Detection of congenital cataracts and other ocular media opacities.

Congenital cataracts and other ocular media opacities are a leading cause of preventable childhood blindness. Because of the importance of early recognition and treatment of congenital media opacities in newborn infants, we designed a study to determine the ability of relatively inexperienced examiners to detect such ocular abnormalities with either of two instruments. Eight third-year medical students examined eight children and young adults with ocular media opacities and eight age-matched normal subjects with an ophthalmoscope or a retinoscope. With respect to detection of abnormalities requiring referral to an ophthalmologist, there was an underreferral rate of 7% and overreferral rate of 5%. There was no significant difference between instruments. Based on an estimated incidence of congenital cataracts of 0.4%, the positive predictive value of this screening in the population of newborn infants is 18.7% and the negative predictive value is 99.96%. Therefore, overreferral is unavoidable in the effort to detect infants with congenital media opacities. We conclude that this examination can be easily taught and accurately performed with the readily available ophthalmoscope. The importance and technique of examining the red reflex should be stressed in the training of those caring for newborns.