CRYSTALLINE LENS THICKNESS AND REFRACTIVE ERROR IN CHILDREN

Title CRYSTALLINE LENS THICKNESS AND REFRACTIVE ERROR IN CHILDREN
Author, Co-Author Karla Zadnik, Donald Mutti, Robert Fusaro, Anthony Adams
Topic
Year
1994
Day
Tuesday
Program Number
4:00 pm
Room
San Diego Ballroom A
Affiliation
Abstract Most previous studies indicate that the eye's crystalline lens grows continually throughout life, but cross-sectional results of crystalline lens thinning during childhood have been reported. We investigated childhood changes in crystalline lens thickness using longitudinal data from the Orinda Longitudinal Study of Myopia, which is a community-based study of normal eye growth and myopia development in schoolchildren. A-scan ultrasonographic right eye lens thickness measurements on 869 children aged 6 to 14 years over a 1-3 year time span were analyzed along with their Canon R-1 cycloplegic autorefractor measurements in the vertical meridian. Using a mixed model analysis of covariance, we estimated that, on average, the crystalline lens thins in its axial dimension between the ages of 6 and 9 years by almost 0.2 mm, with little change after the age of 9 years. The myopes in this study have thinner crystalline lenses than do the emmetropes, and the emmetropes have thinner lenses than the hyperopes. This suggests not only that the crystalline lens thins during the period of coordinated ocular growth between the ages of 6 and 9 years, but, that, moreover, lens thickness is associated with refractive error. Eye growth leading to myopia may result in thinner lenses as the crystalline lens exhausts its ability to compensate for axial elongation. If mechanical forces play a role in the process of human emmetropization and the etiology of refractive error, more complex, visually-guided feedback loops may not be needed to explain the normal eye growth that results in emmetropization. Supported by NEI grant R01 EY08893.
Affiliation of Co-Authors
Outline