Visual impairment attributable to uncorrected refractive error and other causes in the Ghanaian youth: The University of Cape Coast Survey

Fixation disparity and refractive error among first-year optometry students

PURPOSE

To determine the fixation disparity and refractive error of first-year optometry students to ascertain any relationship between them and also identify any association between fixation disparity and visual symptoms at near.

METHOD

It was an analytical cross-sectional study involving 85 participants aged 17 to 27 years (18.60 ± 1.37), 41% of whom were males. Subjective refraction was done at 3 m and fixation disparity was measured with and without spectacle correction using the Wesson Fixation Disparity Card. All analysis was set within a 95% confidence interval with a p-value ≤ 0.05 considered statistically significant.

RESULTS

Refractive error ranged from 0.25 SEQ (spherical equivalent) to 5.50 SEQ. Mean fixation disparity ranged from 2.9 ± 2.6 to 3.9 ± 2.8 min arc. There was no statistically significant correlation between refractive error and fixation disparity without correction (r = -0.180, p = 0.098) and with correction (r = 0.155, p = 0.157). For fixation disparity in the ortho and exo direction, mean fixation disparity with correction of participants who experienced headaches during or after reading (5.1 ± 2.6 min arc) was significantly higher (p = 0.032) than participants who did not (2.0 ± 2.6 min arc).

CONCLUSION

Myopia is common among first-year optometry students. Refractive error has no significant effect on fixation disparity. Headache is significantly associated with exo fixation disparity at near.

[Validation study on self-reported visual impairment among undergraduate students at the Federal University of Pelotas]

The objectives of the study were to assess the prevalence of self-reported visual impairment among undergraduate students between 18 and 39 years of age at the Federal University of Pelotas, and to validate a question about visual impairment in a subsample of the participants. A cross-sectional study was conducted by asking the question "Do you have any difficulty seeing up close and/or in the distance?" As the gold standard for the validation study, visual acuity (VA) was measured using the Snellen chart. Patients with VA less than 20/40 in either eye were considered to have reduced VA. The prevalence of self-reported visual impairment was 37.3% (95% CI: 35.1-39.6) and VA less than 20/40 in either eye was 6.9% (95% CI: 5.3-8.9). The question revealed sensitivity of 71.4% (95 CI: 57.8-82.7), specificity of 66.9% (95% CI: 63.4-70.2), positive predictive value of 13.8% (95% CI: 10.0-18.3), and negative predictive value of 96.9% (95% CI: 95,1-98.2). The results indicated a high prevalence of self-reported visual impairment among university students. The question showed reasonable sensitivity and specificity and high negative predictive value and may be used for screening for ophthalmological evaluation among young adult university students.

Prevalence and determinants of uncorrected refractive error among a socially vulnerable older adult population living in Armenia

OBJECTIVE

This study estimated the prevalence of uncorrected refractive error (URE) and its determinants in a socially vulnerable older population living in Armenia.

STUDY DESIGN

The study design used in the stidy is a cross-sectional study.

METHODS

A total of 485 people responded to a survey on sociodemographic characteristics, spectacle use, and ophthalmic services' use. All participants underwent a comprehensive ophthalmic examination including assessment of presenting and best-corrected visual acuity, measuring intraocular pressure and dilated eye fundus examination. Patients who had presenting visual acuity (<6/12) but improved ≥ one line with/without available spectacles after refraction in the better eye were considered to have URE. Descriptive statistics described the sample and estimated the prevalence of the URE in the population. Logistic regression models were used to evaluate its determinants.

RESULTS

The mean age of participants was 74.5 (7.27) years, ranging from 51 to 94 years. Women constituted the majority of participants (86%). The prevalence of URE in the better eye was 26%. In bivariate analysis, those who were older and who had less than 10 years of education had higher odds of URE than younger and more educated respondents. In multivariable analysis, only education remained associated with URE (OR = 3.71; 95% CI: 1.10-12.5). The rate of normal vision (≥6/12) improved from 58.9% to 81.5%, whereas the rate of visual impairment (<6/12) decreased from 41.1% to 18.5% after best correction in the better eye.

CONCLUSION

The prevalence of URE was high in this study population. The findings warrant the need for eye screening and provision of affordable spectacle correction to the target population in Armenia.

Prevalence of Refractive Error and Visual Impairment among Rural Dwellers in Mashonaland Central Province, Zimbabwe

Purpose

To determine the prevalence of refractive error and visual impairment in a rural population of Zimbabwe.

Methods

This community-based, cross-sectional study used a multi-stage sampling to select the participants from households in four communities within three rural districts in Mashonaland Central Province. Participants' demographic data were collated, and their presenting visual acuity (VA) was measured using the logMAR E chart. Clinical refraction was preceded by an anterior segment and posterior segment eye examinations. Visual impairment was defined as presenting VA worse than 6/12 (0.3 logMAR) in the better eye. Descriptive statistics were presented as frequencies.

Results

A total of 519 participants were involved in this study. Their ages ranged from 5 to 100 years (mean age = 50.94; standard deviation ± 21.12 years). Out of the 519 participants, 233 (44.9%) were male, and 286 (55.1%) were female. The prevalence of visual impairment was 56.8% (95% confidence interval [CI]: 55.7-67.2), and blindness was 13.1% (95% CI: 11.2-17.6). The prevalence of near visual impairment based on presenting near VA (N = 408) was 78.6% (95% CI: 78.1-85.4). The two most common causes of visual impairment were uncorrected refractive errors (UREs) (54.2%) and cataract (24.8%). The most common cause of blindness was cataract (41.2%). Hypermetropia (56.9%) was the most common refractive error.

Conclusions

A high burden of visual impairment due to UREs and cataracts was observed among the rural dwellers of Zimbabwe. Public health education, access to refractive error services, and cataract surgery are necessary to mitigate this high burden of visual impairment.

Impact of Axial Eye Size on Retinal Microvasculature Density in the Macular Region

Mechanical tissue stresses are important contributors to the increased risk of sight-threatening pathology in larger, more myopic eyes. The contribution of altered ocular vasculature to the development of this pathology is less well defined. The current study investigated the impact of eye size on the superficial vasculature of the macula. Subjects (n = 104) aged 18–50, with no history of ocular or vascular disease, or myopia control, were recruited from university staff and student populations in Australia and Hong Kong. Refractive error, ocular size, retinal morphology and vascular morphology were quantified through open field autorefraction, ocular biometry and ocular coherence tomography angiography. Morphology of the superficial retinal capillary plexus was assessed over a 3 × 3 mm fovea-centred area. Perfusion area and vessel length densities were analysed relative to axial eye length and retinal thickness. A significant inverse association was found between axial length and vascular density measures (perfusion area density r² = 0.186, p < 0.001; and vessel length density r² = 0.102, p = 0.001). Perfusion area and vessel length densities were reduced by 5.8% (p = 0.001) in the longest, relative to the shortest, eyes. The aggregated ganglion cell layer inner plexiform layer thickness was also inversely associated with eye size (r² = 0.083, p = 0.003), and reduced, by 8.1% (p < 0.001), in the longest eyes. An inverse association of eye size and superficial retinal vasculature density, that is not simply explained by retinal expansion or image magnification factors, was confirmed. These data support the hypothesis that ongoing metabolic challenges may underlie the development of myopia-related and -associated pathology in larger eyes.

Visual impairment and social isolation, depression and life satisfaction among older adults in Ghana: analysis of the WHO's Study on global AGEing and adult health (SAGE) Wave 2

AIM

To estimate the prevalence of visual impairment (VI) and associated factors and further quantify its association with social isolation, depression and life satisfaction among older adults in Ghana.

METHODS

WHO Study on Global AGEing and Adult Health Ghana dataset for older adults 50 years and above was used for this study. Social isolation, depression and life satisfaction were our primary outcomes with VI being our secondary outcome. We employed negative binomial, Poisson and generalised negative binomial regression models individually modified with Coarsened Exact Matching method of analysis. All analysis was performed by adopting robust SE estimation using Stata V.15.

RESULTS

The prevalence of VI was 17.1% (95% CI14.3 to 20.2) and the factors associated include age groups, educational level, religion, region, where the participant was born, and difficulty in work/households activity (p<0.05). The inferential analysis shows that the significant log-likelihood score of social isolation and life satisfaction for older adults with VI was 0.25 more (95% CI 0.03 to 0.47) and 0.04 less (95% CI -0.08 to -0.01), respectively, compared with those without VI. The prevalence of depression among older adults with VI was significantly 90% higher compared with non-VI (adjusted prevalence ratio (95% CI) = 1.90 (1.17 to 3.09), p<0.001).

CONCLUSION

The prevalence of VI is associated with increasing age, educational level and self-rated health. VI was identified to be associated with social isolation, depression and diminishing life satisfaction. In order to achieve sustainable development goal #3, a national focus on geriatric care as part of the implementation of the National Ageing Policy will garner improvement in the quality of life of older adults with visual VI in Ghana. Eye health practitioners at all levels of the health systems should consider the psychosocial consequences of VI for the optimum care of the older adult client.

Visual Impairment and Spectacle Use in University Students in Central China: The Anyang University Students Eye Study

PURPOSE

To investigate the prevalence and associations of visual impairment and spectacle use in university students in central China.

DESIGN

Cross-sectional study.

METHODS

This study included students aged 16-26 years in China. Study subjects from 2 universities underwent distance visual acuity (VA) assessment in both eyes with a logarithm of the minimum angle of resolution chart and their refractions were measured by cycloplegic autorefraction. Blindness was defined as presenting VA less than three-sixtieth in the better eye (World Health Organization definition), and visual impairment was defined as presenting VA less than six-twelfths.

RESULTS

Overall, 9710 undergraduates were enumerated, 7704 (79.3%) subjects were included in this study. The prevalence of uncorrected VA less than six-twelfths and less than three-sixtieth in the better eye were 69.9% and 0.9%, respectively. Only 77.0% (4148/5388) of subjects with uncorrected VA in the better eye of less than six-twelfths wore glasses. For presenting VA, the prevalence of mild (VA <6/12 to 6/18), moderate (VA <6/18 to 6/60), and severe (VA <6/60 to 3/60) visual impairment was 6.3%, 11.2%, and 0.7%, respectively. Overall, 71.7% (4300/6001) of students with myopia (spherical equivalent ≤-0.5 diopters) wore spectacles. In multiple logistic regression analysis, visual impairment was associated with female sex (P < .001) and lower year level of education (P = .006) when presenting with VA.

CONCLUSIONS

This study has documented a relatively high prevalence of visual impairment and relatively low spectacle coverage in Chinese university students. Given the potential impact of visual impairment, target education and accessible refraction services are highly important to solve the problem.

Global prevalence and causes of visual impairment with special reference to the general population of Saudi Arabia

Objective:

This review was undertaken to highlight the worldwide prevalence and causes of visual impairment (VI), on the basis of a wide range of recent and clearly defined data and in comparison with published articles from the Kingdom of Saudi Arabia.

Methods:

These data are mainly based on PubMed indexed journal articles. Some representative surveys from each of the six WHO regions across the globe were included in this review with special reference to Saudi Arabian studies.

Results:

Published literature show that the prevalence and causes of VI varies markedly in different parts of the world and from region to region within the same country. Cataract, uncorrected refractive errors and glaucoma were shown to be the leading causes of VI worldwide and in Saudi Arabia. Diabetic retinopathy was found to have more contribution in Saudi Arabia due the higher prevalence of diabetes mellitus in this country.

Conclusion:

Epidemiological surveys about the prevalence and causes of VI are crucial for the formulation of preventive and curative measures. Data about VI are still scarce with a need to make wider population based surveys, worldwide and in Saudi Arabia for in-depth evaluation of the problem and better strategies to reduce the burden of VI.

Retinal Microvasculopathy Is Common in HIV/AIDS Patients: A Cross-Sectional Study at the Cape Coast Teaching Hospital, Ghana

Purpose. The purpose of this study was to evaluate the ocular disorders in HIV positive patients attending the Cape Coast Teaching Hospital, Ghana. Methods. A cross-sectional study using systematic random sampling was conducted on 295 HIV positive patients. Data collection consisted of semistructured questionnaires, laboratory investigation, medical profile, and ophthalmic examination. Statistical association tests including χ², independent t-test, and ANOVA were done. A p value ≤ 0.05 was considered statistically significant. Results. Of the 295 participants, 205 (69.5%) were on antiretroviral therapy while 90 (30.3%) were not on therapy. Majority of the participants (162, 54.9%) were in clinical stage two, followed by stages three (68, 23.1%), one (62, 21%), and four (3, 1%), respectively. The overall prevalence of ocular disorders was 5.8%. The most common HIV related ocular disorder was HIV retinal microvasculopathy (58.8%), followed by herpes zoster ophthalmicus and Toxoplasma retinochoroiditis, both representing 11.8% of ocular disorders seen. Cytomegalovirus retinitis, Bell's palsy, and optic neuritis were the least common (5.9%). CMV retinitis recorded the highest viral load of 1,474,676 copies/mL and mean CD4 count of 136 cells/mm³. The mean CD4 count for participants with HIV related ocular disorders was significantly lower compared to participants without disorders (t = 2.5, p = 0.012). Participants with ocular disorders also recorded significantly higher mean viral loads than those who did not have ocular disorders (t = 2.8, p = 0.006). Conclusion. Lower CD4 counts and high viral load copies were associated with the manifestation of HIV related ocular disorders.