Field testing of the plusoptiX S04 photoscreener

The reliability of the angle of deviation measurement from the Photo-Hirschberg tests and Krimsky tests

OBJECTIVE

To compare the angle of deviation measured from Photo-Hirschberg testing and Krimsky testing, with that from an alternate prism cover test (APCT) in strabismus patients.

METHODS

A cross-sectional study was conducted in Songklanagarind Hospital, Thailand. Thirty-three strabismus patients were photographed for analysis by Photo-Hirschberg testing using computer software. The corneal light reflex displacement, converted into prism diopter (PD), was compared to the angle of deviation measured with APCT. Twenty-eight strabismus patients were tested with the Krimsky test. Data were analyzed using Pearson correlation and paired t-tests. The study excluded 4 intermittent exotropia cases, 1 intermittent esotropia case and 2 which cases missing data for krimsky test.

RESULTS

The mean±SD of the deviation angle, measured by APCT with a fixation target at 30 cm and 6 m; were 48.09±16.34PD and 47.82±15.73 PD, respectively. At 1 m, the difference in the angle of deviation measured from APCT and the Photo-Hirschberg test within 10 PD were 58.8% and 63.6%, for ET and XT, respectively. The difference in the angle of deviation measured from APCT and Krimsky tests within 10 PD in ET and XT were 86.7% and 80.0%, respectively. At 4 m, the difference in angle of deviation measured from APCT and Photo-Hirschberg tests within 10 PD in ET and XT were 58.8% and 54.5%, respectively; whereas, the difference in the angle of deviation measured from APCT and Krimsky tests within 10 PD in ET and XT were 80.0% and 70.0%, respectively.

CONCLUSION

The reliability of Krimsky test was better than Photo-Hirschberg test for measuring an angle of deviation.

A Systematic Review of Current Teleophthalmology Services in New Zealand Compared to the Four Comparable Countries of the United Kingdom, Australia, United States of America (USA) and Canada

Background

Over 700,000 New Zealanders (NZ), particularly elderly and Māori, live without timely access to specialist ophthalmology services. Teleophthalmology is a widely recognised tool that can assist in overcoming resource and distance barriers. Teleophthalmology gained unprecedented traction in NZ during the COVID-19 pandemic and subsequent lockdown. However, its provision is still limited and there are equity issues. The aim of this study was to conduct a systematic review identifying, describing and contrasting teleophthalmology services in NZ with the comparable countries of Australia, USA, Canada and the United Kingdom.

Methods

The electronic databases Embase, PubMed, Web of Science, Google Scholar and Google were systemically searched using the keywords: telemedicine, ophthalmology, tele-ophthalmology/teleophthalmology. The searches were filtered to the countries above, with no time constraints. An integrative approach was used to synthesise findings.

Results

One hundred and thirty-two studies were identified describing 90 discrete teleophthalmology services. Articles spanned from 1997 to 2020. Models were categorised into general eye care (n=21; 16%); emergency/trauma (n=6; 4.5%); school screening (n=25; 19%); artificial intelligence (AI) (n=23; 18%); and disease-specific models of care (MOC) (n=57; 43%). The most common diseases addressed were diabetic retinopathy (n=23; 17%); retinopathy of prematurity (n=9; 7%); and glaucoma (n=8; 6%). Programs were mainly centred in the US (n=72; 54.5%), followed by the UK (n=29; 22%), then Canada (n=16; 12%), Australia (n=13; 10%), with the fewest identified in NZ (n=3; 2%). Models generally involved an ophthalmologist consultative service, remote supervision and triaging. Most models involved local clinicians transmitting fed-forward or live images.

Conclusion

Teleophthalmology will likely play a crucial role in the future of eye care. COVID-19 has offered a unique opportunity to observe the use of teleophthalmology services globally. Feed-forward and, increasingly, live-based teleophthalmology services have demonstrated feasibility and cost-effectiveness in similar countries internationally. New Zealand’s teleophthalmology services, however, are currently limited. Investing in strategic partnerships and technology at a national level can advance health equities in ophthalmic care.

Vision screening in newborns and early childhood

We looked at existing recommendations and supporting evidence on the effectiveness of screening for visual disorders in newborns and small infants, and in children between six months and five years of age.We conducted a literature search up to the 5th of August 2019 by using key terms and manual search in selected sources. We summarized the recommendations and the strength of the recommendations when and as reported by the authors. We summarized the main findings of systematic reviews with the certainty of the evidence as reported on the accuracy of screening tests for detecting visual alterations; the efficacy of treatment for improving visual acuity, school performance, and quality of life; and potential harms derived from vision screening and treating visual alterations.Although there is little evidence supporting its validity and effectiveness, examining all newborns for congenital cataract and retinoblastoma through the red reflex examination is widely accepted due to the severity of both diseases and the good outcomes reached by early detection and treatment.Overall, there is a moderate certainty of evidence that visual screening in children between three and five years provides a moderate net benefit, as assessed by the US Preventive Services Task Force: vision screening tests are accurate for detecting amblyopia and its risk factors, and their treatment is associated with visual improvement. There is uncertain evidence on whether vision screening in children under three years of age provides net benefits. Among populations with a low prevalence of vision abnormalities, screening the youngest is associated with an increased rate of false positives, leading to unnecessary additional assessment.

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.

Scope and costs of autorefraction and photoscreening for childhood amblyopia-a systematic narrative review in relation to the EUSCREEN project data

Background

Amblyopia screening can target reduced visual acuity (VA), its refractive risk factors, or both. VA testing is imprecise under 4 years of age, so automated risk-factor photoscreening appears an attractive option. This review considers photoscreening used in community services, focusing on costs, cost-effectiveness and scope of use, compared with EUSCREEN project Country Reports describing how photo- and automated screening is used internationally.

Methods

A systematic narrative review was carried out of all English language photoscreening literature to September 10th 2018, using publicly available search terms. Where costs were considered, a CASP economic evaluation checklist was used to assess data quality.

Results

Of 370 abstracts reviewed, 55 reported large-scale community photoscreening projects. Five addressed cost-effectiveness specifically, without original data. Photoscreening was a stand-alone, single, test event in 71% of projects. In contrast, 25 of 45 EUSCREEN Country Reports showed that if adopted, photoscreening often supplements other tests in established programmes and is rarely used as a stand-alone test. Reported costs varied widely and evidence of cost-effectiveness was sparse in the literature, or in international practice. Only eight (13%) papers compared the diagnostic accuracy or cost-effectiveness of photoscreening and VA testing, and when they did, cost-effectiveness of photoscreening compared unfavourably.

Discussion

Evidence that photoscreening reduces amblyopia or strabismus prevalence or improves overall outcomes is weak, as is evidence of cost-effectiveness, compared to later VA screening. Currently, the most cost-effective option seems to be a later, expert VA screening with the opportunity for a re-test before referral.

Plusoptix photoscreener use for paediatric vision screening in Flanders and Iran

PURPOSE

Photoscreening assesses risk factors for amblyopia, as an alternative to measurement of visual acuity (VA) to detect amblyopia, on the premise that its early correction could prevent development of amblyopia. We studied implementations of Plusoptix photoscreening in existing population-based screening in Flanders and Iran.

METHODS

In Flanders, VA is measured at age 3, 4 and 6, photoscreening was added to existing screening at age 1 and 2.5 years in 2013. In Iran, VA is measured at ages 3-6 years, photoscreening was added at ages 3-6 years between 2011 and 2016. Plusoptix use was analysed in the literature for detection of risk factors for amblyopia and amblyopia itself, for ages 0-3 and for 4-6. A questionnaire, containing seven domains: existing vision screening, addition of photoscreening, implementation in screening program, training, attendance, diagnosis and treatment, and costs was distributed. In Iran, screening procedures were observed on site.

RESULTS

Implementation of Plusoptix photoscreening was mainly analysed from questionnaires and interviews, its effectiveness from literature data. In Flanders, of 56 759 children photoscreened at age one (81% of children born in 2013), 9.2% had been referred, 13% of these were treated, mostly with glasses, resulting in an increase of 4-year-old children wearing glasses from 4.7% to 6.4%. In Iran, 90% of children aged 3-6 years participated in vision screening in 2016, but only those who failed the vision test were subjected to photoscreening.

CONCLUSIONS

In Flanders, the use of Plusoptix photoscreening at ages 1 and 2.5 resulted in an increase of children wearing glasses, but it remains unknown how many cases of amblyopia have been prevented. Studies are needed to determine the relation between size and sort of refractive error and strabismus, and the increased chance to develop amblyopia.

Prevalence of visual impairment in school-going children among the rural and urban setups in the Udupi district of Karnataka, India: A cross-sectional study

AIM

The aim of this study is to estimate the prevalence of visual impairment among school-going children in Udupi district, Karnataka.

MATERIALS AND METHODS

A cross-sectional study across eleven schools from both urban and rural parts of Udupi taluk was conducted to report the magnitude of visual impairment among the schoolchildren. Complex survey design was used in allocating the sample size through stratification and clustering. Totally 1784 schoolchildren between the age groups of 5 and 15 years participated in the study. Presenting visual acuity and objective refraction was measured using computerized logMAR acuity charts and Plusoptix A09 photorefractor, respectively. Manifest ocular deviation or squint was also recorded.

RESULTS

The mean age of the students was found to be 10.62 ± 2.72 years. The prevalence of visual impairment, i.e., visual acuity worse than or equal to 20/40 in the better eye was found to be 4.32% (95% confidence interval: 3.38%, 5.26%). The prevalence rate was significantly higher among students from urban area (5.6%) compared to those from rural area (3.6%) (P = 0.011).

CONCLUSION

Visual impairment was found to be 4.32% in the school-going population of Udupi district. Effective and user-friendly devices aided the visual deficit screening including refractive error and squint.

Effectiveness of the GoCheck Kids Vision Screener in Detecting Amblyopia Risk Factors

PURPOSE

The GoCheck Kids smartphone photoscreening app (Gobiquity Mobile Health, Scottsdale, Arizona, USA), introduced in 2014, is marketed to pediatricians with little published validation. We wished to evaluate the GoCheck Kids Screener for accuracy in detecting amblyopia risk factors (ARF) using 2013 American Association for Pediatric Ophthalmology and Strabismus guidelines.

DESIGN

Validity assessment.

METHODS

Children 6 months to 6 years of age presenting from October 2016 to August 2017 were included. Children were screened with the GoCheck preloaded Nokia Lumia 1020, software version 4.6 with image processing version R4d, prior to undergoing a comprehensive eye examination by a pediatric ophthalmologist masked to the screener results. Determination of the presence of age-specific ARF was made based upon the examination and compared with the GoCheck recommendation.

RESULTS

A total of 206 children were included (average age 43 months). When compared to examination, GoCheck had a sensitivity of 76.0% and specificity of 67.2% in detecting ARF. Positive predictive value was 57.0% and negative predictive value 83.0%. The screener results of 13 children were changed from "no risk factors" to "risk factors identified" based on the GoCheck remote review process. Four images remained "not gradable" and screening was unsuccessful in 3 children.

CONCLUSION

In our high-risk population, this version of the Gocheck Kids smartphone app was useful in identifying ARF in children who are often not able to cooperate with visual acuity testing. This study informs pediatricians about the efficacy of this new screener as they make decisions about how to best detect vision problems in young children.

Tests for detecting strabismus in children aged 1 to 6 years in the community

BACKGROUND

Strabismus (misalignment of the eyes) is a risk factor for impaired visual development both of visual acuity and of stereopsis. Detection of strabismus in the community by non-expert examiners may be performed using a number of different index tests that include direct measures of misalignment (corneal or fundus reflex tests), or indirect measures such as stereopsis and visual acuity. The reference test to detect strabismus by trained professionals is the cover‒uncover test.

OBJECTIVES

To assess and compare the accuracy of tests, alone or in combination, for detection of strabismus in children aged 1 to 6 years, in a community setting by non-expert screeners or primary care professionals to inform healthcare commissioners setting up childhood screening programmes.Secondary objectives were to investigate sources of heterogeneity of diagnostic accuracy.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 12) (which contains the Cochrane Eyes and Vision Trials Register) in the Cochrane Library, the Health Technology Assessment Database (HTAD) in the Cochrane Library (2016, Issue 4), MEDLINE Ovid (1946 to 5 January 2017), Embase Ovid (1947 to 5 January 2017), CINAHL (January 1937 to 5 January 2017), Web of Science Conference Proceedings Citation Index-Science (CPCI-S) (January 1990 to 5 January 2017), BIOSIS Previews (January 1969 to 5 January 2017), MEDION (to 18 August 2014), the Aggressive Research Intelligence Facility database (ARIF) (to 5 January 2017), the ISRCTN registry (www.isrctn.com/editAdvancedSearch); searched 5 January 2017, ClinicalTrials.gov (www.clinicaltrials.gov); searched 5 January 2017 and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 5 January 2017. We did not use any date or language restrictions in the electronic searches for trials. In addition, orthoptic journals and conference proceedings without electronic listings were searched.

SELECTION CRITERIA

All prospective or retrospective population-based test accuracy studies of consecutive participants were included. Studies compared a single or combination of index tests with the reference test. Only those studies with sufficient data for analysis were included specifically to calculate sensitivity and specificity and determine diagnostic accuracy.Participants were aged 1 to 6 years. Studies reporting participants outside this range were included if subgroup data were available.Permitted settings included population-based vision screening programmes or opportunistic screening programmes, such as those performed in schools.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. In brief, two review authors independently assessed titles and abstracts for eligibility and extracted the data, with a third senior author resolving any disagreement. We analysed data primarily for specificity and sensitivity.

MAIN RESULTS

One study from a total of 1236 papers, abstracts and trials was eligible for inclusion with a total number of participants of 335 of which 271 completed both the screening test and the gold standard test. The screening test using an automated photoscreener had a sensitivity of 0.46 (95% confidence interval (CI) 0.19 to 0.75) and specificity of 0.97 (CI 0.94 to 0.99). The overall number affected by strabismus was low at 13 (4.8%).

AUTHORS' CONCLUSIONS

There is very limited data in the literature to ascertain the accuracy of tests for detecting strabismus in the community as performed by non-expert screeners. A large prospective study to compare methods would be required to determine which tests have the greatest accuracy.

Advantages, limitations, and diagnostic accuracy of photoscreeners in early detection of amblyopia: a review

Amblyopia detection is important to ensure proper visual development and avoid permanent decrease of visual acuity. This condition does not produce symptoms, so it is difficult to diagnose if a vision problem actually exists. However, because amblyopia treatment is limited by age, early diagnosis is of paramount relevance. Traditional vision screening (conducted in <3 years) is related with difficulty in getting cooperation from a subject to conduct the eye exam, so accurate objective methods to improve amblyopia detection are necessary. Handheld devices used for photoscreening or autorefraction could offer advantages to improve amblyopia screening because they reduce exploration time to just few seconds, no subject collaboration is needed, and they provide objective information. The purpose of this review is to summarize the main functions and clinical applicability of commercially available devices for early detection of amblyopia and to describe their differences, advantages, and limitations. Although the studies reviewed are heterogeneous (due to wide differences in referral criteria, use of different risk factors, different types of samples studied, etc), these devices provide objective measures in a quick and objective way with a simple outcome report: retest, pass, or refer. However, due to major limitations, these devices are not recommended, and their use in clinical practice is limited.

Accuracy of PlusOptix A09 distance refraction in pediatric myopia and hyperopia

Background

The PlusOptix photoscreeners (PlusOptix GmbH, Nuremberg, Germany) is used in many vision screening programs. The purpose of the present study was to further explore the accuracy of the PlusOptix A09 photoscreener in children with ametropia (myopia or hyperopia).

Methods

A total of 70 eyes (35 children) were prospectively included. Before administration with the cycloplegia treatment 1 % cyclopentolate hydrochloride, children underwent refraction measurement with the PlusOptix A09. A refraction was then performed after cycloplegia with either Retinomax hand-held or Nidek autorefractor before and after 3 years old, respectively.

Results

The median (interquartile range) age was 58 (18 to 86) months. The mean (SD) spherical equivalent differed between PlusOptix A09 and cycloplegic autorefraction (+0.54 [1.82] D vs +1.06 [2.04] D, p = 0.04). PlusOptix A09 refraction was positively correlated with cycloplegic autorefraction (r = 0.81, p < 0.001) with higher coefficient in myopic than in hyperopic children (r = 0.91, p = 0.0002 and r = 0.52, p = 0.01, respectively). The mean (SD) difference between PlusOptix A09 and cycloplegic autorefraction was higher with hyperopia than myopia (0.73 [1.34] vs 0.05 [0.66], p = 0.01). The proportion of children with < 1-D difference between cycloplegic and PlusOptix A09 refraction was 68.8 %, higher with myopia than hyperopia (90 % vs 54.5 %, p = 0.01).

Conclusion

The spherical equivalent value with non-cycloplegic PlusOptix A09 refraction is closer to that with cycloplegic autorefraction than non-cycloplegic autorefraction. The PlusOptix A09 photoscreener underestimated the hyperopia of 0.73 D and slightly overestimated myopia of 0.05 D. The PlusOptix A09 could be used for screening with higher accuracy in myopic than hyperopic children.

Accuracy and Repeatability of Refractive Error Measurements by Photorefractometry

Purpose:

To determine the accuracy of photorefraction and autorefraction as compared to cycloautorefraction and to detect the repeatability of photorefraction.

Methods:

This diagnostic study included the right eyes of 86 children aged 7-12 years. Refractive status was measured using photorefraction (PlusoptiX SO₄, GmbH, Nürnberg, Germany) and autorefraction (Topcon RM800, USA) with and without cycloplegia. Photorefraction for each eye was performed three times to assess repeatability.

Results:

The overall agreement between photorefraction and cycloautorefraction was over 81% for all refractive errors. Photorefractometry had acceptable sensitivity and specificity for myopia and astigmatism. There was no statistically significant difference considering myopia and astigmatism in all comparisons, while the difference was significant for hyperopia using both amblyogenic (P = 0.006) and nonamblyogenic criteria (P = 0.001). A myopic shift of 1.21 diopter (D) and 1.58 D occurred with photorefraction in nonamblyogenic and amblyogenic hyperopia, respectively. Using revised cut-off points of + 1.12 D and + 2.6 D instead of + 2.00 D and + 3.50 D improved the sensitivity of photorefractometry to 84.62% and 69.23%, respectively. The repeatability of photorefraction for measurement of myopia, astigmatism and hyperopia was acceptable (intra-cluster correlation [ICC]: 0.98, 0.94 and 0.77, respectively). Autorefraction results were significantly different from cycloautorefraction in hyperopia (P < 0.0001), but comparable in myopia and astigmatism. Also, noncycloglegic autorefraction results were similar to photorefraction in this study.

Conclusion:

Although photorefraction was accurate for measurement of myopia and astigmatism, its sensitivity for hyperopia was low which could be improved by considering revised cut-off points. Considering cut-off points, photorefraction can be used as a screening method.

Field Evaluation of Automated Vision Screening Instruments: Impact of Referral Criteria Choice on Screening Outcome

PURPOSE

Automated vision screeners can identify children with amblyopia risk factors. Two screening instruments having different referral criteria were evaluated in a community setting: SPOT (Pediavision, Lake Mary, FL) (sensitive manufacturer's referral criteria) and plusoptiX S08 (Plusoptix GmbH, Nuremberg, Germany) (specific modified Arthur referral criteria).

METHODS

All children were screened by SPOT, and referred children were then screened using plusoptiX. Referred children received a gold standard examination to determine whether amblyopia risk factors were present.

RESULTS

A total of 2,801 treatment-naïve children were screened using SPOT. Of these, 307 (11.0%) were referred by SPOT and subsequently screened by plusoptiX; 100 received a gold standard examination. Amblyopia risk factors were present in 43% (43 of 100) referred by SPOT compared to 72.7% (32 of 44) for plusoptiX. Eleven of 56 referred by SPOT had amblyopia risk factors that would have been missed by plusoptiX, including three with mild amblyopia.

CONCLUSIONS

PlusoptiX with modified Arthur referral criteria can be a highly specific screening device detecting amblyopia risk factors without missing children with moderate/severe amblyopia.

Performance of the Plusoptix A09 photoscreener in detecting amblyopia risk factors in Chinese children attending an eye clinic

Purpose

To assess the accuracy of the Plusoptix A09 photoscreener in detecting amblyopia risk factors in children and determine referral criteria when using Plusoptix A09 for a large-scale vision screening.

Methods

Pediatric patients attending our eye clinic underwent a comprehensive ophthalmic examination that included photorefraction, orthoptic examination, anterior segment assessment, fundus examination and cycloplegic retinoscopy. The measurements were collected for statistical analyses.

Results

One hundred and seventy-eight children (mean age ± SD: 6.2±2.4 years, range: 2.2 to 14.1 years) were included in the study. The mean spherical equivalent (SE) obtained using Plusoptix A09 (P_SE) was 0.57 D lower than that obtained from cycloplegic retinoscopy (CR_SE) (P = 0.00). However, there was no statistically significant difference of Jackson cross cylinder J₀ and J₄₅ between Plusoptix A09 (P_J) and cycloplegic retinoscopy (CR_J) (P = 0.14, P = 0.26). The relationship of SE obtained from Plusoptix A09 and SE obtained from cycloplegic retinoscopy was presented as the equation: CR_SE = 0.358 + 0.776 P_SE + 0.064 P_SE² + 0.011 P_SE³. Based on the Receiver Operating Characteristic (ROC) curve, the Plusoptix A09 had an overall sensitivity of 94.9% and specificity of 67.5% for detecting refractive amblyopia risk factors. The sensitivity and specificity of the Plusoptix A09 for detection of strabismus were 40.7% and 98.3%, respectively; detection of amblyopia and/or strabismus was 84.7% and 63.2%, respectively.

Conclusions

The Plusoptix A09 photoscreener underestimated hyperopia and overestimated myopia according to SE when compared with cycloplegic retinoscopy. The accuracy of the Plusoptix A09 in detecting amblyopia risk factors in children could be improved by the regression equation and optimized criteria for refractive amblyopia risk factors developed in the present study. Moreover, the Plusoptix A09 photoscreener is not suitable for a large-scale strabismus screening when it is applied solely.

Photorefraction estimates of refractive power varies with the ethnic origin of human eyes

Eccentric infrared photorefraction is an attractive tool for measuring refractive errors of young children and uncooperative subjects, for it allows quick and non-invasive acquisition of data from both eyes simultaneously over a reasonably large dioptric range. Accuracy of refraction in this technique depends on calibration of luminance slope formed across the pupil into diopters (defocus calibration factor). Commercial photorefractors, like the PowerRef 3™ used in this study, employ an universal defocus calibration factor from one population (Caucasian) to convert raw data of all populations. This study reports significantly larger defocus calibration factors of PowerRef 3™ in 132 East Asian, African and Indian eyes, relative to the machine's default calibration (p < 0.001). The calibration slope of 50 Indian eyes was over-estimated by 64 ± 11% (mean ± 95%CI), vis-à-vis, retinoscopy (p < 0.001). The error reduced to ~6–7% upon rescaling the data using a calibration factor specific for Indian eyes or to that individual (p > 0.9, relative to no over-estimation). Our results therefore strongly suggest the use of an ethnicity- or individual-specific defocus calibration factor for accurate estimation of refraction using photorefraction. Inaccurate refraction estimates due to calibration errors will otherwise severely undermine the advantages of this technique.

Combining automated vision screening with on-site examinations in 23 schools: ReFocus on Children Program 2012 to 2013

PURPOSE

The Association for the Blind and Visually Impaired (ABVI) began the ReFocus on Children Program to assist school nurses in providing vision screening for at-risk children in the Charleston County School District in South Carolina.

METHODS

In 2012 to 2013, 2,750 low-income school children ages 3 to 5 years were screened using the Plusoptix Vision screener (Atlanta, GA). Further examinations were performed on 419 (56%) children referred and glasses prescribed and provided for 192 children (positive predictive value 46%). In 2013, teacher feedback questionnaires were sent to the 23 schools.

RESULTS

Teacher feedback questionnaires had a 49% response rate. Of teachers responding to the questionnaire, 70% reported the children liked wearing their glasses. Teachers provided observations of positive impact, including improved academic performance.

CONCLUSIONS

Nurses appreciated that the entire process was efficient and completed in school, simplifying care and follow-up. The authors encourage partnerships between schools, nonprofit agencies, and healthcare providers to improve screening and access to comprehensive vision care for young children.

Vision screening for children 36 to <72 months: recommended practices

PURPOSE

This article provides recommendations for screening children aged 36 to younger than 72 months for eye and visual system disorders. The recommendations were developed by the National Expert Panel to the National Center for Children's Vision and Eye Health, sponsored by Prevent Blindness, and funded by the Maternal and Child Health Bureau of the Health Resources and Services Administration, United States Department of Health and Human Services. The recommendations describe both best and acceptable practice standards. Targeted vision disorders for screening are primarily amblyopia, strabismus, significant refractive error, and associated risk factors. The recommended screening tests are intended for use by lay screeners, nurses, and other personnel who screen children in educational, community, public health, or primary health care settings. Characteristics of children who should be examined by an optometrist or ophthalmologist rather than undergo vision screening are also described.

RESULTS

There are two current best practice vision screening methods for children aged 36 to younger than 72 months: (1) monocular visual acuity testing using single HOTV letters or LEA Symbols surrounded by crowding bars at a 5-ft (1.5 m) test distance, with the child responding by either matching or naming, or (2) instrument-based testing using the Retinomax autorefractor or the SureSight Vision Screener with the Vision in Preschoolers Study data software installed (version 2.24 or 2.25 set to minus cylinder form). Using the Plusoptix Photoscreener is acceptable practice, as is adding stereoacuity testing using the PASS (Preschool Assessment of Stereopsis with a Smile) stereotest as a supplemental procedure to visual acuity testing or autorefraction.

CONCLUSIONS

The National Expert Panel recommends that children aged 36 to younger than 72 months be screened annually (best practice) or at least once (accepted minimum standard) using one of the best practice approaches. Technological updates will be maintained at http://nationalcenter.preventblindness.org.

The effectiveness of the Spot Vision Screener in detecting amblyopia risk factors

PURPOSE

To evaluate the updated Spot Vision Screener (PediaVision, Welch Allyn, Skaneateles Falls, NY) in detecting amblyopia risk factors using 2013 guidelines of American Association for Pediatric Ophthalmology and Strabismus (AAPOS).

METHODS

In this prospective study, patients seen from June 2012 to November 2013 were tested with the Spot prior to examination by a pediatric ophthalmologist who was masked to test results. The following data were analyzed: age, subject testability, examination findings, and systemic and ocular pathology. Children were divided into three age groups to determine gold standard results according to the AAPOS guidelines.

RESULTS

A total of 444 children (average age, 72 months) were included. Compared to the ophthalmologist's examination, the Spot sensitivity was 87.7% and the specificity was 75.9% in detecting amblyopia risk factors. Sensitivity did not differ significantly between age groups, although the positive predictive value improved in the older age groups.

CONCLUSIONS

In our study cohort, the Spot provided good specificity and sensitivity in detecting amblyopia risk factors according 2013 AAPOS criteria, with minor improvements with updated versions.

Photoscreeners in the pediatric eye office: compared testability and refractions on high-risk children

PURPOSE

To compare refractive data and testability of Spot (PediaVision) and Plusoptix A09 (Plusoptix, Inc) photoscreeners and to compare each device with traditional cycloplegic retinoscopy.

DESIGN

Prospective, interventional case series.

METHODS

After informed consent, patients underwent testing with the Spot and Plusoptix photoscreeners before their examination by a pediatric ophthalmologist masked to the results. Data including testability and estimated refractions were entered into a Research Electronic Data Capture database for statistical analysis.

RESULTS

A total of 265 children were enrolled (mean age, 6.0 ± 3.4 years). Both devices produced a computer printout result in 250 (94.3%) of the patients. The Spot photoscreener provided a refractive estimate in all computer printouts, whereas the Plusoptix, used binocularly, provided a refractive estimate in 75.2% (188/250) of the printouts. Compared with cycloplegic retinoscopy, both devices underestimated hyperopia or overestimated myopia (-1.35 diopters [D] and -0.64 D, Spot and Plusoptix, respectively) and overestimated astigmatism (0.36 D and 0.32 D, Spot and Plusoptix, respectively). The intraclass correlation coefficient for spherical equivalents indicated good agreement between cycloplegic retinoscopy and Spot (0.806) and excellent agreement between cycloplegic retinoscopy and Plusoptix (0.898).

CONCLUSIONS

The Spot photoscreener provided refractive data on a greater percentage of children. The photorefractors correlated with cycloplegic retinoscopy refractive findings for sphere and spherical equivalents, but underestimated hyperopia or overestimated myopia and overestimated astigmatism. The binocular refractions of Plusoptix agreed more closely with the refractions of our pediatric ophthalmologists.

Photoscreeners in the pediatric eye office: compared testability and refractions on high-risk children

PURPOSE

To compare refractive data and testability of Spot (PediaVision) and Plusoptix A09 (Plusoptix, Inc) photoscreeners and to compare each device with traditional cycloplegic retinoscopy.

DESIGN

Prospective, interventional case series.

METHODS

After informed consent, patients underwent testing with the Spot and Plusoptix photoscreeners before their examination by a pediatric ophthalmologist masked to the results. Data including testability and estimated refractions were entered into a Research Electronic Data Capture database for statistical analysis.

RESULTS

A total of 265 children were enrolled (mean age, 6.0 ± 3.4 years). Both devices produced a computer printout result in 250 (94.3%) of the patients. The Spot photoscreener provided a refractive estimate in all computer printouts, whereas the Plusoptix, used binocularly, provided a refractive estimate in 75.2% (188/250) of the printouts. Compared with cycloplegic retinoscopy, both devices underestimated hyperopia or overestimated myopia (-1.35 diopters [D] and -0.64 D, Spot and Plusoptix, respectively) and overestimated astigmatism (0.36 D and 0.32 D, Spot and Plusoptix, respectively). The intraclass correlation coefficient for spherical equivalents indicated good agreement between cycloplegic retinoscopy and Spot (0.806) and excellent agreement between cycloplegic retinoscopy and Plusoptix (0.898).

CONCLUSIONS

The Spot photoscreener provided refractive data on a greater percentage of children. The photorefractors correlated with cycloplegic retinoscopy refractive findings for sphere and spherical equivalents, but underestimated hyperopia or overestimated myopia and overestimated astigmatism. The binocular refractions of Plusoptix agreed more closely with the refractions of our pediatric ophthalmologists.

A comparison of referral criteria used by the plusoptiX photoscreener

PURPOSE

To evaluate the sensitivity, specificity, and predictive value of 7 different referral criteria used for the plusoptiX photoscreener on the same cohort of children.

METHODS

Retrospective chart review of patients presenting to a pediatric ophthalmology clinic who underwent plusoptiX photoscreening as part of a comprehensive examination. We applied multiple referral criteria from previously published studies as well as the manufacturer's criteria in order to calculate specificity, sensitivity, and predictive value differences between the various referral criteria. We compared all criteria to the results of a pediatric ophthalmology examination based upon the 2003 American Association for Pediatric Ophthalmology and Strabismus (AAPOS) criteria, as well as the newly accepted revision of the AAPOS referral criteria.

RESULTS

109 children were examined with a thorough pediatric ophthalmic exam and with the plusoptiX photoscreener. Of these, 58 (53%) were confirmed to demonstrate amblyopia risk factors, according to 2003 AAPOS criteria. The plusoptiX referral criteria were adjusted to match 7 different published plusoptiX referral paradigms so that the differing referral paradigms could be analyzed for sensitivity and specificity. When comparing the differing plusoptiX referral paradigms to 2003 AAPOS criteria, the sensitivity/specificity of the 7 different paradigms were respectively: Matta/Silbert 98%/80%, Arthur (2) 67%/96%, Arnold 81%/96%, Arthur 81%/92%, PediaVision 80%/94%, plusoptiX 98%/41%, AAPOS 74%/86%. When comparing the 7 differing referral paradigms to the newly approved (2013) AAPOS criteria, the sensitivity/specificity were respectively: Matta/Silbert 98%/68%, Arthur (2) 73%/92%, Arnold 92%/90%, Arthur 86%/85%, PediaVision 90%/92%, plusoptiX 98%/35%, AAPOS 87%/87%.

CONCLUSION

There are multiple referral criteria available for the plusoptiX photoscreener. Screening programs need to evaluate their own requirements with respect to desired sensitivity and specificity and decide on the most appropriate referral criteria for their program. The "Arnold" criteria is the best at maximizing sensitivity and specificity utilizing the 2003 "AAPOS" criteria and the "Arnold" and "PediaVision" were best at maximizing sensitivity and specificity for the newly accepted AAPOS referral criteria. Screening programs will need to decide the level of sensitivity and specificity that they wish to obtain, but for most screening programs the "Arnold" criteria may be preferred.

Preschool vision screening: update on guidelines and techniques

PURPOSE OF REVIEW

To discuss the current preschool vision screening (PVS) guidelines and review some of the newest vision screening techniques. The different vision screening practices and barriers to screening are discussed.

RECENT FINDINGS

Vision screening guidelines, which have been developed in response to the advances in technology and increased understanding of the developing visual system, have been recently updated by some of the major medical organizations that endorse vision screening. With advances in vision screening technology, there is a growing trend for screening at younger ages.

SUMMARY

PVS has been widely endorsed by various medical organizations as an effective way to detect preventable and treatable vision problems of childhood. Although PVS is widely recommended, actual screening rates remain low. There are several real and perceived barriers to screening which often prevents successful screening programs. Current vision screening guidelines take into account the recent advances in technology. With the development of new devices, vision screening can effectively be performed at younger ages.

Preschool vision screening in primary care pediatric practice

OBJECTIVES

We determined the efficacy of pediatric-based preschool vision screening, as knowledge of vision screening effectiveness in primary care pediatrics is incomplete.

METHODS

Pediatricians and staff at nine primary care pediatric practices were trained in vision screening, and practices screened children aged 3-5 years from May 2007 through July 2008. Children failing or considered untestable were referred for pediatric ophthalmology examinations. We determined rates of testability, failure, referral, and ophthalmologic examination completion, as well as positive predictive values (PPVs) of screening failure and untestability. We also surveyed practices to assess the ease and accuracy of preschool vision screening.

RESULTS

Of 2,933 children screened, 93 (3.2%) failed the vision screening and 349 (11.9%) were untestable. Untestability was highest (27.1%) among 3-year-olds. The PPV for failing any aspect of the vision screening was 66.7%; for children aged 3, 4, and 5 years, the PPVs for failing were 30.0%, 77.8%, and 87.5%, respectively. However, only 38.7% of children who failed the vision screening received ophthalmologic examinations, despite multiple follow-up attempts. Pediatricians rated the ease and accuracy of screening 3-year-old children lower than for screening older children.

CONCLUSIONS

Visual acuity-based screening had good PPV for vision loss for 4- and 5-year-old children but was less successful for 3-year-olds. Rates of referral and ophthalmologic examination completion were low, especially among children from low-income families.

A comparison of different autorefractors with retinoscopy in children

PURPOSE

To compare the results of different refractive error measurement devices including table-mounted and hand-held autorefractors and videoretinoscopy with cycloplegic retinoscopy (CR) in children to evaluate the usability and reliability of these devices in measuring refractive errors.

METHODS

Two hundred eyes of 100 children underwent autorefraction using table-mounted autorefractor with and without cycloplegia and videoretinoscopy after cycloplegia. All results were compared statistically.

RESULTS

The mean spheric values (SV) and spherical equivalent values (SEV) of the non-cycloplegic table-mounted autorefractor were found to be significantly lower and those of the cycloplegic table-mounted autorefractor were found to be significantly higher than CR results. There was no statistically significant difference in terms of mean SV and SEV between the hand-held autorefractor and CR. Although the mean SV using videoretinoscopy were 0.15 diopters lower than CR, this difference was not significant. Comparing CR with the other refraction methods, all devices correlated with each other. Sensitivity in diagnosing myopia was low for all methods but sensitivity in diagnosing hyperopia and astigmatism was high for table-mounted and hand-held autorefractors. The other reliability parameters were found to be similar for all devices.

CONCLUSIONS

Both videoretinoscopy and hand-held autorefractor can be used in both screening and examination for children as an alternative to CR and table-mounted autorefractor.

Instrument-based pediatric vision screening policy statement

A policy statement describing the use of automated vision screening technology (instrument-based vision screening) is presented. Screening for amblyogenic refractive error with instrument-based screening is not dependent on behavioral responses of children, as when visual acuity is measured. Instrument-based screening is quick, requires minimal cooperation of the child, and is especially useful in the preverbal, preliterate, or developmentally delayed child. Children younger than 4 years can benefit from instrument-based screening, and visual acuity testing can be used reliably in older children. Adoption of this new technology is highly dependent on third-party payment policies, which could present a significant barrier to adoption.

Modification of Plusoptix referral criteria to enhance sensitivity and specificity during pediatric vision screening

PURPOSE

To determine the impact of using several different proposed sets of referral criteria on the specificity and sensitivity of the plusoptiX S08 photoscreener for detecting amblyopia risk factors.

METHODS

During a 2-month period, 144 children ages 9 months to 14 years were screened at the Tennessee Lions Eye Center before receiving a comprehensive eye examination and cycloplegic refraction. Three previously published sets of referral criteria were used for screening, including the manufacturer's criteria and the criteria proposed by Arthur and colleagues, which are nearly identical to the gold standard examination failure thresholds proposed by the Vision Screening Committee of the American Association of Pediatric Ophthalmology and Strabismus (AAPOS). Modifications of these criteria also were evaluated. The screening results obtained by the plusoptiX S08 were compared with the results from the gold standard pediatric ophthalmologic examination, and the respective sensitivities and specificities of each set of referral criteria in detecting amblyopia risk factors identified by the AAPOS Vision Screening Committee were calculated.

RESULTS

The manufacturer's criteria yielded high sensitivity (100%) but very low specificity (37%). The Arthur criteria, which used the values for the AAPOS-defined amblyopia risk factors as referral criteria, maintained sensitivity (89%) and greatly improved specificity (76%). Two modifications of the Arthur criteria further increased specificity with minimal loss of sensitivity.

CONCLUSIONS

The manufacturer's criteria have excellent sensitivity but low specificity, warranting modification; other criteria increase specificity with minimal effect on sensitivity.

Validation of plusoptiX S04 photoscreener as a vision screening tool in children with intellectual disability

PURPOSE

Intellectual disability (ID) is a major public health issue, affecting more than 1% of children worldwide. Pediatric vision screening using standard eye charts may be challenging for children with ID, who may benefit from a quick noninvasive vision screening tool. This study evaluated the accuracy of plusoptiX S04 (Plusoptix Gmbh, Nuremberg, Germany) in detecting amblyopia risk factors in children with ID.

METHODS

Children diagnosed with ID according to age-appropriate psychological tests were examined consecutively. Vision screening was performed using the plusoptiX S04 prior to complete ophthalmological examination, including cycloplegic refraction. Pass/refer screening results was compared with findings of ophthalmological examination. Amblyogenic risk factors were defined according to American Association for Pediatric Ophthalmology and Strabismus referral criteria.

RESULTS

A total of 182 infants and children were examined. Only 3% of children were uncooperative for screening. Ophthalmological examination detected amblyogenic risk factors in 32% of patients. The sensitivity of plusoptiX S04 was 95% (95% CI, 85.6%-98.9%), and specificity was 50% (95% CI, 40.8%-59.1%). The positive predictive value was 47% (95% CI, 37.7%-56.4%) and the negative predictive value was 95.4% (95% CI, 87.1%-99.1%).

CONCLUSIONS

High sensitivity and negative predictive values suggest that the plusoptiX S04 will detect most children with ID who have amblyogenic risk factors, but one-half of all children referred will have no risk factors.

Screening for visual impairment in children ages 1-5 years: update for the USPSTF

CONTEXT

Screening could identify preschool-aged children with vision problems at a critical period of visual development and lead to treatments that could improve vision.

OBJECTIVE

To determine the effectiveness of screening preschool-aged children for impaired visual acuity on health outcomes.

METHODS

We searched Medline from 1950 to July 2009 and the Cochrane Library through the third quarter of 2009, reviewed reference lists, and consulted experts. We selected randomized trials and controlled observational studies on preschool vision screening and treatments, and studies of diagnostic accuracy of screening tests. One investigator abstracted relevant data, and a second investigator checked data abstraction and quality assessments.

RESULTS

Direct evidence on the effectiveness of preschool vision screening for improving visual acuity or other clinical outcomes remains limited and does not adequately address whether screening is more effective than no screening. Regarding indirect evidence, a number of screening tests have utility for identification of preschool-aged children with vision problems. Diagnostic accuracy did not clearly differ for children stratified according to age, although testability rates were generally lower in children 1 to 3 years of age. Treatments for amblyopia or unilateral refractive error were associated with mild improvements in visual acuity compared with no treatment. No study has evaluated school performance or other functional outcomes.

CONCLUSIONS

Although treatments for amblyopia or unilateral refractive error can improve vision in preschool-aged children and screening tests have utility for identifying vision problems, additional studies are needed to better understand the effects of screening compared with no screening.

Screening for refractive errors in children: the plusoptiX S08 and the Retinomax K-plus2 performed by a lay screener compared to cycloplegic retinoscopy

PURPOSE

To evaluate the performance of the autorefractor Retinomax K-plus2 and the photoscreener plusoptiX S08 in measuring refractive errors by comparing them with cycloplegic retinoscopy (CR) and to assess limitations associated with their use.

METHODS

Cross-sectional study to compare data from CR, performed by an orthoptist, to data from Retinomax K-plus2 and plusoptiX S08 performed by a lay screener. Sensitivity and specificity for the detection of significant refractive errors were determined according to American Academy of Pediatric Ophthalmology and Strabismus criteria.

RESULTS

Two hundred children were included, with a mean age of 5.2 ± 2.6 years (3 months to 11 years). Compared to CR, the plusoptiX S08 showed a mean difference of -1.13 ± 1.25 D (95% limits of agreement [LOA], -3.59 to +1.32) for spherical equivalent (SE) and -0.23 ± 0.53 D (LOA, -1.28 to +0.81) for the cylinder. Mean difference for the Retinomax K-plus2 before cycloplegia was -0.08 ± 0.58 D (LOA, -1.23 to +1.06) for SE and 0.03 ± 0.38 D (LOA, -0.72 to +0.78) for the cylinder; after cycloplegia -2.11 ± 1.64 D (LOA, -5.33 to +1.10) for SE and -0.06 ± 0.47 D (LOA, -0.98 to +0.86) for the cylinder. Sensitivity for detecting hyperopia >3.5 D with the plusoptiX S08 was 33.3%, the Retinomax before cycloplegia 31.0% and after cycloplegia 84.6% and high for detecting myopia, astigmatism, and anisometropia.

CONCLUSIONS

Retinomax K-plus2 and plusoptiX S08 have high sensitivity for the detection of myopia, astigmatism, and anisometropia compared to cycloplegic retinoscopy; however, when used without cycloplegia, hyperopia is underestimated.

The accuracy of photoscreening at detecting treatable ocular conditions in children with Down syndrome

BACKGROUND

Children with Down syndrome (DS) have an increased prevalence of ocular disorders, including amblyopia, strabismus, and refractive error. Health maintenance guidelines from the Down Syndrome Medical Interest Group recommend ophthalmologic examinations every 1 to 2 years for these children. Photoscreening may be a cost-effective option for subsequent screening evaluations after an initial complete examination, but no study has evaluated the accuracy of photoscreening in children with DS. The purpose of this study is to determine the sensitivity, specificity, and positive and negative predictive values of photoscreening in detecting treatable ocular conditions in children with DS.

METHODS

Photoscreening and complete ophthalmologic evaluations were performed in 50 consecutive 3- to 10-year-old children with DS. Sensitivity, specificity, and positive and negative predictive values were calculated with the use of ophthalmologic examination findings as the reference standard.

RESULTS

Most children were able to complete photoscreening (94% with Medical Technology and Innovations [MTI] and 90% with Visiscreen OSS-C [VR]). Many children had an identified diagnosis on ophthalmologic examination (n = 46, 92%). Of these, approximately one-half (n = 27, 54%) had one or more condition(s) requiring treatment. Both the MTI and VR photoscreening devices had a sensitivity of 93% (95% confidence interval 0.76-0.99) for detecting treatable ocular conditions. The specificities for the MTI and VR photoscreening were 0.35 (0.18-0.57) and 0.55 (0.34-0.74), respectively.

CONCLUSIONS

Photoscreening is sensitive but less specific at detecting treatable ocular conditions in children with DS. In specific instances, the use of photoscreening in the DS population has the potential to save time and expense related to routine eye examinations, particularly in children with a normal baseline comprehensive examination.

A pilot study evaluating the use of EyeSpy video game software to perform vision screening in school-aged children

PURPOSE

To compare the vision-screening results of school-aged children tested with EyeSpy software and those of children examined by a pediatric ophthalmologist. We also compared combined results of an electronic visual acuity (EVA) tester and stereopsis testing to the results of a professional eye examination.

METHODS

In this pilot study, all children were tested with an EyeSpy and ETDRS EVA tester, followed by ocular examination including stereopsis assessment and cyclopegic refraction. The order of presentation of the EVA and EyeSpy assessments was assigned randomly. The EyeSpy test was performed twice (with an occlusive eyepatch and red-blue dissociative goggles). EyeSpy registered pass or refer results for visual acuity testing at a threshold of 20/32 visual acuity and stereopsis of 300 arcsec. Similar threshold values were used in the EVA/stereopsis testing.

RESULTS

The average age of 72 subjects was 11.4 +/- 2.2 years. Prevalence of visual impairment was 25 (34.7%) of 72 as reported by the professional examination. The sensitivity, specificity, and conventional positive likelihood ratio were 88%, 87%, and 6.8 when EyeSpy was used with a patch; 88%, 74%, and 3.44 when EyeSpy was used with goggles; and 88%, 94%, and 13.79 for EVA/stereospsis, respectively, compared with the gold-standard professional eye examination. EyeSpy screening results using a patch were not significantly different than those of a professional examination (p = 0.508). The 2 results concurred in 63 (87.5%) of 72 subjects.

CONCLUSIONS

EyeSpy software has potential for use as a vision-screening device. The use of EyeSpy with an occlusive patch outperformed EyeSpy with dissociative glasses.