Prevalence and associated factors of myopia among high school students in Gondar town, northwest Ethiopia, 2016

Abstract

IntroductionMyopia is an important cause of correctable visual impairment and preventable blindness worldwide. Prevalence rates are approximately 20%–35% among the older teenage population globally. It has a medical burden of pathologic complications such as maculopathy and glaucomatous optic neuropathy. High school students experience high-performance and study pressures in the preparation for the final national examination. As a result they are exposed to excessive near work and indoor activities. They are also ignored for regular screening.ObjectiveTo determine the prevalence and associated factors of myopia among high school students in Gondar town, Ethiopia.MethodsAn institution-based cross-sectional study was conducted on 498 high school students with systematic random sampling method from April 18 to April 29, 2016, in three full-cycle high schools (9th–12th grades). A standardized structured questionnaire, Snellen acuity chart, pinhole, retinoscope, trial case lenses, pen torch, and direct ophthalmoscope were used to collect data.ResultsA total of 495 study participants were included, and they had a mean age of 17.48±1.59 years. The prevalence of myopia was 11.9% (95% confidence interval [CI]: 10.2, 17.9). Family history of myopia (adjusted odds ratio [AOR]=8.08 [95% CI: 4.30, 15.16]), school being private (AOR=2.88 [95% CI: 1.02, 8.11]), longer time spent for near work (AOR=2.89 [95% CI: 1.12, 7.43]), longer time spent partaking in indoor activities (AOR=4.32 [95% CI: 1.69, 10.99]), shorter near working distance (AOR=3.06 [95% CI: 1.33, 7.06]), lack of outdoor sport activities (AOR=2.27 [95% CI: 1.05, 4.90]), use of visual display units (AOR=2.81 [95% CI: 1.30, 6.10]), and abnormal ocular findings (AOR=6.69 [CI: 3.43, 13.03]) were found to be independently associated with myopia.ConclusionThe prevalence of myopia was 11.9%. Family history for myopia, school being private, longer time spent partaking in indoor activities, shorter working distance, lack of outdoor sport activities, use of visual display units, and presence of abnormal ocular findings were positively associated with myopia.

Prevalence and associated factors of myopia among school children in Bahir Dar city, Northwest Ethiopia, 2019

“…Myopia, commonly known as short-sightedness, is a state of refraction in which parallel rays of light coming from infinity are brought to focus in front of the retina due to having a long axial length or steep corneal curvature [ 1 ]. It is the leading cause of correctable visual impairment and preventable blindness worldwide [ 2 ]. The clinical feature of myopia includes reduction of distance vision, diminished color vision and contrast sensitivity [ 3 ].…”

“…Whereas in a study done among black Africans children the prevalence rate reaches from 3% to 9.4% [ 10 ]. A study conducted in Gondar, Ethiopia among high school students showed a prevalence rate of myopia as 11.8% [ 2 ].…”

“…Myopia is the result of a combination of genetic and environmental factors [ 1 , 6 , 11 ], but the increases in myopia prevalence during the past century in certain societies argue strongly for a greater environmental inffuence [ 1 ]. It has been associated with age, sex, intensity of schooling, family history of myopia, time to outdoor activity, type of school, near working distance, and exposure to near work activities [ 2 , 11 – 14 ]. As there is no universally accepted method for the prevention of myopia onset, it is important to identify modifiable risk factors associated with its development.…”

“…The economic costs of myopia are also high [ 6 ]. It has a considerable burden on individuals and society that can harm career choice, ocular health, and sometimes self-esteem [ 2 , 8 ]. Public health interventions are essential to descend the growing myopia prevalence and its associated burden [ 7 ].…”

Corneal curvature in young high myopic undergraduates in southern Nigeria

“…3 The causes of myopia are unclear, although evidence supports both genetic and environmental components; it has been associated with socioeconomic status, level and length of education, parental myopia, exposure to near work, level of intelligence and amount of time spent for indoor activities. 4 Ocular biometrics, in this case corneal curvature are also among the most important factors affecting refractive errors. The participants of the World health Organisation-Brien Holden Vision Institute's, Joint Scientific meeting on Myopia in Sydney, Australia agreed that a classification of high myopia as -5.00D is the best definition, as a person who has -5.00D uncorrected myopia has a visual acuity of 6/172, which is much worse than the threshold for blindness (<3/60 in the better eye).…”