Abstract
Purpose: :
To determine the contribution of higher order aberrations in the development and/or progression of refractive error.
Methods: :
Total ocular aberrations were measured for a sample of 614 cyclopleged right eyes of adolescents (mean age, 16.9±0.4 years), pupil diameter of 5mm using COAS aberrometer, in Sydney Adolescent Vascular and Eye Study (SAVES) in 2009-2010. These 614 eyes were measured previously in the Sydney Myopia Study in 2004-2005 (mean age, 12.6 ± 0.4 years).
Results: :
157 eyes (25.6%) had myopic shift (spherical equivalent (SE) change over a period of 5 years more than -0.50 D) 432 eyes (70.4%) had no shift (SE between -0.50 and +0.50D) and 25 eyes (4%) had hyperopic shift (SE > +0.50D). Change over time in average corneal curvature, Z(3,-3), Z(4,-4), Z(4,0), Z(5,-3), Z(6,0), HOA root mean square (RMS), and in addition age, axial length and average corneal curvature at baseline significantly correlated to the change in SE. Among these, only the change in Z(4,0) had a higher correlation coefficient (r = 0.525, slope = 6.7, p<0.05) in relation to the change in SE. With a myopic shift in SE, there was a decrease in Z(4,0) (baseline visit = 0.060±0.060µm, current visit = 0.033±0.050µm, p<0.05) and with a hyperopic shift there was an increase in Z(4,0) (baseline visit = 0.025±0.037µm, current visit = 0.093±0.052µm, p<0.05).
Conclusions: :
An association exists between change in Z(4,0) and a change in refractive error and may possibly be the result of the change in curvature, asphericity and distribution of gradient refractive index of the growing crystalline lens.
Keywords: myopia • aberrations • refractive error development