Peripheral XXXX in myopic, emmetropic, and hyperopic young subjects.

@entity1 @entity940 @entity2516 @entity911 @entity1714
To gain more insight into the relationship between foveal and peripheral @entity2516 in @entity1 , spheres, cylinders, and their axes were binocularly measured across the visual field in myopic, emmetropic, and hyperopic groups of young subjects. Both automated infrared photorefraction (the "PowerRefractor"; www. plusoptix.de) and a double-pass technique were used because the PowerRefractor provided extensive data from the central 44 deg of the visual field in a very convenient and fast way. Two-dimensional maps for the average cross cylinders and spherical equivalents, as well as for the axes of the power meridians of the cylinders, were created. A small amount of lower-field @entity1714 was detected with a significant vertical gradient in spherical equivalents. In the central visual field there was little difference among the three refractive groups. The established double-pass technique provided complementary data also from the far periphery. At 45 deg eccentricity the double-pass technique revealed relatively more hyperopic spherical equivalents in myopic subjects than in emmetropic subjects [+/-2.73 +/- 2.85 D relative to the fovea, p < 0.01 (+/- standard deviation)] and more myopic spherical equivalents in hyperopic subjects (-3.84 +/- 2.86 D relative to the fovea, p < 0.01). Owing to the pronounced peripheral @entity940 , spherical equivalents (refractions with respect to the plane of the circle of least @entity911 ) became myopic relative to the fovea in all three groups. The finding of general peripheral @entity1714 was unexpected. Its possible roles in foveal refractive development are discussed.
