Pennie F C, Wood I C, Olsen C, White S, Charman W N
Department of Optometry and Neuroscience, UMIST, PO Box 88, M60 1QD, Manchester, UK.
Vision Res. 2001 Sep;41(21):2799-810. doi: 10.1016/s0042-6989(01)00169-9.
Changes in ocular axial dimensions and refraction were followed longitudinally, using ultrasonography and retinoscopy, during the first year of life (mean ages 4-53 weeks) of a group of 20 full-term infants (10 male, 10 female). Using a mixed-model regression analysis, axial length changes as a function of time were found to be best described by a quadratic expression (AL=17.190+0.128x-0.0013x(2), where AL is the axial length in mm and x is the age in weeks), while anterior chamber depth changed linearly (ACD=2.619+0.018x, where ACD is the anterior chamber depth in mm): lens thickness was essentially constant. Spherical equivalent refraction through most of the first year showed a steady reduction in hypermetropia (SER=2.982-0.032x, where SER is the spherical equivalent refraction in dioptres): astigmatism also tended to diminish. Mean hyperopic refractive errors through the year were negatively correlated with corresponding axial lengths (SER=12.583-0.541AL), but some individual subjects showed marked departures from this pattern. These results are discussed in relation to concepts of emmetropization.
