Prevalence of blindness and cataract surgical outcomes in Takeo Province, Cambodia

Spectacle Coverage Rate After Cataract Surgery in an Urban Area in Indonesia

Purpose

Uncorrected refractive errors after cataract surgery contribute to visual impairments. The aim of this study was to investigate the spectacle coverage rate (SCR) following cataract surgery and its relationship with socioeconomic factors in an urban city in Indonesia.

Patients and Methods

This population-based cross-sectional study was conducted in 2015 in Jakarta. The former participants of the Rapid Assessment of Avoidable Blindness (RAAB) survey had a history of cataract surgery and met either of the following criteria: (1) wore spectacles with presenting visual acuity (PVA) 6/12 or (2) had PVA less than 6/12 regardless of spectacle use but achieved the best visual acuity (BVA) 6/12 with pinhole correction.

Results

Of the 2998 participants of the RAAB survey, 173 (5.6%) (252 eyes) had a history of cataract surgery, among whom 53 (86 eyes) met our inclusion criteria. The SCR was 69.8% and was associated with age group, household income level, education level, and physicians' recommendation of spectacle wear. Participants who were of nonproductive age (80%), had the highest household income level (88.2%), the highest level of education (87.5%), and had been recommended for spectacle use by their physicians (80.9%) demonstrated higher SCR. Participants with the highest household income had the highest SCR. Patients who had received a physician's recommendation showed a higher SCR and were 26 times more likely to wear spectacles (odds ratio [OR] 25.99, 95% CI 2.59-260.10).

Conclusion

There is an unmet need for refractive errors after cataract surgery. Factors such as household income levels and physician recommendations were predictive of spectacle wear.

Real-world visual outcomes of cataract surgery based on population-based studies: a systematic review

BACKGROUND/AIMS

Quantity of cataract surgery has long been an important public health indicator to assess health accessibility, however the quality of care has been less investigated. We aimed to summarise the up-to-date evidences to assess the real-world visual outcomes after cataract surgery in different settings.

METHODS

A systematic review was undertaken in October 2021. Population-based cross-sectional and longitudinal studies reporting vision-related outcomes after cataract surgery published from 2006 onward were included. A meta-analysis was not planned.

RESULTS

Twenty-six cross-sectional studies from low-income and middle-income countries (LMICs) and five cross-sectional studies from high-income countries (HICs) were included. The proportions of participants with postoperative presenting visual acuity (VA) ≥0.32 (20/60) were all over 70% in all HICS studies, but mostly below 70% in LMICS studies, ranging from 29.9% to 80.5%. Significant difference in postoperative VA was also observed within countries. The leading causes for postoperative visual impairment (defined mostly as presenting VA <20/60) mainly included refractive error, ocular comorbidities and surgical complications including posterior capsule opacification, except for one study in Nigeria wherein the leading cause was aphakia. Only four population-based cohort studies were included with 5-20 years of follow-up time, generally demonstrating no significant changes in postoperative visual outcomes during the follow-up.

CONCLUSIONS

We observed large inequality in the visual outcomes and principal causes of visual impairment after cataract surgery among different countries and regions. Structured quality control and enhancement programmes are needed to improve the outcomes of cataract surgery and reduce inequality.

Prevalence and causes of visual impairment and blindness in Lao People's Democratic Republic: the Vientiane Eye Study

AIMS

To determine the prevalence and causes of visual impairment and blindness in Vientiane Province, the Lao People's Democratic Republic (Lao PDR).

METHODS

We conducted a population-based, cross-sectional study of 1264 participants aged 40 years and older from urban and rural areas of Vientiane Province. The ophthalmic examination included presenting and pinhole Snellen visual acuity (VA) with an illiterate E chart, slit-lamp examination of the anterior segment and dilated stereoscopic fundus examination. Visual impairment and blindness were defined by both presenting and pinhole VA based on the better eye according to WHO criteria: VA worse than 6/12 to 6/18 for mild impairment, VA worse than 6/18 to 6/60 for moderate impairment, VA worse than 6/60 to 3/60 for severe impairment and VA worse than 3/60 for blindness.

RESULTS

Comprehensive ophthalmic examinations were performed on 1264 participants (77.8% participation rate). Population-weighted prevalence of presenting bilateral blindness was 1.4% (95% CI 0.8 to 2.0) and bilateral visual impairment was 22.4% (95% CI 14.7 to 30.1). After pinhole correction, the corresponding prevalence of blindness was 1.3% (95% CI 0.8 to 2.0) and that of visual impairment was 12.6% (95% CI 8.2 to 16.9). Cataract was the leading cause of presenting bilateral blindness (52.9%), whereas uncorrected refractive error was the predominant cause of presenting visual impairment (40.3%).

CONCLUSIONS

Visual impairment and blindness remain major public health problems in Lao PDR. There is an ongoing need to fund ophthalmic care resources and community education programmes to improve access to healthcare in this region.

The effect of poor vision on economic farm performance: Evidence from rural Cambodia

Roughly one-fifth of the global population is affected by poor visual acuity. Despite the fact that inhabitants of rural areas in low-income countries are most distressed by this, no prior research has studied the impact of poor visual acuity on the economic performance of farms. We conduct a standardized eye test with 288 farm managers in rural Cambodia and find that around 30 percent of our sample suffers from poor visual acuity in terms of nearsightedness (myopia). Our analyses indicate a statistically significant and economically meaningful association of poor visual acuity with economic farm performance. Our results show that gross margins for cropping activities per year could be, on average, around 630 USD higher if farm managers were able to correct for poor vision. Our results suggest that poor visual acuity impairs farm managers from tapping the full potential of their business, which in turn decreases their chance to break the vicious cycle of poverty.

Corneal Blindness in Asia: A Systematic Review and Meta-Analysis to Identify Challenges and Opportunities

PURPOSE

To describe the causes and prevalence of moderate-to-severe visual impairment (MSVI) and blindness from corneal diseases, as well as corneal transplantation across Asia.

METHODS

A meta-analysis of the published literature to identify population-based surveys conducted from 2008 to 2019 in 22 Asian countries regarding the prevalence and causes of MSVI and blindness from corneal disease, and a review of national corneal transplant data and eye bank statistics.

RESULTS

A total of 5307 records were screened to identify 57 reports that were used to estimate a prevalence of MSVI and blindness caused by corneal diseases in Asia of 0.38% (95% confidence interval, 0.29%-0.48%). The most frequent corneal diseases were infectious keratitis, trauma, and pseudophakic bullous keratopathy. As expected, these represented the most common indications for corneal transplantation, although the percentages in each country differed based on the level of economic development, with pseudophakic bullous keratopathy being the most common indication in countries with higher gross national income per capita. Despite this, endothelial keratoplasty is not the most commonly performed form of corneal transplantation in any Asian country and represents only a small percentage of keratoplasty procedures performed in most countries.

CONCLUSIONS

The prevalence of MSVI and blindness from corneal disease in Asia is approximately 0.4%, with a nearly 20-fold difference in the national prevalence across the region. The indications for keratoplasty, reflective of the causes of corneal dysfunction, also vary, more so according to the gross national income than to geographic location, and only a few Asian countries have rates of corneal transplantation above international means.

Diagnostic Accuracy of Rapid Assessment of Avoidable Blindness: A Population-based Assessment

OBJECTIVES

To evaluate the diagnostic accuracy of rapid assessment of avoidable blindness (RAAB).

DESIGN

Population-based diagnostic accuracy study.

METHODS

A total of 2145 (95.3%, 2145/2250) subjects aged 50 years and older who participated in the RAAB survey were included. All the recruited participants underwent ophthalmic examination according to the RAAB protocol and then were reexamined with instruments in a mobile eye clinic set up in a village center on the same day. Examination in the mobile clinic included standardized visual acuity (VA) tests using logMAR charts, refraction, slit-lamp biomicroscopy, and dilated fundal examination with a binocular indirect ophthalmoscope. Blindness and economic blindness were defined as VA in the better-seeing eye <3/60 and <6/60, respectively. Visual impairment (VI) was defined as VA <6/18 in the better eye. The primary cause of blindness and VI was defined according to the cause of VI in the participant's better eye.

MAIN OUTCOME MEASURES

The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and area under the curve (AUC) of receiver operating characteristics of RAAB for detection of blindness and the principal causes of VI.

RESULTS

A total of 1816 subjects (84.7%), including 686 men (37.8%) and 1130 women (62.2%), underwent ophthalmic examination in the mobile eye clinic. The mean (±standard deviation) age was 64.4 ± 9.6 years. The sensitivities, specificities, AUC, PLR, and NLR of RAAB were 90.3%, 99.3%, 0.948, 124.0, and 0.10, respectively, for detection of blindness (presenting visual acuity, PVA <3/60); 89.5%, 98.7%, 0.940, 69.2, and 0.11, respectively, for detection of economic blindness (PVA <6/60); and 90.3%, 97.7%, 0.940, 38.7, and 0.10, respectively, for detection of VI (PVA <6/18). The sensitivities, specificities, AUC, PLR, and NLR were 90.5%, 98.1%, 0.943, 48.1, and 0.10; and 60.4%, 98.7%, 0.796, 46.4, and 0.40 for detection of VI (PVA <6/18) owing to cataract and refractive error, respectively.

CONCLUSION

The diagnostic performances of RAAB were high for detecting the prevalence of blindness, VI, and VI owing to cataract.

Validating a tool to assess eye health knowledge, attitude and practice in Cambodia and Vietnam

AIM

To develop an eye health knowledge, attitude and practice (EH-KAP) field-based assessment tool for use in implementing effective eye health care services.

METHODS

An instrument development and validation study. A Vietnam EH-KAP dataset were used to identify and eliminate redundant questions to develop a standardized tool. Face validity was assessed by the KAP survey team. Internal validity (congruency/criterion) was assessed by comparing descriptive analysis of two datasets (n=531; n=38) collected from the same sampling frame at different time points. Weighted scores were calculated for each construct. Kappa values for test-retest and inter-observer agreement were calculated to check the reliability of responses. The modified version was assessed by analysing the raw and ungrouped data. Responses were weighted and agreement was tested by comparing construct scores.

RESULTS

Totally 38 respondents were included in this validation process (mean age 58.5y). Mean scores for knowledge were 9.15 (old questionnaire n=531) and 5.05 (modified version). For attitude, the scores were 2.23 and 2.42, and for practice the scores were 3.33 and 2.21. Test-retest agreement was between 62% to 93% (Kappa 0.24 to 0.86) for the ungrouped raw data, and 55% to 72% (Kappa 0.42 to 0.65) for KAP domain. Inter-observer Kappa value for ungrouped data was 0.37 and 0.45 for the weighted scores.

CONCLUSION

This standardized tool applied at critical time points can assess trends in KAP within the same population and for comparison across groups. If used alongside a Rapid Assessment of Avoidable Blindness (RAAB), this tool provides a comprehensive perspective on eye-health of a population.

Formative research for the development of an Eye Health Strategic Planning and Evaluation Framework and a Checklist: A health systems approach

This formative research process aimed to develop an Eye Health Strategic Planning and Evaluation Framework and indicator Checklist. The research process utilized a multi-phased multiple methods approach including literature review, initial expert review (n = 27), findings from a Cambodian Avoidable Blindness Initiative demonstration project (2009-2012), observation and analysis of four rural sites of the Indian LV Prasad Eye Institute Pyramid Model (n = 21), and finally, a critique by Cambodian government eye health professionals/staff (n = 15), health center staff and community representatives (n = 77) and patients (n = 62). Results from three Cambodian population-based surveys (KAP n = 599, patient follow-up n = 354, and RAAB 4650) also informed the development of the Framework and the Checklist. The Framework domains include: situation analysis, determinants of accessibility, service delivery systems, operation systems, networks and linkages, outcomes, and impact. Domains were subdivided into 59 components. The Checklist consists of 253 indicator items. The Eye Health Strategic Planning and Evaluation Framework and the Checklist can assist policy makers, program planners, and evaluators to develop a comprehensive whole of systems approach to eye health care to improve coverage and utilization of services.

Roles of the eye care workforce for task sharing in management of diabetic retinopathy in Cambodia

AIM

To identify the current roles of eye and health care workers in eye care delivery and investigate their potential roles in screening and detection for management of diabetic retinopathy (DR) through task sharing.

METHODS

Purposive sampling of 24 participants including health administrators, members from non-government organizations and all available eye care workers in Takeo province were recruited. This cross sectional mixed method study comprised a survey and in-depth interviews. Data were collected from medical records at Caritas Takeo Eye Hospital (CTEH) and Kiri Vong District Referral Hospital Vision Centre, and a survey and interviews with participants were done to explore the potential roles for task sharing in DR management. Qualitative data were transcribed into a text program and then entered into N-Vivo (version 10) software for data management and analysis.

RESULTS

From 2009 to 2012, a total of 105 178 patients were examined and 14 030 eye surgeries were performed in CTEH by three ophthalmologists supported by ophthalmic nurses in operating and eye examination for patients. Between January 2011 and September 2012, 151 patients (72 males) with retinal pathology including 125 (83%) with DR visited CTEH. In addition 170 patients with diabetes were referred to CTEH for eye examinations from Mo Po Tsyo screening programs for people with diabetes. Factors favouring task sharing included high demand for eye care services and scarcity of ophthalmologists.

CONCLUSION

Task sharing and team work for eye care services is functional. Participants favor the potential role of ophthalmic nurses in screening for DR through task sharing.

Prevalence of visual impairment and outcomes of cataract surgery in Chaonan, South China

Purpose

To estimate the prevalence and causes of blindness and visual impairment (VI), and report the outcomes of cataract surgery in Chaonan Region, Guangdong Province, southern China

Design

Cross-sectional population-based survey

Participants

A total of 3484 participants including 1397 men (40.1%) and 2087 women (59.9%) aged ≥50 years were examined (94.2% response rate).

Method

A two-stage cluster sampling procedure was used to select 3700 participants aged ≥50 years from 74 clusters of Chaonan Region. Participants were examined according to the Rapid Assessment of Avoidable Blindness (RAAB) method. Blindness and visual impairment (VI) were defined by the World Health Organization criteria. Participants with visual acuity (VA) < 6/18 in either eye were examined by ophthalmologists. The primary causes of blindness and VI were reported with reference to the participant’s better eye.

Main outcome measures

Prevalence and main causes of blindness, severe visual impairment (SVI), VI and the outcomes of cataract surgery

Results

The standardized prevalence rates of blindness, SVI, and VI were 2.4% (95% confidence interval [CI], 1.9–2.9%), 1.0% (95% CI, 0.7–1.4%), and 6.4% (95% CI, 5.6%– 7.1%), respectively. The principal cause of blindness and SVI was cataract, accounting for 67.1% and 67.6% respectively, and the principal cause of VI was refractive error (46.9%). One hundred and fifty five out of 3484 (4.4%) people (211 eyes) had cataract surgery. Of the 211 eyes that had cataract surgery, 96.7% were pseudophakic. 67.2% of the 211 operated eyes had a presenting visual acuity (PVA) of 6/18 or better.

Conclusions

The prevalence of blindness, SVI, and VI was high among rural residents in Chaonan. Cataract remained the leading cause of avoidable blindness. Outcomes of cataract surgery performed in rural private clinics were suboptimal. Quality-control initiatives such as hands-on training program should be introduced to improve cataract surgery outcomes.

Corneal blindness and current major treatment concern-graft scarcity

According to World Health Organization, the global prevalence of blindness in 2010 was 39 million people, among which 4% were due to corneal opacities. Often, the sole resort for visual restoration of patients with damaged corneas is corneal transplantation. However, despite rapid developments of surgical techniques, instrumentations and immunosuppressive agents, corneal blindness remains a prevalent global health issue. This is largely due to the scarcity of good quality corneal grafts. In this review, the causes of corneal blindness, its major treatment options, and the major contributory factors of corneal graft scarcity with potential solutions are discussed.