Strategies to improve follow-up of children after surgery for cataract: findings from Child Eye Health Tertiary Facilities in sub-Saharan Africa and South Asia

PurposeWe sought to conduct a systematic literature review on follow-up of children with ocular surgical management (primarily childhood cataract) in developing countries. Second, we sought to determine the current practices regarding follow-up for clinical, optical, low vision, rehabilitation, and educational placement among children receiving surgical services at Child Eye Health Tertiary Facilities (CEHTF) in sub-Saharan Africa (SSA) and South Asia.MethodsA systematic literature review was conducted. Separately, we conducted a cross-sectional study among CEHTF in SSA and South Asia (India, Nepal, and Bangladesh) to assess current capacities and practices related to follow-up and educational placement.ResultsThe articles that met the systematic review eligibility criteria could be grouped into two areas: factors and strategies to improve post-operative follow-up and educational placement of children after surgery. Among the 106 CEHTF in SSA and South Asia, responses were provided by 75 CEHTF. Only 59% of CEHTF reported having a Childhood Blindness and Low Vision Coordinator; having a coordinator was associated with having appropriate follow-up mechanisms in place. Educational referral practices were associated with having a low-vision technician, having low-vision devices, and having donor support for these services.ConclusionsThe systematic literature review revealed evidence of poor follow-up after surgical interventions for cataract and other conditions, but also showed that follow-up could be improved significantly if specific strategies were adopted. Approaches to follow-up are generally inadequate at most facilities and there is little external support for follow-up. Findings suggest that funding and supporting a coordinator would assist in ensuring that good practices for follow-up (cell phone reminders, patient tracking, and reimbursement of transport) were followed.

Primary eye care skills scores for health workers in routine and enhanced supervision settings

INTRODUCTION

Primary health care in Tanzania is provided at two types of health units, the dispensary and the health centre. Theoretically, primary health workers (with knowledge of primary eye care [PEC]) are ideally placed to identify people in need of eye care services. In Tanzania, they are expected to be able to identify, treat, or correctly refer a number of eye conditions including cataract, trauma, presbyopia, and the 'red eye'. They are also expected to be able to measure visual acuity correctly and to educate the community about prevention.

OBJECTIVES

The objective was to determine the effect of enhanced supervision of health workers on PEC knowledge and skills in Kilimanjaro Region, Tanzania.

STUDY DESIGN

This was a quasi-experimental, cluster randomized intervention study of an enhanced supervisory method compared to a routine supervisory method; 36 dispensaries were randomly allocated into the two groups.

PARTICIPANTS

Health workers based at government dispensaries in Mwanga District.

DATA COLLECTION

Participants were interviewed pre and post intervention and the information was recorded using a standardized pretested questionnaire.

RESULTS

Mean scores of knowledge in healthcare workers was higher in the intervention group (score = 6.43, 80.4% improvement) compared to the non-intervention group (score = 4.71, 58.9% improvement). The ability to describe and demonstrate vision testing was better (score = 1.8) in the enhanced supervision group compared to the routine supervision group (score = 0.88, P = 0.03). There was a high level of attrition (24%) within one year from the time of baseline survey, especially amongst clinical officers (44%).

CONCLUSION

During the pilot study, enhanced supervision improved PEC knowledge and skills of health workers compared to health workers with routine supervision.

RECOMMENDATIONS

Training in PEC needs revision to become more practicum-based. There is need to revise supervision guidelines (to be skills-based) and the supervision skills of district eye coordinators (DECs) need to be enhanced. There is a huge need to improve governance (accountability and rule of law) of health staff.

Primary eye care in sub-Saharan African: do we have the evidence needed to scale up training and service delivery?

The models for addressing the delivery of an eye-care service in sub-Saharan Africa have seen considerable revision in the last 30 years, and the on-going challenges, as well as the future needs, will probably require many more changes and new systems. There is a need to assess the different models that are currently employed, in order to ensure that all potential contributions to the elimination of avoidable blindness are used; the evolving concept of primary eye care (PEC) requires such assessment. For the current review, the published literature on eye care provided by general front-line healthworkers was screened for articles that provided evidence of the impact of such PEC on the general delivery of eye care in sub-Saharan Africa. Of the 103 relevant articles detected, only three provided evidence of the effectiveness of PEC and the authors of all three of these articles suggested that such eye care was not meeting the needs or expectations of the target populations, the trainers, or programmes of eye care. Among the main problems identified were a lack of a clear definition of the scope of practice for PEC, the need for clarifying the specific skills that a front-line healthworker could perform correctly, and the changing needs and expectations for the delivery of an eye-care service in Africa. If PEC is to become adequately grounded in Africa, the generation of further evidence of the effectiveness and limitations of such care would be a prudent move.

Ocular hypotension and hypotony in multibacillary leprosy patients; at diagnosis, during and after completion of multidrug therapy

The prevalence and incidence of ocular hypotony (IOP < 7 mm Hg) and factors associated with them were determined in a Leprosy Referral Centre at Tamilnadu, India. Applanation intraocular pressures were measured every six months in a cohort of newly diagnosed multibacillary (MB) leprosy patients who were followed-up during the two year period of multidrug therapy (MDT) and for five years thereafter. Transient hypotony was present in two patients at the time of diagnosis, in 3 patients during MDT and in 9 patients after MDT with a cumulative prevalence of 4.65%. Transient ocular hypotension was present in 24 patients (8%) at disease diagnosis. 25 patients developed hypotension during MDT that was associated with trichiasis (HR 8.83 95% CI 2.06, 37.78 p = 0.003) and flare or/and cells (HR 4.60 95% CI 1.08, 19.64 p = 0.039). 29 patients developed ocular hypotension after MDT that was associated with punctate keratitis and uveal involvement. In general, MB leprosy patients with hypotension had a mean IOP of 12.60 mm Hg which differed significantly (p < 0.0001) from the mean IOP of 14.9 mm Hg in those who did not have hypotension. Transient hypotension and hypotony in MB leprosy patients are associated with signs of intraocular inflammation.

Estimating numbers of blind children for planning services: findings in Kilimanjaro, Tanzania

AIM

Childhood blindness is included in the VISION 2020 initiative. However, childhood blindness is rare, so there is limited population-based evidence to assist with the planning of services. We carried out a survey of childhood blindness in Kilimanjaro Region, Tanzania, to generate information needed for planning eye care services.

METHODS

The study was carried out in parallel with a Rapid Assessment of Avoidable Blindness (RAAB) survey. Villages within Kilimanjaro Region were selected on a probability-proportional-to-size basis. Key informants in each village were trained to identify children with any vision problems; a visiting team assessed the children to determine visual status and arranged for further assessment as needed at hospital. The files of children at schools for the blind in the Region were reviewed to identify children in schools from the selected study villages.

RESULTS

Among the 95 040 children in the 72 villages sampled, 13 children were identified as blind; an additional three children were found in the schools for the blind. The prevalence of blindness was 0.17 per 1000 children; the causes of blindness varied but there was no vitamin A- or measles-related corneal blindness and only one case of unoperated cataract.

DISCUSSION

The low prevalence of blindness in children suggests that efforts at reducing childhood blindness in Kilimanjaro Region have been effective. Planners there should focus on community-based approaches to ensure that blind children have appropriate rehabilitation services and educational placements. While it remains impractical to carry out large childhood blindness surveys, this approach attached to a RAAB survey may be useful for generating information for planning services.

Inappropriate enrollment of children in schools for the visually impaired in east Africa

BACKGROUND

Many visually impaired children can learn to read print with appropriate training and simple visual aids. This may allow them to attend normal schools and to be integrated into society, which has lifelong benefits. Yet, in Africa, many visually impaired children are enrolled in special schools and taught only Braille. The purpose of this analysis was to document the extent of inappropriate enrollment of visually impaired children in special schools and annexes for the blind in four African countries.

METHODS

Schools were selected through a population-proportional-to-size method so that they would represent all children attending special schools in Kenya, Malawi, Tanzania and Uganda. Children were examined by ophthalmologists trained in standardised methods to determine visual acuity and the cause of decreased acuity.

RESULTS

Of 1062 children examined in special schools and annexes for the blind, 361 (34%, 95% CI 31.2, 36.8) had visual acuity >or=6/60; the most common cause of visual impairment was retinal disease. Of the 120 children with normal vision (>or=6/18), 69 (57.5%) had two normal eyes, 21 (17.5%) had an obvious ocular disfigurement in the fellow eye and 10 (8.4%) had had successful cataract surgery.

CONCLUSIONS

In these countries, many children are placed inappropriately in special schools and annexes for the blind. The reasons are multiple and to rectify the situation will require advocacy and cooperation between ministries of health and education.

Measuring cataract surgical services in children: an example from Tanzania

BACKGROUND

Childhood cataract is becoming increasingly recognised as a priority for reducing childhood blindness in developing countries. However, there have been no standard methods to monitor progress in providing this service, besides sporadic reports of surgeries performed.

METHODS

Information on all children receiving surgery for congenital/developmental cataract in the two Child Eye Health Tertiary Facilities (CEHTF) in Tanzania was collected for 2004-6. An annual childhood cataract surgical rate (CCSR) was calculated per region. Male-to-female ratios were also generated by region of residence.

RESULTS

Overall, the CCSR (2006) in Tanzania was 9.9 per million population, ranging from 32.3 for regions where CEHTF are located to 5.4 for regions not adjacent to CEHTF regions. There were, on average, 148 boys for every 100 girls receiving surgery.

CONCLUSION

Practical application of a measure of service delivery for childhood cataract has been useful in identifying gaps in utilisation of existing services by region as well as by gender. Testing in other settings would be helpful. An apparent inequity in use of services by girls requires attention.

Productivity of key informants for identifying blind children: evidence from a pilot study in Malawi

OBJECTIVES

To determine the productivity of village-based 'key informants' (KIs) in identifying blind children.

MATERIALS AND METHODS

Ngabu subdistrict (population 101,000) of Chikwawa district was divided into KI catchment areas. KIs, selected by local village leaders, were trained to register children reported to be blind or with severe visual impairment. These children were clinically assessed at designated centres.

RESULTS

In total, 44 KIs were selected and trained to cover 196 villages in Ngabu. They identified and referred 151 children, 37 of whom were blind (presenting vision <3/60 best eye). Overall, village leaders tended to choose female KIs (80%) compared to male KIs (20%); however, male KIs tended to be more productive, identifying 4.22 children each (compared to 3.23 for female KIs). Male KIs were 2.7 times more likely to identify blind children compared to female KIs. Only 25% of all identified blind children of school going age were in school.

CONCLUSIONS

KIs may be effective in identifying blind children in the community; however, additional work is needed to determine who will be the most effective KI in a community and whether gender roles will limit interpretation of findings from KIs activities.

Acceptance of cataract surgery in a cohort of Tanzanians with operable cataract

BACKGROUND

In spite of recent increases in the number of surgeries carried out within some hospitals and programmes in sub-Saharan Africa, there are indications that the acceptance of cataract surgery remains quite low.

METHODS

We conducted a population-based prospective (cohort) study of cataract patients from 12 villages in Hai district of Kilimanjaro region, Tanzania. Those identified with operable cataract were informed of the regular community programmes (within 5 km) in place providing transportation and high-quality surgery. At years 1 and 2 after the survey, we traced the patients to determine uptake of cataract surgery.

RESULTS

Among patients eligible for surgery (128), 31 could not be followed up after 1 year due to deaths, moving, and refusal. Among the remaining patients, 18 accepted surgery in the first year and four accepted in the second year. Among these 22 patients, only five were blind or with severe visual impairment. The most elderly were those least likely to accept surgery.

DISCUSSION

Even with bridging strategies in place to make cataract surgery accessible and affordable, the uptake of cataract surgery remains low. Strategies aimed to identifying and referring all patients recognizing vision loss as a personal disability rather than using predefined vision cutoffs will likely be most successful in reducing the burden of vision loss due to cataract.

Incidence of ocular complications in patients with multibacillary leprosy after completion of a 2 year course of multidrug therapy

AIM

To evaluate the incidence of and risk factors for ocular complications in multibacillary (MB) leprosy patients following completion of 2 year, fixed duration, multidrug therapy (MDT).

METHODS

Biannual eye examinations were conducted prospectively on a cohort of MB patients who had completed MDT and followed up for 5 years. The incidence of ocular pathology was calculated as the number of events per person year of event free follow up of patients who did not have the specific finding before completion of MDT.

RESULTS

278 patients had one or more follow up visits after completion of MDT. The incidence of lagophthalmos was 0.24%/patient year (95% CI 0.10% to 0.37%); corneal opacity, 5.35%/patient year (95% CI 4.27% to 6.70%); uveal involvement, 3.78%/patient year (95% CI 2.96% to 4.83%); and cataract that reduced vision to 6/18 or less, 2.4%/patient year (95% CI 1.77% to 3.26%). Overall, 5.65%/patient year (95% CI 4.51% to 7.09%) developed leprosy related ocular disease and 3.86%/patient year (95% CI 3.00% to 4.95%) developed leprosy related, potentially blinding ocular pathology during the period following MDT. Age and other disability also predicted incident eye disease.

CONCLUSIONS

Every year, approximately 5.6% of patients with MB who have completed MDT can be expected to develop new ocular complications of leprosy, which often (3.9%) are potentially vision threatening. Because many of these complications cannot be detected without slit lamp examination, periodic monitoring, particularly of older patients and those with other disability, is recommended, in order to detect and treat ocular complications satisfactorily.

Incidence of ocular morbidity among multibacillary leprosy patients during a 2 year course of multidrug therapy

AIM

To evaluate the incidence of and risk factors for ocular complications in multibacillary (MB) leprosy patients during their 2 year, fixed duration, multidrug therapy (MDT).

METHODS

Periodic eye examinations were conducted prospectively on a cohort of 301 consecutive newly diagnosed MB patients every 6 months during their 2 year course of MDT. Incidence of ocular pathology was calculated as the number of events per person year of event free follow up of patients who did not have the specific finding at baseline.

RESULTS

292 (97%) patients had one or more follow up visits. The incidence of lagophthalmos was 1.2%/patient year (95% CI 0.5% to 2.8%); corneal opacity was 7.4%/patient year (95% CI 5.1% to 10.6%); uveal involvement was 5.1%/patient year (95% CI 3.3% to 7.8%), and cataract that reduced vision to 6/18 or less was seen in 4.3%/patient year (95% CI 2.7% to 6.9%) of patients. Overall, 23 individuals (5.8%/patient year, 95% CI 3.9 to 8.8) developed leprosy related potentially blinding pathology during the 2 years of MDT.

CONCLUSIONS

Approximately 20% of patients with MB leprosy can be expected to develop ocular complications of leprosy during a 2 year course of MDT, many (11%) of which are potentially vision threatening. Ophthalmological monitoring to detect and treat ocular complications at defined intervals during MDT is indicated.

Distance to water source and altitude in relation to active trachoma in Rombo district, Tanzania

OBJECTIVES

To investigate the relationship between distance to water source, altitude and active trachoma in children in Rombo district, Tanzania.

METHODS

In each of Rombo's 64 villages, 10 balozis (groups of 8-40 households) were selected at random and all resident children aged 1-9 years were examined for clinical signs of active trachoma. The households of these children and village water sources were mapped using differentially corrected global positioning system data to determine each household's altitude and distance to the nearest water supply.

RESULTS

We examined 12 415 children and diagnosed 1171 cases of active trachoma (weighted prevalence=9.1%, 95% CI: 8.0, 10.2%). Active trachoma prevalence ranged from 0% to 33.7% across villages. Increasing distance to the nearest water source was significantly associated with rising trachoma prevalence (age-adjusted odds ratio for infection (OR) for highest quartile compared to lowest=3.56, 95% CI 2.47, 5.14, P for trend <0.0001). Altitude was significantly inversely associated with trachoma prevalence (age-adjusted OR for highest quartile compared to lowest=0.55, 95% CI 0.41, 0.75, P for trend <0.0001). These associations remained significant after adjustment in multivariate analysis.

CONCLUSIONS

Trachoma is endemic in Rombo district, although the prevalence varies considerably between villages. Spatial mapping is a useful method for analysing risk factors for active trachoma.

Delay in presentation to hospital for surgery for congenital and developmental cataract in Tanzania

BACKGROUND

Childhood cataract is a leading cause of blindness in children in eastern Africa. High quality surgical services have been established at a few tertiary facilities in the region; however, there appears to be delay in presentation to hospital.

METHODS

Parents or guardians of all children presenting to KCMC Hospital or CCBRT Hospital with congenital (recognised since birth or within the first year) or developmental (cataract leading to reduction in vision after 1 year of age) cataract were interviewed regarding the actions taken (and timing of these) before coming to hospital. Demographic information was also collected. For analysis children were grouped as either late presenters (more than 12 months after recognition) or not late presenters (within 12 months of recognition) and predictors of late presentation were assessed.

RESULTS

Among 178 children (74 congenital cataract and 104 developmental cataract) analysed, the mean delay between recognition by the caregiver and presentation to hospital was 34 months, almost 3 years. The median delay was 18 months-9 months for congenital cataract and 24 months for developmental cataract. Long delay in presentation was associated with having developmental cataract, living far from the hospital, and low socio-educational status of the mother. Among children with congenital cataract, having another sibling increased the likelihood of early presentation.

CONCLUSION

Delay in presentation remains a significant problem for children needing surgery for congenital or developmental cataract. Parents who have multiple children may be more likely to seek early treatment, possibly because their expectations of achievable sight at a young age are based on previous experience of their older children. Educational efforts should aim to reach the most "unreachable" (those living the furthest from the hospital and having the lowest socio-educational status of the mother).

The social and family dynamics behind the uptake of cataract surgery: findings from Kilimanjaro region, Tanzania

AIMS

To describe and understand better the barriers that elderly cataract patients in Kilimanjaro region (Tanzania) experience at the family level in order to access surgery.

METHODS

A phenomenological study carried out in the catchment area of a teaching hospital in Kilimanjaro Region. 60 semi-structured interviews were conducted with patients and ex-cataract patients.

RESULTS

The perceived need for sight and for surgery appears partly socially constructed at the family level. It was found that women were less likely to express a need for sight for fear of being seen as a burden. Furthermore, young heads of family are more inclined to support old men than old women. The consensus is that asking children for help can be difficult. Going for cataract surgery must be seen as a social process where elderly patients might have to wait or negotiate support for weeks, months, or even years.

CONCLUSIONS

Eye programmes must promote the benefits of cataract surgery to all family members, not just to the patient. A changing social climate, changing expectations of vision, and evolving cost sharing systems will have significant, sometimes contradictory, impacts on use of eye care services. Strategies for reaching those without access to financial resources need to be strengthened.

Increasing cataract surgery to meet Vision 2020 targets; experience from two rural programmes in east Africa

BACKGROUND

The numbers of cataract surgeries done in sub-Saharan Africa fall short of Vision 2020 targets. Over a few years, two programmes in rural east Africa both achieved significant increases in the number of cataract surgeries they provide, resulting in cataract surgical rates of 1583 for Kwale District in Kenya and 1165 for Kilimanjaro Region in Tanzania. Key components of success in these two programmes are described.

METHODS

Data were collected on standard indicators and key personnel interviewed to describe the results and compare the methods employed to increase cataract surgical rates by the Kwale District Eye Centre programme and the Kilimanjaro regional Vision 2020 programme.

RESULTS

Key components of success shared by the programmes included: (1) programmes in the community and at the hospital are closely linked so that they increase capacity together; (2) community programmes are "patient friendly," providing service in one stop; (3) the examination team includes eye workers with enough skill to provide treatment and decide who is operable so that patients are not transported needlessly or sent through a lengthy referral chain; (4) sites for visits in the community are selected according to population distribution and they are visited according to a regular schedule.

CONCLUSION

The development of "bridging strategies" that create a strong link between hospitals providing clinical service and communities needing these services is a key component to realising Vision 2020 goals in sub-Saharan Africa.

Cataract surgical coverage and outcome in the Tibet Autonomous Region of China

BACKGROUND

A recently published, population based survey of the Tibet Autonomous Region (TAR) of China reported on low vision, blindness, and blinding conditions. This paper presents detailed findings from that survey regarding cataract, including prevalence, cataract surgical coverage, surgical outcome, and barriers to use of services.

METHODS

The Tibet Eye Care Assessment (TECA) was a prevalence survey of people from randomly selected households from three of the seven provinces of the TAR (Lhoka, Nakchu, and Lingzhr), representing its three main environmental regions. The survey, conducted in 1999 and 2000, assessed visual acuity, cause of vision loss, and eye care services.

RESULTS

Among the 15,900 people enumerated, 12,644 were examined (79.6%). Cataract prevalence was 5.2% and 13.8%, for the total population, and those over age 50, respectively. Cataract surgical coverage (vision <6/60) for people age 50 and older (85-90% of cataract blind) was 56% overall, 70% for men and 47% for women. The most common barriers to use of cataract surgical services were distance and cost. In the 216 eyes with cataract surgery, 60% were aphakic and 40% were pseudophakic. Pseudophakic surgery left 19% of eyes blind (<6/60) and an additional 20% of eyes with poor vision (6/24-6/60). Aphakic surgery left 24% of eyes blind and an additional 21% of eyes with poor vision. Even though more women remained blind than men, 28% versus 18% respectively, the different was not statistically significant (p = 0.25).

CONCLUSIONS

Cataract surgical coverage was remarkably high despite the difficulty of providing services to such an isolated and sparse population. Cataract surgical outcome was poor for both aphakic and pseudophakic surgery. Two main priorities are improving cataract surgical quality and cataract surgical coverage, particularly for women.

Determinants of patient satisfaction with cataract surgery and length of time on the waiting list

AIMS

To assess determinants of patient satisfaction with their waiting time (WT) and cataract surgery outcome.

METHODS

A prospective cohort of consecutive patients waiting for cataract surgery were assessed by their ophthalmologist. Satisfaction, maximum acceptable waiting time (MAWT), urgency, visual function, visual acuity (VA), and health related quality of life (EQ-5D) were assessed using mailed questionnaires before surgery and 8-10 weeks after surgery. Ordinal logistic regression was used to build explanatory models.

RESULTS

166 patients (61.9% female, mean age 73.4 years) had a mean WT of 16 weeks. Patients whose actual WT was shorter than their MAWT had greater odds of being satisfied with their WT than those whose WT was longer (adjusted OR 3.86, 95% CI 1.38 to 10.74). Improvement in visual function (OR 3.19, 95% CI 1.78 to 5.73), and VA (OR 4.27, 95% CI 1.70 to 10.68) significantly predicted satisfaction with surgery. Models were adjusted for age and sex.

CONCLUSION

Patient perspectives on MAWT and satisfaction with WT are important inputs to the process of determining WT standards for levels of patient priority. Patient expectation of WT may mediate satisfaction with actual WT.

One year recurrence of trachomatous trichiasis in routinely operated Cuenod Nataf procedure cases in Vietnam

BACKGROUND

Recurrence of trichiasis following surgery remains unacceptably high, regardless of the surgical procedure. Few prospective studies of sufficient size are available to assess the rate of recurrence and the factors contributing to recurrence. A prospective study of the modified Cuenod Nataf surgical procedure was conducted in Vietnam to determine recurrence and co-factors.

METHODS

The prospective study of Cuenod Nataf surgery for trachomatous trichiasis took place in four districts of Vietnam. All patients from identified villages who had surgery were followed for a period of 1 year. 10 Surgeons using standard techniques and recording procedures carried out the surgery. The presence of an eyelash touching the eyeball in the operated eye was considered as recurrence. Information on all subjects was recorded preoperatively, intraoperatively, and postoperatively. An independent examiner recorded postoperative information. Relative risks were calculated to assess the contribution of various risk factors to recurrence (by eye and by person). Cox proportional hazards modelling was used to assess the independent contribution of relevant factors to the outcome.

RESULTS

471 individuals had trichiasis surgery; 463 were followed for a period of 1 year. Overall, the recurrence rate was 10.8% (95% CI 8.0 to 13.6). Among people having surgery recurrence (one or both eyes) was most common in the most elderly (relative risk (RR) 2.49) and among those with a history of previous surgery (RR = 2.49). Cox proportional hazards analysis (by eye) revealed that visual acuity, conjunctival scarring, and suture adjustment were associated with recurrence at 1 year.

CONCLUSION

The Cuenod Nataf procedure, which is well accepted in the community and by eye care providers in Vietnam, has an acceptable 1 year success rate. Individuals with severe conjunctival scarring have the highest rate of recurrence suggesting that other surgical approaches are needed to manage these patients or that these patients need to be educated regarding the risk of recurrence. Active follow up of these patients would be warranted. The association with suture adjustment requires further investigation.

Sociodemographic characteristics associated with blindness in a Nile Delta governorate of Egypt

BACKGROUND

Globally, blindness is associated with old age and being female. Other sociodemographic and socioeconomic status characteristics associated with blindness have included educational attainment, and occupation. These factors reflect exposure to specific risk factors for blinding eye diseases and utilisation of preventive and curative services by specific sectors of the population.

METHODS

A population based survey of blindness and trachoma was conducted in Menofiya governorate in Egypt. 3322 adults 50 years of age and over were sampled from throughout the governorate (population 2.7 million). Visual acuity and clinical conditions were recorded and interviews with respondents were conducted.

RESULTS

Overall, blindness (<6/60 presenting vision in the better eye) was recorded in 13% of the study population. Besides age and sex, other factors associated with blindness (logistic regression) were marital status and poor sanitation in the household.

CONCLUSION

Socioeconomic status does not appear to be a significant factor associated with blindness in adults in this setting. Instead, sociocultural factors, in particular, characteristics associated with gender sensitive decision making within households, are likely to be more important considerations in understanding blindness in these communities. Successfully combating blindness in the Nile Delta of Egypt will require gender sensitive efforts aimed at timely and effective utilisation of eye care services.

Blindness and eye diseases in Tibet: findings from a randomised, population based survey

BACKGROUND

Public health officials of the Tibet Autonomous Region (TAR) of China requested a survey of blindness, eye diseases, and eye care service utilisation to assist the development of a 10 year blindness prevention and treatment plan. The objective of the survey was to determine the prevalence of blindness and visual impairment, as well as cataract surgical coverage and surgical outcome in the TAR.

METHODS

The Tibet Eye Care Assessment was a cross sectional prevalence study of three of the seven prefectures (provinces) of the TAR (Lhoka, Nakchu, and Lingzhr) selected to represent its three main environmental regions. The survey sample was selected using a random multistage cluster method. Two teams conducted the survey in a standardised fashion in each prefecture, Lhoka during May and Nakchu during June 1999, and Lingzhr during May 2000. Visual acuity, cause of vision loss, trachoma, and vitamin A deficiency were included in the clinical examination.

RESULTS

Among the 15,900 people enumerated, 12,644 were examined for an overall response rate of 79.6%. The crude prevalence of blindness (presenting better eye visual acuity of less than 6/60) was 2.3%; age and sex adjusted blindness prevalence was 1.4% (95% CI 1.3 to 1.5). Visual impairment (better eye presenting visual acuity of 6/24 to 6/60) was found in 10.9% (95% CI 10.5 to 11.2) of the population (age and sex adjusted). Cataract was the primary cause of blindness (50.7%), followed by macular degeneration (12.7%) and corneal opacity (9.7%).

CONCLUSION

Blindness is a serious public health problem in Tibet, with prevalence higher than in similar studies in eastern China. As elsewhere in the world, women have an excess burden of blindness compared to men. About 75% of blindness in Tibet can be either prevented or treated. Eye care planning for Tibet must focus on cataract, particularly among women.

Changes in blindness prevalence over 16 years in Malawi: reduced prevalence but increased numbers of blind

BACKGROUND/AIMS

In the coming two decades significant increases in the burden of blindness are anticipated unless concerted efforts are made to improve eye care in developing countries. Evidence of changing prevalence rates or numbers of blind people are few. The change in blindness prevalence and the number of blind people in an adult population of Malawi was measured over a 16 year period.

METHODS

In 1999 a population based survey of blindness in adults (age 50+) was conducted in Chikwawa district of Malawi. Visual acuity and cause of vision loss were recorded for each eye independently. Blindness was defined as presenting better eye vision of <6/60. Findings from a 1983 survey of blindness in the same district (using similar methods) were re-analysed to be comparable with the survey conducted in 1999.

RESULTS

Among 1630 enumerated adults 89% were examined. The age adjusted prevalence of blindness in the adult population was 5.4% and more common in women than men. In each age group the prevalence of blindness was lower in 1999 than in 1983; the overall reduction in blindness was 31%. During this period the 50+ population in Malawi increased almost twofold. Extrapolating the Chikwawa district data to the Malawi population reveals that the number of blind people has increased by 24%; the increase is primarily because of the large increase in the size of the most elderly group, aged 70 and above.

CONCLUSION

The majority of blind people in Chikwawa (1983 and 1999) are in the age group 70 and over. This group has had the largest proportional increase in population size in this time. Services in this population have improved in the intervening 16 years and yet there was still an increase in the number of blind people. There was little change in excess blindness in women, suggesting that the same barriers that prevented utilisation of services in 1983 probably persist in 1999. Efforts to reach the most elderly and to reach women are needed to lead to a reduction in blind people in settings such as rural Malawi.

Low vision and blindness in adults in Gurage Zone, central Ethiopia

AIM

To determine the magnitude and causes of low vision and blindness in the Gurage zone, central Ethiopia.

METHODS

A cross sectional study using a multistage cluster sampling technique was used to identify the study subjects. Visual acuity was recorded for all adults 40 years and older. Subjects who had a visual acuity of <6/18 were examined by an ophthalmologist to determine the cause of low vision or blindness.

RESULTS

From the enumerated population, 2693 (90.8%) were examined. The prevalence of blindness (<3/60 better eye presenting vision) was 7.9% (95% CI 6.9 to 8.9) and of low vision (6/24-3/60 better eye presenting vision) was 12.1% (95% CI 10.9 to 13.3). Monocular blindness was recorded in 16.3% of the population. Blindness and low vision increased with age. The odds of low vision and blindness in women were 1.8 times that of the men. The leading causes of blindness were cataract (46.1%), trachoma (22.9%), and glaucoma (7.6%). While the prevalence of vision reducing cataract increased with age, the prevalence of trachoma related vision loss did not increase with age, suggesting that trichiasis related vision loss in this population might not be cumulative.

CONCLUSION

The magnitude of low vision and blindness is high in this zone and requires urgent intervention, particularly for women. Further investigation of the pattern of vision loss, particularly as a result of trachomatous trichiasis, is warranted.

Eye disease in multibacillary leprosy patients at the time of their leprosy diagnosis: findings from the Longitudinal Study of Ocular Leprosy (LOSOL) in India, the Philippines and Ethiopia

Existing prevalence surveys do not provide adequate information to estimate the magnitude of ocular pathology or vision loss in leprosy patients. We sought to determine the prevalence of ocular findings and related risk factors in leprosy patients at the time of their disease diagnosis. We also sought to determine if there were geographic differences and whether these were due to different demographic characteristics of the populations. The study was undertaken at Schieffelin Leprosy Research & Training Centre (Karigiri, India), Leonard Wood Memorial Leprosy Institute (Cebu, Philippines), and (for 3 years only) ALERT (Addis Ababa, Ethiopia). Newly diagnosed multibacillary (MB) leprosy patients as well as MB cases relapsed after dapsone monotherapy were eligible for enrollment. In each study site, the target population was 300. Standardized examinations were conducted between 1991 and 1998. Patient enrollment included 301 patients in Karigiri, 289 patients in Cebu, and 101 patients in Addis Ababa. The age-adjusted prevalence of blindness (< 6/60 in the better eye) and visual impairment (6/24-6/60) was 2.8% and 5.2%, respectively. Lagophthalmos and leprosy related uveal changes were detected in 3.3% (95% CI 2.0-4.7%) and 4.1% (95% CI 2.4-5.7) of patients, respectively. Overall, 11% (95% CI 8.5-13.2%) of newly enrolled MB patients had potentially blinding leprosy related ocular pathology. Lagophthalmos was associated with increasing age, a short duration between onset and diagnosis, and a previous reaction involving the face. Uveal conditions were associated with increasing age. Overall, eye disease was more common in Indian and Ethiopian patients compared to Filipino patients; however, differences were not significant when controlling for age and clinical (non-ocular) factors. Patients with potentially blinding leprosy related pathology were over three times more likely to have other (hand and foot) disabilities than patients without pathology. Differences in the prevalence of blindness and potentially blinding leprosy related ocular pathology between the sites could be accounted for by the differences in age and other clinical factors of the patients at the different sites. Findings suggest that, even in the face of active leprosy control efforts, around 11% of patients will have potentially blinding pathology at the time of their diagnosis and 2.8% will be blind. If those patients with lagophthalmos or blindness are considered appropriate for referral for more detailed assessment, approximately 4% of newly diagnosed leprosy patients will require active follow-up for eye care; including those with reaction involving the face will result in 9.4% of patients requiring active follow-up. These people are likely to be older, with a reaction involving the face, and/or with other disabilities than those not requiring active follow-up.

The burden of trachoma in the rural Nile Delta of Egypt: a survey of Menofiya governorate

BACKGROUND

Evidence of widespread distribution of trachoma in Egypt had not been clarified as previous surveys were limited to individual communities which may not have been representative of the general population. The Nile Delta of Egypt presents a unique environment for trachoma to persist. Economic improvements in the past decade have affected even the poorest rural environments; availability of electricity is now found in many rural communities. Availability of water in Nile Delta has always been good but poor hygienic conditions have been the primary factor in trachoma transmission. A survey of trachoma was undertaken in Menofiya governorate to determine if Egypt should be identified as trachoma endemic and targeted for trachoma control efforts.

METHODS

A multistage random cluster study design was used with the target population defined as adults aged 50 and over and children aged 2-6 years from throughout the governorate. Among preschool children only trachoma was graded while among adults presenting visual acuity and cause of vision loss or blindness were also recorded. Adults were interviewed regarding past trichiasis surgery; those currently with trichiasis or a history of trichiasis surgery were also interviewed regarding outcome of surgery.

RESULTS

A total of 3272 children aged 2-6 and 3322 adults age 50+ were enumerated. Among the children 81.3% were examined and among the adults 73.0% were examined. Active trachoma (follicles (TF) and/or intense inflammation (TI)) was found among 36.5% (95% confidence interval (CI) 34.7-38.3%) of the children. TI was 1.89 (95% CI 1.22-2.94) times more common in rural children compared to urban children. The prevalence of trichiasis (TT) in adults was 6.5%; women had an age adjusted odds of trichiasis of 1.68 (95% CI 1.18-2.39) compared to men. Trichiasis was 2.11 times (95% CI 1.33-3.37) more common in rural Menofiya compared to urban Menofiya. TT accounts for blindness (presenting vision <3/60) in 8% of patients and accounts for 13.2% of visual impairment. Overall, trichiasis surgical coverage was 34.4%, slightly higher among men than women. The outcome of trichiasis surgery was poor in 44.4% of cases.

CONCLUSION

Trachoma is a serious public health problem in Menofiya governorate and a significant contributor to vision loss. These findings would suggest that continued poor hygienic conditions in rural Egypt have limited the reduction of active trachoma even in the face of significant improvements in socioeconomic status. Furthermore, the high proportion of trichiasis surgery cases with a poor outcome would indicate a need to reassess current surgical practices in Egypt and improve training and monitoring.

Reliability and reproducibility of a Chinese-language visual function assessment

OBJECTIVE

The purpose of the study was to validate a Chinese-language visual function assessment within the context of a routine cataract surgery practice and to assess the contribution of the method of questionnaire administration.

DESIGN

The visual function assessment (VFA) was translated into Chinese. Two groups of study subjects were recruited: Chinese who did not speak English and Chinese conversant in English. Consecutive preoperative cataract patients of Chinese ancestry presenting to an urban ophthalmology practice were recruited. The questionnaire was administered in person or by telephone interview. Pre-operative visual acuity was recorded. Visual function scores were analyzed to assess reliability and correlation with visual acuity.

RESULTS

Among the 186 potential study subjects, 155 patients completed the study The Chinese-language visual function assessment had good internal consistency (Cronbach alpha = 0.97, inter-item correlations = 0.43 to 0.96) . Reliability (with regard to the English version) and test-retest reproducibility of the Chinese questionnaire were strong with intraclass correlation coefficients greater than 0.60. The method of administration contributed to the measures of reliability and reproducibility.

CONCLUSION

These results show that a Chinese-language version of the VFA questionnaire is reliable and valid. In industrialized countries with large Chinese-speaking populations and newly developed countries of East and Southeast Asia, the visual function assessment may be helpful in assisting routine clinical patient evaluation and cross-cultural outcome assessment programmes. Our findings also suggest that self-administered visual function assessments may be more reliable and valid than interview-generated assessments.

Contribution of multiple glaucoma medications to visual function and quality of life in patients with glaucoma

BACKGROUND

Previous studies examining the correlation between medical treatment and overall quality of life in patients with glaucoma assessed differences between a glaucoma population and a matched group (without glaucoma) and were not aimed specifically at detecting a relation between visual acuity, visual field status and medication use, and visual function and quality of life. We performed a study to determine this relation in patients with chronic open-angle glaucoma (COAG).

METHODS

The study was cross-sectional. Of 235 English-speaking patients with a diagnosis of COAG, normal-pressure glaucoma or suspected glaucoma (receiving therapy) seen in a university-based glaucoma practice between Feb. 1 and Apr. 30, 1998, 224 (95.3%) agreed to participate. All subjects completed two questionnaires: the Visual Function Assessment and the EQ-5D, assessing health status (quality of life). Visual acuity, diagnosis, age, sex, country of birth, type and number of medications for topical and for oral use, dosage, and history of laser treatment and surgery were extracted from the medical record. Pearson rank correlation and multivariate analyses were performed.

RESULTS

On univariate analysis visual function was correlated with age, visual acuity, number of glaucoma medications, number of applications of eyedrops, mean deviation in better eye, mean deviation in worse eye, and lower hemifield involvement in both eyes. On multivariate analysis only visual acuity and visual field status were independently associated with visual function. Univariate analysis showed that health status was correlated with age, visual function and number of medications for oral use; however, age failed to retain statistical significance in the regression analysis.

INTERPRETATION

Our results suggest that the number of glaucoma medications is not predictive of quality of life.

Knowledge, attitudes and practices regarding evidence-based medicine and outcome assessment: a survey of British Columbia cataract surgeons

BACKGROUND

While the advantages of practising evidence-based medicine are well-documented, it is frequently suggested that doctors' attitudes are a major roadblock to its implementation. We carried out a survey to determine the knowledge, attitudes and practices of British Columbia cataract surgeons regarding evidence-based medicine and outcome assessment.

METHODS

The survey was conducted in the spring of 1999. The study population was drawn from the directory of the British Columbia College of Physicians and Surgeons. A 16-item questionnaire designed to elicit the knowledge of, attitudes toward and use of evidence-based medicine and outcome assessment was sent to all surgeons performing cataract surgery in British Columbia.

RESULTS

Of the 103 eligible participants, 70 (68%) returned completed questionnaires. Surgeons affiliated with the University of British Columbia were more likely to respond than those not affiliated with the university (81% vs. 58%) (p < 0.05). Most surgeons (89%) viewed the responsibility of monitoring quality of care as primarily their own. Although 79% of the respondents felt that outcome assessment is an effective method for determining quality of care, less than half (49%) reported that they routinely include some form of outcome assessment in their clinical practice. There was wide variation in the respondents' understanding of the nature of outcome assessment and evidence-based medicine. Respondents professed little inclination or motivation to committing time or resources to an outcome program. They also expressed concerns over the use of outcome data for external management activities.

INTERPRETATION

Cataract surgeons in British Columbia clearly appreciate the advantages of outcome assessment, but translation of this understanding into practice is limited. There appears to be a need for further education on outcome assessment and evidence-based medicine through academic bodies and professional societies.

Lagophthalmos surgery in leprosy: findings from a population-based survey in Korea

Lagophthalmos continues to be a serious problem in cured leprosy patients. We conducted a population-based survey of lagophthalmos surgical coverage (LSC), barriers to lagophthalmos surgery and outcome of lagophthalmos surgery in leprosy patients in South Korea. In our survey, there were 60 patients with lagophthalmos who had needed surgery (> 5 mm gap), 34 of whom had received surgery, resulting in a lagophthalmos surgery coverage of 57%. Among the 34 patients who had received lagophthalmos surgery, 18 needed further surgery. Among those who had never had surgery, none of the demographic indicators predicted surgical uptake; the primary reason given for failure to have surgery was lack of knowledge about it. Outcome of surgery (by eye) showed that 29% of eyes still had a gap of 5 mm or more. The frequency of symptoms (tearing, blurring of vision, pain, etc.) was high. Even in settings with a good eye care infrastructure, such as Korea, uptake of surgery can still be low and results may not be satisfactory to patients. There is a need for practical guidelines for leprosy control programmes in the areas of (a) patient recognition, (b) patient education, (c) monitoring the uptake of surgery, and (d) monitoring the outcome of surgery to ensure the best possible outcome.

Blindness in Africa: present situation and future needs

AIM

To review the prevalence and causes of blindness in sub-Saharan Africa, the existing services and limitations, and the Vision 2020 goals for the future.

METHODS

Methodologically sound population based surveys published in the past 20 years are reviewed and results for prevalence and causes of blindness are tabulated. The current resources and needs according to recent publications and international working groups are described.

CONCLUSIONS

Blindness prevalence rates vary widely but the evidence suggests that approximately 1% of Africans are blind. The major cause is cataract; trachoma and glaucoma are also important causes of blindness. The bulk of blindness in the region is preventable or curable. Efforts should focus on eye problems which are universally present and for which there are cost effective remedies, such as cataract and refractive problems and on those problems which occur focally and can be prevented by primary healthcare measures, such as trachoma, onchocerciasis, and vitamin A deficiency. Major development of staffing levels, infrastructure, and community programmes will be necessary to achieve Vision 2020 goals.

Cataract in leprosy patients: cataract surgical coverage, barriers to acceptance of surgery, and outcome of surgery in a population based survey in Korea

BACKGROUND/AIMS

Cataract is the leading cause of blindness in leprosy patients. There is no population based information on the cataract surgical coverage, barriers to use of surgical services, and outcome of surgery in these patients. We sought to determine these measures of cataract programme effectiveness in a cured leprosy population in South Korea.

METHODS

The population consisted of residents of six leprosy resettlement villages in central South Korea. All residents were invited to participate in a study of eye disease and interviewed regarding use of surgical services and reasons for not using these services.

RESULTS

The cataract surgical coverage in this population was 55.4% when <6/18 was used as the cut off and increased to 78.3% when the cut off was <6/60. Barriers reported by patients included being told by the doctor that the cataract was not mature and a perception by the patient that there was no need for surgery. Among patients who had aphakic surgery, 71% were still blind in the operative eye while among patients who had pseudophakic surgery, 14% were still blind (presenting vision). Blindness in pseudophakic patients could be reduced to 3% with spectacle correction.

CONCLUSION

Cataract prevalence in leprosy patients will increase as life expectancy continues to increase. Leprosy control programmes will need to develop activities aimed at reducing the burden of cataract. Recommendations include establishing collaborative agreements with ophthalmological services to provide high quality IOL surgery to these patients, training of health staff to identify and refer patients in need of surgery, monitoring the uptake of cataract surgery among patients needing services, and monitoring the outcome of surgery to improve refractive outcome.

Recurrence of trichiasis: a long-term follow-up study in the Sultanate of Oman

BACKGROUND

The prevalence of long-term trichiasis recurrence following tarsal rotation and electro-epilation procedures has not been determined. A non-concurrent prospective study of surgical cases of trichiasis was therefore undertaken in Oman.

METHODS

A sample of 603 surgical cases of trichiasis (approximately half tarsal rotation and half electro-epilation) was followed for an average of 3.1 years to determine recurrence. Recurrence was defined as either mild (<5 lashes touching the globe) or severe (5 or more lashes touching the globe).

RESULTS

Overall, 56% (95% confidence interval of 50.6%-61.0%) of all surgical cases recurred; ranging from 61.8% of tarsal rotation patients to 50.6% of electro-epilation patients. Severe recurrence was detected among 27% of tarsal rotation patients and 10% of electro-epilation patients. Recurrence was associated with female sex, residence in a high-risk region, and time since surgery.

DISCUSSION

The risk of recurrence after electro-epilation and bilamellar tarsal rotation surgery is high; strategies that account for recurrence need to be introduced.

Reduction of trachoma in the absence of antibiotic treatment: evidence from a population-based survey in Malawi

PURPOSE

A survey was conducted in Chikwawa District, Malawi in order to compare the current prevalence of trachoma with a similar survey in 1983.

METHODS

Using random cluster household sampling, children aged 1 to 6 and adults aged 50 or older were enumerated and examined for the presence of trachoma.

RESULTS

Among the 1313 children enumerated, 1249 (95.1%) were examined and among the 1431 adults enumerated, 1221 (85.3%) were examined. The prevalence of active trachoma among the children was 13.9% (11.9-15.9%), 10.0% in males and 14.4% in females. The prevalence of active trachoma varied significantly among the 25 clusters, ranging from 3.9% to 38.2% with 5 clusters (20%) having a prevalence >20%. Signs of trachomatous trichiasis were observed in 1.0% of adults examined. Active disease in 1999 was associated with a longer distance to the primary water source.

CONCLUSIONS

Since 1983 there has been no mass antibiotic treatment programme in the district and little change in socioeconomic status. However, compared to the 1983 findings, active trachoma has been reduced by over 50% (p < 0.001) and trachomatous trichiasis by over 80%. In the 16-year interim (especially in the past 7 years) health, water and hygiene programmes were initiated and we hypothesize that the reduction in active disease is likely due to these changes. Our findings suggest that sustained reductions in active trachoma can be achieved without community-based antibiotic distribution.

Interobserver variability of optic disk variables measured by confocal scanning laser tomography

PURPOSE

To assess the interobserver variation of confocal laser scanning tomographic measurements of the optic nerve head and to address the question of whether the addition of clinical optic disk photographs is helpful in outlining the optic disk margin and in reducing the observer-related variation of the measurements.

PATIENTS AND METHODS

Optic disk variables for 16 eyes of 16 patients with glaucoma, generated by confocal laser scanning laser tomography (Heidelberg Retina Tomograph), were independently evaluated by four experienced glaucoma specialists, and the interobserver variability was calculated. A second separate review by the same observers included the use of clinical stereoscopic color optic nerve head photographs to aid definition of the optic disk margin.

RESULTS

Optic disk parameters with the smallest interobserver variation were cup shape measure, maximum cup depth, height variation contour, and mean height contour. The intraobserver variation of these parameters did not increase when clinical optic disk slides were additionally available. Parameters with the highest interobserver variation were volume below surface, volume below reference, volume above surface, and volume above reference. The observer variation of these optic disk parameters increased significantly for two of the four examiners when clinical optic disk slides were additionally available for outlining the optic disk margin.

CONCLUSION

Confocal laser scanning tomography of the optic nerve head can be improved significantly if clinical optic disk photographs are additionally available to help in outlining the optic disk margin. Because interobserver variation in the tomographic optic disk measurements can be significant, even if experienced observer are involved, tomographic optic disk measurements may be centralized in reading centers in the case of multicenter studies.

Gender and blindness: a meta-analysis of population-based prevalence surveys

BACKGROUND

Many individual surveys of blindness have reported slightly higher rates of blindness for women. In order to gain a continent-by-continent and global sense of the burden of blindness by sex we conducted a meta-analysis of published, population-based surveys of blindness.

METHOD

Published reports were collected using a predetermined search protocol involving commercial electronic databases, hand-searching of references and direct contact with researchers. Studies were included that were population-based, included clinical examination and had a minimum sample size of 1000. The studies were critically appraised to determine methodological rigour. Data were analysed using the Cochrane Collaboration Review Manager.

RESULTS

The overall odds ratio (age-adjusted) of blind women to men is 1.43 (95% CI 1.33-1.53), ranging from 1.39 (95% CI 1.20-1.61) in Africa, 1.41 (95% CI 1.29-1.54) in Asia, and 1.63 (95% CI 1.30-2.05) in industrialised countries. There was good homogeneity of findings from Africa, Asia, and the industrialised countries. Globally, women bear excess blindness compared to men. In these surveys, overall, women account for 64.5% of all blind people. The excess of blindness in women was marked among the elderly and not due only to differential life expectancy.

CONCLUSION

The excess burden of blindness among women is likely due to a number of factors, which are different in industrialised countries compared to developing countries. Particular attention to gender differences in blindness is needed in the creation of targets for blindness reduction and in the development of interventions.

Progression of eye disease in "cured" leprosy patients: implications for understanding the pathophysiology of ocular disease and for addressing eyecare needs

BACKGROUND

Ocular damage in leprosy is due either to nerve damage or infiltration by mycobacteria. There is currently little information about the magnitude and nature of incident ocular pathology in cured leprosy patients. This information would increase our understanding of the pathophysiology of ocular involvement in leprosy and help in developing programmes to address the eyecare needs of leprosy patients who have been released from treatment. The cumulative incidence of leprosy related ocular pathology and cataract was measured during an 11 year follow up period in cured leprosy patients released from treatment in Korea.

METHODS

In 1988 standardised eye examinations were performed on 501 patients in eight resettlement villages in central South Korea. In May 1999 standardised eye examinations were repeated in this population.

RESULTS

Among the patients in whom there was no sight threatening leprosy related ocular disease (lagophthalmos, posterior synechia, or keratitis) in 1988, 14.7% developed one or more of these conditions. Overall, among those with no vision reducing cataract in 1988, 26.4% had developed a vision reducing lens opacity in at least one eye. Among patients examined in both 1988 and 1999, 14.3% developed visual impairment and 5.7% developed blindness.

CONCLUSION

This study demonstrates that leprosy related ocular pathology progresses in some patients even after they are cured mycobiologically. The progressive leprosy related lesions are the result of chronic nerve damage; ocular lesions due to infiltration by Mycobacterium leprae did not develop. Based on the factors found to be associated with development of the most visually significant findings (posterior synechia, keratitis, and cataract) certain patients should be targeted at discharge for active follow up eye care. We suggest that patients with lagophthalmos (even in gentle closure), trichiasis, small pupils, and posterior synechiae should be screened regularly for the development of lagophthalmos in forced closure, keratitis, and cataract.

Age-related macular degeneration in Chinese-Canadians

BACKGROUND

Ethnicity has long been suspected to play a role in the risk of macular degeneration as well as its neovascular complications. We carried out a study to determine the prevalence of retinal diseases in Chinese-Canadians presenting for fluorescein angiography compared to a matched group of Canadians of European origin.

METHODS

We reviewed 20,000 consecutive fluorescein angiograms obtained between December 1987 and November 1993 at a tertiary referral centre for ophthalmic care in Vancouver. All patients identified by name as being of Chinese ancestry were identified and matched to a patient of European ancestry. The two groups were compared in regard to the prevalence of specific retinal diseases, including age-related macular degeneration (AMD).

RESULTS

Among the first 10,000 fluorescein angiograms, 417 patients of Chinese ancestry were identified, of whom 61 (14.6%) had the primary diagnosis of AMD. The rate among the patients of European ancestry was 30.4% (127/417) (odds ratio [OR] 2.12, 95% confidence interval [CI] 1.79 to 2.56) (p < 0.001). A total of 88 ethnic Chinese patients were identified among the subsequent 10,000 angiograms. Pigment epithelial detachments were more than twice as common in the overall group of ethnic Chinese patients as in their counterparts of European ancestry (OR 2.6, 95% CI 0.7 to 10.1). Choroidal neovascularization was 1.6 times more common in the latter group (95% CI 0.98 to 2.8).

INTERPRETATION

The findings support the growing clinical observations of a lower prevalence of AMD in nonwhite populations in addition to an increased prevalence of pigment epithelial detachments in ethnic Chinese patients.

Creation and testing of a practical visual function assessment for use in Africa: correlation with visual acuity, contrast sensitivity, and near vision in Malawian adults

AIM

To develop and test a practical visual function assessment for use in developing countries.

METHODS

Using focus group discussions and interviews with eyecare workers and low vision specialists in Malawi, 13 questions related to visual characteristics of activities of daily living were designed. Patients presenting to an eye clinic were recruited and interviewed. Visual acuity, near vision, and contrast sensitivity were measured. Analysis sought to determine the degree of correlation between the vision indices and visual function.

RESULTS

The visual function questionnaire was easy to administer. Visual function correlated with visual acuity, contrast sensitivity, near vision, and patient reported visual problem. People with a higher frequency of "not applicable" responses had lower visual function scores. Multivariate modelling revealed that visual acuity and number of questions felt to be applicable were independently associated with visual function. Reducing the questionnaire to nine questions did not affect the degree of correlation with any of the visual indices.

CONCLUSION

The authors' visual function assessment correlates well with different measures of visual acuity. People with reduced vision for a prolonged period may no longer consider doing certain tasks and the number of questions considered appropriate by an individual may be an additional measure of visual function. Assessment of visual function by health workers may be a valuable tool in improving surgical uptake by encouraging both health personnel and patients to recognise that they have difficulties undertaking activities of daily living as well as a measure of monitoring and evaluating cataract outcomes.

Corneal endothelial deposits in patients with HIV infection or AIDS: epidemiologic evidence of the contribution of rifabutin

BACKGROUND

We noted a number of patients with unusual fine, stellate corneal endothelial deposits. The distribution of the deposits appeared to be concentric, involving mostly the periphery. We postulated that the changes might be related to the use of rifabutin rather than to cytomegalovirus (CMV) retinitis. We conducted a study among patients infected with HIV to assess the factors associated with these corneal changes.

METHODS

All patients with HIV infection or AIDS who presented to an ocular AIDS clinic in Vancouver between May 16 and July 4, 1996, were examined for the presence of corneal endothelial deposits. The clinical history was noted in a masked fashion.

RESULTS

Of the 162 patients examined, 25 showed fine, diffuse, white, stellate corneal endothelial deposits occurring predominantly in the periphery. The presence of the deposits was associated with rifabutin use (odds ratio 5.6, 95% confidence interval 2.5 to 12.9) independent of the presence of CMV retinitis, the CD4 count, the presence of uveitis and use of other medications.

INTERPRETATION

Corneal endothelial deposits found in patients with HIV infection are associated with rifabutin use independent of the presence of CMV retinitis. The deposits should be monitored to determine their clinical significance.

An epidemiologic investigation of unexpected refractive errors following cataract surgery

OBJECTIVE

To determine the extent and magnitude of unexpected refractive errors following cataract surgery with intraocular lens (IOL) implantation and to determine what characteristics were associated with the errors.

DESIGN

In this nonconcurrent prospective study, preoperative, intraoperative and postoperative information was collected from the charts of the 523 consecutive patients who underwent cataract extraction and polymethylmethacrylate IOL implantation performed by one of nine participating surgeons between Jan. 1 and Apr. 30, 1995, or the same dates in 1996.

SETTING

University-affiliated eye care centre in Vancouver.

OUTCOME MEASURE

Postoperative excess correction, calculated for each patient by subtracting the actual postoperative spherical equivalent from the expected spherical equivalent. Eyes with an excess correction of more than 1.00 dioptre were considered "overcorrected."

RESULTS

Univariate analysis showed that the formula used to calculate the lens power, axial length, year of surgery, A-constant/surgeon factor used and lens manufacturer were associated with overcorrection. In a logistic regression model, lens manufacturer was the only variable independently associated with overcorrection.

CONCLUSIONS

Routine reporting and follow-up is necessary to identify this kind of "outbreak" and the associated factors. The current guidelines of the Health Protection Branch, Health Canada, for evaluation of IOLs that have changed manufacturers are not adequate to identify the kind of error that we detected.

Visual function among corneal disease patients waiting for penetrating keratoplasty in British Columbia

PURPOSE

We sought to test the applicability of a well-documented visual function assessment (VF-14) in corneal disease patients wait-listed for penetrating keratoplasty to determine if it would be a valuable addition to a priority scheme.

METHODS

A systematic random sample of patients wait-listed for penetrating keratoplasty in British Columbia was selected and administered the VF-14.

RESULTS

The mean VF-14 score was 67.2; it was correlated with best corrected vision. Immigrants had lower VF-14 scores and they considered fewer of the questions applicable to them. There was a correlation between the number of questions considered applicable and the VF-14 score.

CONCLUSIONS

As currently constituted the VF-14 is probably not a useful tool in a multi-cultural population in North America. We propose revisions to the visual function assessment and suggest its inclusion in a priority scheme for penetrating keratoplasty that also includes pain and other clinical indices.

Association between measures of vitamin A and the ocular fundus findings in cerebral malaria

OBJECTIVE

To investigate the relationship between serum vitamin A levels and conjunctival impression cytology and retinal whitening present in Malawian children with cerebral malaria.

METHODS

Standard retinal examination and conjunctival impression cytology were performed at hospital admission on 101 consecutively admitted children with cerebral malaria. Blood samples were drawn from 56 children at 24 hours, frozen at -20 degrees C, and transported for assessment of vitamin A levels by high-performance liquid chromatography. Associations among fundus findings and vitamin A measurements were sought.

RESULTS

The whitening of the retina that we have previously described in children with cerebral malaria was found to be associated with a mean+/-SD serum vitamin A level of 0.29+/-0.1 micromol/L, compared with a mean vitamin A level of 0.41+/-0.2 micromol/L in children without retinal whitening. Children with retinal whitening were 2.77 (95% CI, 1.06-7.3) times more likely to have abnormal conjunctival impression cytology results than those without whitening. No child had any clinical or ophthalmologic evidence of chronic vitamin A deficiency.

CONCLUSIONS

The retinal whitening described in children with cerebral malaria is associated with low serum vitamin A levels and with abnormal conjunctival impression cytology results and may be due to acute vitamin A deficiency at the tissue level.

Retinal nerve fiber layer height in high-tension glaucoma and healthy eyes

PURPOSE

To determine the correlations between the retinal nerve fiber layer height measured by Heidelberg Retina Tomograph, version 1.11, and visual field indices in healthy individuals and patients with glaucoma.

METHODS

One eye was randomly chosen from 48 patients with glaucoma and 60 healthy individuals. All participants were classified using Humprey visual field, program 30-2 (Humphrey Instruments, Inc., San Leandro, CA, U.S.A.); mean deviation, pattern standard deviation, short-term fluctuation, and corrected pattern standard deviation were measured. Superior and inferior mean deviation were calculated. For each participants the mean Heidelberg Retina Tomograph was generated from three 10 degrees Heidelberg Retina Tomograph pictures. The Student t test was used to compare healthy and glaucomatous retinal nerve fiber layer (RNFL) mean degree values every 5 degrees. A global measurement, superior sector (25 degrees-125 degrees), nasal sector (130 degrees-230 degrees), inferior sector (235 degrees-335 degrees), temporal sector (340 degrees-20 degrees), and polar sector (superior + inferior) were calculated. The global, superior, nasal, inferior, temporal, and polar RNFL height (RNFLH) were compared between healthy individuals and patients with glaucoma. The correlation between global, superior, inferior, and polar retinal nerve fiber layer height and visual field was calculated.

RESULTS

A significant difference was found for RNFLH mean from 45 degrees to 330 degrees and for the distribution of the means (as reflected by the standard deviation) from 85 degrees to 100 degrees, 260 degrees to 295 degrees, and 335 degrees to 5 degrees. From these data we created three new sectors: new superior sector (from 85 degrees to 100 degrees), new inferior sector (from 260 degrees to 295 degrees), and new polar sector (combining the new superior and the new inferior sector). Comparing the healthy individuals to the patients with glaucoma, the mean RNFLH values for each sector were found to differ significantly (p < 0.001), with the exception of the temporal sector. Significant correlations (p < 0.001) between the global RNFLH and mean deviation (r = -0.36), pattern standard deviation (r = 0.49), and corrected pattern standard deviation (r = 0.48) were found in healthy participants and those with glaucoma. The strongest correlations (p < 0.001) were found between the pattern standard deviation and the corrected pattern standard deviation with the new polar sector (r = 0.60 and r = 0.59, respectively).

CONCLUSIONS

We found that the strongest correlations with the visual field were with the new polar and new inferior sector.