13 diopter (D) in group 1 and −1.00 in group 2, which were more myopic than group 4. Median cylindrical power in group 1 was 0.25 D, and was the lowest among all groups. In group 1, median anisometropia was 0.38 D and median corneal astigmatism value was 1.13 D; both values were lowest in group 1. With regard to binocular function, 89.6% of the subjects in group 1 had 60 arcseconds or better in near stereopsis and 98.8% had no detectable strabismus, which were significantly different from the findings in the other groups. The percentage of subjects in group 1 who had 80 arcseconds or worse in near stereopsis was 10.4%. In contrast, 90.9% of the subjects in group 4 had 80 arcseconds or worse in near stereopsis, and 18.2% had intermittent or manifest strabismus.

Conclusion

We suggest that examination of refraction and stereopsis in preschool-age children undergoing vision screening is an important supplement to visual acuity testing.