Prevalence of the refractive errors by age and gender: the Mashhad eye study of Iran
Article first published online: 29 JUN 2011
© 2011 The Authors. Clinical and Experimental Ophthalmology © 2011 Royal Australian and New Zealand College of Ophthalmologists
Clinical & Experimental Ophthalmology
Volume 39, Issue 8, pages 743–751, November 2011
How to Cite
Ostadimoghaddam, H., Fotouhi, A., Hashemi, H., Yekta, A., Heravian, J., Rezvan, F., Ghadimi, H., Rezvan, B. and Khabazkhoob, M. (2011), Prevalence of the refractive errors by age and gender: the Mashhad eye study of Iran. Clinical & Experimental Ophthalmology, 39: 743–751. doi: 10.1111/j.1442-9071.2011.02584.x
- Issue published online: 3 NOV 2011
- Article first published online: 29 JUN 2011
- Accepted manuscript online: 18 APR 2011 08:23AM EST
- Received 30 November 2010; accepted 2 March 2011.
Background: Refractive errors are a common eye problem. Considering the low number of population-based studies in Iran in this regard, we decided to determine the prevalence rates of myopia and hyperopia in a population in Mashhad, Iran.
Design: Cross-sectional population-based study.
Participants: Random cluster sampling. Of 4453 selected individuals from the urban population of Mashhad, 70.4% participated.
Methods: Refractive error was determined using manifest (age >15 years) and cycloplegic refraction (age ≤15 years). Myopia was defined as a spherical equivalent of −0.5 diopter or worse. An spherical equivalent of +0.5 diopter or worse for non-cycloplegic refraction and an spherical equivalent of +2 diopter or worse for cycloplegic refraction was used to define hyperopia.
Main Outcome Measures: Prevalence of refractive errors.
Results: The prevalence of myopia and hyperopia in individuals ≤15 years old was 3.64% (95% CI: 2.19–5.09) and 27.4% (95%CI: 23.72–31.09), respectively. The same measurements for subjects >15 years of age was 22.36% (95%CI: 20.06–24.66) and 34.21% (95%CI: 31.57–36.85), respectively. Myopia was found to increase with age in individuals ≤15 years and decrease with age in individuals >15 years of age. The rate of hyperopia showed a significant increase with age in individuals >15 years. The prevalence of astigmatism was 25.64% (95%CI: 23.76–27.51).
Conclusions: In children and the elderly, hyperopia is the most prevalent refractive error. After hyperopia, astigmatism is also of importance in older ages. Age is the most important demographic factor associated with different types of refractive errors.