Photorefraction screening in premature infants

Abstract

Background: Photorefraction is a screening technique capable of detecting potentially amblyogenic ophthalmic abnormalities. This screening technique was included as part of a longitudinal outpatient follow-up program of premature infants. The purpose of this investigation is to test the applicability of this screening method in a population of infants at risk for visual compromise.

Methods: One-hundred eighty-two premature infants older than 3 months chronologic age were screened using a commercially available, off-axis photorefraction device. Ophthalmic examinations were performed concomitant with each photorefraction. In most cases, photorefractions were performed before and after administration of cycloplegic medications. All photorefractions were analyzed by an observer masked to the results of the ophthalmic examination.

Results: For the 182 patients, the mean birth weight and mean gestational age were 1034.5 g and 28.2 weeks, respectively. The prevalence of ophthalmic abnormalities in the study population was 18%. Sensitivity and specificity rates for the overall screening were 77% and 90%, respectively. Photorefractions were analyzable in 77% of patients studied, with the remaining 23% of our study population unsuccessfully screened. Very young infants (younger than 3 months corrected age) were particularly difficult to photograph, as evidenced by the preponderance of these patients (85%) in the nonanalyzable group. The readability of photorefractions in black infants was improved when cycloplegia was used for the photorefraction.

Conclusion: Photorefraction screening was an acceptable method of screening for ophthalmic abnormalities in a group of premature infants. Future studies of photorefraction screening techniques in premature infants will need to improve the success rate in young infants, perhaps by improving the fixation device.