Visual function at 35 and 40 weeks' postmenstrual age in low-risk preterm infants.
OBJECTIVE
The objectives of this study were to (1) assess visual function in low-risk preterm infants at 35 and 40 weeks' postmenstrual age, (2) compare preterm visual abilities at term-equivalent age with term-born infants, and (3) evaluate effects of preterm extrauterine life on early visual function.


METHODS
Visual function was assessed by using a validated test battery at 35 and 40 weeks' postmenstrual age in 109 low-risk preterm infants who were born at <31 weeks' gestation. The preterm findings were compared with data from term-born infants collected by using the same test protocol.


RESULTS
All preterm infants completed both assessments. The 35-week responses were generally less mature than those at 40 weeks. Preterm infants at both ages were significantly more mature than term-born infants for ocular movements and vertical and arc tracking and at 40 weeks for stripe discrimination. In contrast, tracking a colored stimulus, attention at distance, and stripe discrimination were more mature at term age (in both term-born and preterm infants) than at 35 weeks.


CONCLUSIONS
Our findings provide data for visual function at 35 and 40 weeks' postmenstrual age in low-risk preterm infants. The results suggest that early extrauterine experience may accelerate the maturation of aspects of visual function related to ocular stability and tracking but does not seem to affect other aspects that may be more cortically mediated.
Ricci
Daniela
D
Catholic University, Pediatric Neurology Unit, Largo Gemelli 8, 00168 Rome, Italy.
Cesarini
Laura
L
Romeo
Domenico M M
DM
Gallini
Francesca
F
Serrao
Francesca
F
Groppo
Michela
M
De Carli
Agnese
A
Cota
Francesco
F
Lepore
Domenico
D
Molle
Fernando
F
Ratiglia
Roberto
R
De Carolis
Maria Pia
MP
Mosca
Fabio
F
Romagnoli
Costantino
C
Guzzetta
Francesco
F
Cowan
Frances
F
Ramenghi
Luca A
LA
Mercuri
Eugenio
E
D000367:Age Factors; D002657:Child Development / Q000502:physiology*; D015331:Cohort Studies; D005133:Eye Movements / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007558:Italy; D008297:Male; D008597:Menstrual Cycle; D011336:Probability; D012016:Reference Values; D012189:Retrospective Studies; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D047929:Term Birth; D015351:Vision Screening / Q000379:methods*; D014785:Vision, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*