Electroretinographic assessment of retinal function in preterm infants using the RETeval™ device: a proposal for reference data

Abstract Purpose To establish age-adjusted flicker ERG reference values in premature infants through serial recordings, aiming to characterize retinal functional maturation and support diagnostic interpretation in retinopathy of prematurity screening. Methods This prospective longitudinal study was conducted between April 2022 and October 2023 across six public neonatal care centers in Rio de Janeiro, Brazil. Premature infants eligible for ROP screening (birth weight ≤1500 g and/or gestational age ≤32 weeks) underwent serial retinal examinations with binocular indirect ophthalmoscopy and flicker electroretinography. Examinations were discontinued at ROP treatment indication or at 42 weeks postmenstrual age. Flicker ERG recordings were performed using a hand-held RETeval® device equipped with small-sized Sensor Strip™ skin electrodes. A 30 cd·s/m 2 white flicker stimulus at 28.3 Hz was delivered according to a standardized protocol. Recordings were repeated to ensure reproducibility and analyzed according to postmenstrual age (PMA). Results Of the 199 premature infants, 94 (171 eyes) who never progressed beyond stage 0 ROP were included in the reference analysis. Serial ERG recordings demonstrated a consistent decrease in implicit time and increase in amplitude with advancing PMA. At 32–34 weeks PMA, the upper reference limits (97.5th percentile) were 44.8 ms and 8.5 µV, respectively, compared with 43.5 ms and 24.9 µV at 40–42 weeks PMA. Conclusion Age-adjusted ERG reference values derived from serial recordings characterize retinal functional maturation in preterm infants, providing a framework for ERG interpretation during routine ROP screening and future studies of retinal development .