Fernando Molle

Visual Function at 35 and 40 Weeks' Postmenstrual Age in Low-Risk Preterm Infants

OBJECTIVES. 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.

Identification of the preferential gaze position through evaluation of visual fatigue in a selected group of VDU operators

A selected group of VDU workers were tested in an attempt to achieve objective evidence of visual fatigue and to identify a preferential monitor/gaze position during a particular work setting. Each subject was scored in a two-phase test. The highest mean scores were achieved when the monitor was lowered with respect to the primary/gaze position; the scores obtained with the monitor in primary or upward gaze position were significantly lower (p<0.001). The downward gaze position should be considered more comfortable for both innervational and anatomical factors, as stated in previous studies of ocular mobility. A reduction of vertical saccades could also play a role in lessening visual fatigue in this gaze position.