Rapid assessment of avoidable blindness and needs assessment of cataract surgical services in Satkhira District, Bangladesh.

AIMS: To estimate the magnitude and causes of blindness in people aged > or =50 years in Satkhira district, Bangladesh, and to assess the availability of cataract surgical services. METHODS: 106 clusters of 50 people aged > or =50 years were selected by probability-proportionate to size sampling. Households were selected by compact segment sampling. Eligible participants had their visual acuity measured. Those with visual acuity <6/18 were examined by an ophthalmologist. A needs assessment of surgical services was conducted by interviewing service providers. RESULTS: 4868 people were examined (response rate 91.9%). The prevalence of bilateral blindness was 2.9% (95% confidence interval (CI) 2.4% to 3.5%), that of severe visual impairment was 1.6% (95% CI 1.2% to 2.0%) and that of visual impairment was 8.4% (95% CI 7.5% to 9.3%). 79% of bilateral blindness was due to cataract. The cataract surgical coverage was moderate; 61% of people with bilateral cataract blindness (visual acuity <3/60) had undergone surgery. 20% of the 213 eyes that had undergone cataract surgery had a best-corrected poor outcome (visual acuity <6/60). The cataract surgical rate (CSR) in Satkhira was 547 cataract surgeries per million people per year. CONCLUSIONS: Although the prevalence of blindness and visual impairment was lower than expected, the CSR is inadequate to meet the existing need, and the quality of surgery needs to be improved.

[Avoidable visual impairment in The Netherlands: the project "Vision 2020 Netherlands" of the World Health Organization]. / Vermijdbare slechtziendheid in Nederland: het project 'Vision 2020 Netherlands' van de Wereldgezondheidsorganisatie.

In the year 2004 there were an estimated 220,000-320,000 people in The Netherlands with visual impairment. In 150,000-220,000 (70%) of them the visual impairment is either curable or could have been prevented. Those most at risk are people with intellectual disabilities, elderly people in care institutions, elderly people in general and diabetics. 'Vision 2020 Netherlands', an initiative of the World Health Organization, was launched to eliminate avoidable visual impairment in the Netherlands by the year 2020 by means of awareness campaigns, implementation of screening programmes and by expanding eye care capacity through efficient cooperation between the professional groups involved in eye care.

Routine monitoring of visual outcome of cataract surgery. Part 1: Development of an instrument.

AIM: To develop a system for routine monitoring of visual outcome after cataract surgery. METHODS: Staff from eight eye centres in Asia and Africa defined the data collection form and report formats to be used for monitoring visual outcome after cataract surgery. Several operational research questions were raised and methods developed to address them. The system was field tested for 6 months and the operational studies undertaken. The system was finalised based upon the experience gained. FINDINGS: Two different systems for data collection were developed: a manual paper tally system and a computer system (cataract surgery record forms (CSRF)). Both systems report on operative complications; the proportion with good outcome (can see 6/18) and poor outcome (cannot see 6/60); and causes of poor outcome. Data are collected at discharge and at specified time intervals at follow up. Both systems were well accepted. CONCLUSION: The major problem in field testing was data entry errors in centres using the computerised system. Routine monitoring of cataract outcome should be used by individual surgeons or centres to follow trends in their own results over time, and not to compare surgeons, in an atmosphere of trust and support. Visual acuity at discharge, which can readily be collected on all patients, can be used providing it is appreciated that the final results will be much better. Rapid feedback of results can enhance the consciousness of the eye surgeons to causes of poor outcome. Accuracy in data entry and an efficient flow of record forms are essential.

Routine monitoring of visual outcome of cataract surgery. Part 2: Results from eight study centres.

AIM: To determine whether monitoring of cataract outcome can be implemented as a routine activity in different hospital settings in Africa and Asia, and to assess the impact of routine monitoring. METHODS: Eight eye centres in Asia and Africa were involved in the study between 1 June and 31 December 2000. Seven centres used a specifically designed cataract surgery record form with computerised data entry and analysis (CCSRF), and one centre used a manual recording form (MCSRF). Data were used to evaluate quality of data entry, follow up after surgery, and to assess trends in the proportion of complications and visual outcome after surgery. FINDINGS: The reporting systems were accepted and used by all centres, and data were recorded for 5198 cataract operations. Overall, 54% of eyes were followed for 8 weeks or more and 41% for 6 months. Follow up rates varied between centres from nil to almost 100%. Visual acuity tended to improve over time. The outcome could be improved at all follow up periods by providing best spectacle correction. At 8 weeks or more follow up, surgical complications or inadequate spectacle correction accounted for 72% of the causes of poor outcome. Three centres showed a significant reduction in complication rates over the course of the 6 month study. Data entry was identified as a problem and the CCSRF software has been modified to include consistency checks to reduce data entry errors. CONCLUSION: A simple system to monitor cataract outcome has been successfully field tested. The results suggest that monitoring can sensitise surgeons to quality control, which can lead to a decrease in complication rates and improved visual outcomes.

Cataract blindness in Turkmenistan: results of a national survey.

AIM: To present results of a rapid assessment of cataract in Turkmenistan. METHODS: 6120 eligible people of 50 years and older were selected by systematic random sampling from the whole of Turkmenistan. A total of 6011 people were examined (coverage 98.2%). RESULTS: Cataract is the major cause of bilateral blindness (54%), followed by glaucoma (25%). The age and sex adjusted prevalence of bilateral cataract blindness (VA <3/60) in people of 50 years and older was 0.6% (95% CI: 0.4 to 0.9), with a cataract surgical coverage of 75% (people). For VA <6/60 the prevalence was 2.6% (95% CI: 2.1 to 3.2) in people aged 50 and above, approximately 0.26% of the total population. In this last group the surgical coverage was 44% (people) and 32% (eyes). Of the patients operated with IOL implantation 8.2% could not see 6/60, 44.8% of those operated without IOL could not see 6/60. The main barrier to cataract surgery was indifference ("old age, no need for surgery"), followed by "waiting for maturity." CONCLUSION: To increase the cataract surgical coverage in Turkmenistan the intake criteria should be lowered to VA <6/60 or less. At the same time the visual outcome of surgery can be improved by expanding the number of IOL surgeries and routine monitoring of cataract outcome. Additional investments will be required to provide all eye surgeons with appropriate equipment and skills for IOL surgery.

Trial of the Trachoma Rapid Assessment methodology in The Gambia.

PURPOSE: To test the validity and repeatability of a newly designed Trachoma Rapid Assessment (TRA) methodology. METHOD: Results from an initial TRA in 20 villages (TRA1) are compared with those of a second validation TRA (TRA2) after 6 weeks in 13 villages, randomly selected out of the original 20, conducted by different field staff. Findings of TRA1 and TRA2 are compared with those of a door-to-door survey of the entire population of all 13 villages. RESULTS: There is a considerable amount of variation between the results of TRA1 and TRA2 and between the results of both TRA's and the door-to-door survey. Even indicators that should have remained the same, like distance to Primary Health Centre or distance to trichiasis surgery facility, scored differently. CONCLUSIONS: The TRA methodology is easy to use and the results are quickly available. The scoring system indicates which intervention(s) of the SAFE strategy are needed and facilitates priority setting. The definition of some indicators, like availability and use of latrines, may need modification. In some cases, the scoring system seems to exaggerate differences between the actual findings. The consistency between two TRA's in the same village is low and the accuracy in measuring the actual situation is doubtful.

Results of school eye screening of 5.4 million children in India--a five-year follow-up study.

PURPOSE: To assess results of a vision screening programme in schools in India, 5 years after its introduction. MATERIAL: Questionnaires on school eye screening activities were sent to 200 randomly selected districts. METHODS: Data from 61 districts were analysed, using process indicators to assess performance at different stages of the screening procedure. RESULTS: Teachers screened 5.39 million children in 61 districts. Refraction was done on 205,082 children (3.8%) and 43,922 children (0.8%) were provided with spectacles. Children of 10-15 years have more refractive errors. Different stages in the procedure are evaluated. CONCLUSION: Vision screening in schools has been taken up successfully in many districts in India. This has reduced the workload of eye care staff and increased the coverage. The simplicity of the procedure facilitates widespread application. Many parents take their children to the private sector for services. Monitoring and reporting needs to be improved.

Monitoring visual outcome of cataract surgery in India.

Two simple methods of assessing visual outcome following cataract surgery were evaluated in India. The first used data obtained from standardized patient records of cataract surgery. The second used data from population-based rapid epidemiological assessments. Analysis of 4168 hospital and eye camp records showed that, with the available standard correction, a good outcome (visual acuity > or = 6/18) was achieved in 37.8%, a borderline outcome (visual acuity 6/246-6/60) in 45.6% and a poor outcome (visual acuity 6/60) in 16.6% of instances. Of 2401 aphakic/pseudophakic eyes examined in a cross-sectional population-based study, outcome was good in 43.5% and poor in 26.4%. For 776 eyes examined in a similar study in a different state, outcome was good in 49.9% and poor in 23.9%. These assessments indicate that outcome with available correction was poor in 15-25% of eyes following cataract surgery. Visual outcome is likely to improve when better correction for aphakia can be provided. Further assessment of the causes of poor visual outcome is needed. The visual outcome following cataract surgery could be monitored on a regular basis by ophthalmologists, using either of the methods evaluated, an exercise which in itself is likely to improve the outcome of surgery. When the proportion of poor outcomes is high (> 10%) further investigation into the causes is warranted.

Changing trends in barriers to cataract surgery in India.

Cataract is a major cause of blindness in Asia. Efforts in India to provide cataract surgical services have had limited success in reaching the cataract-blind population. Earlier studies identified the major barriers to cataract surgery as poverty, lack of transportation or felt need, or sex related; and the critical barriers in rural areas as lack of awareness, difficult access, and cost. Compared with these earlier data, the results of the present study in Karnataka State indicate a shift in the character of the barriers. They now appear to be more related to case selection and service provision. These shifts are analysed and alternative strategies to increase the uptake to cataract surgery are recommended.

Follow-up study of blindness attributed to cataract in Karnataka State, India.

AIM: Presentation of the results of rapid assessments of bilateral cataract blindness in persons 50 years of age and older in 19 districts of Karnataka State, India. MATERIALS: A total of 21,950 persons 50 years of age and older in 19 out of 20 districts were examined. In each district, 15 clusters were randomly selected and in each cluster the visual acuity and lens status were assessed in 90 persons 50 years of age and older. METHODS: Systematic Random Cluster Sampling was used. Assuming a prevalence of at least 4.3% and a design effect of 1.5, the survey was designed to give an estimated prevalence with a sampling error of 20% or less at 80% confidence. Visual acuity was measured with a tumbling E chart at 6 meters distance with available correction. Lens status was assessed by distant direct ophthalmoscopy with undilated pupil under semi-dark conditions. RESULTS: The average age and sex adjusted prevalence of cataract blindness was 4.93%, with a variation of 1.58% to 7.24% in different districts. The prevalence in females was higher than in males. Cataract Surgical Coverage, an indicator for coverage and service utilization, varied from 42% to 68% in different districts. On average, males had a higher coverage than females. Of all aphakic eyes in the sample, 26.4% could not see 6/60. Barriers to cataract surgery are linked to service providers. CONCLUSIONS: Rapid assessments for cataract blindness in persons aged 50 years and older can be conducted at district level in India with existing resources and at affordable costs. The results suggest an increase in cataract blindness since the previous survey of 1986. The long-term visual outcome needs improvement. Change in barriers to cataract surgery requires a shift in health education strategy and messages. The large variation in prevalence justifies district-level surveys. A change in the sampling frame from 15 clusters of 90 to 28 x 40 or 37 x 30 will increase the precision.

CATARACT SURGICAL COVERAGE: An indicator to measure the impact of cataract intervention programmes.

AIM: To describe Cataract Surgical Coverage (CSC) as an indicator to measure the impact of cataract intervention programmes. METHODS AND MATERIALS: Cataract Surgical Coverage, both for 'eyes' as well as 'persons', was calculated from community based surveys conducted in 19 rural districts in the south-west and one urban district in the north-west of India. RESULTS: Cataract Surgical Coverage (VA<3/60) ranged from 42% to 68% (for persons) and from 22% to 45% (for eyes) in 19 districts of Karnataka State. The coverage for males was higher than for females. In Ahmedabad the coverage was high with 93% for persons and 83%for eyes. DISCUSSION: Together with prevalence data, Cataract Surgical Coverage can provide important information on the impact of cataract intervention programmes. Regular assessment of prevalence and coverage indicators through focused community surveys will reveal trends. Coverage indicators are also important as input data for mathematical models to predict future trends in cataract blindness.

Rapid assessment of prevalence of cataract blindness at district level.

AIM: To find an optimal cluster size and number of clusters for a reasonable estimate of the prevalence of cataract blindness in people aged > or = 50 years in 19 rural districts of a state in India. MATERIALS: Cluster sampling methodology was used in 19 rural districts of Karnataka State, India. In each district, 15 clusters were randomly selected and 90 people aged > or = 50 years were examined in each cluster. As a result the visual acuity and lens status of a total of 22,218 people were assessed. METHODS: For each district, the design effect for cluster size ranging from 20 to 90 was calculated and the optimal cluster size and the required number of clusters to achieve an accuracy of 1% errors and 80% confidence was assessed. RESULTS: The age and gender adjusted prevalence of cataract blindness varied from 1.58% to 7.24%, which justifies district level surveys. The design effect is nearly 1.5 for clusters of sizes 30 and 40. With an average prevalence of 4.93% with 1% error and 80% confidence level, the optimal number of clusters is 37 and 28 for a cluster size of 30 and 40 respectively and the average sample size for a district around 1100. CONCLUSIONS: Rapid assessments for cataract blindness in those aged > or = 50 years can be conducted at district level in India with existing resources and at affordable costs. These provide reliable data, essential for effective monitoring and planning. Other parameters, for instance, surgical coverage can also be assessed. The availability of standardized software for data entry and analysis and strict adherence to survey procedures is essential.

Cataract blindness on the rise? Results of a door-to-door examination in Mohadi.

A census survey in Mohadi block, Bhandara district of Maharashtra, indicated that the prevalence of blindness and cataract blindness has increased, compared with the 1986 survey. Around one third of the persons blind from cataract have been covered by surgical services. To increase coverage, more emphasis on information, education and communication is essential.

Monitoring and evaluating cataract intervention in India.

AIM: To identify indicators to monitor and evaluate the cataract intervention programme in India. METHODS: Available data on blindness due to cataract, demography, staffing levels, and infrastructure available under the programme were reviewed. Four key elements of the programme were identified: the magnitude of blindness due to cataract and the need for surgical services; the available resources; the output, in quantity and in quality, as well as the resource utilisation; and lastly the impact this has on society and the problem of blindness due to cataract. Indicators to quantify these key elements were designed and available data were used to calculate the defined indicators. RESULTS: At least 2.5 million sight restoring cataract operations will have to be performed annually. Staffing levels and infrastructure resources at present allow for increased output. The effectiveness of cataract services can be increased with better case selection. CONCLUSION: The use of these indicators provides an insight into the dynamics of the problem of cataract blindness and its intervention. They facilitate adequate management and evaluation of the efficiency and effectiveness of the intervention programme and may ensure optimal utilisation of the available resources for cataract surgery.

Cost-effective screening of schoolchildren for refractive errors.

Uncorrected refractive errors are the main cause of severely impaired vision in India. This in itself indicates that there is a shortage of basic eye care services and spectacles, and too little public awareness of the need for them. A simple method for screening schoolchildren for refractive errors is described and the results are analysed. Evaluation of the materials used and the accuracy of the screening shows that this method can be used successfully by teachers.

Diffuse retinal pigment epitheliopathy.

19 patients showing the features of diffuse retinal pigment epitheliopathy, as described by Zweng and Little, were studied. Diffuse retinal pigment epitheliopathy resembles both pigment epithelial detachment and central nervous choriopathy, but can be differentiated by the following characteristic features: widespread distribution of small pigment epithelial detachments, little or no leakage visible on the fluorescence angiogram, extensive pigmentary changes, chronic course with exacerbations and remissions, and fair visual prognosis.