Contact lens electroretinography in preterm infants from 32 weeks after conception: a development in current methodology

Aim-To assess the feasibility of using a contact lens electrode to record t he electroretinogram (ERG) in preterm infants less than 35 weeks after conc eption. Methods-The ERG was recorded from seven very low birthweight preterm infant s on a total of 14 occasions using an infant monkey contact lens electrode. Age at recording the first ERG ranged from 23 to 51 days (gestational age 32-34 weeks), and weight ranged upwards from 1100 g. Results-No complications were observed. With advancing age and maturity the dark adapted rod threshold decreased, indicating increased retinal sensiti vity. Conclusions-Contact lens recording of the ERG from extremely small immature preterm infants is a practicable and well tolerated procedure. This method of recording the ERG will enable further evaluation of retinal development in this vulnerable population.