Prevalence of Refractive Errors in Iranian University Students in Kazerun

Prevalence of refractive errors in population aged 50 years and over: The Gilan eye study

PURPOSE

To describe the prevalence of refractive error (RE) and its association with other environmental and health factors among population aged ≥50 years who lived in Gilan, Iran in 2014.

METHODS

In this population-based cross-sectional study, 3281 individuals aged ≥50 years living in Gilan for at least 6 months were enrolled. The prevalence of different types of REs including myopia (spherical equivalent (SE)≤-0.50D), high myopia (SE ≤ -6.00D), hyperopia (SE≥ + 0.50D), high hyperopia (SE≥ + 3.00D), astigmatism (cylinder < -0.50D) and high astigmatism (cylinder < -2.25D) were determined. Anisometropia was defined as the SE difference of ≥1.00D between the two eyes. Associated factors including age, body mass index (BMI) and education were also studied.

RESULTS

2587 eligible individuals (58% female subjects) with the mean age of 62.6 ± 8.8 years participated (87.6% response rate). The prevalence of myopia, hyperopia and astigmatism was 19.2%, 48.6% and 57.4%, respectively. 3.6% high hyperopia, 0.5% high myopia and 4.5% high astigmatism were identified. The positive simultaneous effects3 of older age (Odds Ratio (OR) = 3.14), nuclear (OR = 1.71) and posterior subcapsular (OR = 1.61) cataracts as well as the negative effects of higher levels of education (OR = 0.28) were obtained on myopia. Higher BMI was found as a risk factor for hyperopia (OR = 1.67), while older patients were less likely to be hyperopic (OR = 0.31).

CONCLUSION

Higher incidence of myopia and astigmatism was found in patients aged over 70 years. It was also found that patients at older ages who suffered with cataracts were at a higher risk of myopia, while elderly people with greater BMI were at a higher risk of hyperopia.

Epidemiology and trends in the uptake of refractive error services in Harare, Zimbabwe: a hospital-based retrospective study

Aim

The study aimed to determine the epidemiology and evaluate the trends in the uptake of refractive error services in Harare.

Methods

A clinic-based retrospective study at the Greenwood Park Eye Centre and its three subsidiaries was conducted from January 1, 2015 to December 31, 2020.

Results

12,216 patients' records were retrieved, out of which 1074 (8.79%) had refractive error cases. The prevalence of visual impairment at presentation was 5.80% [95% CI: 5.39 - 6.23]. Among those with refractive error, the sample prevalence of visual impairment before correction was 41.30% [CI: 38.3 - 44.3, 95%], and 2.20% [95% CI: 1.4 - 3.3] after correction. There was inconsistency in the percentage utilization of refractive error services, with the highest being 42.60% in 2015. Refractive error types were related to age, employment position, and type of visual impairment prior to refractive error treatment.

Conclusion

There was a low percentage of refractive error services uptake in urban Zimbabwe.

The prevalence of refractive errors in college students in Israel

PURPOSE

To determine the prevalence of refractive errors in Jewish and Arab college students in Israel and associations with ethnicity and sex.

METHODS

In this retrospective cross-sectional study, first-year college students underwent non-cycloplegic autorefraction and answered a questionnaire to assess age, sex, and self-identified ethnicity. Spherical equivalent refractive error (SER) was calculated, and the prevalence of hyperopia (>+0.50 Diopter, D), emmetropia (>-0.50 to +0.50 D), myopia (≤-0.50D, low ≤-0.50 to >-3.0D, moderate <-3.0 to >-6.0D, high ≤-6.0D), and astigmatism (>0.50D) were determined. Groups were compared using Chi-square or Fisher test. Univariate and multivariate analyses were conducted to identify factors associated with refractive errors.

RESULTS

Participants (n = 807) had a mean age of 22.1 ± 2.6 years (range: 17-30 years) and SER of -1.7 ± 2.2D (range: -13.3 to +5.7D). The prevalence and 95% confidence internal of myopia was 66.3% (63.0-69.6). Jewish students had a higher prevalence than Arab students for myopia (69.2% vs 60.3%), moderate (18.5% vs 12.2%) and high myopia (5.9% vs 1.9%) and astigmatism (51.4% vs 43.9%, p<0.05 for all), but not low myopia or hyperopia. Females had a higher prevalence of myopia than males (68.1% vs 58.7%, p<0.03). Jewish ethnicity was associated with myopia (OR=1.48, p = 0.01) and moderate myopia (OR=1.72, p = 0.01), and studying optometry was associated with moderate myopia (OR=1.63, p = 0.02). Sex and age were not associated with myopia.

CONCLUSION

Myopia prevalence in Israeli college students is high, showing associations with Jewish, but not Arab, ethnicity, suggesting that ethnic factors may play a role in the refractive differences between Arabs and Jews.

Prevalence of reduced visual acuity among adolescents in Jiaocheng County, Shanxi Province

Purpose

To investigate the prevalence of reduced visual acuity among adolescents in Jiaocheng County, Shanxi Province.

Methods

Fourteen thousand fifty-one Jiaocheng County students aged 7 to 21 were chosen to engage in this research project in 2019. For uncorrected distance visual acuity (UCDVA) testing, a 5 m standard logarithmic visual sharpness E chart was utilized, and for diopter examination of those with reduced UCDVA, computerized optometry was used. The factors linked to reduced UCDVA in students were investigated using logistic regression analysis.

Results

In Jiaocheng County, Shanxi Province, the prevalence of reduced UCDVA among adolescents was 77.54% in 2019, with the highest rate of severely reduced UCDVA at 47.58% and myopia accounting for the highest proportion of reduced UCDVA, with myopia rates above 90% in all age groups. Girls, those who live in counties, those who are anxious about their studies, and those who dedicate more time to schoolwork are more prone to suffer from a decrease in UCDVA; those who spend more time outdoors and get adequate sleep are less likely to have reduced UCDVA, according to logistic regression analysis.

Conclusion

Adolescents in Jiaocheng County, Shanxi Province, have a high prevalence of reduced UCDVA, and interventions targeting key populations should be increased based on effective prevention and control of reduced UCDVA among local adolescents.

Prevalence of refractive errors and color vision deficiency in a population of industry-workers in Abhar, Iran

Visual impairment due to refractive errors and color vision deficiency (CVD) can affect the visual abilities of workers in workplace. Identifying the prevalence of common visual problems helps us to prevent and treat occupational ocular problems.This study was conducted on 2600 males referring from companies for a routine medical exam to Occupational Medicine Center. In all subjects, visual acuity and refraction were measured. Assessment of color vision was performed by Ishihara color test. In present study, right eyes of subjects were selected to statistical analysis.The mean spherical equivalent was -0.19 ± 1.39 diopter with a range of -11.00 to +10.00 diopter. Whereas 71% of persons were emmetropic, 20% and 9% of them were myopic and hypermetropic, respectively. From a total subjects, 164 of them had CVD with prevalence of color blindness of 6.3%. In comparison with normal subjects, CVD had no significant effect on refractive findings of our subjects (P > .05).Our data present the prevalence of refractive errors and color blindness among Iranian industry-workers. Compared with other studies, our subjects have a lower prevalence of refractive errors, and similar rate of prevalence of color blindness.

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.

The prevalence of refractive errors in the Middle East: a systematic review and meta-analysis

PURPOSE

The purpose of the present study was to evaluate the prevalence of refractive errors in the Middle East region.

METHODS

In this meta-analysis, a structured strategy was applied to search databases PubMed, Web of Science, Scopus, and Google Scholar, databases as well as the reference lists of the selected articles to identify cross-sectional studies assessing the prevalence of refractive errors in the Middle East region until September 2019. The outcome measure was the prevalence of refractive errors, including myopia, hyperopia, and astigmatism, in two age groups of ≤ 15 years and > 15 years. The study results were combined using a random effects model at a confidence level of 95%.

RESULTS

The prevalence of myopia, hyperopia, and astigmatism was 4% (95% CI 4, 5), 8% (95% CI 6, 10), and 15% (95% CI 10, 19) in people less than or equal to 15 years and 30% (95% CI 25, 34), 21% (95% CI 15, 28), and 24% (95% CI 16, 31) in subjects over 15 years, respectively. The prevalence of myopia, hyperopia, and astigmatism was 3.5%, 12.4%, and 9.0% in male and 4.2%, 13.1%, and 9.9% in female subjects aged ≤ 15 years, respectively. In subjects aged > 15 years, the prevalence was 31.7%, 14.5%, and 31.5% in males and 31.9%, 11.2%, and 31% in females, respectively.

CONCLUSION

The prevalence of hyperopia is relatively high in Middle Eastern children, while the prevalence of myopia is higher in adults in this region. It seems that astigmatism is not a serious refractive problem in this region compared to the rest of the world.