POSTNATAL RETINAL DEVELOPMENT AS MEASURED BY THE ELECTRORETINOGRAM INPREMATURE-INFANTS

Light-adapted and dark-adapted electroretinograms were obtained in 27 premature infants who were screened for retinopathy of prematurity sho rtly after birth. Thirteen showed no retinopathy and 13 had mild to mo derate retinopathy, which ranged from stage I, zone III (International Classification) to stage III, zone II. Measurements were made during the first 16 months of life. The configuration of the waveforms under both photopic and scotopic conditions changed during this period showi ng increased amplitudes of both the a- and the b-waves. A scotopic int ensity series was performed and the b-wave amplitudes and implicit tim es were measured, The b-wave amplitude data were averaged for three ad ult control subjects, for infants without retinopathy of prematurity m easured at 3-4 and at 6-7 months and for infants with retinopathy of p rematurity measured at 3-4 and at 6-7 months. The Naka-Rushton functio n was fitted to the average data. The Rmax increased from 3 to 6 month s and from 6 months to adulthood, and the Isat values decreased over t his age range. The b-wave implicit times were within normal range in t he 6-month data. There was no difference in Rmax or Isat for infants w ith and without ROP.