Objective: To investigate the incidence, prevalence, and causes of visual impairment in children born at full term and to determine conditions and factors associated with visual impairment.
Design: Retrospective, cross-sectional, population-based study.
Participants: All visually impaired individuals from 0 to 17 years of age who were born at full term from 1972 through 1989 in Finland and recorded in the Finnish Register of Visual Impairment (n = 556) were eligible for this study.
Methods: Data in the Finnish Register of Visual Impairment relating to 556 subjects were supplemented with data from hospital records and other national registers (Register of Births, Register of Congenital Malformations, Finnish Care Register, and Finnish Cancer Register). Data relating to the children born at full term were compared with Finnish perinatal and vital statistics and with data concerning children born prematurely. The chi-square test (Mantel-Haenszel) and stepwise logistic regression analysis were used in statistical analysis of the data.
Main outcome measures: Visual acuity, time of onset of visual impairment, ophthalmic diagnosis of visual impairment, systemic disease, multiple handicap, 5-minute Apgar score, prenatal disorders, perinatal disorders, disorders arising during infancy and childhood, and treatment.
Results: Four hundred thirty-one of the 556 individuals with visual impairment (78%) had been born at full term. Visual impairment was predominantly associated with genetic (53%) and prenatal (34%) factors. Ocular malformations (34%), retinal diseases (31%), and neuro-ophthalmologic disorders (26%) were the main ophthalmic diagnoses. Optic nerve atrophy (20%) and congenital cataract (13%) were the most common single diagnoses. The occurrence of blindness, systemic disease, and multiple handicap was 40%, 43%, and 45%, respectively.
Conclusions: The incidence of visual impairment in children born at full term did not decline during the 2 decades covered by this study. The findings reflected the lack of treatment for genetic eye diseases. The results also confirmed an obvious need for further understanding of mechanisms underlying congenital anomalies of the human visual system.