The prevalence of amblyopia in 7–9-year-old schoolchildren in Mashhad

Background: To determine the prevalence of amblyopia in schoolchildren aged 7–9 years old in Mashhad, Iran. Methods: This was a cross-sectional, community-based study with schoolchildren aged 7–9 years old. We randomly selected 20 of 189 elementary schools (three schools per district; 10 male-segregated and 10 female-segregated schools) from a proportional combination of public schools across Mashhad. Basic vision exams were performed. If amblyopia was suspected, children underwent supplementary vision exams. The diagnostic criterion for amblyopia was a best corrected visual acuity (BCVA) in one or both eyes equal to or worse than 20/40 or an interocular difference of more than two lines in BCVA without any significant organic pathology. Results: A total of 2831 children were included in the study. All children were examined comprehensively by an optometrist, and amblyopia was detected in 49/2831 (1.7% [95% CI, 1.22?2.18]). Of the 49 children with amblyopia, 20 (40.8%) were amblyopic in the right eye, 9 (18.4%) in the left eye, and 20 (40.8%) in both eyes. Twenty-four (49%) were first graders, 15 (30.6%) were second graders, and 10 (20.4%) were third graders. The most prevalent subtype of amblyopia was anisometropic amblyopia (57.1%, [95% CI, 43.24?70.96]). Conclusions: Considering the prevalence of amblyopia among schoolchildren aged 7–9 years old (1.7%), timely detection of amblyopia through preschool screening programs is essential for early treatment or prevention of further visual impairment during childhood. How to cite this article: Shahpary S, Ramin S, Azimi A, Heyrani M. The prevalence of amblyopia in 7-9-year-old schoolchildren in Mashhad. Med Hypothesis Discov Innov Optom.2021 Spring; 2(1): 18-23. DOI: https://doi.org/10.51329/mehdioptometry121

MYOPIA IN PRE-SCHOOL CHILDREN AND MOBILE PHONES

The eye is the most important human sensation and it can captures almost 90% of informations from the surrounding area. The mechanism of the photo-camera's operation, for example, is made on the basis of the function of the eye, in that mode the reflected light of subjects is reflecting on the cornea, passes through the pupil, adjusts and then falls on the retina of the eye, so that is, it forms the image for the object. Myopia or short-sightedness is a refractive anomaly in which the rays of light break in front of the retina, causing short-sighted people to close their eyes, trying to get a sharp picture of the distant objects that they see blurry, and see them relatively well in the vicinity. As a cosmopolitan problem and according to the aetiological factors, myopia can occur at all ages and in both sexes, but more often in female. The total number of myopia patients is in continuously increasing over the last decade, as a result of intense and unmanaged use of mobile smart phones and computers. This is a descriptive epidemiological survey, with statistical processing and data analysis for several months in 2017, where 890 children aged 2.5 to 6 years were actively involved in the kindergartens in Shtip, Republic of Macedonia. Of these, 428 (48.09%) were male, and 462 (51.91%) were female. The screening was performed during the stay of children in kindergartens, using a 2WIN mobile binocular refractometer for detection of refractive errors, visual anomalies and measurement of the pupillary parameters. According to the results of our pilot-study, as well as the anamnestic data from the parents of children and kindergarten educators on the manner, about the duration and purpose of the use of mobile smart phones (screen size, mismatched picture light, viewing longer than 30 minutes/day due to obedience in nutrition, mutual competition, etc.), in 485 of the respondents or 54.78%, the results were closest/within the normal range. Deviations from the reference values were observed in 405 children, ie 45.23% of children, who were manifested as refractory disorders, or 280 with suspicion of development of strabismus, then 119 with initial myopia, and the others with visual astigmatism during the examination. Screening contributed to early detection, diagnosis and timely good treatment of uncorrected refractory anomalies, as well as determining the need and benefit of introducing a regular preschool screening program for visual disturbances. In view of the rapid development of technology and the possibilities it offers through mobile applications, in response to child's curiosity for the world, it was concluded that in the onset of myopia in pre-school children, there is also a very small amount of time spent on daily ultraviolet light in nature. The moderate and controlled use of mobile smart phones (just a few minutes in the day for children over five years) and well menaged the adaptation of smart phones’ tools to the child's vision, contribute to the preservation and promotion of the overall health of children.