Rationale, Design, and Demographic Characteristics of the Handan Offspring Myopia Study

Purpose: The Handan Offspring Myopia Study (HOMS) aims to investigate the familial associations of myopia between parents and their offspring. Methods: Children aged 6-18 years, residing in 6 villages where all people aged >= 30 years had participated in The Handan Eye Study in 2006-2007, were selected for the current eye study between March and June 2010. A mobile clinic was set up in the 6 villages for comprehensive eye examinations, including visual acuity, ocular biometry, cycloplegic autorefraction and retinal photography. Results: Of 1238 eligible individuals, 878 children (70.2%; 52.6% male) from 541 families were recruited. Mean age of the children was 10.5 +/- 2.5 years. The prevalence of myopia (spherical equivalent refraction < 0.5 diopter) was 23.5% (males 16.8%, females 30.8%). The prevalence of low vision (presenting visual acuity >= 20/400 but <20/60) in the better eye was 7.1%. A higher number of females had low vision at the time of presentation (9.2%) compared to males (5.2%, p = 0.02). The prevalence of low vision in the worse eye was 10.6% (males 6.7%, females 14.9%, p<0.001). The majority of visual impairment in the better-seeing (56/62, 90.3%) as well as the worse-seeing (84/93, 90.3%) eye was correctable. Conclusions: The HOMS examined about 70% of eligible Han Chinese offspring of Handan Eye Study participants in a rural region of northern China. Results from the HOMS will provide key information about the prevalence of refractive errors and eye diseases in rural Chinese children.