Refractive errors among children, adolescents and adults attending eye clinics in Mexico

Prevalence of refractive errors in children of Puerto Rico

AIM

To determine the prevalence of refractive error in 5- to 17-year-old schoolchildren in Puerto Rico.

METHODS

A quantitative descriptive study of 2867 children aged 5 to 17y from all seven educational regions of Puerto Rico was conducted from 2016-2019. Refractive error was determined via static and subjective refraction. Children with distance acuity ≤20/40 or near visual acuity ≤20/32 had a cycloplegic refraction. Data analysis included descriptive statistics, correlation coefficient, Kruskal-Wallis, Chi-square, and t test calculations.

RESULTS

Twenty percent of the children had a spherical equivalent refractive error ≤ -0.50 D, 3.2% had a spherical equivalent ≥ +2.00 D, and 10.4% had astigmatism ≥1 D. There was a statistically (but non-clinically) significant myopic change in spherical equivalent refractive error with age (P<0.001). The prevalence of myopia increased with age (P<0.001) but not hyperopia (P=0.59) or astigmatism (P=0.51). Males had a significantly higher hyperopic spherical equivalent than females (P<0.001). Females had a higher prevalence of myopia (P<0.001) than males, but there was no difference in the hyperopia (P=0.74) or astigmatism prevalence (P=0.87).

CONCLUSION

The prevalence of a spherical equivalent equal to or less than -0.50 D (myopia, 20.7%) is one of the highest among similar-aged children worldwide. Further studies should explore the rate of myopia progression in children in Puerto Rico. Individual children must be monitored to examine the need for treatment of myopia progression.

Analysis of Peripapillary Intrachoroidal Cavitation and Myopic Peripapillary Distortions in Polar Regions by Optical Coherence Tomography

Purpose

To compare the peripapillary polar characteristics in eyes combining peripapillary staphyloma and gamma peripapillary atrophy according to whether peripapillary intrachoroidal cavitation (PICC) was present or absent (combination-group).

Patients and methods

This prospective non-interventional cross-sectional study included 667 eyes of 334 subjects. From the polar peripapillary regions to the opening of Bruch’s membrane, the following elements and their topographic relationships were analyzed using optical coherence tomography sections: configuration of the posterior curvature of the choroid, visibility of the subarachnoid space (SAS), and suprachoroidal detachment (SCD). Chi-squared and Fisher exact tests were used for statistical analysis.

Results

The protrusion of the posterior choroidal wall, with anterior elevation on either side, observed in both groups progressed and transformed into a wedge-shaped deformity on the side of gamma peripapillary atrophy. This wedge configuration was significantly more frequent in PICC-group than in combination-group (p = 0.004 and p < 0.001) for the upper and lower poles, respectively. SAS was more frequently observed in PICC-group than in combination-group (p = 0.002 and p < 0.001) for the upper and lower poles, respectively. SCD was detected exclusively in PICC-group (p < 0.001, both poles). The wedge-shaped configuration and the SCD were aligned antero-posteriorly with the SAS.

Conclusion

We confirmed that PICC is an SCD. We observed its constant alignment with the SAS. We suggest that the tensile forces of the optic nerve sheaths during adduction promote the collapse of the scleral flange onto the SAS, leading to PICC. Further studies are warranted to confirm this hypothesis.

Impact of Refractive Errors on the Academic Performance of High School Children of Lahore

Introduction

The process of learning begins in childhood and accurate vision can greatly affects a child's learning capacity. It is documented that visual impairment in children can have a significant impact on their performance at school as well as their social interaction and development.

Objective

This research aimed to study the impact of refractive corrections on the academic performance of high school children in Lahore.

Methodology

A total of 2,000 students with equal distribution of gender, public, private school, and locality were included in the study. All students were screened for defective vision. The academic performance before and after corrections was recorded on the prescribed proforma.

Results

The prevalence of refractive error was high among the public high schools 244 (59.2%) as compared to the private schools 168 (40.8%). The area-based prevalence was higher among the students in urban settings 255 (62%) while in rural it was 157 (38%). It was found that in the public sector, the average score of academic results before the intervention was 56.39 ± 13.24 which was increased to 60.27 ± 14.94 after the intervention while in the private sector, before the intervention, the average score was 63.53 ± 17.50 which was improved to 67.12 ± 18.48. It was found to be statistically significant at p-value &lt; 0.05.

Conclusion

A significant impact was observed in the average academic scores of the results after refractive corrections.

Gender and age distribution of refractive errors in an optometric clinical population

AIM

To determine the patterns of distribution of refractive errors in a clinical sample of patients examined in an optometry practice.

METHOD

In this retrospective study, the clinic records of 6687 patients aged 6 to 85 years comprising 2168 (32.2%) males and 4519 (67.5%) females were reviewed. Refractive error were analysed according to gender, age, as well as types and categories including axis of astigmatism using the vector power analysis method where the traditional sphero-cylinder was transformed into J0 (primary) and J45 (oblique) astigmatic components.

RESULTS

Only the analysis for right eye was reported as right and left spherical equivalent were similar. The mean with standard deviations for refractive errors were: Myopia: -1.95 ± 2.6, hyperopia: 1.04  ± 0.9, astigmatism: -1.22 ± 0.71 and anisometropia: -0.01 ± 2.5 DS. The distributions with significant changes included males that were significantly more myopic and astigmatic, while females were more hyperopic across the age groups. Furthermore, myopia decreased, while hyperopia, astigmatism and anisometropia increased with increasing age. Unique findings from this study include: myopia peaked earlier, second hyperopic shift commenced after age 82 years and the distribution of severity of astigmatism contrasts with previous understanding.

CONCLUSION

Although the patterns of distribution of refractive errors in patients aged 6 to 85 years corroborates previous findings, myopia and hyperopia peak, as well as severity of astigmatism were unique to the present study. Results from non-clinic populations will be useful to confirm trends reported in this study.

Types and Presentation of Refractive Error among Individuals Aged 0-30 Years: Hospital-Based Cross-Sectional Study, Yemen

BACKGROUND

Refractive errors are the most common cause of visual impairment worldwide. Its proportion varied among societies and is considered as a public health challenge. Symptoms and signs associated with refractive errors are the most worrisome and common presentations in the general practice in eye clinics.

AIM

The goal of this study was to determine the types and presentations of refractive error among the 0-30-year-old Yemeni population to aid early identification, diagnosis, referral, and treatment. Methodology. A cross-sectional study including 1,500 out-patients aged from 0 to 30 years attending the ophthalmology clinic in Sanaa, Yemen (between 2012 and 2015). All patients underwent visual acuity examination, autorefractometer, and anterior and posterior segment examination and were grouped according to type, that is, myopia, hyperopia, and astigmatism.

RESULTS

Hyperopia was the most common single diagnosis (53.3%) followed by myopia (33.3%). Astigmatism was uncommon as a single diagnosis (13.4%) but commonly associated with hyperopia or myopia. Myopia was more common in males (42.9%) than in females (25%). Hyperopia was more in females (62.5%) than in males (42.9%). Age groups most affected by refractive errors were 13-18 years (27.7%), 19-24 years (24.8%), and 25-30 years (24.6%), respectively. Decreased vision (53%) was a common presentation in myopia and astigmatism (41.5%) and less in hyperopia (39.6%). Headache was common in astigmatism (56%), hyperopia (28.8%), and myopia (17.8%). Muscle imbalance, namely, exotropia (27.2%), is mainly found in myopia and esotropia (24.3%) in hyperopia.

CONCLUSIONS

In addition to decreased vision, our patients with refractive errors mostly complain of headaches with clear variations with age and type of refractive error. Early identification and proper categorization of refractive errors by age, gender, and other demographics by general physicians in primary care can better deduce and make useful referrals to eye specialists.

A Serial Cross-Sectional Analysis of the Prevalence, Risk Factors and Geographic Variations of Reduced Visual Acuity in Primary and Secondary Students from 2000 to 2017 in Hong Kong

Background: We would like to investigate the prevalence trend, potential risk factors and geographic features of reduced visual acuity (VA) in primary and secondary schoolchildren of Hong Kong. Methods: This was a serial cross-sectional study using historical data of schoolchildren aged 6 to 15 years from the annual health checks conducted at Student Health Service Centers across Hong Kong, for the school years of 2000/2001 to 2016/2017. Results: The prevalence of reduced VA increased from 49.23% (95% CI, 48.99-49.47) in 2000/2001 to 54.34% (95% CI, 54.10-54.58) in 2011/2012 but decreased to 51.42% (95% CI, 51.17-51.66) in 2016/2017. Girls were less susceptible than boys at age 6-7 (and in grade primary 1-2), but more susceptible at older ages. The prevalence in junior grades increased while the risk effect of grade reduced over the past 17 years. Geographic variation on the risk for reduced VA existed and spatial autocorrelation was positive. The difference in prevalence of reduced VA between Hong Kong and mainland China has decreased in recent years. Cross-border students living in mainland China were associated with a lower risk for reduced VA. Conclusions: Further study was proposed to investigate the environmental association between students living in and outside Hong Kong with the prevalence of reduced VA. Multi-level research should also be conducted to investigate the influence of compositional and contextual factors on the prevalence of reduced VA.

A review on the epidemiology of myopia in school children worldwide

Background

Due to high prevalence myopia has gained importance in epidemiological studies. Children with early onset are at particular risk of complications associated with myopia, as progression over time might result in high myopia and myopic macular degeneration. Both genetic and environmental factors play a role in the increasing prevalence of myopia. The aim of this study is to review the current literature on epidemiology and risk factors for myopia in school children (aged 6–19 years) around the world.

Main body

PubMed and Medline were searched for the following keywords: prevalence, incidence, myopia, refractive error, risk factors, children and visual impairment. English language articles published between Jan 2013 and Mar 2019 were included in the study. Studies were critically reviewed for study methodology and robustness of data. Eighty studies were included in this literature review.

Myopia prevalence remains higher in Asia (60%) compared with Europe (40%) using cycloplegic refraction examinations. Studies reporting on non-cycloplegic measurements show exceptionally high myopia prevalence rates in school children in East Asia (73%), and high rates in North America (42%). Low prevalence under 10% was described in African and South American children. In recent studies, risk factors for myopia in schoolchildren included low outdoor time and near work, dim light exposure, the use of LED lamps for homework, low sleeping hours, reading distance less than 25 cm and living in an urban environment.

Conclusion

Low levels of outdoor activity and near work are well-established risk factors for myopia; this review provides evidence on additional environmental risk factors. New epidemiological studies should be carried out on implementation of public health strategies to tackle and avoid myopia. As the myopia prevalence rates in non-cycloplegic studies are overestimated, we recommend considering only cycloplegic measurements.

Prevalence of visual impairment and refractive errors in an urban area of Mexico

AIM

To determine the distribution of refractive errors in a school-age population in Quintana Roo (Mexico) in the framework of an international cooperation campaign for the prevention of blindness.

METHODS

A sample of 2647 school-age children (ranging from 5 to 14 years old) with a mean age of 9.1±1.9 years old were tested by trained volunteers for distance visual acuity (VA) and refractive errors. The first screening examination included uncorrected distance visual acuity (UDVA) and VA with a +2.00 D lens. Inclusion criteria for a second complete cycloplegic eye examination performed by an optometrist were UDVA <20/25 (0.10 logMAR or 0.8 decimal) and/or VA with +2.00 D ≥20/25.

RESULTS

A total of 633 (23.9%) children underwent the second complete eye examination. Mean logMAR UDVA was 0.035±0.094 (range 1.00 to 0.00 logMAR) for the right eyes and 0.036±0.160 (range 1.00 to 0.00 logMAR) for the left eyes. Bilateral amblyopia was found in 17 children (2.7% of refracted eyes; 0.64% of the total). The main reason for visual impairment (VI) in the sample analyzed was found to be refractive errors. In 12 children (1.9% of refracted eyes; 0.45% of the total) the VI was bilateral and 9 (1.4% of refracted eyes; 0.34% of the total) achieved a corrected distance visual acuity of 20/25 or better in both eyes. Mean magnitude of sphere and refractive cylinder was +0.20±0.96 D and -0.43±0.85 D in right eyes, and +0.24±1.08 and -0.43±0.83 D in left eyes. The proportion of myopic eyes [standard equivalent (SE) ≤-0.50 D] was 4.6% of the whole sample (5290 eyes). The mean magnitude of myopia was -0.84±3.44 D for the right eyes and -0.82±5.21 D for the left eyes. The proportion of hyperopic patients (SE≥+2.00 D) was 2.4% (15/633), which corresponded to 0.60% of the whole sample (32/5290 eyes). No statistically significant correlation of age to manifest sphere or cylinder was found.

CONCLUSION

VI due to uncorrected refractive errors can be easily corrected with glasses but it is still a burden to be treated. Myopia is prevalent in this sample. More efforts towards correcting uncorrected refractive errors are needed.

Prevalence and pattern of refractive errors among Saudi adults

Background & Objectives:

Refractive Errors (RE) are responsible for major portion of the treatable visual impairment and avoidable blindness in the world. The prevalence of RE varies with age, gender, ethnicity, geographical locations and also from time to time due to progresse in eye care services. We aimed to study the prevalence of RE and assess their patterns among Saudi adults of Arar city, the capital of Northern Border Region of Saudi Arabia.

Methods:

This is a cross-sectional, population-based study. A total number of 966 Saudi adults aged 16 to 39 years were enrolled. The patterns of their RE were studied through auto-refraction evaluation.

Results:

The prevalence of RE was 45.8%. The most frequent type of RE was myopia in 24.4%, followed by hyperopia 11.9% and astigmatism in 9.5% cases. Ages and genders significantly affect the prevalence of the different patterns of RE (0.033 and 0.012, respectively).

Conclusion:

The prevalence of RE in Arar city is slightly lower than that previously published in the same targeted age group. Myopia is the main RE. More awareness programs, especially among young adults are recommended for better outcomes.