Myopia in China: a population-based cross-sectional, histological, and experimental study

Abstract Background The prevalence of myopia has markedly increased within the past three decades, in particular in China. Because of myopic retinopathy and myopia-associated glaucoma, myopia has become one of the leading blinding disorders. Methods Conducting population-based studies and school-based investigations, we assessed prevalence and incidence of myopia and associated factors in children, university students, and adults in urban and rural regions of different Chinese provinces. We performed histomorphometric studies on human eyes, and examined whether the intraocular application of an antibody to amphiregulin was associated with a reduction of experimentally induced myopic axial elongation of eyes in guinea pigs. This study was approved by the ethics committee of the Shandong University of Traditional Chinese Medicine. Findings In nine population-based studies with up to 560 000 child and adult participants, the prevalence of myopia was about 80% in 18-year-old school children and 17% in adults aged 40 years and older. These figures were significantly higher in urban regions than in rural regions (OR 1·63, 95% CI 1·51–1·75, p 0·40) of axial length, as was Bruch's membrane thickness. Intraocular application of amphiregulin antibody reduced axial elongation in guinea pigs in a dosage-dependent manner (p=0·002; regression coefficient −0·58, 95% CI of difference 0·20 to 0·63). Interpretation These findings suggest that the increase in prevalence of myopia in the young Chinese generation is associated with lifestyle factors. The histological findings indicated that myopic axial elongation was associated with formation of Bruch's membrane in the midperiphery. Since the retinal pigment epithelium has receptors for amphiregulin, a member of the epithelial growth factor family, this hypothesis fits with the finding that amphiregulin antibody was associated with a dosage-dependent reduction in axial elongation. Further studies are warranted on the medical reduction of axial myopisation by amphiregulin antibody. Funding None.