Uniocular childhood blindness: a prospective study.
This prospective study examines uniocular blindness among children younger than 16 attending a large pediatric ophthalmology department. The aim was to identify the causes of uniocular blindness and determine how much is preventable. We defined blindness according to the World Health Organization definition of vision worse than or equal to 3/60. All children who attended the department and were blind in one eye during the period of the study were included. A history was taken, visual acuity was assessed by an age-appropriate method, and an ocular examination was carried out. When necessary, the child also was seen by an orthoptist or pediatrician. A total of 71 patients were identified. At the time of diagnosis, the patients varied in age from a few weeks to 15 years. The causes were classified into one of the following diagnostic categories: chromosomal/genetic (8.5%), prenatal (47.9%), perinatal (7.0%), or childhood (36.6%). Many cases are prenatal in origin and are not preventable. Other causes that are difficult to prevent include retinoblastoma, toxocariasis, and trauma. One cause, amblyopia, may be preventable or treatable in most instances if detected early. Most cases of uniocular blindness are not preventable; however, protective glasses should be encouraged to prevent injury to the good eye.