Abstract
Purpose: :
Myopia is a common cause of blindness worldwide. We aimed to investigate the risk of visual impairment and blindness in a large population-based study in Caucasians.
Methods: :
6380 persons underwent a complete ophthalmologic examination including refractive error and best-corrected visual acuity (VA) in the population-based Rotterdam Study. We used the WHO and US criteria for visual impairment (VA <0.3 and >=0.05) and blindness (WHO: VA <0.05; US: VA<=0.1), and calculated the risk of visual decline for simple myopia (-1D to -5D) and high myopia (<-5D) with multiple logistic regression analysis using emmetropia as the reference category.
Results: :
650 (10.1 %) persons were diagnosed with simple myopia and 148 (2.3%) had high myopia. The prevalence of visual impairment (WHO) was 1.1% for emmetropia,1.0% for simple myopia, and 2.7% for high myopia; the prevalence of blindness (WHO) was 0.2%, 0.1%, 2.7%; the prevalence of legal blindness (US) was 0.2%, 0.4%, 3.2%, respectively. For simple myopia, the odds ratio (OR) of visual impairment was 1.59 (95%CI: 0.88-2.63); the OR of blindness was 0.85 (95%CI: 0.38-1.91). The OR of legal blindness was 0.84 (95%CI:0.42-1.68). For high myopia, the OR of visual impairment was 4.80 (95%CI: 2.26-10.30); the OR of blindness was 5.79 (95%CI: 2.71-12.38); and the OR of legal blindness was 5.47 (95%CI: 2.78-10.74).
Conclusions: :
High myopia is a serious public health problem in the middle-age and elderly population. The visual consequences at this age are usually irreversible. Therefore, research strategies that focus on early development of myopia may be more effective for the future prevention of blindness.
Keywords: myopia • clinical (human) or epidemiologic studies: outcomes/complications • clinical (human) or epidemiologic studies: prevalence/incidence