Timing of initial screening examinations for retinopathy of prematurity.

OBJECTIVE: To test a screening protocol for retinopathy of prematurity (ROP) that uses the dual criteria of postconceptional age and chronological age, rather than a single parameter, to determine precisely when to begin eye examinations.
METHODS: We retrospectively reviewed medical records of 179 infants (326 eyes) who had undergone laser treatment for threshold ROP. We entered their chronological and postconceptional ages at treatment into a database and evaluated various screening parameters to determine the combination of criteria that would allow us to safely postpone the initial eye examinations.
RESULTS: Screening infants at 7 weeks of chronological age or 34 weeks of postconceptional age (whichever comes first), but not before 5 weeks of chronological age, seems to reliably detect the onset of threshold ROP while reducing the number of unnecessary early examinations.
CONCLUSION: Simultaneously applied dual criteria of chronological age and postconceptional age may be a superior method of determining when to initiate ROP examinations and is preferable to using either chronological age or postconceptional age alone.