Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Global Blindness: Understanding refractive error

916 views

Published on

Uncorrected refractive error is a major cause of visual impairment in the world after cataract. Estimates from 2004 indicate that over 8 million people are blind and over 145 million are visually impaired because they lack refractive correction. In this presentation we define refractive error in the context of public health and describe its epidemiology. We then go on to explore the factors which affect refractive error service delivery and school health programmes.

© 2016 International Centre for Eye Health, London School of Hygiene & Tropical Medicine. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license.

Taken from the free online course: Global Blindness: Planning and Managing Eye Care Services. We encourage the use and adaptation of this resource for teaching and learning. Find more Open Educational Resources for eye care on our website at http://iceh.lshtm.ac.uk/oer

Published in: Education
  • Login to see the comments

Global Blindness: Understanding refractive error

  1. 1. Global Blindness: Planning and managing eye care services Understanding refractive error
  2. 2. Learning outcomes Define refractive error and describe its epidemiology Explore considerations for service delivery at community level Appraise school health programmes and their management
  3. 3. Refractive error is a presenting visual acuity of < 6/18 which can be corrected by refraction or by pin hole - temporarily
  4. 4. Correctable myopia is worse than -1 dioptre Correctable hyperopia is +3 dioptres or more Correct astigmatism of 1.5 dioptres or more
  5. 5. International Classification of Disease
  6. 6. Uncorrected refractive error is the second major cause of blindness and low vision in the world 8 million blind 145 million visually impaired
  7. 7. Who is most affected by refractive error? In children aged under 15, higher prevalence found in urban areas
  8. 8. Who is most affected by refractive error? 94 million people aged over 50
  9. 9. The largest burden of refractive error is in India and China More research is needed
  10. 10. Why is there so much refractive error? Lack of vision testing for children Lack of refractive services Limited affordability
  11. 11. Why is there so much refractive error? Sometimes spectacles are not regarded as essential Cultural disincentives
  12. 12. Impact of visual impairment from refractive error Isolation and fewer opportunities Limited educational performance and success
  13. 13. Impact of visual impairment from refractive error Lower quality of life and poverty More exposure to morbidities and higher mortality rates
  14. 14. Two strategies for improving access Plan for a population of 50,000 Focus on increasing demand and supply
  15. 15. Primary level
  16. 16. Estimating demand for spectacles Calculate from prevalence data for the target population
  17. 17. Estimating demand for spectacles Where no data is available, 20% of the total population is reasonable estimate
  18. 18. Creating demand: social marketing
  19. 19. Creating demand: school health programmes
  20. 20. Creating demand: in the workplace
  21. 21. Creating demand: promotion & access
  22. 22. Equipment
  23. 23. Equipment
  24. 24. Equipment
  25. 25. Vision testing Priority age group: Children aged 12 – 14 years Each eye is tested: If vision <6/12 in either eye then refer
  26. 26. Vision testing School teachers can be trained to do an initial visual assessment Teachers are provided with: Vision kit Referra l protoco l Support
  27. 27. School vision testing programmes Recruit science teachers and teachers who wear spectacles Teachers must have support of school authorities
  28. 28. Vision testing in schools: Key points Teachers must be trained and supported Test each eye Children that fail the 6/12 visual acuity cut off must be referred, using an agreed method
  29. 29. School vision testing programmes Train teachers to refer each case they identify All testing and referral information should be recorded Children who are prescribed spectacles should also be followed up
  30. 30. School vision testing programmes Support and counselling must be provided to parents and children
  31. 31. Monitor school vision testing programmes in order to know: Coverage Uptake of referral Effectiveness of teacher training Acceptance of correction
  32. 32. Monitoring example 5,000 children enrolled 3,000 children vision tested
  33. 33. Coverage = 5,000 children enrolled 3,000 children vision tested 3,000 5,000 x 100 = 60%
  34. 34. Uptake = 110 children referred 75 children present 75 110 x 100 = 68%
  35. 35. Correct referrals = 75 children present 55 children referred 75 110 x 100 = 73%
  36. 36. Acceptance rate = 55 children referred 40 children accept correction 40 55 x 100 = 73%
  37. 37. Data can be monitored on a monthly basis and used to adjust the intervention
  38. 38. Vision testing in schools can have a huge impact
  39. 39. Services need to be planned with: Effective communic- ation Good monitoring and management Adequate resources
  40. 40. In conclusion Refractive error is the second most important cause of visual impairment and blindness globally Correction is relatively simple and the challenges are in access, affordability and acceptance
  41. 41. In conclusion Comprehensive service delivery at community level is essential School vision testing is an important strategy
  42. 42. Written by Dr Daksha Patel © 2016 International Centre for Eye Health, London School of Hygiene & Tropical Medicine. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International license. Taken from the free online course: Global Blindness: Planning and Managing Eye Care Services. We encourage the use and adaptation of this resource for teaching and learning. Find more Open Educational Resources for eye care on our website at http://iceh.lshtm.ac.uk/oer

×