Prevalence and Causes of Visual Impairment in Fundong District,North West Cameroon: Results of a Population-Based Survey

Purpose: To estimate the prevalence and causes of visual impairment in Fundong Health District, North West Cameroon.

Methods: A total of 51 clusters of 80 people (all ages) were sampled with probability proportionate to size and compact segment sampling. Visual acuity (VA) was measured with a tumbling “E” chart. An ophthalmic nurse examined people with VA<6/18 in either eye. The presence of hearing and physical impairments were assessed using clinical examination, and self-reported visual problems using the Washington Group Short Set.

Results: In total, 4080 people were enumerated of whom 3567 were screened (response rate 87%). The overall prevalence of visual impairment was 2.3% (95% CI 1.8–3.0%) and blindness was 0.6% (0.3–1.0%). The prevalence of both blindness and visual impairment increased rapidly with age, so that the vast majority of cases of visual impairment (84%) and blindness (82%) were in people aged 50+. Posterior segment disease and cataract were the main causes of blindness and visual impairment, with refractive error also an important cause of visual impairment. Cataract surgical coverage (proportion of all cataracts that had received surgery) was relatively high (87% of people at VA<6/60). Post-surgery outcomes were poor, with 31% of operated eyes having VA<6/60. Among the 82 people with visual impairment, 22% had a physical impairment or epilepsy and 30% had a hearing impairment. Self-reported difficulties in vision were relatively closely related to clinical measures of visual impairment.

Conclusions: Ophthalmic programmes in Cameroon need to incorporate control of posterior segment diseases while also working to improve outcomes after cataract surgery.     

Rapid assessment of avoidable blindness: Prevalence of blindness,visual impairment and diabetes in nuevo leon,Mexico 2014

Purpose: To estimate the prevalence of blindness, visual impairment, diabetes mellitus, and diabetic retinopathy in patients aged 50 years and older in the State of Nuevo León, Mexico.

Methods: Ninety-one clusters of 60 people aged 50+ were selected randomly and a rapid assessment of avoidable blindness (RAAB) was conducted. Participants had their visual acuity and cause of visual impairment assessed, underwent a random glucose test and fundoscopy under mydriasis if they had diabetes. The diabetic retinopathy (DR) degree was classified according to the Scottish diabetic retinopathy grading scheme.

Results: From the sample 5,055 (92.6%) people were examined. The blindness prevalence was 1.7% (95% Confidence Interval: 1.3–2.1%). Cataract (32.6%), DR (29.1%) and glaucoma (16.3%) were the leading causes of blindness. The prevalence of severe, moderate, and early visual impairment was 1.0%, 5.1%, and 7.7%, respectively. Among respondents, 31% had diabetes and 8.1% of them was not diagnosed prior to the study. Of all participants with diabetes, 50% had glucose levels of 200 mg/dl or higher and 15.7% had sight-threatening diabetic retinopathy.

Conclusions: Besides strengthening of cataract intervention activities, more ophthalmic services for diabetic retinopathy and glaucoma control are needed in Nuevo León to provide timely intervention to prevent blindness.     

Generating Evidence for Program Planning: Rapid Assessment of Avoidable Blindness in Bangladesh

Purpose: There is a lack of data on the prevalence and causes of blindness in Bangladesh, which is important to plan effective eye health programs and advocate support services to achieve the goals of Vision 2020.

Methods: We conducted a rapid assessment of avoidable blindness (RAAB) in 8 districts of Bangladesh (January 2010 – December 2012) to establish the prevalence and causes of blindness. People aged ≥50 years were selected, and eligible participants had visual acuity (VA) measured. Ocular examinations were performed in those with VA<6/18. Additional information was collected for those who had or had not undergone cataract surgery to understand service barriers and quality of service.

Results: In total, 21,596 people were examined, of which 471 (2.2%, 95% confidence interval, CI, 2.0–2.4%) were blind. The primary cause of blindness was cataract (75.8%). The majority of blindness (86.2%) was avoidable. Cataract and refractive error were the primary causes of severe visual impairment (73.6%) and moderate visual impairment (63.6%), respectively. Cataract surgical coverage for blind persons was 69.3% (males 76.6%, females 64.3%, P<0.001). The magnitude of blindness among people aged ≥50 years was estimated to be 563,200 people (95% CI 512,000–614,400), of whom 426,342 had un-operated cataract.

Conclusions: In Bangladesh, the majority of blindness (86.2%) among people aged ≥50 years was avoidable, and cataract was the most important cause of avoidable blindness. Improving cataract surgical services and refraction services would be the most important step towards the elimination of avoidable blindness in Bangladesh.     

Prevalence of refractive error,presbyopia, and unmet need of spectacle coverage in a northern district of Bangladesh: Rapid Assessment of Refractive Error study

Purpose: To determine the prevalence of refractive error (RE), presbyopia, spectacle coverage, and barriers to uptake optical services in Bangladesh.

Method: Rapid assessment of refractive error (RARE) study following the RARE protocol was conducted in a northern district (i.e., Sirajganj) of Bangladesh (January 2010–December 2012). People aged 15–49 years were selected, and eligible participants had habitual distance and near visual acuity (VA) measured and ocular examinations were performed in those with VA<6/18. Those with phakic eyes with VA <6/18, but improving to ≥6/18 with pinhole or optical correction, were considered as RE and people aged ≥35 years with binocular unaided near vision of <N8 were considered presbyopic.

Result : A total of 3,043 people were examined, of which 143 had RE (4.7%, 95% CI: 3.9–5.5). Among people aged ≥35 years (n = 1402), 869 had presbyopia (62.0, 95% CI: 59.4–64.5). Spectacle coverage for RE and presbyopia were 13.3% (95% CI 7.7–18.9) and 3.2% (95% CI 2.2–4.6), respectively. “Unaware of the problem” was the main reason for not utilizing any optical services among the people with RE (92.8%) and presbyopia (89.5%). Extrapolating the survey findings to the 2011 national census data, the magnitude of RE among people aged 15–49 years in Bangladesh is estimated to be 3,493,980 people (95% CI 2,899,260–4,088,700), of whom 3,029,280 people do not use any spectacles.

Conclusion : The burden of RE and presbyopia is substantial in Bangladesh. Improving awareness and availability of refraction services is required to correct REs and presbyopia in Bangladesh.     

Gender-related effects of vision impairment characteristics on depression in Korea

Purpose: To investigate the gender-specific associations between perceived vision impairment and symptoms of depression.

Methods: We used the data from the 2012 Korean Longitudinal Study of Aging database of 7448 individuals aged 45 years and older. Questionnaires assessing depression symptoms and perceived visual impairment at near, distance, and in general were administered. Logistic regression analyses were used to evaluate if visual impairment could lead to depression, adjusting for the potential confounders of age, socioeconomic status (household income, education level, marital status, and employment status), and health behaviors (alcohol consumption, smoking, and physical activity level) after gender stratification.

Results: Perceived general and near vision impairment were significantly associated with symptoms of depression in males (odds ratio [OR] = 2.78 and 2.54; 95% confidence interval [CI], 1.91–4.04 and 1.78–3.63). Perceived general and distance vision impairment were significantly associated with symptoms of depression in females (OR = 2.16 and 2.08; 95% CI, 1.67–2.79 and 1.61–2.69). General sight with near vision impairment in males and general sight with distance vision impairment in females could be stronger predictors of depression than other vision impairment combinations (area under the receiver operating characteristic curve [AUROC], 0.6461; p = 0.0425 in males; AUROC, 0.6270; p = 0.0318 in females).

Conclusion Gender differences were found in the characteristics of visual impairment on symptoms of depression. Ophthalmologists should be aware that near vision impairment in males and distance vision impairment in females have an adjunctive effect that might contribute to symptoms of depression.     

The Association of Health-Related Quality of Life with Severity of Visual Impairment among People Aged 40–64 Years: Findings from the 2006–2010 Behavioral Risk Factor Surveillance System

Purpose: To examine the association of health-related quality of life (HRQoL) with severity of visual impairment among people aged 40–64 years.

Methods: We used cross-sectional data from the 2006–2010 Behavioral Risk Factor Surveillance System to examine six measures of HRQoL: self-reported health, physically unhealthy days, mentally unhealthy days, activity limitation days, life satisfaction, and disability. Visual impairment was categorized as no, a little, or moderate/severe. We examined the association between visual impairment and HRQoL using logistic regression accounting for the survey’s complex design.

Results: Overall, 23.0% of the participants reported a little difficult seeing, while 16.8% reported moderate/severe difficulty seeing. People aged 40–64 years with moderate/severe visual impairment had more frequent (≥14) physically unhealthy days, mentally unhealthy days, and activity limitation days in the last 30 days, as well as greater life dissatisfaction, greater disability, and poorer health compared to people reporting no or a little visual impairment. After controlling for covariates (age, sex, marital status, race/ethnicity, education, income, state, year, health insurance, heart disease, stroke, heart attack, body mass index, leisure-time activity, smoking, and medical care costs), and compared to people with no visual impairment, those with moderate/severe visual impairment were more likely to have fair/poor health (odds ratio, OR, 2.01, 95% confidence interval, CI, 1.82–2.23), life dissatisfaction (OR 2.06, 95% CI 1.80–2.35), disability (OR 1.95, 95% CI 1.80–2.13), and frequent physically unhealthy days (OR 1.69, 95% CI 1.52–1.88), mentally unhealthy days (OR 1.84, 95% CI 1.66–2.05), and activity limitation days (OR 1.94, 95% CI 1.71–2.20; all p < 0.0001).

Conclusion: Poor HRQoL was strongly associated with moderate/severe visual impairment among people aged 40–64 years.     

The prevalence and risk factors of visual impairment among rural residents aged 50 years and above in Yugan county,China

Purpose: The purpose of the study is to assess the prevalence of visual impairment (PVI) among rural residents aged 50 years and above in Yugan county, China. Researchers analyzed risk factors and obtained scientific baseline information for blindness prevention and control.

Methods: Stratified cluster random sampling was used in randomly selecting 5540 rural residents aged ≥50 in Yugan county. Eligible residents were invited to receive visual acuity measurement via ophthalmic examinations. Multivariable logistic regression was performed to analyze any risk factors.

Results: A total of 5119 rural residents participated the ophthalmic examination and investigation. The PVI was 19.2%. The prevalence of moderate and severe visual impairment (≥20/400 and <20/60) was 16.9%, and blindness (<20/400) was 2.27%. Multivariable logistic regression showed that age, gender, education, occupation, marital status, drinking attitude, dietary habits, amount of sleep, and daily fruit intake were the main factors that were most predictive of the PVI.

Conclusion: The PVI among rural residents aged 50 years and above in Yugan county was higher than many other districts. Preventive work in Yuan and other local regions should be focused on older, separated/divorced, or widowed individuals, and those with a lower level of education. Strengthening public awareness consists of educating the public about visual health promotion and blindness intervention, including healthy diet and healthy habits, which will help to reduce visual impairment of the population.     

Prevalence and Causes of Visual Impairment and Blindness among Cocoa Farmers in Ghana

Purpose: To determine the prevalence and causes of visual impairment and blindness among cocoa farmers in Ghana in order to formulate early intervention strategies.

Methods: A cross-sectional study using multistage random sampling from four cocoa growing districts in Ghana was conducted from November 2013 to April 2014. A total of 512 cocoa farmers aged 40 years and older were interviewed and examined. The brief interview questionnaire was administered to elicit information on the demographics and socioeconomic details of participants. The examination included assessment of visual acuity (VA), retinoscopy, subjective refraction, direct ophthalmoscopy, slit-lamp biomicroscopy and intraocular pressure (IOP). For quality assurance, a random sample of cocoa farmers were selected and re-examined independently.

Results: Moderate to severe visual impairment (VA <6/18 to 3/60 in the better-seeing eye) was present in 89 participants (17.4%) and 27 (5.3%) were blind (presenting VA <3/60 in the better eye) defined using presenting VA. The main causes of visual impairment were cataract (45, 38.8%), uncorrected refractive error (42, 36.2%), posterior segment disorders (15, 12.9%), and corneal opacity (11, 9.5%).

Conclusion: The prevalence of visual impairment and blindness among cocoa farmers in Ghana is relatively high. The major causes of visual impairment and blindness are largely preventable or treatable, indicating the need for early eye care service interventions.     

Evaluating Self-Refraction and Ready-Made Spectacles for Treatment of Uncorrected Refractive Error

Purpose: Uncorrected refractive error is the leading cause of visual impairment worldwide and has significant quality of life and economic implications. Treatment with subjective refraction and custom-made spectacles requires expensive equipment and highly trained personnel. We examine several alternatives.

Methods: Patients were taught to self-refract using two devices: AdSpecs and the I-test Vision Screener. Ready-made spectacles were fit to the self-refraction and visual acuity (VA) was measured. Donated-spectacles were fit to subjective refraction and VA was measured. Self-refraction and donated spectacles spherical equivalent (SE) and VA were compared to subjective refraction SE and VA.

Results: About 57 patients (102 eyes) were enrolled in the study. Patients accurately determined refractive power with self-refraction by both AdSpecs and the I-test (compared to subjective refraction SE, r² = 0.97 and r² = 0.94, respectively). SE of donated spectacles fit well with self-refraction SE (r² = 0.91). There was no significant difference between best-corrected VA by subjective refraction and VA treated by ready-made spectacles fit to self-refraction by either device (analysis of variance (ANOVA), p non-significant). Patients fit with donated spectacles had significantly worse VA than best-corrected VA by subjective refraction (ANOVA, p < 0.01), although 80% improved to >20/40.

Conclusion: Patients accurately self-refract using both devices and ready-made spectacles fit to self-refraction have excellent visual outcomes. Donated spectacles have worse visual outcomes but might be useful in a subset of patients. Ready-made spectacles fit to self-refraction may provide a treatment alternative to uncorrected refractive error.     

Student-led screening of school children for refractive error correction

Purpose: Detection and correction of uncorrected refractive errors among 12 million children is an overwhelming task for the 500 currently available eye-care professionals in Nepal. A mid-term review of VISION 2020 goals in Nepal has recommended utilizing alternative human resources that could screen children for visual impairment. This study was conducted to assess the validity of vision screening of school children by trained high school students when compared to optometrist testing as the gold standard.

Methods: A total of 150 students were selected, based on their merit by the headmasters of 25 schools in Nepal and trained for two days by optometrists to screen visual acuity of their peers. Visual acuity ≤ 6/12 in either eye was referred as abnormal vision. A random sample of 1,209 screened students was selected and their visual acuity was reassessed by optometrists under the same settings adopted by trained students. Using optometrist scores as the gold standard, screening results of trained students were analyzed for validity.

Results: Mean age of screened students was 12.2 ± 3.03 years (range: 4–19 years) and 57.4% of them were female. Sensitivity of vision screening test done by trained students was 81.7% and the specificity was 97.6%. A positive predictive value of the test was 77.3% and negative predictive value was 98.2%.

Conclusions: With high sensitivity and specificity values, vision screening done by trained students is effective for screening visual acuity of school children. Countries with limited eye-care professionals and infrastructures can effectively train and utilize students for timely detection of poor vision among children.     

Associations with retinal vascular occlusions in a diverse,urban population

Purpose: Retinal vascular occlusions can lead to sudden and permanent visual impairment or blindness. Few epidemiological studies on retinal vascular occlusions have been conducted, especially on diverse populations.

Methods: This is a retrospective case-control study of all incident retinal vascular occlusions occurring during a three and one-half year study period at Montefiore Medical Center, capturing all potential cases by diagnosis codes. Patients with retinal venous occlusions (RVO) and retinal arterial occlusions (RAO) were analyzed separately and compared to age-matched control groups.

Results: All potential charts (n = 700) were reviewed, confirming 214 RVO and 35 RAO incident cases. In multivariable analyses, RVO was associated with type 2 diabetes mellitus (OR 2.41, p < 0.001), history of cerebrovascular accident (OR 2.14, p = 0.011), hypertension (OR 1.83, p = 0.004), glaucoma (OR 6.91, p < 0.001), black race (OR 3.72, p < 0.001), and male gender (OR 2.19 p < 0.001). RAO was significantly associated with current and former smoking combined (OR 8.95, p = 0.021) and male gender (OR 2.56, p = 0.038).

Conclusion: Cardiovascular risk factors and glaucoma are reaffirmed as significant predictors of retinal vascular occlusions in a diverse patient population. Retinal vascular occlusions are more common in certain races and ethnicities, and further study into this may help identify high-risk individuals based on demographics.     

Willingness to pay for cataract surgery is much lower than actual costs in Zamfara state,northern Nigeria

Purpose: Direct medical and non-medical costs incurred by those undergoing subsidised cataract surgery at Gusau eye clinic, Zamfara state, were recently determined. The aim of this study was to assess the willingness to pay for cataract surgery among adults with severe visual impairment or blindness from cataract in rural Zamfara and to compare this to actual costs.

Methods: In three rural villages served by Gusau eye clinic, key informants helped identify 80 adults with bilateral severe visual impairment or blindness (<6/60), with cataract being the cause in at least one eye. The median amount participants were willing to pay for cataract surgery was determined. The proportion willing to pay actual costs of the (i) subsidised surgical fee (US$18.5), (ii) average non-medical expenses (US$25.2), and (iii) average total expenses (US$51.2) at Gusau eye clinic were calculated. Where participants would seek funds for surgery was determined.

Results: Among 80 participants (38% women), most (n = 73, 91%) were willing to pay something, ranging from <US$1 to US$186 (median US$18.5, interquartile range 6.2–31.1). Approximately half of the participants (n = 41) were willing to pay US$18.5 (78% men), one-third (n = 26) were willing to pay US$25.2 (77% men); and 11% (n = 9) were willing to pay US$51.2 (all men). Only six participants (8%) already had the money to pay; one quarter (n = 20) would need to sell possessions to raise the funds.

Conclusion: Willingness to pay for cataract surgery among adults with operable cataract in rural Zamfara state is far lower than current costs of undergoing surgery. People who were widowed—most of whom were women—were willing to pay least. Further financial support is required for cataract surgery to be universally accessible.     

Validity of Teacher-Based Vision Screening and Factors Associated with the Accuracy of Vision Screening in Vietnamese Children

Purpose: To assess validity of teacher-based vision screening and elicit factors associated with accuracy of vision screening in Vietnam.

Methods: After brief training, teachers independently measured visual acuity (VA) in 555 children aged 12–15 years in Ba Ria – Vung Tau Province. Teacher VA measurements were compared to those of refractionists. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for uncorrected VA (UVA) and presenting VA (PVA) 20/40 or worse in either eye. Chi-square, Fisher’s exact test and multivariate logistic regression were used to assess factors associated with accuracy of vision screening. Level of significance was set at 5%.

Results: Trained teachers in Vietnam demonstrated 86.7% sensitivity, 95.7% specificity, 86.7% positive predictive value and 95.7% negative predictive value in identifying children with visual impairment using the UVA measurement. PVA measurement revealed low accuracy for teachers, which was significantly associated with child’s age, sex, spectacle wear and myopic status, but UVA measurement showed no such associations.

Conclusions: Better accuracy was achieved in measurement of VA and identification of children with visual impairment using UVA measurement compared to PVA. UVA measurement is recommended for teacher-based vision screening programs.     

Attitudes and perceptions of eye care workers and health administrators regarding task sharing in screening and detection for management of diabetic retinopathy in Pakistan

Purpose: The shortage of ophthalmologists in many countries is a major barrier to timely provision of eye care. A team work approach to screen, detect and manage diabetic retinopathy (DR) could achieve greater screening coverage of people with diabetes to prevent vision loss. This study aimed to assess the attitudes and perceptions of eye care workers and health administrators regarding task sharing for management of DR.

Methods: Using purposive sampling, 121 eye and health care workers in five selected hospitals in two provinces in Pakistan were recruited. A cross-sectional survey explored the possibility for involvement of optometrists and mid-level eye care workers to share tasks with ophthalmologists for DR management and the potential outcomes of task sharing, through multiple choice and open-ended questions.

Results: Ninety-six (79%) participants–doctors (n = 56), optometrists (n = 29) and mid-level eye care workers (n = 11) responded to the survey. All participants supported task sharing in screening and detection for management of DR. There was no significant difference among the groups with respect to their positive attitude towards task sharing (p = 0.22). The majority in each group believed that the task sharing would not degrade the quality of care (p = 0.48). Two potential major outcomes of task sharing in the eye care system included the benefits for people with diabetes and potential DR and the strengthening of the health care system.

Conclusion: Task sharing among various cadres of eye care workers has the potential to improve screening coverage of people with diabetes to prevent visual loss from DR.     

The Economic Impact of Blindness in Europe

Purpose: To estimate the annual loss of productivity from blindness and moderate to severe visual impairment (MSVI) in the population aged >50 years in the European Union (EU).

Methods: We estimated the cost of lost productivity using three simple models reported in the literature based on (1) minimum wage (MW), (2) gross national income (GNI), and (3) purchasing power parity-adjusted gross domestic product (GDP-PPP) losses. In the first two models, assumptions included that all individuals worked until 65 years of age, and that half of all visual impairment cases in the >50-year age group would be in those aged between 50 and 65 years. Loss of productivity was estimated to be 100% for blind individuals and 30% for those with MSVI. None of these models included direct medical costs related to visual impairment.

Results: The estimated number of blind people in the EU population aged >50 years is ~1.28 million, with a further 9.99 million living with MSVI. Based on the three models, the estimated cost of blindness is €7.81 billion, €6.29 billion and €17.29 billion and that of MSVI €18.02 billion, €24.80 billion and €39.23 billion, with their combined costs €25.83 billion, €31.09 billion and €56.52 billion, respectively. The estimates from the MW and adjusted GDP-PPP models were generally comparable, whereas the GNI model estimates were higher, probably reflecting the lack of adjustment for unemployment.

Conclusion: The cost of blindness and MSVI in the EU is substantial. Wider use of available cost-effective treatment and prevention strategies may reduce the burden significantly.     

Five-Year Incidence of Visual Impairment in Middle-Aged Iranians: The Shahroud Eye Cohort Study

Purpose: To study the 5-year incidence of visual impairment and its causes and risk factors, in the middle-aged Iranian sample of the Shahroud Eye Cohort Study (ShECS).

Methods: Data from subjects who had participated in both phases of the ShECS were used to determine age- and sex-specific incidence rates of visual impairment using the World Health Organization (WHO) definitions for bilateral low vision (visual acuity, VA, >0.5 and ≤1.3 LogMAR in the better eye) and blindness (VA worse than 1.3 LogMAR in the better eye). Risk ratios (RR) and 95% confidence intervals (CIs) were calculated using multivariable log-binomial regression.

Results: Of the 5079 ShECS I survivors, 4737 (93.3%) completed the 5-year follow-up. Their mean age at baseline was 50.9 ± 6.2 years, and 58.9% were female. The incidence of visual impairment was 1.12% (95% CI 0.82–1.42%) by presenting VA and 0.19% (95% CI 0.07–0.32%) by best-corrected VA; leading causes of the former were uncorrected refractive error (81.3%) and diabetic retinopathy (15.1%). In the multivariable model, risk factors for incident visual impairment by presenting VA were older age (RR 1.05, p = 0.044), lower education (RR 0.89, p = 0.002), and diabetes (RR 3.74, p < 0.001).

Conclusion: This is the first incidence study of visual impairment in a middle-aged Iranian population. Since age is a major risk factor, the number of visually impaired is expected to increase as the population ages, and less treatable causes such as diabetic retinopathy begin to surface. Measures for tackling uncorrected refractive error and enhancing diabetes screening and preventive programs are recommended.     

Scanning laser ophthalmoscopy in an elderly Indian population

Purpose: To study optic nerve head (ONH) characteristics using scanning laser ophthalmoscopy, Heidelberg retina tomograph (HRT), in an elderly population.

Methods: A population-based, cross-sectional study included 1460 eyes of 1460 consecutive, subjects >60 years, in North India. All subjects underwent a detailed ophthalmic evaluation and imaged on HRT. Stereometric parameters, Moorfields regression analysis (MRA) and discriminant function analysis were analyzed. Correlation between ONH parameters and disc area, age, sex, and intraocular pressure was analyzed.

Results: Disc size had a normal Gaussian distribution (2.22 ± 0.48 mm²), but all other stereometric parameters showed a wide variation.

MRA found 1320 (90.4%) eyes within normal limits, 71 (4.86%), borderline limits, and 69 (4.73%) outside normal limits.

Comparison of eyes meeting International Society of Geographical and Epidemiological Ophthalmology criteria for a glaucoma suspect, C:D > 0.7, with those that did not show a statistically significant difference in the cup area, rim area, rim disc ratio, and cup volume (p = 0.02, 0.02, 0.02, 0.03, respectively).

An Intraocular pressure (IOP) ≥21 mmHg was seen in 3.01%, and only 12 eyes out of 1460, 0.82%, had an IOP ≥21 mmHg and a cup:disc ratio of more than 0.7. A van Herick estimation of < Grade 3 was seen in 19.4%

Conclusions: Stereometric parameter data, MRA, and clinical examination in this population at high risk for glaucoma found that about 10% of individuals over 60 years of age could be classified as glaucoma suspects and would need further evaluation.     

The National Eye Survey of Trinidad and Tobago (NESTT): Rationale,Objectives and Methodology

Purpose: This paper describes the rationale, study design and procedures of the National Eye Survey of Trinidad and Tobago (NESTT). The main objective of this survey is to obtain prevalence estimates of vision impairment and blindness for planning and policy development.

Methods: A population-based, cross-sectional survey was undertaken using random multistage cluster sampling, with probability-proportionate-to-size methods. Eligible participants aged 5 years and older were sampled from the non-institutional population in each of 120 cluster segments. Presenting distance and near visual acuity were screened in their communities. People aged 40 years and older, and selected younger people, were invited for comprehensive clinic assessment. The interview included information on potential risk factors for vision loss, associated costs and quality of life. The examination included measurement of anthropometrics, blood glucose, refraction, ocular biometry, corneal hysteresis, and detailed assessment of the anterior and posterior segments, with photography and optical coherence tomography imaging. Adult participants were invited to donate saliva samples for DNA extraction and storage.

Results: The fieldwork was conducted over 13 months in 2013–2014. A representative sample of 10,651 individuals in 3410 households within 120 cluster segments identified 9913 people who were eligible for recruitment.

Conclusion: The study methodology was robust and adequate to provide the first population-based estimates of the prevalence and causes of visual impairment and blindness in Trinidad and Tobago. Information was also gathered on risk factors, costs and quality of life associated with vision loss, and on normal ocular parameters for the population aged 40 years and older.     

Advanced glaucoma at presentation is associated with poor follow-up among glaucoma patients attending a tertiary eye facility in Southern Nigeria

Purpose: Globally, particularly in Africa, poor compliance with medication is a major problem in glaucoma management but little is known about follow-up rates among African glaucoma patients. The aim of this study was to determine rates of follow-up among glaucoma patients attending a tertiary hospital in southern Nigeria and investigate predictors of poor follow-up.

Methods: Data were extracted from medical records of new glaucoma patients who attended the hospital between June 2011 and May 2013. Socio-demographic and clinical parameters (visual acuity; stage of glaucoma) recorded at diagnosis were extracted using a pre-tested form. Follow-up was defined as good if they had attended within 9 months of the study date, inadequate when the last follow-up was more than 9 months and failed if they did not attend any follow-up or the most recent visit was more than 14 months from the study date. Univariate and multivariable analyses were undertaken to explore predictors of poor follow-up (inadequate plus failed).

Results: Three hundred forty-eight patients were recruited, 54% were male and the mean age was 52.7 (range 16–88) years. Follow-up was as follows: good 28.4%, inadequate 46.6%, failed 25%. Overall, 71.6% had poor follow-up. Independent predictors of poor follow-up were poorer visual acuity (OR 3.85, 95% confidence interval (CI) 1.25–11.80 for visual impairment; OR 4.11, 95% CI 1.32–12.81 for blind) and end-stage glaucoma (OR 3.55 (1.31–9.62), p = 0.01).

Conclusion: Enhanced counselling of patients with moderate to advanced glaucoma and visual impairment is required to improve follow-up and hence glaucoma management.     

Pediatric Eye Trauma in the Republic of Tajikistan: More Than Meets the Eye

Purpose: Pediatric eye injury (PEI) is the leading cause of preventable monocular vision loss in children, with an estimated prevalence of 5.7 million cases. Epidemiological information on PEI is rare, skewed towards high-income countries, and commonly overlooked by non-governmental ophthalmological organizations. This study aims to quantitatively and qualitatively determine incidence of PEI in the Republic of Tajikistan.

Methods: Data were collected from all pediatric eye injury records (N = 454) admitted to three pediatric ophthalmology hospitals in two regions of Tajikistan between 2010 and 2012.

Results: A review of the records revealed a cumulative annual incidence of 12.8 PEI cases/100,000, with marked inter- and intra-regional differences. Mean age was 7.0 years (95% confidence interval, CI, 6.7–7.4), and male to female ratio was 2.5:1. PEI occurred predominantly outdoors (63%), in rural settings (76%) during unsupervised play, and typically resulted from the eye being hit (53%) by a pointed object (51%), resulting in an open-globe injury (56%). Median time-to-presentation was 24 hours (range 9.6 hours–10 days) and median duration of hospitalization was 15 days (range 2–29 days). Of the 454 cases, 111 (25%) resulted in a blind eye, 62 (14%) in severe visual impairment, and 45 (10%) in moderate visual impairment.

Conclusions: PEI is a major cause of pediatric monocular visual impairment in Tajikistan, with a high rural incidence of severe blinding injuries. Potential risks and outcomes relate to Tajikistan’s cultural, historical, and physical settings. We anticipate that the information provided by this study will facilitate development of culturally derived strategies to reduce PEI in Tajikistan.