Abstract
Abstract: :
Purpose:Test the hypothesis that retinal dysfunction in infants with resolved ROP predicts myopia in early childhood. ROP occurs at ages during which the photoreceptors and neural retina are immature, and ocular growth and refractive development are in progress. The retina is known to be an important controller of experimental myopia. Methods:We used psychophysical and ERG procedures to evaluate scotopic function in infants (n = 10) with resolved ROP (categorized according to Quinn et al., 1998, by maximum acute phase: None, n=1; Mild, n=5; Moderate, n=1; Severe, n=3) who then had cycloplegic refractions measured longitudinally until at least age 2 years. Dark adapted, scotopic thresholds in parafoveal (10 eccentric) and peripheral (30 eccentric) retina were measured using a preferential looking procedure and compared to those of normal term born infants (Hansen & Fulton, 1999). Receptoral and post receptoral components of the ERG responses to a 5 log unit range of full field stimuli were analyzed and compared to those of normal infants ( Fulton & Hansen, 2000). Spherical equivalents were compared to those of normal infants (Mayer et al., 2001). Results: By age 2 years, 4 children had become myopic (Spherical equivalent -4.5 to -10 D) which is below the lower limit ( -1.10D) of the 99% Prediction Interval (PI) for normal. In 6, spherical equivalents have remained within the PI throughout the course. As infants, all 4 who became myopic had ERG signs of significant deficits in rod cell function and correlated deficits in post receptoral response components; furthermore, parafoveal (10 eccentric) thresholds were elevated in early infancy. In the 6 with normal refractive development, ERGs and thresholds in infancy were normal. Conclusion:Abnormalities of rod and rod mediated vision in infancy are among the risk factors for myopia in children with a history of ROP.
Keywords: 623 visual development: infancy and childhood • 572 retinopathy of prematurity • 481 myopia