Dark-adapted oscillatory potentials in preterm infants with and without retinopathy of prematurity

Abstract

To describe the appearance and maturation of dark-adapted oscillatory potentials (OPs) in electroretinograms (ERGs) recorded from preterm infants, and to determine any effect of retinopathy of prematurity (ROP). Dark-adapted ERGs were recorded in conjunction with screening for ROP and at outpatient follow-up, using a flash luminance of 11.3 scot cdsm(-2) (4.06 phot cdsm(-2)). Eligible infants were born before 31weeks' gestation and/or weighed ≤1,250grams at birth. Presence or absence of OPs was established for 68 ERG recordings from 38 infants at maturities ranging from 30weeks' postmenstrual age (PMA) to 28weeks' post-term corrected age. 20 infants did not develop ROP, eight developed stage 1, one stage 2 and one stage 3 disease which regressed spontaneously. Eight infants received treatment for threshold ROP. OPs were present in 50% of infants at 36weeks' PMA and in all by 50weeks' PMA. The earliest appearance of OPs was at 30+5 weeks' PMA. Individual OP amplitudes increased and peak time of individual OPs decreased with increasing maturity. For infants with threshold ROP summed OP amplitudes tended to be smaller prior to treatment (6.5 vs 9.9μV, P=0.09) and were significantly smaller by 50weeks' PMA (14 vs 30μV, P=0.007). OP1 was less likely to be present in infants who developed stage 3 or worse ROP (P=0.000). Dark-adapted OPs are recordable in some preterm infants from 30weeks' PMA. Relative suppression of early OPs is a potential marker for developing ROP.