Presentation on theme: "RAPID ASSESSMENT OF REFRACTIVE ERROR (RARE)"— Presentation transcript:
1 RAPID ASSESSMENT OF REFRACTIVE ERROR (RARE) This course describes data collection issues at various levels for different decision making purposes. Speakers will address tools from the perspectives of point of service to implementers, to donors, to industry, and also at the national and to regional levels. The strengths and limitations of current approaches will be discussed by each speaker and the potential for integration in health systems.At the conclusion of this course, participants will:Define data collection needs at various levels of eye careApply monitoring tools for different programme needsUse existing data for making decisions about planning servicesPrepare results-based reports for stakeholders at various levelsExplore the use of social networking technology in data collectionProfessor Kovin NaidooGlobal Programs DirectorIAPB AFRICA CHAIRPERSON
2 Uncorrected Refractive Error (URE) “The Crisis” URE is most common cause of Visual impairment (VI) worldwide and 2nd most common cause of blindness1,2URE drives children and adults further into poverty:3Limits opportunities to educationEmploymentSeriously impacts quality of life and productivityLink between poverty and VI due to URE places heavy economic burden on individuals families affected nationsResnikoff S, Pascolini D, Mariotti S, Pokharel P. Global magnitude of visual impairment caused by uncorrected refractive errors in Bull World Health Organ 2008;86:63-70.2. Holden BA, Fricke T, Ho S, Wong R, Schlenther G, Cronje S, et al. Global vision impairment due to uncorrected presbyopia. Arch Ophthalmol 2008;126:3. Durban Declaration on Refractive error and service development
3 What is the status of URE?4 Prevalence of Visual Impairment158 million cases of Distance VI544 million cases of Near VIHuman Resources Required47000 full-time refractionists18000 ophthalmic dispensersCost of Human Resource DevelopmentUS $20-28 billionEstimated loss in global GDP due to DVIUS $ 202 billionImplications4. Fricke, Holden, Wilson, Schlenther, Naidoo, Resnikoff, Frick. Global cost of correcting vision impairment from uncorrected refractive error. Bulletin of WHOThere were an estimated 158 million cases of distance vision impairment and 544 million cases of near vision impairment caused by URE worldwide in Approximately additional full-time functional clinical refractionists and ophthalmic dispensers would be required to provide refractive care services for these individuals. The global cost of educating the additional personnel and of establishing, maintaining and operating the refractive care facilities needed was estimated to be around 20 billion United States dollars (US$) and the upper-limit cost was US$ 28 billion. The estimated loss in global gross domestic product due to distance vision impairment caused by URE was US$ 202 billion annuallyConclusion The cost of establishing and operating the educational and refractive care facilities required to deal with vision impairment resulting from URE was a small proportion of the global loss in productivity associated with that vision impairment.Implications
4 Historical Situation Paucity of Data Refractive data elicited through: RESC studiesFrom community to schoolChildren onlyConventional Population based studiesProhibitively expensiveHigh level of expertiseFew and far betweenLag between completion and Program implementation timelines
5 CONTEXT SETTING Why and where do we need data National level PlanningEvaluationAwarenessAdvocacyRegional levelEstablish priorities for investment in regionsInformation needed at national level provides:Information on the needsAwarenessAdvocacyInformation needed at Regional level enables:Needs
6 RARE Evolved out of RACSS and RAABS RapidQuickCost effectiveAssessmentSimpleResultsRefractive ErrorPrevalenceBarriers
7 EXPAND to the national or even global context How does RARE data help?RARE data can be used in a top-down or bottom-up approach.TOP-DOWNGloballymil VImil BlindRARE STUDIESLOCATEBlindandVIRegionalRARERARE STUDIESEXPAND to the national or even global contextIn looking at it as a TOP-Down approach, we know that there are according to recent stats by Pascolini et al, globally 285 mil people with VI and 246 blind. RARE studies allow us to LOCATE these individuals and then allows to take the appropriate action. At the national level, there are several approaches that can be employed to address this dire situation.Alternatively, we can look at it as a bottom-up approach. We conduct RARE studies at region levels and then if the sample is representative, we can expand broadly to national and in some cases, even global …. Kovin we should do this with SA RARE data….i hav asked Farai/research team to provide this.BOTTOM-UP
9 Target GroupRARE studies used to assess prevalence of URE, presbyopia, spectacle coverage, and barriers to uptake of services for refractive errors and presbyopia5Studies are focused on:Younger age groups more affected by REPresbyopia15-49 years
10 Uncorrected Refractive Error (URE) DefinitionsConditionDefinitionVisual ImpairmentBinocular Presenting VA<6/12 in the better eyeUncorrected Refractive Error (URE)Presenting VA<6/12 but improving ≥6/12 with pinholePresbyopiaBinocular near vision < N8 at33-35cms
11 Uncorrected Presbyopia Corrected Presbyopia (Met need) DefinitionsDefinitionDescriptionURE(Unmet need)Unaided VA <6/12 but improving to 6/12 or better with pinhole and no spectaclesUncorrected PresbyopiaBinocular Unaided near vision <N8 in subjects aged >35 years with no distance VI and no spectaclesCorrected RE(Met need)Unaided VA<6/18 but improved to 6/18 or better with spectaclesCorrected Presbyopia (Met need)Unaided near vision < N8, but improved to N8 or better with their spectacles
12 RARE Toolkit Equipment Purpose Snellen chart (E, Alphabet optotypes) Distance Visual AcuityMeasuring tape or StringMeasure testing distance: subject and chartMultiple pinhole occluderPresenting VA, if VA<6/12N notation chartNear visionTorch lightExternal examinationReady made spectacles (+1.0 to +3.0 Ds)Best corrected near vision assessment in individuals with presbyopia
13 OUTPUTS OF RARE STUDIES Magnitude of RE (uncorrected)Prevalence of presbyopiaSpectacle coverage and utilisation patternsUnderstanding barriers to access of servicesProvide baseline informationTrends in prevalence determined on follow up studiesWhat is the impact of gathering this information? ....
16 Current and future RARE studies Studies conductedEritreaGhanaUgandaSouth AfricaTanzaniaStudies in preparationMozambiqueGambiaZambiaCameroonEthiopiaMalawi
17 MAJOR BARRIERS IDENTIFIED IN RARE STUDIES CONDUCTED Affordability of the spectacle examAware of problem but felt no need for consultationUnaware of problemCannot afford the cost of glasses
18 Comparison of visual impairment and refractive error prevalence across various RARE studies Presbyopia was present in 690 (63.7%, 95% CI, %) subjects aged over 35 years. Spectacle coverage for refractive error was 29% and for presbyopia it was 19%.CONCLUSIONS:There is a large unmet need for refractive correction in this area in India. Rapid assessment methods are an effective means of assessing the need for services and the impact of models of care.FYI: Reasons for looking at age and sex adjusted data: The age and sex adjusted rate can be considered an average of each of the individual age or gender specific rates, but rather than being a simple average, it is a weighted average with each age or gender specific rate weighted by the proportion of people in the same age or gender group in the standard population.
20 ReferencesResnikoff S, Pascolini D, Mariotti S, Pokharel P. Global magnitude of visual impairment caused by uncorrected refractive errors in Bull World Health Organ 2008;86:63-70.Holden BA, Fricke T, Ho S, Wong R, Schlenther G, Cronje S, et al. Global vision impairment due to uncorrected presbyopia. Arch Ophthalmol 2008;126:Fricke TR, Holden BA, Wilson DA, Schlenther G, Naidoo KS, Resnikoff S and Frick KD. Global cost of correcting vision impairment from uncorrected refractive error.Naidoo KS, Wallace DB, Holden, BA, Minto H, Faal HB, Dube P. The challenge of uncorrected refractive error: driving the agenda of the Durban Declaration on refractive error and service development. Clin Exp Opt 2010: 93(3):Marmamula S, Keeffe JE, Rao GN. Uncorrected refractive errors, presbyopia and spectacle coverage: Results from a Rapid Assessment of Refractive Error survey. Ophthalmic Epidemiology 2009;16:Marmamula et al. Population-based cross-sectional study of barriers to utilisation of refraction services in South India: Rapid Assessment of Refractive Errors (RARE) Study. British Medical Journal.
21 Acknowledgements Pirindha Govender Brien Holden Vision Institute (Public Health Division) – Research Department