Introduction
Uncorrected refractive errors and especially myopia are the leading disorders that cause vision loss in the world.1Recently, it has been reported that over 157 million people suffer from vision loss related to mid or severe refractive disorders globally.1 The estimated cost of this burden to the global economy has been reported that to be over US $ 269 billion annually.2 Accordingly, refractive defects present a major public health problem in the world.
The most common refractive error type is hypermetropia in the postnatal term.3 The post-natal hyperopic state regresses over time due to physiological emmetropization mechanisms associated with alters in the axial length of the eyeball, lens, and corneal refractive power. If the emmetropization mechanism fails or delays during this period due to environmental or hereditary reasons, refractive errors occur.4-6 Although underlying risk factors and onset mechanisms are known, the underlying mechanisms of refractive errors is not fully understood yet.
Epidemiological indicators have shown that there has been a significant increase in the prevalence of myopia in the last decade. Clinically, early diagnosis of myopia initial and progression is crucial to control this refractive error. Eventually, uncorrected myopia may have a risk of complications related to detachment or neovascularization of the retina, early cataracts, and glaucoma.7 These complications not only related to the high socio-economic treatment costs but also may arise irreversible conditions for patients, such as blindness.
Clinical studies are essential to analyze the refractive errors and ocular biometric changes of the populations in the onset age ranges of myopia.8 Such information is also necessary due to understanding the progressive nature of refractive errors. Rozemaet al. 9 have reported that monitoring the progression of ocular biometric parameters on school-age children up to adolescence was an ideal method for interpreting biometric changes related to the initiation of myopia. However, the above-mentioned epidemiologic data of 7-12-year-old children are not available for Turkish population in the literature.
Wolffsohn et al. 10 have reported that potential myopia calculators could be beneficial tools to reflect the average potential outcome based on research data. Authors have emphasized that the data should be collected based on carefully selected cases examined for between 2 and 5 years only. To the best of our knowledge, no methods have been prescribed yet to calculate the amount of refractive error onset in school-age children. Also, it has been reported that such optic calculators could be employed as a guide to estimate the risk of developing myopia. Possibly, such optic calculators might be employed as a guide to estimate the risk of developing myopia.11
With this motivation, the current study aims to correlate the repetitive measurements, their onset biometric parameters that may indicate progressions, such as refractive errors. More specifically, we aimed at evaluating consecutive measurements of the biometric parameters, age, and refraction error in a Turkish population at primary school age. The null hypothesis of this cohort study assumes that there was no correlation or regression amongst the consecutive measurements.