A longitudinal study of the biometric and refractive changes in full-term infants during the first year of life.
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.
Pennie
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FC
Department of Optometry and Neuroscience, UMIST, PO Box 88, M60 1QD, Manchester, UK.
Wood
I C
IC
Olsen
C
C
White
S
S
Charman
W N
WN
D000367:Age Factors; D000704:Analysis of Variance; D000867:Anterior Chamber / Q000000981:diagnostic imaging / Q000254:growth & development; D005123:Eye / Q000000981:diagnostic imaging* / Q000254:growth & development; D005260:Female; D006801:Humans; D007223:Infant; D007908:Lens, Crystalline / Q000000981:diagnostic imaging / Q000254:growth & development; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D009184:Mydriatics; D012029:Refraction, Ocular; D012044:Regression Analysis; D012737:Sex Factors; D014463:Ultrasonography
D009184:Mydriatics