Low Vision and Blindness in Bulgarian Children with Developmental Delay

Abstract

Introduction. Visual impairment and blindness are very common in children with developmental delay, seriously harming their intellectual, social, learning and even physical development. Most common reasons for mild visual impairment are refractive errors and amblyopia, while optic nerve atrophy, retinal diseases and central cortical impairment are the leading causes for low vision (moderate and severe visual impairment) and blindness. Visual and ocular problems in intellectually disabled children are often neglected and even treatable diseases are ignored. Purpose. The aim of our study was to determine the incidence and main reasons for low vision and blindness in Bulgarian children with mental retardation. Patients and Methods. A prospective study of ocular status of 403 children (0 – 18 years) with mental retardation was performed. All patients had detail ophthalmologic exam according to their age and intellectual disabilities. Results. A total of 403 patients – 241 (59.8%) males and 162 (40.2%) females were enrolled in the study. Binocular moderate to severe visual impairment and blindness were diagnosed in 42 (10.4%) children. Detected ocular pathologies were congenital nystagmus (3.2%), optic nerve atrophy (2.7%), retinopathy of prematurity (2.5%), central cortical blindness (1.2%) and congenital anomalies (0.7%). Conclusion. Children with mental retardation are risk group for ocular and visual pathologies, causing not just visual impairment but severe problems and blindness. And nevertheless, most cases of low vision and blindness are unavoidable, implementation of yearly screening ocular exams of mentally retarded children must be adopted on national level for encompassing the high rate of treatable or correctable visual problems.