Longitudinal changes in corneal asphericity in myopia.
OBJECTIVE
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.


CONCLUSIONS
These data show a shift to a more positive Q (in the oblate direction) with increased myopia.
Horner
D G
DG
Indiana University School of Optometry, Borish Center for Ophthalmic Research, Bloomington 47405-3680, USA. hornerdg@indiana.edu
Soni
P S
PS
Vyas
N
N
Himebaugh
N L
NL
D000293:Adolescent; D002648:Child; D003315:Cornea / Q000000981:diagnostic imaging / Q000503:physiopathology*; D019781:Corneal Topography; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D009216:Myopia / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011379:Prognosis; D012029:Refraction, Ocular; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014463:Ultrasonography; D014792:Visual Acuity