D G Horner1, P S Soni, N Vyas, N L Himebaugh. 1. Indiana University School of Optometry, Borish Center for Ophthalmic Research, Bloomington 47405-3680, USA. hornerdg@indiana.edu
Abstract
PURPOSE: To report the change in shape of the peripheral cornea (asphericity, Q) as it relates to myopia progression in adolescence. METHODS: Forty-eight subjects with initial ages between 11 and 13 years of age were observed for 5 years. Each subject had participated in a variety of soft contact lens studies and all had worn daily wear soft contact lenses successfully for the 2 years before collection of the second data set. RESULTS: Myopia increased by an average of 1.46 D and was strongly correlated with a 0.56-mm increase in axial length. There was no contribution to the change in myopia from the change in central radius of the cornea. A significant (p < 0.01, one tail) correlation was found between Q and the progression of myopia. Principal axis analysis yielded a slope of -0.04 in Q per diopter of increase in myopia. CONCLUSION: These data show a shift to a more positive Q (in the oblate direction) with increased myopia.
PURPOSE: To report the change in shape of the peripheral cornea (asphericity, Q) as it relates to myopia progression in adolescence. METHODS: Forty-eight subjects with initial ages between 11 and 13 years of age were observed for 5 years. Each subject had participated in a variety of soft contact lens studies and all had worn daily wear soft contact lenses successfully for the 2 years before collection of the second data set. RESULTS:Myopia increased by an average of 1.46 D and was strongly correlated with a 0.56-mm increase in axial length. There was no contribution to the change in myopia from the change in central radius of the cornea. A significant (p < 0.01, one tail) correlation was found between Q and the progression of myopia. Principal axis analysis yielded a slope of -0.04 in Q per diopter of increase in myopia. CONCLUSION: These data show a shift to a more positive Q (in the oblate direction) with increased myopia.