A population based eye survey of older adults in Tirunelveli district of south India: blindness, cataract surgery, and visual outcomes
P K Nirmalan, R D Thulasiraj, V Maneksha, R Rahmathullah, R Ramakrishnan, S R Munoz, A Padmavathi, L B Ellwein
Aims: To assess the prevalence of vision impairment, blindness, and cataract surgery and to evaluate visual acuity outcomes after cataract surgery in a south Indian population.
Methods: Cluster sampling was used to randomly select a cross sectional sample of people >50 years of age living in the Tirunelveli district of south India. Eligible subjects in 28 clusters were enumerated through a door to door household survey. Visual acuity measurements and ocular examinations were performed at a selected site within each of the clusters in early 2000. The principal cause of visual impairment was identified for eyes with presenting visual acuity <6/18. Independent replicate testing for quality assurance monitoring was performed in subjects with reduced vision and in a sample of those with normal vision for six of the study clusters. Results: A total of 5795 people in 3986 households were enumerated and 5411 (93.37%) were examined. The prevalence of presenting and best corrected visual acuity > 6/18 in both eyes was 59.4% and 75.7%, respectively. Presenting vision <6/60 in both eyes (the definition of blindness in India ) was found in 11.0% , and in 4.6% with best correction. Presenting blindness was associated with older age, female sex, and illiteracy. Cataract was the principal cause of blindness in at least one eye in 70.6% of blind people. The prevalence of cataract surgery was 11.8% - with an estimated 56.5% of the cataract blind already operated on. Surgical coverage was inversely associated with illiteracy and with female sex in rural areas. Within the cataract operated sample, 31.7% had presenting visual acuity > 6/18 in both eyes and 11.8% were <6/60; 40% were bilaterally operated on, with 63% pseudophakic. Presenting vision was <6/60 in 40.7% of aphakic eyes and in 5.1% of pseudophakic eyes; with best correction the percentages were 17.6% and 3.7%, respectively. Refractive error, including uncorrected aphakia, was the main cause of visual impairment in cataract operated eyes. Vision <6/18 was associated with cataract surgery in government, as opposed to that in non-governmental/private facilities. Age, sex, literacy, and area of residence were not predictors of visual outcomes. Conclusion: Treatable blindness, particularly that associated with cataract and refractive error, remains a significant problem among older adults in south Indian populations, especially in females, the illiterate, and those living in rural areas. Further study is needed to better understand why a significant proportion of the cataract blind are not taking advantage of free of charge eye care services offered by the Aravind Eye Hospital and others in the district. While continuing to increase cataract surgical volume to reduce blindness, emphasis must also be placed on improving post-operative visual acuity outcomes. Published courtesy of: Br J Ophthalmol 2002; 86: 505-512
Does prospective monitoring improve cataract surgery outcomes in Africa?
D Yorston, S Gichuhi, M Wood, A Foster
Aims: To determine if prospective monitoring influences cataract surgical outcomes in east Africa.
Methods: A prospective observational study of all routine extracapsular cataract extractions with posterior chamber lens implants carried out at Kikuyu Eye Unit, Kenya, between 1 January 1999 and 31 December 1999.
Results: Out of 1845 eligible eyes 1800 were included in the study. Two months’ follow-up was available in 67.2% of patients. The proportion achieving a good outcome increased steadily from 77.1% in the first quarter to 89.4% in the fourth quarter (c2 for trend, p<0.001). There was no change in the incidence of operative complications; however the proportion of patients achieving a good visual outcome following vitreous loss increased from 47.2% in the first 6 months to 71.0% in the last 6 months (c2 p<0.05). Of the eyes with poor outcome (best corrected acuity <6/60 at 2 months) half were due to pre-existing eye diseases. The proportion of patients with known ocular co-morbidity decreased from 10.2% in the first quarter to 5.9% in the fourth quarter (c2 for trend, p<0.05). Poor outcome was associated with age over 80 years, known diabetes, pre-operative bilateral blindness, any ocular co-morbidity, and intra-operative vitreous loss. Conclusion: This study demonstrates improvement in visual outcome results after cataract surgery over a 1 year period. Monitoring of outcomes appears to be associated with a change in surgeons’ attitudes, leading to greater emphasis on appropriate case selection, better management of surgical complications, and improved visual outcomes. Published courtesy of Br J Ophthalmol 2002; 86: 543-547
News and notices in Comm Eye Health Vol. 15 No. 43 2002 –
- Professor Gordon Johnson’s ‘retirement’
- Courses at Aravind Eye Hospital
- International Council of Ophthalmology assessments for Ophthalmologists
- We are moving!
- Helping children who are blind: family and community support for children with vision problems
- Royal College of Ophthalmologists: notice to all candidates