To compare the visual impairment and blindness causes of students in the Beijing School for the Blind over 30 years.

The cross-sectional survey was conducted in July, 2019. Among of 110 students in the Beijing School for the Blind, there were 76 males and 34 females with an average age of (15.6±5.1) years-old (ranging from 7 to 33 years-old). The record and self-designed survey form were collected according to World Health Organization (WHO)/Prevention of Blindness eye examination record system. The basic information, history of ocular disease, history of systemic disease, birth history and family history were recorded in detail through parent questionnaire. All students were couducted ophthalmological examinations including far and near visual acuity, slit-lamp microscope, and fundus photography. Students′ visual impairment were graded according to WHO′s standard. The main causes of blindness/severe visual impairment were analyzed by the medical history and results of examinations. Meanwhile, surveys in the years of 1989, and 2000 were compared to analyze the longitudinal trends of visual impairment and blindness causes. Countable data such as gender, causes, classification of visual impairment were expressed as cases and percentages. Age was expressed as ±s. The results of 3 surveys were analyzed by tabular comparisons.

Of 110 students, blindness, the numbers of students with severe visual impairment and moderate visual impairment were 87, 20, and 3, accounting for 79.1%, 18.2%, and 2.7%, respectively. The common anatomical sites caused visual impairment were retina/vitreous, optic nerve, whole globe, lens, cornea, and brain. The corresponding numbers of students were 39, 30, 11, 11, 6, and 5, accounting for 35.5%, 27.3%, 10%, 10%, 5.5%, and 4.5%, respectively. The top 3 of main ocular diseases caused blindness/severe visual impairment were 14 cases with congenital glaucoma, 10 cases with congenital cataract, 10 cases with optic nerve atrophy and 9 cases with retinitis pigmentosa, accounting for 12.7%, 9.1%, 9.1% and 8.2%, respectively. Blindness/severe visual impairment was considered as avoidable in 57 cases (51.8%), of which 13.6% (15 cases) were preventable and 38.2% (42 cases) were treatable. The longitudinal study (in 1989, 2000, 2019) showed that the proportion of blindness raised from 58.9% to 79.1%, and the leading etiological causes of blindness/severe visual impairment were congenital and hereditary factors. Among of causes, congenital glaucoma ascending from the third to the first.

Congenital and hereditary ocular diseases remain the major causes of visual impairment in the Beijing School for the Blind. Early diagnosis and standardized treatment for diseases should be strengthened. The preschool screening and low-vision rehabilitation should be carried forward, which became the priority of prevention and treatment of childhood blindness.