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Presentation on theme: "RAPID ASSESSMENT OF REFRACTIVE ERROR (RARE)"— Presentation transcript:

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 care Apply monitoring tools for different programme needs Use existing data for making decisions about planning services Prepare results-based reports for stakeholders at various levels Explore the use of social networking technology in data collection Professor Kovin Naidoo Global Programs Director IAPB 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 blindness1,2 URE drives children and adults further into poverty:3 Limits opportunities to education Employment Seriously impacts quality of life and productivity Link between poverty and VI due to URE places heavy economic burden on individuals  families  affected nations Resnikoff 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 Impairment 158 million cases of Distance VI 544 million cases of Near VI Human Resources Required 47000 full-time refractionists 18000 ophthalmic dispensers Cost of Human Resource Development US $20-28 billion Estimated loss in global GDP due to DVI US $ 202 billion Implications 4. Fricke, Holden, Wilson, Schlenther, Naidoo, Resnikoff, Frick. Global cost of correcting vision impairment from uncorrected refractive error. Bulletin of WHO There 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 annually Conclusion 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 studies From community to school Children only Conventional Population based studies Prohibitively expensive High level of expertise Few and far between Lag between completion and Program implementation timelines

5 CONTEXT SETTING Why and where do we need data National level
Planning Evaluation Awareness Advocacy Regional level Establish priorities for investment in regions Information needed at national level provides: Information on the needs Awareness Advocacy Information needed at Regional level enables: Needs

6 RARE Evolved out of RACSS and RAABS
Rapid Quick Cost effective Assessment Simple Results Refractive Error Prevalence Barriers

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-DOWN Globally mil VI mil Blind RARE STUDIES LOCATE Blind and VI Regional RARE RARE STUDIES EXPAND to the national or even global context In 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 Group RARE studies used to assess prevalence of URE, presbyopia, spectacle coverage, and barriers to uptake of services for refractive errors and presbyopia5 Studies are focused on: Younger age groups more affected by RE Presbyopia 15-49 years

10 Uncorrected Refractive Error (URE)
Definitions Condition Definition Visual Impairment Binocular Presenting VA<6/12 in the better eye Uncorrected Refractive Error (URE) Presenting VA<6/12 but improving ≥6/12 with pinhole Presbyopia Binocular near vision < N8 at 33-35cms

11 Uncorrected Presbyopia Corrected Presbyopia (Met need)
Definitions Definition Description URE (Unmet need) Unaided VA <6/12 but improving to 6/12 or better with pinhole and no spectacles Uncorrected Presbyopia Binocular Unaided near vision <N8 in subjects aged >35 years with no distance VI and no spectacles Corrected RE (Met need) Unaided VA<6/18 but improved to 6/18 or better with spectacles Corrected 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 Acuity Measuring tape or String Measure testing distance: subject and chart Multiple pinhole occluder Presenting VA, if VA<6/12 N notation chart Near vision Torch light External examination Ready made spectacles (+1.0 to +3.0 Ds) Best corrected near vision assessment in individuals with presbyopia

Magnitude of RE (uncorrected) Prevalence of presbyopia Spectacle coverage and utilisation patterns Understanding barriers to access of services Provide baseline information Trends in prevalence determined on follow up studies What is the impact of gathering this information? ....

14 Spectacle Coverage [met need’ ] [(‘met need’ + ‘unmet need’) X 100]

15 Barriers – URE6

16 Current and future RARE studies
Studies conducted Eritrea Ghana Uganda South Africa Tanzania Studies in preparation Mozambique Gambia Zambia Cameroon Ethiopia Malawi

Affordability of the spectacle exam Aware of problem but felt no need for consultation Unaware of problem Cannot 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 References Resnikoff 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


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