Optic disc morphology in premature infants.

Background: To date, little is known about the morphology of optic discs in premature infants. However, optic disc morphology and optic nerve development are two factors that potentially influence visual function in infants. Thus we analysed the morphology of the optic disc and its correlation with gestational age and birth weight.

Methods: In a retrospective trial, we assessed the widefield images (RetCam system) of 111 optic discs of 61 premature infants. We evaluated the form of the optic disc, defined by the ratio of the vertical to the horizontal diameter, the presence or absence of visible disc cupping, the cup to disc ratio and the presence or absence of a double ring (a concentric paler zone around the optic disc).

Results: 110 of 111 optic discs had a vertical-oval form. We found a significant negative correlation between the form of the optic disc and birth weight (p=0.003) and gestational age (p=0.03); 75% of optic discs showed a double ring and 89% had visible disc cupping.

Conclusions: In our study, premature birth was associated with the presence of a double ring. A low birth weight and low gestational age influence the form of the optic disc.