Impact of Persisting Amblyopia on Socioeconomic, Health, and Well-Being Outcomes in Adult Life: Findings From the UK Biobank.

OBJECTIVES: This study aimed to investigate associations between persisting amblyopia into adulthood and its "real-life" impacts and inform the current debate about the value of childhood vision screening programs. METHODS: Associations between persisting amblyopia and diverse socioeconomic, health, and well-being outcomes were investigated in multivariable-adjusted (sex, age, ethnicity, deprivation) regression models, with 126 400 participants (aged 40-70 years) of the UK Biobank with complete ophthalmic data. Analysis by age group (cohort 1, 60-70 years; cohort 2, 50-59 years; cohort 3, 40-49 years) assessed temporal trends. RESULTS: Of 3395 (3%) participants with confirmed amblyopia, overall 77% (2627) had persisting amblyopia, declining from 78% in cohort 1 to 73% in cohort 3. The odds of persisting amblyopia were 5.91 (5.24-6.66) and 2.49 (2.21-2.81) times greater in cohort 1 and cohort 2, respectively, than cohort 3. The odds were also higher for more socioeconomically deprived groups and for white ethnicity. Reduced participation in sport, adverse general and mental health, and well-being were all independently associated with persisting amblyopia, with the strongest associations in the youngest cohorts. Associations with lower educational attainment and economic outcomes were only evident in the oldest cohort. CONCLUSIONS: There has been a decline in the overall frequency of persisting amblyopia since the introduction of universal child vision screening in the United Kingdom. Nevertheless, most adults treated for amblyopia in childhood have persisting vision deficits. There was no evidence that persisting amblyopia has vision-mediated effects on educational, employment-related, or economic outcomes. The observed adverse outcomes were largely those not directly mediated by vision. Patients undergoing treatment should be counseled about long-term outcomes.

Validation and cost-effectiveness of a home-based screening system for amblyopia.

PURPOSE: To investigate the cost-effectiveness of a novel home-based screening system for amblyopia and amblyogenic risk factors. DESIGN: Evaluation of diagnostic test or technology. PARTICIPANTS: Two thousand four hundred forty-two preschoolers 3 to 6 years of age from 10 kindergartens randomly selected from Guangzhou participated in the study in 2009. METHODS: Preschoolers were assessed for amblyopia and amblyogenic risk factors by their parents using the home-based screening system and were re-evaluated by professionals who conducted a comprehensive eye examination. MAIN OUTCOME MEASURES: Sensitivity, specificity, positive predictive value, negative predictive value, and the cost-benefit of the home-based screening system were calculated by comparing the results from the home-assessed model and those from the professional evaluation. RESULTS: Three thousand three hundred children were invited to participate in the study, and 2308 (1216 boys and 1092 girls) completed all of the procedures. Twenty-four amblyopes were found by professional examinations. Fifteen of these amblyopes had not been diagnosed previously, and 12 of them were detected by the home-assessment model. The sensitivity, specificity, positive predictive value, and negative predictive value were 80.0%, 94.1%, 8.2%, and 99.9%, respectively. Professional examinations cost an average of US $1131.00 per case of amblyopia detected, whereas the cost was only US $266.00 per case for the home-based method. For amblyogenic factors, 50, 87, and 96 children were classified into grade I, II, or III according to the professional examinations. The corresponding numbers in the home-based system were 23, 29, and 15, respectively. Accordingly, the true positive rates were 46.0%, 33.3%, and 15.6% for each grade. CONCLUSIONS: The home-based amblyopia screening system was found to be a simple, effective, and cost-beneficial method for amblyopia screening and amblyogenic risk factors. The approach offers a practical option for developing areas with large populations. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

The potential cost-effectiveness of amblyopia screening programs.

PURPOSE: To estimate the incremental cost-effective-ness of amblyopia screening at preschool and kindergarten, the costs and benefits of three amblyopia screening scenarios were compared to no screening and to each other: (1) acuity/stereopsis (A/S) screening at kindergarten, (2) A/S screening at preschool and kindergarten, and (3) photoscreening at preschool and A/S screening at kindergarten. METHODS: A probabilistic microsimulation model of amblyopia natural history and response to treatment with screening costs and outcomes estimated from two state programs was programmed. The probability was calculated that no screening and each of the three interventions were most cost-effective per incremental quality-adjusted life year (QALY) gained and case avoided. RESULTS: Assuming a minimal 0.01 utility loss from monocular vision loss, no screening was most cost-effective with a willingness to pay (WTP) of less than $16,000 per QALY gained. A/S screening at kindergarten alone was most cost-effective at a WTP between $17,000 and $21,000. A/S screening at preschool and kindergarten was most cost-effective at a WTP between $22,000 and $75,000, and photoscreening at preschool and A/S screening at kindergarten was most cost-effective at a WTP greater than $75,000. Cost-effectiveness substantially improved when assuming a greater utility loss. All scenarios were cost-effective when assuming a WTP of $10,500 per case of amblyopia cured. CONCLUSION: All three screening interventions evaluated are likely to be considered cost-effective relative to many other potential public health programs. The choice of screening option depends on budgetary resources and the value placed on monocular vision loss prevention by funding agencies.

The economic value added (EVA) resulting from medical care of functional amblyopia, strabismus, (pathologies of binocular vision) and asthma.

INTRODUCTION: Value analysis in health care calculates the economic value added (EVA) that results from improvements in health and health care. Our purpose was to develop an EVA model and to apply the model to typical and hypothetical (instantaneous and perfect) cures for amblyopia, surgical strabismus and asthma, as another, but non-ophthalmological disease standard for comparison, in the United States. METHODS: The model is based on changes in utility and longevity, the associated incremental costs, and an estimate of the value of life. Univariate sensitivity analyses were performed to arrive at a plausible range of outcomes. RESULTS: For the United States, the EVA for current practice amblyopia care is 12.9B dollars (billion) per year, corresponding to a return on investment (ROI) of 10.4% per yr. With substantial increases in investment aimed at maximal improvement ("perfect cure"), the EVA is 32.7B per yr, with ROI of 5.3% per yr. The EVA for typical surgical strabismus care is 10.3B per yr. A perfect cure may yield EVA of 9.6B per yr. The EVA for asthma is 1317B per yr (ROI 20.4% per yr.., while a perfect cure may yield EVA of 110 B per yr. Sensitivity analysis demonstrated the relatively large effects of incidence, utility, and longevity, while incremental costs have a relatively minor effect on the EVA. CONCLUSION: The economic value added by improvements in patient-centered outcomes is very large. Failing to make the necessary investments in research, prevention, detection, prompt treatment and rehabilitation of these diseases, at virtually any conceivable cost, appears economically, medically, morally and ethically deficient and consequently wasteful at very least economically for our society.

Vision screening in preschool children: do the data support universal screening?

BACKGROUND: Comprehensive, systematic reviews on the benefit of vision screening in preschool children were published in 2008 by major national organizations in both Germany and the United Kingdom. These reviews raised public interest in the topic. METHODS: This article contains a discussion of the sensitivity, specificity, efficacy, and cost-effectiveness of preschool vision screening, on the basis of the two national reports mentioned above as well as relevant literature retrieved by a selective PubMed search. RESULTS: All studies that have been published to date on the efficacy of preschool visual screening suffer from methodological flaws. The available data suggest a benefit from screening, though this has not been proven. Model calculations reveal that the positive predictive value of screening tests performed in isolation is inadequate. The authors of the two national reports applied different methods and arrived at similar, but not identical conclusions. Preschool vision screening may also be cost-effective; whether this is the case or not depends on the probability of a long-term benefit--specifically, on the probability of preventing bilateral loss of vision in adulthood. To prevent one such case, it is estimated that 13 cases of childhood amblyopia must be identified and successfully treated (number needed to treat [NNT] = 13). CONCLUSION: The available data do not allow any firm conclusion about the efficacy and cost-effectiveness of preschool vision screening. Further clinical studies are needed to answer these questions.

An audit of the outcome of amblyopia treatment: a retrospective analysis of 322 children.

BACKGROUND/AIMS: Little is known about the effectiveness of occlusion therapy in hospital settings. A retrospective analysis was conducted to assess modalities, outcome and hospital costs of children treated for amblyopia with patching in a UK clinic. METHODS: Notes of 322 children with amblyopia discharged after occlusion treatment were selected consecutively and reviewed. Data collated included age at presentation, amblyopia type, visual acuity (VA; before/after occlusion and at discharge), number of prescribed hours of occlusion, duration of patching treatment, number of glasses prescribed and number of visits attended or failed to attend. Hospital treatment costs were estimated. RESULTS: Mixed amblyopes were prescribed the longest amount of patching (mean 2815 h over 23 months) followed by strabismic (1984 h) and anisometropic (1238 h) amblyopes. 319 amblyopes received glasses and five atropine treatment. The percentage of patients reaching VA of 6/12 was best in the anisometropic and strabismic groups (>75%) and worse in mixed amblyopia (64%). Average hospital costs were estimated at pound1365. CONCLUSION: Although the mean duration of treatment was long, involving many hospital visits, the visual outcome was variable, unsatisfactory (<6/9) and more expensive than necessary. As compliance has been identified as a major problem methods to improve amblyopia treatment are needed, possibly by using educational/motivational intervention.

[A cost analysis of therapy for amblyopia for an outpatient at a university hospital]. / Análise do custo do tratamento da ambliopia para o paciente em hospital universitário.

PURPOSE: To analyze the costs of therapy for amblyopia for an outpatient using occlusion of the normal sighted eye and its visual results. METHODS: A prospective study was performed to evaluate the costs of therapy for amblyopia at the Strabismus Sector of the Hospital São Paulo--Universidade Federal de São Paulo/Escola Paulista de Medicina. Children with amblyopia ranging in age from 3 to 7 years were included in the study. The patients were followed since the diagnosis time until three consecutive visits. At the diagnosis time we prescribed glasses when necessary and total, direct and continuous occlusion of the normal sighted eye. Information about the therapy and the cost of therapy for amblyopia was collected at the following visits. To analyze the results the costs were separated into direct (glasses and occlusors) and indirect (transport, and cost of parent's/guardian's workday). RESULTS: Fourteen patients were analyzed. The mean age was 5.21 years (from 3 to 7 years) and 7 (50%) patients were male and 7 (50%) female. The average of the monthly cost of amblyopia therapy was R$ 59.49 and the average of the annual cost was R$ 714.47. The average monthly cost of therapy for amblyopia represented 12.20% of the monthly family income. CONCLUSIONS: The therapy for amblyopia is efficient and improves visual acuity of the amblyopic eye in 71.43% of the cases. The monthly cost of this therapy is R$ 59.49 being 12.20% of the patient's family income.

Análise do custo do tratamento da ambliopia para o paciente em hospital universitário / A cost analysis of therapy for amblyopia for an outpatient at a university hospital

OBJETIVO: Avaliar os custos do tratamento da ambliopia para o paciente pela oclusão do olho dominante, assim como seu resultado visual. MÉTODOS: Realizou-se estudo prospectivo para avaliar o custo do tratamento de ambliopia por oclusão no Setor de Estrabismo do Hospital São Paulo - Universidade Federal de São Paulo/Escola Paulista de Medicina. Crianças portadoras de ambliopia entre 3 e 7 anos de idade foram incluídas no estudo. Os pacientes foram acompanhados a partir do diagnóstico até três retornos consecutivos. Ao diagnóstico prescreveram-se óculos se necessário e oclusão total, direta e contínua do olho dominante. Nos retornos coletaram-se dados referentes ao tratamento e ao custo do tratamento da ambliopia. Para análise dos resultados os custos foram divididos em diretos (óculos e oclusor) e indiretos (transporte e desconto do dia de trabalho do acompanhante). RESULTADOS: Foram analisados 14 pacientes com idade média de 5,21 anos, sendo 7 (50 por cento) do sexo masculino e 7 (50 por cento) do sexo feminino. Observou-se melhora da acuidade visual em 71,43 por cento dos pacientes. O custo médio mensal do tratamento da ambliopia foi de R$ 59,49 e o custo médio anual de R$ 714,47. O custo médio mensal do tratamento da ambliopia equivale a 12,20 por cento da renda familiar mensal média dos pacientes neste estudo. CONCLUSAO: O tratamento de oclusão da ambliopia é eficiente e melhorou a acuidade visual do olho amblíope em 71,43 por cento dos casos. O custo mensal deste tratamento é de R$ 59,49 e representa 12,20 por cento da renda familiar mensal dos pacientes avaliados.

[Cost-effectiveness of screening for amblyopia]. / Kosteneffektivität von Screening auf Amblyopie.

BACKGROUND: The effectiveness of a screening program for amblyopia has been discussed controversely for several years. While the medical profit is obvious, little is known on the cost-effectiveness of such a screening program. METHODS: By literature research all important variables were determined: incidence of amblyopia, sensitivity of different screening modalities, effectiveness of therapy, costs as well as the loss of utility and life quality by an existing amblyopia. Based on those data in a simple model the costs of a screening program for amblyopia were determined per quality adjusted life year (QALY). The result was analyzed for its stability by sensitivity analysis and compared to the costs of other therapies. RESULTS: Amblyopia occurs with an incidence of approximately 2 % (1.3 - 12 %). Most Screening programs reach a sensitivity of 60 - 90 % and cause costs of 900 - 1400 Euro per detected case. By appropriate therapy with mean costs of 2300 Euro approx. 60 % of the cases obtain useful vision of > 20/40. However, therapy results vary considerably. After discounting the incremental cost-effectiveness ratio (ICER) reaches 7684 Euro/QALY for a screening and treatment program for amblyopia. This is well comparable with other therapies and accepted to be cost-efficient. Sensitivity analysis yielded 24 700 Euro/QALY and 57,633 Euro/QAL with higher discounting for worst case scenarios. CONCLUSION: Screening for amblyopia meets the basic requirements of cost-effectiveness.

Cost effectiveness of treatment for amblyopia: an analysis based on a probabilistic Markov model.

AIMS: To estimate the long term cost effectiveness of treatment for amblyopia in 3 year old children. METHODS: A cost utility analysis was performed using decision analysis including a Markov state transition model. Incremental costs and effects during the children's remaining lifetime were estimated. The model took into account the costs and success rate of treatment as well as effects of unilateral and bilateral visual impairment caused by amblyopia and other eye diseases coming along later in life on quality of life (utility). Model parameter values were obtained from the literature, and from a survey of experts. For the utility of unilateral visual impairment a base value of 0.96 was assumed. Costs were estimated from a third party payer perspective for the year 2002 in Germany. Costs and effects were discounted at 3%. Uncertainty was assessed by univariate and probabilistic sensitivity analysis (Monte-Carlo simulation). RESULTS: The incremental cost effectiveness ratio (ICER) of treatment was euro2369 per quality adjusted life year (QALY). In univariate sensitivity analysis the ICER was most sensitive to uncertainty concerning the utility of unilateral visual impairment-for example, if this utility was 0.99, the ICER would be euro9148/QALY. Monte-Carlo simulation yielded a 95% uncertainty interval for the ICER of euro710/QALY to euro38 696/QALY; the probability of an ICER smaller than euro20 000/QALY was 95%. CONCLUSION: Treatment for amblyopia is likely to be very cost effective. Much of the uncertainty in results comes from the uncertainty regarding the effect of amblyopia on quality of life. In order to reduce this uncertainty the impact of amblyopia on utility should be investigated.