Prevalence of visual impairment, uncorrected refractive errors and effective refractive error coverage in Koshi Province, Nepal - Rapid Assessment of Refractive Errors

BACKGROUND/OBJECTIVE

To determine the prevalence of visual impairment (VI), uncorrected refractive errors (URE), and effective refractive error coverage among individuals aged 15-50 years in Koshi Province, Nepal.

METHODS

A population-based cross-sectional study was conducted in Koshi Province in which 4800 participants were selected from 80 clusters. The study teams visited the selected households and conducted eye examinations. This included monocular unaided (and aided) visual acuity assessment using a Snellen chart with tumbling E optotypes at a distance of 6 meters. Near vision was assessed binocularly using the N notation chart at a fixed distance of 40 cm for each individual. Torchlight examination and distance direct ophthalmoscopy was done. VI was defined as presenting visual acuity worse than 6/12 in the better eye. URE was defined as presenting visual acuity worse than 6/12 and improving to 6/12 or better on using a pinhole. Near Vision Impairment was defined as binocular presenting near vision worse than N8 among those age 35 years and older.

RESULTS

In total, 4057 were examined (84.5% response rate). The prevalence of VI was 3.52% (95% CI:2.89-4.13; n = 143). The prevalence of URE in the better eye was 1.95% (95% CI:1.54-2.42; n = 79). The Refractive Error Coverage and Effective Refractive Error Coverage were 34.8% and 31.3% respectively. The prevalence of NVI was 34.24% (95% CI: 32.1-36.40; n = 666).

CONCLUSION

The prevalence of VI and  URE was low, attributed to the availability and uptake of services in Koshi province in Nepal.

Refractive error, eye care needs and attitude towards spectacle wearing among older Zanzibari craftswomen and implications for developing women-targeted services: a cross-sectional study

BACKGROUND

Aged Zanzibari women are in a disadvantaged position, having high demand for near-vision spectacles. Currently, there is no information on the eye health status of craftswomen, which makes planning a women-targeted project to deliver eye health services to older craftswomen in Zanzibar difficult. We assessed the prevalence of vision impairment, refractive error, presbyopia, effective spectacle coverage (distance and near) and attitude towards spectacle wearing among older Zanzibari craftswomen.

METHODS AND ANALYSIS

This was a cross-sectional study. Unaided and presenting distance and near vision of craftswomen 35 years and older were assessed at the women's co-operatives. We determined the number of those with distance vision poorer than 6/12 and their causes (distance-vision impairment), the number of those with near vision poorer than N8 at 40 cm (presbyopia) and the number of those whose distance and/or near-vision needs were met adequately with their habitual spectacles (effective distance and near spectacle coverages). A piloted and validated questionnaire (15 statements) was used to determine their attitude towards spectacle wearing.

RESULTS

In all, 263 craftswomen participated in the survey (mean age 52.1 years±9.4 years). The prevalence of distance vision impairment among the craftswomen was 29.7% (95% CI 24.2% to 35.6%), the primary cause being uncorrected refractive error (n=51, 65.4%), and none were corrected. The prevalence of presbyopia was 86.6% (95% CI 81.5% to 90.7%, n=231) and the effective near spectacle coverage was 0.99%. The craftswomen showed a positive attitude towards spectacle wearing (strongly agree or agree) based on 12 out of 15 statements.

CONCLUSION

The high burden of vision impairment, uncorrected distance refractive error and presbyopia, and a positive attitude towards spectacle wearing among older craftswomen in Zanzibar indicated the need for women-targeted eye health programmes in low-resource settings.

Regional variations and temporal trends of childhood myopia prevalence in Africa: A systematic review and meta-analysis

PURPOSE

To provide contemporary and future estimates of childhood myopia prevalence in Africa.

METHODS

A systematic online literature search was conducted for articles on childhood (≤18 years) myopia (spherical equivalent [SE] ≤ -0.50D; high myopia: SE ≤ -6.00D) in Africa. Population- or school-based cross-sectional studies published from 1 Jan 2000 to 30 May 2021 were included. Meta-analysis using Freeman-Tukey double arcsine transformation was performed to estimate the prevalence of childhood myopia and high myopia. Myopia prevalence from subgroup analyses for age groups and settings were used as baseline for generating a prediction model using linear regression.

RESULTS

Forty-two studies from 19 (of 54) African countries were included in the meta-analysis (N = 737,859). Overall prevalence of childhood myopia and high myopia were 4.7% (95% CI: 3.3%-6.5%) and 0.6% (95% CI: 0.2%-1.1%), respectively. Estimated prevalence across the African regions was highest in the North (6.8% [95% CI: 4.0%-10.2%]), followed by Southern (6.3% [95% CI: 3.9%-9.1%]), East (4.7% [95% CI: 3.1%-6.7%]) and West (3.5% [95% CI: 1.9%-6.3%]) Africa. Prevalence from 2011 to 2021 was approximately double that from 2000 to 2010 for all studies combined, and between 1.5 and 2.5 times higher for ages 5-11 and 12-18 years, for boys and girls and for urban and rural settings, separately. Childhood myopia prevalence is projected to increase in urban settings and older children to 11.1% and 10.8% by 2030, 14.4% and 14.1% by 2040 and 17.7% and 17.4% by 2050, respectively; marginally higher than projected in the overall population (16.4% by 2050).

CONCLUSIONS

Childhood myopia prevalence has approximately doubled since 2010, with a further threefold increase predicted by 2050. Given this trajectory and the specific public health challenges in Africa, it is imperative to implement basic myopia prevention programmes, enhance spectacle coverage and ophthalmic services and generate more data to understand the changing myopia epidemiology to mitigate the expanding risk of the African population.

Determination of the Standard Visual Criterion for Diagnosing and Treating Presbyopia According to Subjective Patient Symptoms

Presbyopia treatments using various modalities have been developed recently; however, no standard criteria exist for the diagnosis and treatment endpoint. This study assessed the relationship between the near visual acuity (NVA) and the subjective symptoms of phakic presbyopia and determined the numerical NVA threshold to diagnose phakic presbyopia and evaluate the effectiveness of presbyopia treatment. The binocular distance, NVA with habitual correction, and monocular conventional VA were measured. Patients were asked about their awareness of presbyopia and difficulty performing near tasks. This prospective observational study included 70 patients (mean age, 56 years; range, 32-77). Most patients became aware of presbyopia in their late forties, although some had difficulty with vision-related near tasks before becoming aware of presbyopia. Eighty three percent of patients (20/24) experienced difficulty with near vision-related tasks even with excellent NVA at 40 cm with habitual correction of 0.0 logMAR (20/20 in Snellen VA). In conclusion, the current study showed that patients became aware of presbyopia in their late forties, although some had difficulty with near vision-related tasks before becoming aware of presbyopia. Further investigation should include the proposal of appropriate diagnostic criteria for presbyopia and better management for patients with presbyopia.

Unmet need for presbyopia correction and its associated factors among school teachers in Hawassa city, South Ethiopia

BACKGROUND

Presbyopia is a decline in the amplitude of accommodation with the onset in the age range 40-45 years affecting near visual task performance. As the age of presbyopia onset coincides with productive age, it results in great productivity loss especially in those with high near visual demand like teachers. A maximum near vision potential is essential for teachers in ensuring the quality of education, as most of the students' evaluations and scripts are assessed manually in Ethiopia. The prevalence of unmet need for presbyopia correction among school teachers ranges from 38.5-70.4% worldwide. Though presbyopia is a common ocular condition, there is limited evidence regarding the unmet need for presbyopia correction in Ethiopia as well as in Hawassa city. Therefore, this study aimed to determine the magnitude of unmet need for presbyopia correction and its associated factors among school teachers in Hawassa city, South Ethiopia.

METHODS

A school-based cross-sectional study was conducted among teachers older than 35 years. A simple random sampling technique was used to select participants using name lists as a sampling frame from 69 schools. The participants selected underwent for distance and near visual acuity test. Those with distance visual acuity of 6/12 or worse were refracted before near visual acuity test. Information on the spectacle use and associated factors was obtained using the interviewer-administered questionnaire. Data analysis was done using Statistical Package for Social Sciences software version 20. Binary logistic regression analysis was performed to assess association between independent variables and the unmet need for presbyopia correction.

RESULTS

A total of 459 study participants were included in the study with a response rate of 95.21%.The unmet need for presbyopia correction was 51.26% (95%CI: 46.7-55.6%). Female gender (AOR = 2.50; 95%CI: 1.51-4.15), age 36-45 (AOR = 4.12; 95%CI: 1.46-11.76), unaware of presbyopia (AOR = 2.36; 95%CI: 1.2-4.66) and self-rating of current vision as good (AOR = 3.5; 95%CI: 1.61-7.6) were factors significantly associated with the unmet need for presbyopia.

CONCLUSIONS

The burden of unmet need for presbyopia correction is a moderate priority according to the World Health Organization for presbyopia correction services criteria. A school-based presbyopia awareness creation program is important to reduce this huge burden.

Impact of Presbyopia and Its Correction in Low- and Middle-Income Countries

Presbyopia affects more than 1 billion people worldwide, and the number is growing rapidly due to the aging global population. Uncorrected presbyopia is the world's leading cause of vision impairment, and as with other causes. The burden falls unfairly on low- and middle-income countries (LMICs), in which rates of presbyopic correction are as low as 10%. The importance of presbyopia as a cause of vision impairment is further underscored by the fact that it strikes at the heart of the productive working years, although it can be safely and effectively treated with a pair of inexpensive glasses. To galvanize action for programs to address uncorrected presbyopia in the workplace and beyond LMICs, it is crucial to build a solid evidence base detailing the impact of presbyopia and its correction in important areas such as work productivity, activities of daily living, visual function, and quality of life. The aim of this review was to provide an up-to-date reference for program planners and policymakers seeking to build support for programs of presbyopia correction, particularly in low-resource settings.