"Off-the-shelf" spectacles could help millions

Daithí Ó hAnluain
in Chester , England

THE largest vision surveys ever carried out in Bangladesh revealed that 3.2 million adults aged 30 years and older in that country could benefit from spectacle correction. Mr Rupert Bourne, Specialist Registrar Ophthalmology at Moorfields Eye Hospital and collaborating ophthalmologist for the national blindness and low vision survey in Bangladesh , presented the initial results of the study to UKISCRS 2003. The study's objectives included investigating the effect of refractive error and co-existent disease on vision in Bangladesh and assessing need for refractive services. The team also defined and established spectacle coverage, examined factors associated with lack of refractive correction and suggested ways to meet the need.

The target population was 30 years and older, representing 42 million Bangladeshis. The team enumerated a sample of 12,900 subjects, in 154 cluster sites scattered widely across the country. Three teams performed the survey and 11,675 people were ultimately examined (91% of the sample). The survey collected demographic information, measured distance visual acuity with logMAR, and performed an automated refraction on every subject. Those subjects with less than 6/12 vision in either eye were tested for best-corrected visual acuity and then underwent a dilated retinal examination. Some 9,164 (78 %) people had 6/12 VA or better in both eyes while 2511 (21%) were worse than 6/12. Overall, the study found that 6.7% of men and 9.2% of women in Bangladesh could achieve at least 6/12 in the better eye. The team also looked at co-existent disease (with refractive error) and demonstrated that in the case of cataract, refractive correction would halve the numbers with a visual acuity of less than 6/12.

"This means, extrapolating our results for Bangladesh as a whole, that 1.4 million men and 1.8 million women have an unmet need. That is, non-spectacle wearers, who see less than 6/12 in the better eye, but who would see 6/12 or better in the better eye were they to be corrected. And we advanced a definition for spectacle coverage of met need over total need. In men this was 30%, significantly larger than in women, where it was 21%," Dr. Bourne reported.

The research indicates that the number of people in the near normal, moderate, and severe visual impairment groups could be reduced by more than 50% by spectacle correction alone. The team found that specific variables were associated with a lack of refractive correction. "If you are illiterate, if you live in a rural area, haven't been to school or you have a manual occupation you are much more likely to be uncorrected." The survey data will be used to plan and deliver eye-care services, and the Bangladeshi government plans to achieve the targets set by the Vision 2020 initiative.

Vision 2020 is a worldwide concerted effort designed to eliminate avoidable blindness by the year 2020. The program will focus on cataract, onchocerciasis, trachoma, child blindness, xerophthalmia and refractive error.

"So how do we meet the need?" said Mr Bourne. "One option would be to give ‘off- the- shelf' spectacles and this would cope with 72% of the 10% who would benefit from spectacles. That is only one option among many other issues that need to be addressed in Bangladesh . The resources and infrastructure require much more development." "There is a huge backlog of blindness and visual disability worldwide, and this study is a very important contribution showing that a simple measure such as provision of appropriate spectacles can have a significant beneficial impact, said Mr. David Allen, consultant ophthalmologist with Sunderland Eye Infirmary and president of the United Kingdom and Ireland Society of Cataract and Refractive Surgeons (UKISCRS). "It is particularly noticeable that simple spectacle correction would be of greatest advantage to the least privileged. This puts our current concerns in the developed world to correct small pre-existing astigmatic errors into a different context," he added.

Dr. Rupert Bourne,
Specialist Registrar Ophthalmology
Moorfields Eye Hospital
rupert_bourne@hot mail.com

David Allen FRCophth
Sunderland Eye Infirmary
David@allen50.fsnet.co.uk

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