A survey of blindness and low vision in students in a school for the blind in Shanghai, China

Abstract

Objective To determine the causes of severe visual impairment and blindness (SVI/BL) among students in a school for the blind in Shanghai with a view to promote the control of childhood blindness and low vision.Methods A cross-sectional investigation of 163 students was conducted in April 2010.The data were included in the self-designed survey form from World Health Organization/Prevention of Blindness (WHO/PBL) eye examination record system,which includes classifications and etiological categories for visual impairment and blindness,and classifications of the affected anatomic sites of the eye involved in visual impairment and blindness.Distance uncorrected and corrected visual acuity were measured.Autorefraction and subjective refraction were performed if needed.The anterior segment was examined using a handheld slit lamp.The posterior segment was examined by ophthalmoscopy.Number were counted and measured with percentage.Results Of the 163 students,19.6％ were severe visual impairment,54.6％ were blindness,21.5％ had moderate visual impairment and 4.3％ were mildly impaired.The leading etiological causes of SVI/BL were congenital and hereditary factors (37.2％).The anatomical site for SVI/BL was the retina in 41.3％ of the students.The main disease causing SVI/BL was retinopathy of prematurity (ROP) (18.2％).Blinding disease was considered as avoidable in 64 studnets (52.9％),of which 29 cases (24.0％) were preventable,and 35 cases (28.9％) were treatable.The main treatable disease in moderate visual impairment was congenital cataract (15 cases,42.9％).Conclusion The pattern of childhood blindness in Shanghai is similar to that seen in other developed countries.It is recommended to move more quickly to establish a reliable ROP screening and treatment network,and vigorously promote low vision rehabilitation. Key words: Visually impaired persons,children; Vision,low; Data collection; Small-area analysis; Retinopathy of prematurity; Cataract,congenital