The Use of the RETeval Portable Electroretinography Device for Low-Cost Screening: A Mini-Review

Electroretinography (ERG) provides crucial insights into retinal function and the integrity of the visual pathways. However, ERG assessments classically require a complicated technical background with costly equipment. In addition, the placement of corneal or conjunctival electrodes is not always tolerated by the patients, which restricts the measurement for pediatric evaluations. In this short review, we give an overview of the use of the RETeval portable ERG device (LKC Technologies, Inc., Gaithersburg, MD, USA), a modern portable ERG device that can facilitate screening for diseases involving the retina and the optic nerve. We also review its potential to provide ocular biomarkers in systemic pathologies, such as Alzheimer's disease and central nervous system alterations, within the framework of oculomics.

Cost Analysis of Teleophthalmology Screening for Diabetic Retinopathy Using Teleophthalmology Billing Codes

BACKGROUND AND OBJECTIVE

To evaluate the financial sustainability of teleophthalmology screening for diabetic retinopathy (DR) using telehealth billing codes.

PATIENTS AND METHODS

The authors performed an Institutional Review Board-approved retrospective review of medical records, billing data, and quality metrics at the University of California Davis Health System from patients screened for DR through an internal medicine-based telemedicine program using CPT codes 92227 or 92228.

RESULTS

A total of 290 patients received teleophthalmology screening over a 12-month period, resulting in an increase in the DR screening rate from 49% to 63% (P < .0001). The average payment per patient was $19.86, with an estimated cost of $41.02 per patient. The projected per-patient incentive bonus was $43.06 with a downstream referral revenue of $39.38 per patient. One hundred seventy-eight clinic visits were eliminated, providing an estimated cost savings of $42.53 per patient.

CONCLUSION

Sustainable teleophthalmology screening may be achieved by billing telehealth codes but only with health care incentive bonuses, patient referrals, and by accounting for the projected cost-savings of eliminating office visits. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:S26-S34.].

Development of a system based on artificial intelligence to identify visual problems in children: study protocol of the TrackAI project

INTRODUCTION

Around 70% to 80% of the 19 million visually disabled children in the world are due to a preventable or curable disease, if detected early enough. Vision screening in childhood is an evidence-based and cost-effective way to detect visual disorders. However, current screening programmes face several limitations: training required to perform them efficiently, lack of accurate screening tools and poor collaboration from young children.Some of these limitations can be overcome by new digital tools. Implementing a system based on artificial intelligence systems avoid the challenge of interpreting visual outcomes.The objective of the TrackAI Project is to develop a system to identify children with visual disorders. The system will have two main components: a novel visual test implemented in a digital device, DIVE (Device for an Integral Visual Examination); and artificial intelligence algorithms that will run on a smartphone to analyse automatically the visual data gathered by DIVE.

METHODS AND ANALYSIS

This is a multicentre study, with at least five centres located in five geographically diverse study sites participating in the recruitment, covering Europe, USA and Asia.The study will include children aged between 6 months and 14 years, both with normal or abnormal visual development.The project will be divided in two consecutive phases: design and training of an artificial intelligence (AI) algorithm to identify visual problems, and system development and validation. The study protocol will consist of a comprehensive ophthalmological examination, performed by an experienced paediatric ophthalmologist, and an exam of the visual function using a DIVE.For the first part of the study, diagnostic labels will be given to each DIVE exam to train the neural network. For the validation, diagnosis provided by ophthalmologists will be compared with AI system outcomes.

ETHICS AND DISSEMINATION

The study will be conducted in accordance with the principles of Good Clinical Practice. This protocol was approved by the Clinical Research Ethics Committee of Aragón, CEICA, on January 2019 (Code PI18/346).Results will be published in peer-reviewed journals and disseminated in scientific meetings.

TRIAL REGISTRATION NUMBER

ISRCTN17316993.

Screening Siblings for Glaucoma in the UK

The current practice and ideals of ophthalmologists when alerting and screening siblings at risk of chronic simple glaucoma were assessed by means of a questionnaire. Seventy-nine per cent of Trent Region consultants responded, and of these, 18% do not attempt to alert siblings of glaucoma sufferers. Those who do rely on the probands to alert their siblings and the high street optometrists to screen. Under more favourable conditions, all respondents would advise screening for siblings over 40 years of age. Fifty-nine per cent would then advocate the letter as the optimum method of communication and 78% would prefer that an ophthalmologist screen this high risk group.

In a pilot study of a hospital-based screening service, siblings living within a 15 mile radius of the hospital were invited by letter to attend for screening. Ninety per cent attended, of whom 12.5% required treatment and a further 11% careful observation. The cost of detecting a case of treatable disease by this strategy was estimated at £138.

A Comparison of Patched HOTV Visual Acuity and Photoscreening

Early detection of significant vision problems in children is a high priority for pediatricians and school nurses. Routine vision screening is a necessary part of that detection and has traditionally involved acuity charts. However, photoscreening in which “red eye” is elicited to show whether each eye is focusing may outperform routine acuity testing in pediatric offices and schools. This study compares portable acuity testing with photoscreening of preschoolers, kindergarteners, and 1st-graders in 21 elementary schools. School nurses performed enhanced patched acuity testing and two types of photoscreening in a portable tent. Nearly 1,700 children were screened during spring semester 2004, and 14% had confirmatory exams by community eye care professionals. The results indicate that one form of photoscreening using a Gateway DV-S20 digital camera is significantly more sensitive to children with significant vision problems, as well as being the most cost effective (85% specificity and only $0.11 per child). This suggests that the adaptation of photoscreening into a routine vision screening protocol would be beneficial for efficiently detecting vision problems that could lead to amblyopia.

The effect of health insurance coverage on medical care utilization and health outcomes: Evidence from Medicaid adult vision benefits

Increasing the proportion of adults that have regular, comprehensive eye exams and reducing visual impairment due to uncorrected refractive error and other common eye health problems are federal health objectives. We examine the effect of vision insurance on eye care utilization and vision health outcomes by taking advantage of quasi-experimental variation in Medicaid coverage of adult vision care. Using a difference-in-difference-in-difference approach, we find that Medicaid beneficiaries with vision coverage are 4.4 percentage points (p<0.01) more likely to have seen an eye doctor in the past year, 5.3 percentage points (p<0.01) less likely to report needing but not purchasing eyeglasses or contacts due to cost, 2.0 percentage points (p<0.05) less likely to report difficulty seeing with usual vision correction, and 1.2 percentage points (p<0.01) less likely to have a functional limitation due to vision.

Results of a pediatric vision screening program in western South Dakota

BACKGROUND

South Dakota is one of eight states that do not require any vision screening for children. This study describes the results of the first children's vision screening program in the state.

METHODS

Children ages 6 months to 12 years were screened using the SPOT photoscreener by lay volunteers as part of the Northern Plains Eye Foundation's Western South Dakota Children's Vision Screening Initiative (CVSI). Referral criteria were based on the recommendations of the manufacturer. Data was stratified by age group, sex, and percentage of children referred for hyperopia, myopia, astigmatism, anisocoria, anisometropia, and ocular misalignment. The cost benefit of amblyopia treatment in South Dakota was also calculated.

RESULTS

Screenings were completed on 4,784 children from August 2012 to May 2014 with 62 excluded due to age. Mean age of the 4,722 (2,373 females) subjects was 6 years 7 months. Overall, the SPOT device referred 563 (11.9 percent) children. There was no significant difference in referral rate based on sex (p = 0.598). Children aged 73-144 months had the highest referral rate (12.2 percent) and children aged 12-30 months had the lowest referral rate (7.9 percent). The suspected reasons for referral based upon the screenings were as follows: 371 (7.9 percent) astigmatism, 24 (0.5 percent) ocular misalignment, 101 (2.1 percent) anisometropia, 135 (2.9 percent) myopia, 36 (0.8 percent) hyperopia, and 16 (0.3 percent) anisocoria.

CONCLUSIONS

The SPOT photoscreener yielded an acceptable referral rate of 11.9 percent. This study represents an effective model for pediatric vision screening in South Dakota.

Cost-savings analysis of telemedicine use for ophthalmic screening in a rural Appalachian health clinic

Life in mountainous, rural areas poses unique obstacles for ophthalmic care--notably, a lack of access to ophthalmologists and cost of care. Using telemedicine as a screening tool addresses both issues for diabetic retinopathy (DR) screening, as fundus photography has been determined to be sensitive and specific when screening for DR. The American Diabetes Association places a Grade E recommendation on fundus photography as a screening tool. We analyze the financial impact of ophthalmic telemedicine in a mountainous, rural health clinic in West Virginia over a seven year period from 2003-2009. At-risk patients are screened with a fundus camera during routine clinic visits, and the image is interpreted off-site by an ophthalmologist. Patients are either advised to follow up yearly or receive an immediate opthalmic referral. Considering the number of patients screened, travel costs, work missed, overhead, and billing considerations yields a savings of $153.43 per patient visit.

Cost implications, deprivation and geodemographic segmentation analysis of non-attenders (DNA) in an established diabetic retinopathy screening programme

AIM

To ascertain the relationship between socioeconomic status and non attendance alongside the role of geodemographic analysis in identifying reasons for non attendance. To also ascertain the financial implications of non attendance on the service.

METHODS

Retrospective analysis of DNA patients between April 2009 and March 2010. Cost to the service was calculated based on Devon Primary Care Trust tariffs. Deprivation Analysis was based on the Indices of Multiple Deprivation 2007 for England. Geodemographic analysis was done using a commercially available software (MOSAIC Public Sector, Experian Information Solutions Inc.).

RESULTS

22,651 patients were invited for screening with 20,514 screened and 2137 (9.4%) DNA's. Of these, 1757 (82.2%) were DNA 1's while 380 (17.7%) were DNA 2's. Mean age of screened patients was 68 (SD ±14.2), DNA 1's was 62 (SD ±17.3) and DNA 2's was 57 (SD ±18.7).1269 (59%) of DNA's were males and 868 (41%) were females. Cost to the service as calculated by lost earnings from missed appointments came to £78,259. Deprivation analysis showed increasing non attendance rates with increasing deprivation. Geodemographic segmentation analysis revealed that the lowest DNA rates were seen in successful professionals and active retired communities and the highest rates were seen in areas of social housing.

CONCLUSIONS

The study demonstrates an association between non attendance and socioeconomic deprivation. The use of geodemographic analysis programmes can help identify groups that do not respond to traditional postal reminders. More focused and customised strategies can then be developed for these groups to eliminate nonattendance.

Improving access to eye health services in rural Timor-Leste

CONTEXT

Delivering eye health services to people in rural areas, especially in fragile, post-conflict countries, is a major challenge. This article reports on the implementation and evaluation of an innovative district-based outreach service. The main project partners were the Timor-Leste Ministry of Health and an international non-government organization, with assistance from a local non-government organization.

ISSUE

An eye care nurse in Covalima District, a remote location 178 km from Timor-Leste's capital, Dili, was provided with a motor-bike for transport and regular support for outreach eye services to sub-district facilities. Data collected over the first year of operation were examined and included: services provided, spectacles dispensed, health promotion activities conducted and the cost of providing these. The project was also evaluated for its relevance, effectiveness, efficiency, impact and sustainability.

LESSONS LEARNED

In the first 12 months, 55 outreach visits were conducted across the district's seven sub-districts during which 1405 people received vision screening, and 777 spectacles were dispensed. In addition to meeting the five evaluation criteria, compared with the hospital-based eye clinic the outreach service resulted in significantly greater gender equity among eye health service beneficiaries. This pilot project demonstrates what can be achieved when a Ministry of Health (central and district level) and non-government organizations (international and local) work in partnership to support a dedicated health care provider.

The cost-effectiveness of Welcome to Medicare visual acuity screening and a possible alternative welcome to medicare eye evaluation among persons without diagnosed diabetes mellitus

OBJECTIVE

To estimate the cost-effectiveness of visual acuity screening performed in primary care settings and of dilated eye evaluations performed by an eye care professional among new Medicare enrollees with no diagnosed eye disorders. Medicare currently reimburses visual acuity screening for new enrollees during their initial preventive primary care health check, but dilated eye evaluations may be a more cost-effective policy.

DESIGN

Monte Carlo cost-effectiveness simulation model with a total of 50 000 simulated patients with demographic characteristics matched to persons 65 years of age in the US population.

RESULTS

Compared with no screening policy, dilated eye evaluations increased quality-adjusted life-years(QALYs) by 0.008 (95% credible interval [CrI], 0.005-0.011) and increased costs by $94 (95% CrI, −$35 to$222). A visual acuity screening increased QALYs in less than 95% of the simulations (0.001 [95% CrI, −0.002 to 0.004) and increased total costs by $32 (95% CrI, −$97 to $159) per person. The incremental cost-effectiveness ratio of a visual acuity screening and an eye examination compared with no screening were $29 000 and$12 000 per QALY gained, respectively. At a willingness-to-pay value of $15 000 or more per QALY gained, a dilated eye evaluation was the policy option most likely to be cost-effective.

CONCLUSIONS

The currently recommended visual acuity screening showed limited efficacy and cost-effectiveness compared with no screening. In contrast, anew policy of reimbursement for Welcome to Medicare dilated eye evaluations was highly cost-effective.

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.

Informing disinvestment through cost-effectiveness modelling: is lack of data a surmountable barrier?

The mandatory nature of recommendations made by the National Institute for Health and Clinical Excellence (NICE) in the UK has highlighted inherent difficulties in the process of disinvestment in existing technologies to fund NICE-approved technologies. A lack of evidence on candidate technologies means that the process of disinvestment is subject to greater uncertainty than the investment process, and inefficiencies may occur as a result of the inverse evidence law. This article describes a potential disinvestment scenario and the options for the decision maker, including the conduct of value of information analyses. To illustrate the scenario, an economic evaluation of a disinvestment candidate (screening for amblyopia and strabismus) is presented. Only very limited data were available. The reference case analysis found that screening is not cost effective at currently accepted values of a QALY. However, a small utility decrement due to unilateral vision loss reduced the incremental cost per QALY gained, with screening expected to be extremely cost effective. The discussion highlights the specific options to be considered by decision makers in light of the model-based evaluation. It is shown that the evaluation provides useful information to guide the disinvestment decision, providing a range of focused options with respect to the decision and the decision-making process. A combination of explicit model-based evaluation, and pragmatic and generalizable approaches to interpreting uncertainty in the decision-making process is proposed, which should enable informed decisions around the disinvestment of technologies with weak evidence bases.

Vision First, a program to detect and treat eye diseases in young children: the first four years

PURPOSE

The Vision First program began in the fall of 2002 as a community outreach initiative by the Cleveland Clinic Cole Eye Institute in partnership with the Cleveland Metropolitan School District. It was designed to provide free eye examinations to all prekindergarten, kindergarten, and first grade students enrolled in Cleveland City public schools in order to diagnose refractive errors, amblyopia, and strabismus, so that treatment is instituted and the best possible visual outcome attained.

METHODS

Examinations are performed in 2 lanes of a specially outfitted recreational vehicle. All children undergo monocular visual acuity testing at distance and near, stereopsis testing, cover testing at distance and near, testing of versions, and external ocular inspection. If a child fails any part of this examination according to the guidelines set by the American Academy of Pediatrics, cycloplegic drops are instilled and an optometrist refracts the child on location and performs indirect ophthalmoscopy. Glasses are prescribed and follow-up with a pediatric ophthamologist is arranged.

RESULTS

During the first 4 years of the program, 22,988 examinations were performed. Seven percent of children had errors of refraction that necessitated optical correction, about 2.1% had strabismus, and 1.7% had amblyopia. The cost per student per year was around $23 excluding glasses.

CONCLUSIONS

About 10% of 5- and 6-year-old schoolchildren have eye problems that require either glasses or treatment for strabismus or amblyopia. The Vision First model brings eye care professionals to the schools and provides effective comprehensive screening of all children, as well as detailed examination and referral of those with significant eye problems.

[A computerized method for visual acuity assessment]

PURPOSE

To elaborate and to validate a computerized test for visual acuity screening of school-age children.

METHODS

We have created a computerized test for visual acuity assessment with optotypes arranged as those of printed logarithmic charts used in ophthalmic clinic. Ninety seven-year-old students, 8 normal adult volunteers and 10 patients from the Strabismus sector of the Federal University of São Paulo were evaluated by the same examiner and submitted to the visual acuity test through printed visual acuity logarithmic tumble "E" chart and the new computerized test at the same time. Written consent was obtained after clarification about the research project.

RESULTS

Statistical analysis showed excellent correlation between the two methods (r>0.75) besides the slight trend of the computerized test to overestimate visual acuity when compared with the gold standard. Sensitivity of the computerized test was 100% (correctly identified 6 eyes with poor visual acuity) and specificity was 94%.

CONCLUSION

The computerized test can be used as a new clinical tool for visual acuity screening of school-age children and it is fast, easy to perform and inexpensive, besides being more attractive for children. The method releases the examiner from the interpretation of the subject's answers and ensures the procedure's standardization even when more than one examiner performs the test. To better understand the effectiveness of this method for visual screening, one option would be to introduce it in elementary schools, after training the teachers to perform this test.

Predictive value of inexpensive digital eye and vision photoscreening: "PPV of ABCD"

PURPOSE

Some consumer digital cameras have short flash to lens distances (dimensions) ideal for photoscreening so we adopted them into an ongoing Alaska state wide vision screening program, the Alaska Blind Child Discovery (ABCD) Project.

METHODS

Digital cameras with short flash-lens distance were employed by lay screeners trained by a DVD movie. Confirmatory eye examinations by AAPOS (American Association for Pediatric Ophthalmology and Strabismus) criteria were sought from eye doctors.

RESULTS

2900 children were screened in 62 clinics by 14 screeners. Of the 2900 screenings, 99% were readable with 6% refereed as positive for ocular pathology. The positive predictive value was estimated as greater than 80%. The per-screening image cost was less than $0.10 (10 cents) including cameras. Some screeners interpreted images similar to central reading center.

CONCLUSION

Pre-literate community eye and vision photoscreening can be both valid and cost effective.

The cost and yield of photoscreening: impact of photoscreening on overall pediatric ophthalmic costs

BACKGROUND

Approximately 5% of preschool-age children suffer from amblyopia. Many of them have high or unequal hyperopia. Amblyogenic risk factors frequently can be detected by photoscreening.

METHODS

Free photoscreening was offered to Alaskan children ages 1 to 5 from urban and rural screening hubs. Screened images were mailed to the Alaska Blind Child Discovery coordinating center for physician photoscreen interpretation, specifically seeking latent or anisometropic hyperopia. Parents and screeners then were mailed results and information about amblyopia. Follow-up examination data were tallied, and a cost-consequence analysis was developed for various vision screening paradigms and eye care.

RESULTS

From 1996 through 2003, a total of 13,255 screenings were performed with a positive interpretation rate of 4.7%. Penetrance of screening was 22% in urban and 44% in rural communities. Positive predictive value was estimated to be more than 90%. Average cost to screen and inform an Alaskan preschooler was approximately 10.67 dollars, and cost to detect amblyogenic risk factors by photoscreening in an Alaskan was approximately 206 dollars. Compared to American Academy of Pediatrics (AAP) 1995 guidelines, implementing photoscreening added 9%, while mandating complete prekindergarten examination added 49% to overall eye care.

CONCLUSIONS

MTI photoscreening achieved high community penetrance and high positive predictive value for latent hyperopia and other amblyogenic factors. When follow-up costs are considered, adding photoscreening to current AAP guidelines may add 112 dollars per child over 10 years, but probably would assist in the reduction of amblyopia. Penetrance of urban photoscreening likely will remain low unless pediatric vision screening guidelines and reimbursement are revised.

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.

Willingness of eye care practices to evaluate children and accept Medicaid

BACKGROUND

The willingness of eye care providers to evaluate children or to accept Medicaid may be a barrier to care for those with an abnormal screen.

OBJECTIVES

To determine the proportion of eye care practices that would provide diagnostic evaluation for children and accept Medicaid payment and to evaluate the influence of child age and practice characteristics on provision of care or acceptance of Medicaid.

METHODS

We conducted a telephone survey of 364 eye care practices in Michigan, which were randomly selected from telephone directories of 26 rural and urban cities as defined by metropolitan statistical areas.

RESULTS

The response rate was 93%. Most eye care practices, but more optometry-listed practices than ophthalmology-listed ones, would evaluate preschool-aged children (88% vs 73%; P <.01) or school-aged children only (11% vs 7%; P <.01). The proportion of practices willing to evaluate preschool-aged children was lower in urban cities compared with rural cities for optometry-listed (83% vs 96%; P <.01) and ophthalmology-listed practices (67% vs 93%; P <.01). Medicaid acceptance among practices that would evaluate children was higher among ophthalmology-listed than optometry-listed practices (74% vs 59%; P =.01) and did not vary by urban or rural status. Practice size was not associated with willingness to provide care for children. However, among practices that would provide care for children, larger practice size was associated with increased odds of Medicaid acceptance in both optometry-listed and ophthalmology-listed practices.

CONCLUSIONS

These findings contradict the perception that eye care for children is unavailable. More work is needed to understand the relationship of this availability with the accessibility of eye care.

The Need for Routine Eye Examinations

PURPOSE

To determine the incidence and causes of vision loss to assist in the objective determination of the preferred frequency of routine screening for those with normal vision.

METHODS

A prospective, population-based study of people aged 40 or more years. Standardized examination protocols were used that included presenting and best corrected visual acuity, visual field testing, and comprehensive eye examination with dilation.

RESULTS

There were 2529 people with a full data set, including 1590 with a normal baseline examination. The 5-year incidence of vision loss (<6/12 presenting acuity in the worse eye) was 2.39%. Overall, 24 (63%) of 38 of those with vision loss had noticed a change in their vision, and 18 (75%) of these 24 had attended an eye examination. This left only 14 (0.88%) people who had had normal baseline examination results and had asymptomatic vision loss develop over this 5-year period.

CONCLUSIONS

Frequent routine eye examinations of those with normal examination results will have a low yield and may not be cost effective. Health promotion messages should target those who notice a change in vision and those at higher risk such as those with diabetes or a family history of eye disease.

Amblyopia detection by camera: Gateway to portable, inexpensive vision screening (calibration and validation of inexpensive, pocket-sized photoscreeners)

BACKGROUND

Photoscreening can allow early detection of amblyopia. The Gateway DV-S20, and similar models of miniature, digital flash cameras, have similar optical dimensions to existing photoscreeners for less than $200.

METHODS

These cameras were calibrated on known, threshold amblyogenic refractive errors induced by placing minus and toric contact lenses on a normal subject's left eye. The DV-S20 was then applied to known amblyopic patients. Students under age 7 were vision screened with patched acuity and sequential photoscreeners (MTI and Gateway).

RESULTS

The digital cameras and the MTI photoscreeners produced similar magnitude interpretable crescents for amblyopiagenic refractive errors. They had very similar validation with sensitivities of 80-90% and specificities of 98% for serious eye disorders in known patients and school-aged children.

CONCLUSION

Combined with careful interpretation, pocket-sized, digital flash cameras provide a portable and inexpensive digital alternative for pediatric photoscreening. A category 3 CPT code (0065T) can be used for this valid, public health technique: Amblyopia Detection By Camera (ADBC).

Cost-efficient vision screening for astigmatism in native american preschool children

PURPOSE

To design and test a cost-efficient, community-based vision screening program for a population of Native American preschool children in which there is a high prevalence of astigmatism.

METHODS

Based on analysis of vision screening and eye examination data from a preschool population with a 33% prevalence of astigmatism, comparative costs to conduct a 1000-child screening program with a target sensitivity of 90% were estimated for photoscreening, noncycloplegic autorefraction, autokeratometry, and Lea symbols distance visual acuity testing. Results of the cost analysis and examination of sensitivity and specificity data from the preschool population led to development of a hybrid screening program of autokeratometry and visual acuity screening with referral thresholds of 2.25 D of corneal astigmatism or inability to read a 20/63 Lea symbols line on two separate attempts. The screening program was prospectively implemented in a community-based screening of a similar cohort of 167 children, and its efficiency was evaluated by comparison to results of cycloplegic refraction.

RESULTS

The community-based screening showed 96.8% sensitivity and 79.2% specificity for detecting the presence of refractive astigmatism of 1.50 D or more.

CONCLUSIONS

Referring children who have at least 2.25 D of corneal astigmatism or acuity worse than 20/63 on two attempts, provides the high sensitivity and specificity associated with automated keratometry while maintaining an acuity component that can detect other causes of reduced acuity in the absence of astigmatism.

Ophthalmic assessment of children before renal transplantation

OBJECTIVE

To evaluate the usefulness of routine ophthalmic examination before renal transplantation in children.

METHODS

We reviewed the records of ophthalmic assessments of renal transplant recipients at The Hospital for Sick Children, Toronto, Ont., from January 1989 to June 1996. If abnormalities had been found, we determined whether they had previously been documented, were related to the renal disease or other systemic disease, had required intervention or had affected visual function. We calculated the maximum statistical chance of detecting a meaningful eye problem at the pretransplantation assessment. We also estimated the direct cost of the ophthalmic assessment and the effect, if any, of the findings on the patient's medical management.

RESULTS

We included 107 charts. Before the ophthalmic assessment, 32 patients (30%) had known eye problems. The ocular examination detected abnormalities in 46 patients (43%); the abnormalities had not been detected previously in 14 (13%). New, potentially vision-threatening eye disorders were found in 6 (6%) of the patients. No finding affected the short- or long-term management of any patient.

CONCLUSION

Children with chronic renal failure had a high prevalence of ocular abnormalities, but most of the abnormalities did not affect visual function. Although ophthalmic assessment before transplantation did not alter the medical management of the renal transplant patients, consultation may be helpful in selected patients, particularly those who are not already under the care of an optometrist or ophthalmologist and those who have a visual complaint.

A cost-benefit analysis of vision screening methods for preschoolers and school-age children

INTRODUCTION

The purpose of this study was to determine costs and benefits of visual acuity screening (VAS) or photoscreening (PS) in children.

METHODS

A societal-perspective, decision-analytic model compared VAS and PS conducted in three age groups: children 6 to 18 months, 3 to 4 years, and 7 to 8 years old. Literature estimates of sensitivity, specificity, and prevalence were used. Cost estimates and referral rates for surgical treatment were derived from a managed care database and the United States Social Security Administration.

RESULTS

All the benefit-to-cost ratios exceeded 1.0, meaning that all screening programs studied had benefits that exceeded the cost of screening. The total net benefit was highest for PS in children of 3 to 4 years of age (19,412 US dollars) and the least for VAS in children 7 to 8 years of age (15,179 US dollars). The benefit-to-cost ratio was highest for the VAS in children 3 to 4 years of age (162 US dollars) and least for PS in infants 6 to 18 month old (140 US dollars). Sensitivity of the PS instrument and VAS charts were the most influential variables in determining the most cost-beneficial program.

CONCLUSIONS

Based on the best available data, the net benefit of PS in 3 to 4 year old preschool children is greater than VAS in children 7 to 8 years of age, PS in toddlers, and VAS in children 3 to 4 years of age.

Ambulatory photographic screening for diabetic retinopathy in nursing homes

PURPOSE

To evaluate the feasibility and cost of screening for diabetic eye disease in homebound nursing home residents not attending a systematic screening programme.

METHODS

Postal survey identification of residents with diabetes in all nursing homes in Liverpool. An ophthalmologist and nurse performed Bailey-Lovie logmar visual acuity (VA), portable slit-lamp examination, fundus photography, and subjective assessment of ability to cooperate with treatment in a sample of homes. Modified Wisconsin photographic grading was performed. Screen-positive patients were invited to a dedicated assessment clinic. Sight-threatening diabetic eye disease (STED) was defined as any of: moderate preproliferative retinopathy or worse, circinate maculopathy, or exudate within 1 disc diameter of fixation.

RESULTS

A total of 54 (78%) nursing homes responded reporting 199/2427 (8.2%) residents with diabetes. Of these, 64/80 (80%) residents in 17 homes were examined: VA possible in 50 (78%); slit-lamp examination in 56 (88%); gradable photographs in at least one eye in 34 (53%); STED in 12 (35%) patients. In all, 35 (70%) patients had Snellen-equivalent VA worse than 6/12 in the better eye, of whom 13 (26%) were worse than 6/60. Of 29 screen positive patients, 12 attended the assessment clinic: one was unable to cooperate outside the home; 11 continue under ophthalmic review, four for previously undetected STED of which one listed for laser photocoagulation. Total cost pound 16,980; cost per screen event pound 60.30.

CONCLUSIONS

Systematic eye screening in homebound patients with diabetes detects disease but follow-up and treatment is only feasible in a small proportion and at high cost. Alternative targeted assessment is recommended.

The changing world of ancillary benefits

Amid salary and health care benefit cuts, ancillary benefits such as dental, life insurance, long-term disability and vision coverage can communicate employers' concern for their employees as well as serve as recruitment and retention tools. These benefits can be funded by the employer, the employee or both.

A cost-effectiveness model of screening strategies for amblyopia and risk factors and its application in a german setting

PURPOSE

To develop a general setting-independent decision-analytical model that determines the costs, effectiveness, and cost-effectiveness of four screening strategies to detect amblyopia or amblyogenic factors in pre-school children and to apply the model in a German setting.

METHODS

The general setting-independent decision-analytical model was developed from the perspective of society and the statutory health insurance was developed. Outcomes were the total number of newly detected true positive cases of amblyopia and the costs per newly detected true positive case of amblyopia. Strategies were screening of high-risk children up to the age of 1 year (ophthalmologists), screening of all children up to the age of 1 year (ophthalmologists), screening of all children aged 3 to 4 years (pediatricians or general practitioners), and screening of children aged 3 to 4 years visiting kindergarten (orthoptists). For the application example in a German setting, data from the published medical literature were used.

RESULTS

In the base-case analysis of the application example, screening high-risk children by ophthalmologists had the lowest average cost per case detected but became dominated (less effective and more costly than an alternative) if a low (5.3%) probability of familial clustering of strabismus was assumed. Considering the various assumptions tested in the sensitivity analysis, screening of all children up to the age of 1 year by ophthalmologists was the only strategy not dominated by others. Detection rates, including cases detected before screening, were between 72% and 78% for the strategies that screen for all children.

CONCLUSIONS

The model suggests that in Germany, both from a cost-effectiveness and a pure effectiveness point of view, screening all children up to the age of 1 year by ophthalmologists is the preferred strategy to detect amblyopia or amblyogenic factors. All strategies left a significant portion of children undetected.

Screening for diabetic retinopathy in James Bay, Ontario: a cost-effectiveness analysis

BACKGROUND

Retinopathy is a common complication of diabetes mellitus that if detected early by regular retinal examinations can be treated; thus, blindness can be delayed or prevented. Providing high-quality retinal screening is difficult, especially in rural and remote areas. Canada's First Nations population has a higher prevalence of diabetes and is, in general, more geographically isolated than the broader Canadian population. We modelled the cost-effectiveness of retinopathy screening by travelling retina specialists versus retinal photography with a portable digital camera in an isolated First Nations cohort with diabetes.

METHODS

The 2 screening programs were modelled to run concurrently for 5 years, with outcomes evaluated over 10 years. To construct economic models for the population of Cree individuals living in the western James Bay area of northern Ontario, we used available data on the prevalence of diabetes in the area and estimates of the incidence of retinopathy derived from the published literature. We compared the screening models and calculated total costs, visual outcome, costs per sight-year saved and costs per quality-adjusted life year (QALY). We also estimated the costs of implementing a screening program for all First Nations individuals in Ontario with diabetes and no access to an ophthalmologist.

RESULTS

From the perspective of the health care system the camera program was preferable to the specialist-based program. Over 10 years, 67 v. 56 sight years were saved, compared with no screening, at costs of 3900 Canadian dollars v. 9800 Canadian dollars per sight year and 15,000 Canadian dollars v. 37,000 Canadian dollars per QALY. Generalizing these results to the province of Ontario, the camera system could allow most isolated First Nations people with diabetes to be screened for 5 years for approximately 1.2 million Canadian dollars.

INTERPRETATION

A portable retinal camera is a cost-effective means of screening for diabetic retinopathy in isolated communities of at-risk individuals.

Community refinement of glaucoma referrals

AIM

To describe a Manchester-based glaucoma referral refinement scheme designed to reduce the number of false-positive referrals to the hospital eye service. To report on the first years results of this scheme and its financial costs to the NHS.

METHODS

Patients with suspected glaucoma, instead of being referred to their GP and then on to the hospital eye service, were referred to a group of specially trained community optometrists working to an agreed set of referral criteria. Those patients who did not meet the referral criteria were returned to the referring optometrist, while those who met the referral criteria were referred directly to Manchester Royal Eye Hospital. The patient's GP was informed in all cases.

RESULTS

The number of suspect glaucoma cases referred to the Manchester Royal Eye Hospital was reduced by 40%. This figure is close to the percentage of false-positive referrals measured at Manchester Royal Eye Hospital prior to the onset of this study. The information accompanying referral has been improved and the scheme produces a small financial cost saving to the NHS of approximately 17 pounds sterling per patient.

CONCLUSION

Community refinement of suspect glaucoma offers some important benefits over the current referral pathway.

Economic evaluation of orthoptic screening: results of a field study in 121 German kindergartens

PURPOSE

The purpose of this study was to analyze the cost-effectiveness of an orthoptic screening program in kindergarten children.

METHODS

An empiric cost-effectiveness analysis was conducted as part of a field study of orthoptic screening. Three-year-old children (n = 1180) in 121 German kindergartens were screened by orthoptists. The number of newly diagnosed cases of amblyopia and amblyogenic factors (target conditions) was used as the measure of effectiveness. The direct costs of orthoptic screening were calculated from a third-party-payer perspective based on comprehensive measurement of working hours and material costs.

RESULTS

The average cost of a single orthoptic screening examination was 12.58 Euro. This amount consisted of labor costs (10.99 Euro) and costs of materials and traveling (1.60 Euro). With 9.9 children screened on average per kindergarten, average labor time was 279 minutes per kindergarten, or 28 minutes per child. It consisted of time for organization (46%), traveling (16%), preparing the examination site (10%), and the orthoptic examination itself (28%). The total cost of the screening program in all 121 kindergartens (including ophthalmic examination, if required) was 21,253 Euro. Twenty-three new cases of the target conditions were detected. The cost-effectiveness ratio was 924 Euro per detected case. Sensitivity analysis showed that the prevalence and the specificity of orthoptic screening had substantial influence on the cost-effectiveness ratio.

CONCLUSIONS

The data on the cost-effectiveness of orthoptic screening in kindergarten may be used by such third-party payers as health insurance or public health services when deciding about organizing and financing preschool vision-screening programs.

The evaluation of screening policies for diabetic retinopathy using simulation

AIMS

To develop a model for evaluating screening strategies and to use it to determine the cost effectiveness of varying the screening method and the screening interval.

METHODS

A discrete event simulation was designed, validated and run for a population of 500000. Most parameters were derived from peer-reviewed publications.

RESULTS

Standard methods of screening save up to 50% of the potential sight years lost. They give up to 85% of the sight years saved by an idealized gold standard programme using mydriatic seven-field photography reported by an ophthalmologist. The mobile camera, used for annual screening and 6-month follow-up after the detection of background retinopathy, had an estimated cost of pound 449200 per year with pound 2842 per sight year saved. It is less efficient to screen Type 2, rather than Type 1 diabetes mellitus patients, but they contributed to almost three-quarters of the sight years saved.

CONCLUSIONS

The model can evaluate screening intervals and methods on a national or health authority basis. Results indicate that it appears more cost effective to continue to screen outside an ophthalmology clinic, until treatment is needed. Programmes with annual screening, and more frequent screening for those with background retinopathy, are robust to realistic fluctuations in compliance and screening sensitivity.

Current status of screening for diabetic retinopathy in the UK

This article reviews the current status of retinopathy screening schemes in the UK. There is evidence that high-quality diabetic retinopathy screening schemes are in existence but provision is patchy. Many health authorities have ad hoc screening programmes reaching only about 60% of patients, with unacceptable or undocumented efficacy and minimal quality control. Several models of screening are currently in use with the current preferred option being camera-based screening. Digital imaging systems offer the best prospects for image acquisition, although at present evidence of adequate effectiveness only exists for 35 mm film-based systems. The final report of the National Diabetic Retinopathy Screening Programme commissioned by the UK National Screening Committee for inclusion into the national service framework for diabetes, is thus eagerly awaited and should set standards for screening programmes, in order to improve the care of all those with diabetes. Quality assurance will be the main driver in the immediate future of improvements in screening programmes. Research data will provide the evidence to refine techniques and set targets in the longer term, with the emphasis on cost-effectiveness and quality of life.

Economic evaluation of different methods of screening for amblyopia in kindergarten

OBJECTIVE

To compare the cost-effectiveness of 5 methods of screening for untreated amblyopia in kindergarten from a third-party-payer perspective: A) uncorrected monocular visual acuity testing with pass threshold > or =0.5 (20/40) and < or =1 line difference between eyes; B) same as A, but pass threshold > or =0.6 (20/32); C) same as A, plus cover tests and examination of eye motility and head posture; D) same as C, but pass threshold > or =0.6 (20/32); and E) refractive screening without cycloplegia using the Nikon Retinomax autorefractor.

METHODS

A decision-analytic model was used with a time horizon until diagnostic examination. According to the model, all 3-year-old children were screened in kindergarten with 1 of the screening methods. Children with positive screening results were referred to an ophthalmologist for diagnostic examination. Children with inconclusive screening results were either referred to an ophthalmologist directly (option 1) or rescreened by the same method after 1 year and referred to an ophthalmologist if rescreening was positive or inconclusive (option 2). Screening test characteristics and costs were estimated on the basis of a field study in which 1180 3-year-old children were examined by orthoptists in 121 German kindergartens.

RESULTS

Compared with methods A option 1 (A-1), B-1, C-1, C-2, E-1, and E-2, there was at least 1 other method that was both less costly and more effective. The average costs per detected case were lowest for method A-2 (878 Euro), followed by methods B-2 (886 Euro), D-2 (908 Euro), and D-1 (965 Euro). When these methods were compared with each other, the additional costs per extra case detected were 1058 Euro (B-2 vs A-2), 1359 Euro (D-2 vs B-2), and 13 448 Euro (D-1 vs D-2).

CONCLUSIONS

Monocular visual acuity screening with rescreening of inconclusive results had a favorable cost-effectiveness. By adding additional test items, few more cases could be detected. Because of a great proportion of false-negative, false-positive, and inconclusive results, refractive screening was less effective with an unfavorable cost-effectiveness.

[Childhood vision disorders. Screening programs in international comparison]

Worldwide in a number of countries, screening programs aimed at detecting visual disorders in children are established. Repeatedly, proposals are brought forward to optimize already existing programs. Countries without such a program are interested in learning about current models as a guide for planning their own program. This study was performed to take stock of the screening programs for visual dysfunction in children in existence in the years 1999-2000 worldwide. The aspects considered were the child's age at examination, examiner's qualification, type of examinations performed, cost-bearing entity, and cost-efficacy analysis. The health ministries of 190 sovereign countries were asked via a questionnaire for information about possibly existing screening programs. The results of the survey were analyzed quantitatively regarding geographic, political, and socioeconomic aspects, yielding data for the exchange of experience in optimizing existing programs and developing new programs.

Screening and preventable illness

If an agent does not discount the future at a constant rate, as in some forms of myopia, her optimal strategy is unattainable without some commitment device. We apply this familiar idea to a model of screening and disease prevention, and explore how financial incentives can correct suboptimal health choices. In general, myopia need not imply under-screening. While the optimal intervention for prevention effort is a state-invariant subsidy, the optimal intervention for screening may involve a tax or a subsidy. When screening and prevention are coincident, a simple and practical subsidy equal to one minus the discount factor to both screening and intervention is indicated.