Ciliary body thickness and refractive error in children.
OBJECTIVE
To determine whether ciliary body thickness (CBT) is related to refractive error in school-age children.


METHODS
Fifty-three children, 8 to 15 years of age, were recruited. CBT was measured from anterior segment OCT images (Visante; Carl Zeiss Meditec, Inc., Dublin, CA) at 1 (CBT1), 2 (CBT2) and 3 (CBT3) mm posterior to the scleral spur. Cycloplegic refractive error was measured with an autorefractor, and axial length was measured with an optical biometer. Multilevel regression models determined the relationship between CBT measurements and refractive error or axial length. A Bland-Altman analysis was used to assess the between-visit repeatability of the ciliary body measurements.


RESULTS
The between-visits coefficients of repeatability for CBT1, -2, and -3 were 148.04, 165.68, and 110.90, respectively. Thicker measurements at CBT2 (r = -0.29, P = 0.03) and CBT3 (r = -0.38, P = 0.005) were associated with increasingly myopic refractive errors (multilevel model: P < 0.001). Thicker measurements at CBT2 (r = 0.40, P = 0.003) and CBT3 (r = 0.51, P < 0.001) were associated with longer axial lengths (multilevel model: P < 0.001).


CONCLUSIONS
Thicker ciliary body measurements were associated with myopia and a longer axial length. Future studies should determine whether this relationship is also present in animal models of myopia and determine the temporal relationship between thickening of the ciliary muscle and the onset of myopia.
Bailey
Melissa D
MD
Ohio State University College of Optometry, Columbus, Ohio, USA. mbailey@optometry.osu.edu
Sinnott
Loraine T
LT
Mutti
Donald O
DO
D000293:Adolescent; D002648:Child; D002924:Ciliary Body / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D009184:Mydriatics / Q000008:administration & dosage; D009216:Myopia / Q000175:diagnosis*; D011680:Pupil / Q000187:drug effects; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence
D009184:Mydriatics