Causes and 3-year-incidence of blindness in Jing-An District, Shanghai, China 2001-2009

BACKGROUND: Registered data can provide valuable information regarding blindness. The purpose of this study was to evaluate the main causes and 3-year incidence of registered blindness in Jing-An district in Shanghai, China. METHODS: Data from the blindness registry (age, gender and cause of visual disability) were collected and analyzed. The prevalence of blindness for 2003, 2007, 2009 and the 3-year incidence of blindness were calculated. RESULTS: The reported blindness increased significantly from 113.7 per 100,000 in 2003 to 145.8 per 100,000 in 2006 to 165.9 per 100,000 in 2009 (P < 0.05, P < 0.05, respectively). Age significantly affects prevalence; the odd ratios (OR) were 2.57 in the 30 y - 49 y range (P < 0.001), 7.27 in the 50 y - 69 y range (P < 0.001) and 21.2 in the ≥ 70 y (P < 0.001). The 3-year incidence increased from 32.3 per 100,000 in 2001-2003 to 34.2 per 100,000 in 2004-2006 to 40.8 per 100,000 in 2007-2009. The causes of new blindness registered in 2001-2009 were myopic macular degeneration (19.4%), followed by glaucoma (17.7%), age-related macular degeneration (11.8%), optical nerve atrophy (9.4%), retinitis pigmentosa (8.6%), diabetic retinopathy (7.8%) and corneal opacity (5.8%). CONCLUSIONS: The 3-year incidence and prevalence of registered blindness increased in the past 9 years. The leading causes of new blindness were myopic macular degeneration, glaucoma and age-related macular degeneration. The pattern of causes has changed little in the past 9 years and is different from other locations in China. The pattern is similar to that of Taiwan, Hongkong, and Western countries.