Prevalence and causes of visual impairment among adults aged 15-49 years in a rural area of north India - A population-based study

Prevalence of blindness and visual impairment in a coastal region of Southern India: A cross-sectional survey in Prakasam district, Andhra Pradesh

PURPOSE

To estimate the magnitude, determinants, and causes of visual impairment (VI) and blindness among people >40 years.

METHODS

In this cross-sectional survey, 2,968 people >40 years from 34 clusters were examined. A cluster random sampling method with a compact segment sampling technique was used to select the study participants. Prevalence of any VI (presenting visual acuity (PVA) <6/12 in better eye), severe VI (PVA <6/60 - 3/60), and blindness (PVA <3/60 in better eye) were expressed as percentage with 95% confidence interval. Logistic regression was performed to determine the risk factors associated with blindness. A P value of less than 0.05 was considered statistically significant.

RESULTS

The mean age of the participants was 54.6 years (Standard deviation ± 11.2 years). The prevalence of mild, moderate, and severe visual impairment was 14.2% (12.95-15.49), 13.7% (12.46-14.97), and 0.7% (0.47-1.12), respectively. The prevalence of blindness was 1.3% (0.94-1.79, n = 39). The overall prevalence of VI (presenting Visual Acuity <6/12) was 12.0% (95% CI: 10.8-13.2%). The major causes of VI were cataract (78.08%), refractive error (12.07%), and optic atrophy (2.22%), and corneal opacity (2.22%) and the major cause of blindness was cataract (77.27%). Blindness was strongly associated with increasing age- OR 17.1 (95% CI: 4.9-59.8) for people >70 years, and OR 7.6 (95% CI: 2.2-26.5) for people aged between 60 and 69 years compared to those aged 41-50 years and people living near coastal regions (Within 50 km of coast) (OR: 3.9, 95% CI: 1.6-7.3).

CONCLUSION

Blindness and vision impairment are of public health concern in this geographic region. Eye care services need to be augmented to address this challenge.

Improving Access to Eye Care in Rural Communities: PocDoc's Web-Based Visual Acuity Screening Tool

Objective: Visual acuity (VA) testing is crucial for early intervention in cases of visual impairment, especially in rural health care. This study aimed to determine the potential of a web-based VA test (PocDoc) in addressing the unique health care needs of rural areas through the comparison in its effectiveness against the conventional VA test in identifying visual impairment among an Indian rural population. Methods: Prospective comparative study conducted in December 2022 at a tertiary referral eye care center in central India. We evaluated all patients with the PocDoc VA tests using three device types, and the conventional VA test. Bland-Altman plot (BAP) compared PocDoc and conventional VA tests. Fisher's exact tests evaluated associations between categorical parameters. Kruskal-Wallis tests followed by post hoc Dunn's tests identified association between categorical parameters and numerical parameters. Results: We evaluated 428 patients (792 measurements of VA) with mean age 36.7 (±23.3) years. PocDoc resulted in slightly worse VA scores (mean logMAR: 0.345) than conventional (mean logMAR: 0.315). Correlation coefficient between the conventional and PocDoc logMAR VA values was rho = 0.845 and rho2 = 0.7133 (p = 6.617 × 10-215; adjusted p = 2.205 × 10-214). Most data points fell within the interchangeable range of ±0.32 on BAP. Difference between the two methods increased with higher logMAR values, indicating poorer agreement for worse VA scores. Conclusions: Identifying and addressing the unique health care needs of rural populations is critical, including access to appropriate and effective VA testing methods. Validating and improving VA testing methods can ensure early intervention and improve the quality of life for individuals with visual impairment.

Screening for Patients with Visual Acuity Loss in Primary Health Care: A Cross Sectional Study in a Deprived Hungarian Population

Screening for visual acuity loss (VAL) is not applied systematically because of uncertain recommendations based on observations from affordable countries. Our study aimed to evaluate the effectiveness of primary health care-based screening. A cross-sectional investigation was carried out among adults who did not wear glasses and did not visit an ophthalmologist in a year (N = 2070). The risk factor role of sociodemographic factors and the cardiometabolic status for hidden VAL was determined by multivariable linear regression models. The prevalence of unknown VAL of at least 0.5 was 3.7% and 9.1% in adults and in the above-65 population. Female sex (b = 1.27, 95% CI: 0.35; 2.18), age (b = 0.15, 0.12; 0.19), and Roma ethnicity (b = 2.60, 95% CI: 1.22; 3.97) were significant risk factors. Higher than primary school (b_{secondaryschoolwithoutgraduation} = -2.06, 95% CI: -3.64; -0.47; and b_{secondaryschoolwithgraduation} = -2.08, 95% CI: -3.65; -0.51), employment (b = -1.33, 95% CI: -2.25; 0.40), and properly treated diabetes mellitus (b = -2.84, 95% CI: -5.08; -0.60) were protective factors. Above 65 years, female sex (b = 3.85, 95% CI: 0.50; 7.20), age (b = 0.39, 95% CI: 0.10; 0.67), Roma ethnicity (b = 24.79, 95% CI: 13.83; 35.76), and untreated diabetes (b = 7.30, 95% CI: 1.29; 13.31) were associated with VAL. Considering the huge differences between the health care and the population's social status of the recommendation-establishing countries and Hungary which represent non-high-income countries, the uncertain recommendation of VAL screening should not discourage general practitioners from organizing population-based screening for VAL in non-affordable populations.

Association of sunlight exposure with visual impairment in an Indian fishing community

Purpose

Indian fishermen belong to a marginalized population and are continuously exposed to extreme occupational hazards and sunlight. A high prevalence of visual impairment (VI) is reported in the coastal fishing community. We aimed to investigate the association between VI and sunlight exposure measurement (SEM).

Methods

In this cross-sectional observational study, 270 eyes of 135 participants were enrolled from a coastal fishing village. Participants underwent a comprehensive ophthalmic examination, which included best-corrected visual acuity (BCVA), and anterior and posterior segment examination. Ocular Surface Disease Index (OSDI) and SEM questionnaire were administered to estimate the level of dry eye and ultraviolet-B (UV-B) exposure, respectively. VI was defined as presenting visual acuity worse than 6/12 (logarithm of the minimum angle of resolution [logMAR] > 0.3).

Results

The mean age and spherical equivalent were 50.56 ± 11.72 years (range: 18-80 years) and 0.36 ± 1.68 diopters (D) (range: -7.0 to +3.0 D), respectively. Age, SEM, OSDI, fishing as an occupation, and cataract were significantly associated with higher odds of VI in univariate analysis. Refraction, gender, education level, smoking status, amblyopia, systematic, and other ocular diseases were not significantly associated with VI. In the multivariate analysis, age, SEM, and presence of cataract remained significantly associated with a higher risk for VI. The area under the receiver operating characteristic curve values for age and SEM scores demonstrate a fair index of discrimination for the detection of VI.

Conclusion

SEM level is directly associated with a higher risk of VI among fishermen. The fishing community might benefit from regular eye examinations and awareness about the harmful effects of sunlight exposure and preventive measures.

Visual impairment in Ethiopia: Systematic review and meta-analysis

WHO Prevention of Blindness Program launched ‘‘VISION 2020” in 1999 to reduce visual impairment and eradicate avoidable blindness by the year 2020. Ethiopia launched the “VISION 2020” initiative in 2002. This systematic review and meta-analysis aimed to present the national prevalence of visual impairment at the end of “VISION 2020”. Electronic search was conducted on the PubMed, SCOPUS, EMBASE, Web of Science, CINAHL, Google scholar databases for including articles. This systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Endnote reference manager was used for downloading, organizing, and citing articles. Methodological quality was assessed using the Joanna Briggs Institute (JBI) quality appraisal tool for prevalence studies. Statistical analysis was done using the STATA™ software version 14. In this systematic review and meta-analysis, 18 studies involving 14,953 participants were included. The pooled prevalence of visual impairment in Ethiopia after correction for publication bias by Duval and Tweedie’s trim and fill analysis was estimated to be 6.24% (95% confidence interval [CI] = [2.66, 9.82]). The pooled prevalence of visual impairment among school children and adults in Ethiopia was 6.13% (95% CI = [4.27, 7.98]) and 19.89% (95% CI = [10.85, 28.93]), respectively. The most common causes of visual impairment in decreasing order of prevalence were refractive error, cataract, trachoma, glaucoma, and corneal opacity. Amblyopia was the cause of visual impairment among school-age child. The prevalence of visual impairment in Ethiopia was still significant at the end of “VISION 2020” program. Therefore, the program of “VISION 2020” should be extended and other large-scale programs were needed to reduce the prevalence of vision impairment in Ethiopia.

Prevalence of the Burden of Diseases Causing Visual Impairment and Blindness in South Africa in the Period 2010–2020: A Systematic Scoping Review and Meta-Analysis

The prevalence of visual impairment (VI) continues to rise, despite efforts to reduce it. The burden of disease negatively impacts the quality of life, education opportunities, and other developments in various communities. Henceforth, this study aimed to determine and quantify the major causes of VI in South Africa, to ensure accurate interventions in addressing them and to reduce the burden of ocular disease in that context. A systematic scoping review was conducted to map evidence on VI and ocular diseases, using the PRISMA-P guidelines. English studies were searched for on PubMed, Google Scholar, and EBSCOhost using various search terms. The eligible articles underwent screening and ultimately data extraction to identify major causes of VI in South Africa. A meta-analysis further resulted in pooled prevalence estimates (PPE) using the Inverse Variance Heterogeneity (IVhet) model. Of the 13,527 studies screened at three levels, 10 studies met the inclusion criteria for the final review; however, 9 studies were eligible for quality assessment performed by two independent reviewers. The quality index for the included studies was 71.1%. The prevalence of VI was 2% for blindness and 12% for moderate and severe visual impairment (MSVI). Pooled prevalence identified uncorrected refractive error (URE) (43%), cataract (28%), glaucoma (7%), and diabetic retinopathy (4%) as major causes of MSVI. The leading causes of blindness were untreated cataracts (54%), glaucoma (17%), and diabetic retinopathy (57%). Ocular diseases causing VI are avoidable and similar to those of low-to-middle income countries. MSVI were caused by URE, cataract, glaucoma, and diabetic retinopathy. Blindness was mainly caused by cataracts, glaucoma, and diabetic retinopathy. A strategic plan to manage these conditions would largely reduce the burden of VI in the country. Early screenings and interventions to maximize care at primary health levels would decrease the burden of avoidable blindness in the country significantly.

Estimating need and coverage for five priority assistive products: a systematic review of global population-based research

INTRODUCTION

To improve access to assistive products (APs) globally, data must be available to inform evidence-based decision-making, policy development and evaluation, and market-shaping interventions.

METHODS

This systematic review was undertaken to identify studies presenting population-based estimates of need and coverage for five APs (hearing aids, limb prostheses, wheelchairs, glasses and personal digital assistants) grouped by four functional domains (hearing, mobility, vision and cognition).

RESULTS

Data including 656 AP access indicators were extracted from 207 studies, most of which (n=199, 96%) were cross-sectional, either collecting primary (n=167) or using secondary (n=32) data. There was considerable heterogeneity in assessment approaches used and how AP indicators were reported; over half (n=110) used a combination of clinical and self-reported assessment data. Of 35 studies reporting AP use out of all people with functional difficulty in the corresponding functional domains, the proportions ranged from 4.5% to 47.0% for hearing aids, from 0.9% to 17.6% for mobility devices, and from 0.1% to 86.6% for near and distance glasses. Studies reporting AP need indicators demonstrated >60% unmet need for each of the five APs in most settings.

CONCLUSION

Variation in definitions of indicators of AP access have likely led to overestimates/underestimates of need and coverage, particularly, where the relationship between functioning difficulty and the need for an AP is complex. This review demonstrates high unmet need for APs globally, due in part to disparate data across this sector, and emphasises the need to standardise AP data collection and reporting strategies to provide a comparable evidence base to improve access to APs.

A study to assess the knowledge and skills of Accredited Social Health Activists and its retention after training in community-based primary eye care

Purpose:

Community volunteers like Accredited Social Health Activists (ASHAs) could be utilized for linking community and eye care services. Research is needed to effectively utilize them. This study was to assess whether ASHAs could imbibe new knowledge in eye care and conduct vision screening.

Methods: Settings and Design:

A pre-post-intervention study in South Delhi Integrated Vision Centres. It was conducted from January 2016 to March 2017. One day of conceptual training followed by hands-on training in vision screening was imparted to ASHAs. The knowledge was assessed thrice: before, immediately after, and following 1 year after training. The vision screening skill was assessed twice. Descriptive analysis using percentages, mean and standard deviations. Paired t-test was used for assessing the change in scores.

Results:

A total of 102 ASHAs were recruited. A significant increase in the knowledge score of ASHAs before (14.96) and after training (25.38) (P < 0.001) was noted. The knowledge score was sustained at 1 year (21.75). The satisfactory skill of vision screening was seen in 88 (86.3%) ASHAs after training, while 79 (77.5%) ASHAs still retained it after 1 year.

Conclusion:

The potential to involve ASHAs in community-based frontline eye care activities: awareness generation of eye diseases, identification of referrable conditions, and facilitating individuals to seek eye care facilities. This study informs about the duration, frequency, and content of the training. It also provides evidence on the improvement and sustainability of eye care knowledge and skills by ASHAs after conceptual and hands-on training.

Visual status among undergraduate students: Findings from an emerging university in Saudi Arabia

BACKGROUND

Refractive error is an important preventable cause of visual impairment and blindness worldwide. In adult life, reduced vision can potentially affect the academic performance, choice of occupation and socio-economic status. This study aimed to assess the prevalence of refractive errors and related visual impairment among undergraduate male students in Prince Sattam bin Abdulaziz University in Al-Kharj, Saudi Arabia.

METHODS

A descriptive cross-sectional study was employed in the current work. After obtaining an informed consent; each eligible student was asked to fill a self-constructed survey and have screened in the college premises for visual acuity and refractive error. Candidates detected with defective vision have been referred for further examination at well-equipped ophthalmology clinic in the University Hospital.

RESULTS

A total of 420 undergraduate students, with age ranged from 18 to 30 years, have participated in the current study. About 25.0% of the participants have used spectacles at the time of examination. Positive family history of spectacles use was found in 71.4%. Our study showed that visual acuity in the better eye was low in 34.76% of the participants. Seventy-eight students (18.6%) of the total participants reported defective vision and have fulfilled refractometric examination. Of the examined students 83.3% were found to have refractive errors. Astigmatism, 52.6%, was the most frequently encountered refractive error among the participants; followed by myopia, 26.9%; and hypermetropia 2.6%.

CONCLUSION

The current study confirms that refractive error is an important preventable cause of visual impairment. Significant portion of the examined participants were found to have refractive errors recommending further work to improve visual status in undergraduate students.

Habitual visual acuity in a large urban cohort of Western India and factors influencing poor habitual vision

Purpose:

The aim of this study was to determine habitual visual acuity (HVA) in a large urban cohort in western India and identify factors associated with poor HVA.

Methods:

This was a prospective study conducted over 10 days in September 2018 to assess the HVA in individuals attending a 10-day festival in Western India. Participants who volunteered to undergo vision screening and also filled the questionnaire form pertaining to demographic information including their age, gender, address, income, and educational status were included in this study. HVA was recorded with the distance correction that the participants were wearing when they attended the screening. The study evaluated the prevalence of visual acuity 6/6 or <6/6, 6/12, and 6/18 and the factors associated with lower visual acuity.

Results:

Of the 6300 participants, 1660 (26.3%) were females. Majority of the participants were from urban background (6084, 96.6%) and were of younger age group (18–40 years––3786, 60.1%; 41–60 years––2187, 34.7%; >60 years––327, 5.2%). HVA was recorded as 6/6 both eyes in 4136 (65.6%), at least 6/12 both eyes in 5691 (90.3%), and at least 6/18 both eyes in 5974 (94.8%) individuals. Only 11 patients (0.17%) had VA worse than 6/60 with only 3 patients (0.003%) having bilateral VA <6/60. Older age, female sex, lower education status, and low annual income were significant risk factors for poor HVA.

Conclusion:

Poor education, lower income, female gender, and old age are significantly associated with poor HVA even in urban Western India despite relatively easy access to affordable eye care facilities.

Genetic Epidemiology of Primary Congenital Glaucoma in the 22 Arab Countries: A Systematic Review

PURPOSE

Primary congenital glaucoma (PCG) is a rare glaucoma type that develops in early infantile period and contributes to an elevated pressure on ocular cavity. Variants in CYP1B1 gene are the most encountered in PCG cases. The prevalence of PCG is relatively high among Arabs, however its genetic epidemiology remains understudied. This study aims to systematically identify all reported PCG disease-causing variants in the Arab population and investigate their potential genotype-phenotype correlations.

METHODS

We searched four different databases (PubMed, ScienceDirect, Google Scholar, and Scopus) from the time of inception until July 2020. Broad search terms were used to capture all possible information about the genetic epidemiology of PCG among Arabs.

RESULTS

We identified a total of 77 disease-causing variants in 361 patients and 88 families; of these, 33 were unique to Arabs. Sixty-nine variants were identified in the CYP1B1 gene, five variants were in the MYOC gene and single variants were reported in NTF4, FOXC1, and WDR36 genes. The most common reported variant was the c.182 G > A in the CYP1B1 gene. All identified variants were from ten Arab Countries (Saudi Arabia, Kuwait, Oman, Egypt, Morocco, Lebanon, Tunisia, Iraq, Algeria, and Mauritania). We identified 44 shared variants with other ethnicities demonstrated a distinctive genotype-phenotype correlation. Consanguinity was observed in the majority of Arab PCG patients, ranging from 45% to 100%.

CONCLUSION

PCG causing variants were identified in 10 Arab countries, which were mostly detected in the CYB1P1 gene. Arab patients with PCG seem to have distinctive genotype-phenotype correlations.