The potential cost-effectiveness of amblyopia screening programs

Cost-effectiveness of screening for amblyopia among kindergarten children in China

Objective

Current cost-effectiveness analyses of amblyopia screening are mainly from western countries. It remains unclear whether it is cost-effective to implement a preschool amblyopia screening programme in China. Our study aimed to evaluate the cost-effectiveness of a hypothetical kindergarten-based amblyopia screening versus non-screening among 3-year-old children.

Methods

We developed a decision tree combined with a Markov model to compare the cost and effectiveness of screening versus non-screening for 3-year-old children from a third-party payment perspective. The primary outcomes were quality-adjusted life years (QALYs) and the incremental cost-effectiveness ratio (ICER). Costs were obtained from expert opinions in different regions of China. Transition probabilities and health utilities were mainly based on published literature and open sources. Sensitivity analyses were performed to assess the impact of parameters' uncertainty on results.

Results

Base-case analysis demonstrated that the ICER of screening versus non-screening was $17,466/QALY, well below the WTP threshold ($38,223/QALY) for China. One-way sensitivity analysis showed that the prevalence of amblyopia, the transition probability per year from untreated amblyopia to healthy, and the discount rate were the top three factors. The likelihood of cost-effectiveness of screening compared with non-screening was 92.56%, according to probabilistic sensitivity analysis. Scenario analysis also indicated that ICER was lower than the WTP threshold even if the time horizon was shortened or the screening was delayed to the age of 4 or 5.

Conclusions

Amblyopia screening could be considered a cost-effective strategy compared to non-screening for 3-year-old children in China. Screening for children at the age of 4 or 5 may even yield better results.

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.

The cost-effectiveness of different visual acuity screening strategies in three European countries: A microsimulation study

Childhood vision screening programmes in Europe differ by age, frequency and location at which the child is screened, and by the professional who performs the test. The aim of this study is to compare the cost-effectiveness for three countries with different health care structures.

We developed a microsimulation model of amblyopia. The natural history parameters were calibrated to a Dutch observational study. Sensitivity, specificity, attendance, lost to follow-up and costs in the three countries were based on the EUSCREEN Survey. Quality adjusted life-years (QALYs) were calculated using assumed utility loss for unilateral persistent amblyopia (1%) and bilateral visual impairment (8%). We calculated the cost-effectiveness of screening (with 3.5% annual discount) by visual acuity measurement at age 5 years or 4 and 5 years in the Netherlands by nurses in child healthcare centres, in England and Wales by orthoptists in schools and in Romania by urban kindergarten nurses. We compared screening at various ages and with various frequencies.

Assuming an amblyopia prevalence of 36 per 1,000 children, the model predicted that 7.2 cases of persistent amblyopia were prevented in the Netherlands, 6.6 in England and Wales and 4.5 in Romania. The cost-effectiveness was €24,159, €19,981 and €23,589, per QALY gained respectively, compared with no screening. Costs/QALY was influenced most by assumed utility loss of unilateral persistent amblyopia. For all three countries, screening at age 5, or age 4 and 5 years were optimal.

Despite differences in health care structure, vision screening by visual acuity measurement seemed cost-effective in all three countries.

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.].

Canon CP-TX1 camera - As a screening tool for amblyogenic risk factors

Purpose:

To evaluate the Canon CP-TX1 camera as a screening tool for ARFs in a pediatric population and estimate the prevalence of ARFs.

Methods:

In a pediatric outpatient space, largely in the immunization clinic, after obtaining parental consent, we encouraged children to be photographed from a distance of 5 feet in a dim room by using a CP-TX1 camera with the red-eye reduction feature off. Based on the captured red reflex, children were labeled as normal (symmetrical red reflexes in the two eyes, with no visible crescents); all others were considered as abnormal or positive for ARFs. All photographed children were assessed by an optometrist/refractionist for VA by age-appropriate methods. Data were entered into a 2 × 2 contingency table on statpages.org, and diagnostic indices were calculated with 95%CI.

Results:

With a sample of 262 children, we obtained a sensitivity of 0.82, a specificity of 0.98, a positive predictive value of 0.92, a negative predictive value of 0.94, a positive likelihood ratio of 41.06, a negative likelihood ratio of 0.17, and a prevalence of 0.24 for ARFs

Conclusion:

CP-TX1 performed well as a screening tool to identify ARFs in children. Placing such a camera in an immunization clinic offers a chance to identify children with ARFs at a time when amblyopia is eminently reversible.

The Utility of Universal Newborn Eye Screening: A Review

Universal newborn eye screening can identify ocular abnormalities early and help mitigate long-term visual impairment. Traditional neonatal and infant eye screening is administered by neonatologists and pediatricians using the red reflex test. If this test identifies an ocular abnormality, then the patient is examined by an ophthalmologist. Notably, the red reflex test may be unable to detect amblyogenic posterior segment pathology. Recent studies using fundus imaging and telemedicine show reduced cost of human resources and increased sensitivity compared with traditional approaches. In this review, the authors discuss universal newborn eye screening pilot programs with regard to disease prevalence, referral-warranted disease, and cost-effectiveness. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:S6-S16.].

Development of Refractive Parameters in 3- to 6-Year-Old Children and Its Application in Myopia Prediction and Intervention Guidance

OBJECTIVE

To investigate refractive development and prevalence of myopia in children aged 3-6 years in Hebei Province, China, and to explore the developmental law of refraction, so as to clinically guide the prediction and intervention of myopia.

METHODS

In May 2019, a total of 6120 people were inspected in 68 kindergartens in 11 cities in Hebei Province. Child refractive refraction was checked under noncycloplegia using a handheld binocular vision screener (SW-800, SUOER, Tianjin, China). Axial length (AL) and corneal radius of curvature (CR) were measured using an ocular biometry (IOLMaster 500, Carl Zeiss, Germany). Myopia was defined as spherical equivalent (SE) ≤ -0.75 D.

RESULTS

A total of 5506 children aged 3-6 years met the criteria and were included in the statistical analysis. The prevalence of myopia was 3.49% (1.93% at age 3, 2.90% at age 4, 3.78% at age 5, and 3.88% at age 6). Overall, the mean SE was +0.67 ± 1.05 D (+0.81 ± 1.00 D at age 3, +0.79 ± 1.05 D at age 4, +0.67 ± 1.08 D at age 5, and +0.13 ± 1.01 D at age 6); the mean CR was 7.76 ± 0.26 mm (7.78 ± 0.26 mm at age3, 7.75 ± 0.25 mm at age 4, 7.77 ± 0.26 mm at age 5, and 7.76 ± 0.25 mm at age 6); the mean AL was 22.31 ± 0.73 mm (21.98 ± 0.63 mm at age 3, 22.12 ± 0.69 mm at age 4, 22.34 ± 0.73 mm at age 5, and 22.49 ± 0.73 mm at age 6).

CONCLUSIONS

Prevalence of myopia increases with age in children aged 3-6 years in Hebei, China. With the increase of age, CR is basically stable, and AL increases gradually. AL/CR, which is closely related to SE, can be used as an indicator to predict myopia and guide clinical work.

Economic evaluations of vision screening to detect amblyopia and refractive errors in children: a systematic review

OBJECTIVE

To synthesize and appraise economic evaluations of vision screening to detect vision impairment in children.

METHODS

Literature searches were conducted on seven electronic databases, grey literature, and websites of agencies conducting health technology assessments. Studies were included if they (1) were full, comparative economic evaluations that used cost-utility, cost-benefit, cost-effectiveness, cost-consequence, or cost-analysis methods; (2) described screening services designed to detect amblyopia, strabismus, or uncorrected refractive errors in children under 6 years of age; and (3) published after 1994. High-quality studies were synthesized descriptively. Currencies were reported in 2019 Canadian dollars. Quality was assessed with the Pediatric Quality Appraisal Questionnaire (PQAQ).

RESULTS

Vision screening services were conducted by paid staff, volunteers, or health care professionals in schools or clinics. Thirteen studies were published from five countries: China (n = 1), United States (n = 4), United Kingdom (n = 1), Canada (n = 1), and Germany (n = 6). Analytical techniques included cost-utility/cost-effectiveness combination (n = 2), cost-effectiveness analysis (n = 7), cost-utility analysis (n = 1), cost-benefit analysis (n = 1), cost-consequence analysis (n = 1), and cost analysis (n = 1). Incremental cost-effectiveness ratios ranged from C$1,056 to C$151,274 per additional case detected/prevented and from C$9,429 to C$30,254,703 per additional QALY gained, depending on the type of screening service and comparator. Six studies were determined to be of high quality.

CONCLUSION

Vision screening to detect amblyopia for young children may be cost-effective compared with no screening if amblyopia reduced quality of life. Studies varied significantly in the type of screening services and comparators used. Methodological limitations were common. Future studies would be aided immensely by prospective studies on the impact of amblyopia on the health-related quality of life of young children and guidelines on the effective conduct of vision screening.

The Economic Burden of Vision Loss and Blindness in the United States

PURPOSE

To estimate the economic burden of vision loss (VL) in the United States and by state.

DESIGN

Analysis of secondary data sources (American Community Survey [ACS], American Time Use Survey, Bureau of Labor Statistics, Medical Expenditure Panel Survey [MEPS], National and State Health Expenditure Accounts, and National Health Interview Survey [NHIS]) using attributable fraction, regression, and other methods to estimate the incremental direct and indirect 2017 costs of VL.

PARTICIPANTS

People with a yes response to a question asking if they are blind or have serious difficulty seeing even when wearing glasses in the ACS, MEPS, or NHIS.

MAIN OUTCOME MEASURES

We estimated the direct costs of medical, nursing home (NH), and supportive services and the indirect costs of absenteeism, lost household production, reduced labor force participation, and informal care by age group, sex, and state in aggregate and per person with VL.

RESULTS

We estimated an economic burden of VL of $134.2 billion: $98.7 billion in direct costs and $35.5 billion in indirect costs. The largest burden components were NH ($41.8 billion), other medical care services ($30.9 billion), and reduced labor force participation ($16.2 billion), all of which accounted for 66% of the total. Those with VL incurred $16 838 per year in incremental burden. Informal care was the largest burden component for people 0 to 18 years of age, reduced labor force participation was the largest burden component for people 19 to 64 years of age, and NH costs were the largest burden component for people 65 years of age or older. New York, Connecticut, Massachusetts, Rhode Island, and Vermont experienced the highest costs per person with VL. Sensitivity analyses indicate total burden may range between $76 and $218 billion depending on the assumptions used in the model.

CONCLUSIONS

Self-reported VL imposes a substantial economic burden on the United States. Burden accrues in different ways at different ages, leading to state differences in the composition of per-person costs based on the age composition of the population with VL. Information on state variation can help local decision makers target resources better to address the burden of VL.

Prediction and cost-effectiveness comparison of amblyopia screening methods at ages 3-4 years

PURPOSE

Compare the performance of different amblyopia screening tests.

METHODS

Based on exploratory factor analyses (EFA) of different screening tests performed in 3295 children, we created models of screening strategies in a matrix with: uncorrected visual acuity (UCVA), Plusoptix measurements (PO), Randot Stereo-test (SR), and Cover-Test (CT). Receiver Operating Characteristic (ROC) curves and confusion matrix were used to compare performance of different model's algorithm to predict new diagnosis of amblyopia. Estimated screening costs per screened and treated child were compared.

RESULTS

Regression analyses revealed that, although all models predicted amblyopia (all p < 0.001), only models including PO or UCVA had higher prediction capacity (R² > 0.4) and better discriminating ROC curves (AUC > 0.95; p < 0.001). For 96% sensitivity, UCVA + PO was the most cost-effective model, since the estimated average screening costs per treated child, almost doubled and tripled if using PO or UCVA alone, respectively, versus using both exams. When UCVA + PO is not possible to implement, adding SR to either UCVA or PO resulted in cost-savings of 28% and 18%, respectively.

CONCLUSIONS

In a previous unscreened population, aged 3-4 years, screening programs using either UCVA or PO alone, should reconsider doing both tests simultaneously, since, for a high level of sensitivity, using simultaneously UCVA + PO is more cost-effective, per screened, and treated amblyopia. Concerns relating higher time-consuming exams for the combination of UCVA + PO should be surpassed, since costs per treated child drop considerably. When children benefit from good primary-care routine examinations since birth, no benefit was found for using CT in a screening setting. SR showed little benefit.

Costs and effects of conventional vision screening and photoscreening in the Dutch preventive child health care system

Background

Little is known about costs and effects of vision screening strategies to detect amblyopia. Aim of this study was to compare costs and effects of conventional (optotype) vision screening, photoscreening or a combination in children aged 3–6 years.

Methods

Population-based, cross-sectional study in preventive child health care in The Hague. Children aged 3 years (3y), 3 years and 9 months (3y9m) or 5–6 years (5/6y) received the conventional chart vision screening and a test with a photoscreener (Plusoptix S12C). Costs were based on test duration and additional costs for devices and diagnostic work-up.

Results

Two thousand, one hundred and forty-four children were included. The estimated costs per child screened were €17.44, €20.37 and €6.90 for conventional vision screening at 3y, 3y9m and 5/6y, respectively. For photoscreening, these estimates were €6.61, €7.52 and €9.40 and for photoscreening followed by vision screening if the result was unclear (combination) €9.32 (3y) and €9.33 (3y9m). The number of children detected with amblyopia by age were 9, 14 and 5 (conventional screening), 6, 13 and 3 (photoscreening) and 10 (3y) and 15 (3y9m) (combination), respectively. The estimated costs per child diagnosed with amblyopia were €1500, €1050 and €860 for conventional vision screening, €860, €420 and €1940 for photoscreening and €730 (3y) and €450 (3y9m) for the combination.

Conclusions

Combining photoscreening with vision screening seems promising to detect amblyopia in children aged 3y/3y9m, whereas conventional screening seems preferable at 5/6y. As the number of study children with amblyopia is small, further research on the effects of these screening alternatives in detecting children with amblyopia is recommended.

Cost comparison between botulinum neurotoxin and surgery in the treatment of infantile esotropia in a tertiary public hospital

Objective

To compare the cost implications of botulinum neurotoxin (BNT) injection to surgery in infantile esotropia (IE) in a public/government funded hospital.

Methods and analysis

A simple costing comparison was undertaken for a randomised clinical trial in IE. Patients were randomised to receive either BNT or standard surgery. The participants in the BNT arm were further subdivided into subgroups based on their age in months and degree of esotropia in prism dioptres (PD) at presentation: G1 ≤60 PD/24 months, G2 ≤24 months/>60 PD, G3 >24 months/≤60 PD, G4 >24 months/>60 PD. The costs were calculated for each arm from primary treatment to eventual satisfactory outcome defined as orthophoria or microtropia (≤10 PD). A bottom-up costing analysis was done for single and multiple procedures for each arm. Comprehensive variable costs as well as fixed costs were calculated at each point of intervention and expressed in local currency ZAR (US$1=ZAR15.00). Costing was analysed for surgery and BNT subgroups (based on clinical success).

Results

There were 101 patients enrolled in the trial. 54 in the BNT arm and 47 in the surgery arm. Cost for single surgery and single BNT was ZAR 7743.04 and 1713.14, respectively. A favourable clinical outcome was achieved in 72% of surgery arm and 37% of BNT arm. The mean cost for eventual favourable outcome in BNT arm was ZAR9158.08 and in surgery arm ZAR9124.27 (p=0.26). Mean cost in G1 was ZAR6328.45, in G2 ZAR7197.45, in G3 ZAR11891.93 and G4 ZAR12882.44 (p=0.018).

Conclusion

BNT has a cost-benefit in IE and is a viable option in the primary treatment of IE in resource constrained regions. Clinical outcomes and economic benefit in smaller angle of esotropia and younger patients are comparable to surgery.

Mandated Kindergarten Eye Examinations in a US Suburban Clinic: Is It Worth the Cost?

Purpose

The state of Illinois has required an examination by an optometrist or ophthalmologist prior to mandatory kindergarten since 2008. This requirement has allowed us to gather information regarding disease prevalence in a local suburban population.

Methods

A retrospective chart review was undertaken of kindergarten eye examinations performed at the Wheaton Eye Clinic between September 2008 and February 2017. Inclusion criteria included school eye examination as a reason for the visit, and a cycloplegic refraction was completed.

Results

Of 3612 patient charts identified, 1085 satisfied the inclusion criteria, of which 48% were female. The average age of the patients was 5.3 years (range, 3.8 to 6.7). Historical characteristics showed 143 (13%) were premature, 28 (3%) patients were autistic and 109 (10%) were developmentally delayed. On examination, 56 (5%) had <20/40 (WHO mild visual impairment) vision in better seeing eye, 34 (3%) had spherical equivalent refractive error in either eye > +3.50 diopters and one < −3.00 diopters. Fifty-eight patients (5%) were diagnosed with amblyopia and 101 patients (9.3%) were given glasses. Abnormal external exam finding was found in 218 (20%) while 16 (1.5%) had an abnormal fundus finding. Thirteen percent (146/1085) had a clinically relevant diagnosis in our examinations, with a cost of $1635/diagnosis. In total, our follow-up rate was 83% (78/94).

Conclusion

Our rate of treatable ocular conditions discovered via state-mandated kindergarten eye examinations is similar to large-scale screening programs. The cost per condition found with full examinations was substantially higher; however, follow-up was more consistent.

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Amblyopia screening effectiveness at 3-4 years old: a cohort study

Objective

To study the effectiveness of amblyopia screening at ages 3-4.

Methods and Analysis

From a population with no previous screening, a cohort of 2300 children with 3-4 years old attending school (91% of children this age attend school in Portugal), were submitted to a complete ophthalmological evaluation. Amblyopia was diagnosed, treated and followed. Amblyopia prevalence, treatment effectiveness, absolute risk reduction (ARR), number needed to screen (NNS) and relative risk reduction (RRR) were estimated.

Results

Past/present history of amblyopia was higher than 3.1%-4.2%, depending on amblyopia definition normatives. Screening at age 3-4, had estimated ARR=2.09% (95% CI 1.50% to 2.68%) with a reduced risk of amblyopia in adulthood of 87% (RRR). NNS was 47.8 (95% CI 37.3 to 66.7). Treatment effectiveness of new diagnosis was 88% (83% if we include children already followed). 91% of new amblyopia diagnoses were refractive (of which 100% surpassed amblyopia Multi-Ethnic Pediatric Eye Disease Study criteria after treatment), while most strabismic amblyopias were already treated or undertreatment. Only 30% of children with refractive amblyopia risk factors that were not followed by an ophthalmologist, ended up having amblyopia at age 3-4. Eye patch was needed equally in new-diagnosis versus treated-earlier refractive amblyopia.

Conclusions

Screening amblyopia in a whole-population setting at age 3-4 is highly effective. For each 48 children screened at age 3-4, one amblyopia is estimated to be prevented in the future (NNS). Screening earlier may lead to overdiagnosis and overtreatments: Treating all new diagnosis before age 3-4 would have a maximal difference in ARR of 0.3%, with the possible burden of as much as 70% children being unnecessary treated before age 3-4.Involving primary care, with policies for timely referral of suspicious/high-risk preverbal children, plus whole screening at age 3-4 seems a rational/effective way of controlling 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.

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.

Successes and shortfalls of community Plusoptix photoscreening: results from the iSee study in Southwestern Ontario

OBJECTIVE

The purpose of this work is to provide the final results from a community-wide photoscreening program in Southwestern Ontario for children aged 18 to 72 months, and to estimate the prevalence of amblyogenic risk factors in this population.

STUDY DESIGN

Prospective, multisite photoscreening program.

PARTICIPANTS

5959 children aged 18-72 months were recruited and screened in Southwestern Ontario at 210 locations over a period of 3 years and 4 months.

METHODS

Ophthalmic screening examinations were performed with the Plusoptix S12 photoscreener. The threshold for the referral criteria used was the manufacturer's criteria on receiver operating characteristics 4.

RESULTS

The screening was negative in 5386 children (90.4%), positive in 403 (6.8%), and unreadable in 170 (2.9%); 42% of all screened children were ≤36 months old. The estimated amblyogenic risk factor prevalence of anisometropia was 4.0%, astigmatism was 3.1%, hyperopia was 1.1%, myopia was 0.4%, and strabismus was 0.4%. Of the 403 referred children, 99 (24.5%) completed a formal eye examination based on the responses returned to the study site.

CONCLUSIONS

This is the first Canadian study that provides data on amblyogenic risk factors based on a volunteer-led photoscreening program. Photoscreening is an effective screening tool, particularly for pre-school-aged children; however, the lack of mandatory follow-up to ensure that children receive proper treatment based on cycloplegic refraction reduces the efficacy of screening.

Comparison of Photoscreening to Chart Methodology for Vision Screening

The goal of this study is to assess the referral rate accuracy of photoscreening versus the chart methodology in identifying preschool children at risk of amblyopia and amblyogenic refractive error. Vision screenings using the plusoptiX S12 and the LEA chart were performed on 127 children, aged 3-5 years old. Comprehensive eye exams were performed after screenings. The sensitivity and specificity of the plusoptiX S12 were 80.3% and 92.1% and the LEA chart were 43.6% and 94.8%, respectively. The sensitivity of the plusoptiX S12 is significantly higher than the LEA (p value: <.001). After eye exams, 82.9% were correctly passed by the plusoptiX S12 and 64% were correctly passed by the LEA chart (p value: .009). Objective photoscreening is significantly more accurate in identifying preschool children at risk of developing amblyopia and should be considered best practice. The chart methodology provides an inaccurate report on a preschool child's amblyopic risk.

Vision photoscreening of infants and young children in a primary care pediatric office: can it identify asymptomatic treatable amblyopic risk factors?

OBJECTIVE

The purpose of this study was to assess the feasibility and accuracy of vision photoscreening a large cohort of asymptomatic children age 6 months to 6 years.

METHODS

Photoscreening was performed at the 6 and 18 months and annually at the 2- to 5-year scheduled pediatric health assessment visits.

RESULTS

A total of 1976 children underwent photoscreening for amblyopic risk factors during an 18-month period; 167 of them (8.5%) screened positive. Of the 94 study children who were evaluated by a pediatric ophthalmologist, 25 required intervention at their initial visit (26.6%). Ten children were diagnosed with amblyopia, representing 0.5% of all children screened.

CONCLUSION

Vision photoscreening of 1976 young children identified 10 with previously undiagnosed amblyopia and an additional 15 with treatable pre-amblyopic risk factors. It is unlikely that any of these children with serious refractive errors would have been detected without the use of in-office vision photoscreening.

The W.H.E.E.L.S. Preschool Vision Screening Program's Initial Outcomes for 12,402 Children Screened Using the Plusoptix Photoscreener

Objective. To report the results of the W.H.E.E.L.S. Prevent Blindness Mid-Atlantic vision screening program that targets preschoolers using the Plusoptix Photoscreener (Plusoptix Inc., Nuremburg, Germany). Methods. Trained program staff members conducted vision screenings at up to 113 preschool programs in the Richmond metropolitan area for four consecutive years; a cross-sectional analysis was performed. Results and Discussion. From September 2010 to March 2014, 15,075 preschoolers have been offered a free vision screening; 12,402 (82%) have been screened. A total of 3,018 (24%) have failed the screening and were recommended to follow up with an eye care specialist for a comprehensive examination; only 30% reported complying. Significant refractive errors were more frequently the cause for a failed screening. Conclusions. The W.H.E.E.L.S. program has identified a high number of preschoolers with significant amblyopic risk factors that were previously unknown to be present. Undesirably low follow-up reporting outcomes from children who fail a vision screening examination were consistent with other reports. Nevertheless, having a mobile vision screening program that uses photoscreening technology in targeting children prior to school entry is an efficient and cost-effective way to detect vision disorders in a timely manner.

The economic burden of vision loss and eye disorders among the United States population younger than 40 years

OBJECTIVE

To estimate the economic burden of vision loss and eye disorders in the United States population younger than 40 years in 2012.

DESIGN

Econometric and statistical analysis of survey, commercial claims, and census data.

PARTICIPANTS

The United States population younger than 40 years in 2012.

METHODS

We categorized costs based on consensus guidelines. We estimated medical costs attributable to diagnosed eye-related disorders, undiagnosed vision loss, and medical vision aids using Medical Expenditure Panel Survey and MarketScan data. The prevalence of vision impairment and blindness were estimated using National Health and Nutrition Examination Survey data. We estimated costs from lost productivity using Survey of Income and Program Participation. We estimated costs of informal care, low vision aids, special education, school screening, government spending, and transfer payments based on published estimates and federal budgets. We estimated quality-adjusted life years (QALYs) lost based on published utility values.

MAIN OUTCOME MEASURES

Costs and QALYs lost in 2012.

RESULTS

The economic burden of vision loss and eye disorders among the United States population younger than 40 years was $27.5 billion in 2012 (95% confidence interval, $21.5-$37.2 billion), including $5.9 billion for children and $21.6 billion for adults 18 to 39 years of age. Direct costs were $14.5 billion, including $7.3 billion in medical costs for diagnosed disorders, $4.9 billion in refraction correction, $0.5 billion in medical costs for undiagnosed vision loss, and $1.8 billion in other direct costs. Indirect costs were $13 billion, primarily because of $12.2 billion in productivity losses. In addition, vision loss cost society 215 000 QALYs.

CONCLUSIONS

We found a substantial burden resulting from vision loss and eye disorders in the United States population younger than 40 years, a population excluded from previous studies. Monetizing quality-of-life losses at $50 000 per QALY would add $10.8 billion in additional costs, indicating a total economic burden of $38.2 billion. Relative to previously reported estimates for the population 40 years of age and older, more than one third of the total cost of vision loss and eye disorders may be incurred by persons younger than 40 years.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

The Bruckner test variant (BTV): a promising instrument in detecting vision disorders

BACKGROUND AND PURPOSE

In the Netherlands, children are screened for amblyopia based on the early detection of visual disorders (VOV) protocol by child health care physicians. The positive predictive value (PPV) of the Brückner test variant (BTV) as an alternative method was assessed.

PATIENTS AND METHODS

In this historical prospective analysis, the results of the VOV and BTV methods were compared. Results at the ages of 15 and 27 months of 414 children were compared against diagnosis by the ophthalmologist; follow-up was at 72 months.

RESULTS

Visual disorders were found in 12 of 15 children (14 had an abnormal BTV) who underwent ophthalmological examination. The PPV of the BTV was 86%; 12 of the 14 children with an abnormal BTV had a vision disorder in the preverbal phase.

CONCLUSION

The BTV is superior to the VOV method in the early detection of vision disorders and could be a cost-effective public health intervention.