Morphological and functional analysis of the optic nerve in premature and term children with OCT, HRT, and pVEP a ten-year resurvey.

Purpose:Most studies on premature newborns have focused on infants of less than 28 weeks of gestational age (GA) due to their increased risk of developing diseases such as premature retinopathy. Studies on premature infants born between 28 and 35 weeks GA with normal development are less frequent. The aim of our study was to identify subclinical morphological or functional defects in these children. Methods:We evaluated 14 premature newborns at birth (mean gestational age 33.45 weeks) with a neuro-ophthalmological examination and patterned visual evoked potentials (pVEP). The same subjects were surveyed when they were young children (mean age 7.5±0.2 years) using Heidelberg retinal tomography (HRT) and optical coherence tomography (Stratus OCT). pVEP were performed as transient ( temporal frequency 1.96 Hz) and steady-state (7.5 Hz temporal frequency). A complete ophthalmic examination was also performed. The data were compared with those from 15 term newborns who were examined in the same manner (mean age 9.8 ±0.3 years). Results:A statistically significant thickening of the macular temporal and inferior nerve fibers was found on OCT in premature newborns. The thickness of the superior and inferior retinal nerve fiber layer (RFNL) was also reduced. A difference was also found in rim area thickness based on HRT. Multiple significant P values were found in the VEP P100 peak time and steady-state amplitudes at the time of birth, but not at the time of morphological analysis. Conclusions:Healthy, premature newborns may have morphological abnormalities of the optic nerve. These abnormalities do not cause visual acuity or functional decreases.