Analysis of risk factors that cause myopia in pre-school children and primary school students

Abstract

The article summarizes literature data on significant risk factors that cause myopia in children; it also dwells on an algorithm that can be applied by ophthalmologists, pediatricians, family doctors, and medical optometrists to determine risk groups as per myopia, to accomplish dynamic observation, and to implement medical and prophylaxis activities aimed at its prevention. A hereditary factor in myopia development is considered to be the most significant one. There are also several other significant factors such as refraction being greater than +0.75 diopter at an age 6-10; an anterior-posterior axis of the eye being longer than 23.5 mm; pseudo-myopia; relative accommodation resources being lower than 1.0 diopter; axial length over cornea radius ratio (AL/CR) being higher than 3; accommodative convergence over accommodation ratio (AC/A) being higher than 4 pr.diopter / diopter; relative peripheral hypermetropia and off-axis refraction asymmetry when the nasal side of the eye is higher than the temporal one. We paid special attention to influences exerted by the environment and urbanization. High educational and social status of a family results in elevated risks of myopia. We also spotted out several risk factors that could be eliminated; they were hypodynamia under great visual loads and a period of time spent outdoors being shorter than 10 hours a week. Reliable preventive measures include parents’ control over visual activities of a child; imposing limits on visual loads; outdoor activities for not less than 10-14 hours a week; physical exercises and doing some sports; home training to improve accommodation; correction aimed at compensating peripheral hypermetropia and /or inducing myopic defocus; local medical treatment. Early detection of risk factors and direct or indirect influence on them allow preventing myopia or postponing its development for an older age; it results in lower frequency of significant myopia and reduces a number of complicated and severe myopia cases.

Keywords

• myopia in children
• risk factors
• myopia development
• myopia prevention
• myopia predictors
• refraction disorders
• peripheral refraction