Axial length measurement using partial coherence interferometry in myopic children: repeatability of the measurement and comparison with refractive components.
OBJECTIVE
To evaluate the test-retest repeatability of axial length (AL) measurements made with the IOLMaster in children with a wide range of myopic refractive errors, and to clarify the relationship between the AL and other refractive components.


METHODS
The subjects were 95 children (mean age +/- SD, 10.8 +/- 1.3 years; range, 7-13 years; mean refractive error; -4.37 +/- 1.43 D; range, -1.50 to -8.19 D) who participated in a myopia-control trial. The AL of the right eye was measured three times using an IOLMaster, and the mean value was regarded as the representative measurement. After 5 min, the measurement was performed again, and the repeatability was evaluated by analyzing the distribution of differences between the two measurements. The relationships between the AL and age, cycloplegic autorefraction (RE), and corneal radius of curvature (CR) were also examined.


RESULTS
The repeatability of the IOLMaster measurements was +/-0.05 mm (corresponding to a refractive error of +/-0.12 D) and was not affected by age or RE. AL was negatively correlated with RE (RE = -0.68 x AL + 12.74, r = -0.37) and positively correlated with CR (CR = 0.21 x AL + 2.53, r = 0.69). The highest correlation was found between the ratio of AL to CR and RE (AL/CR = -0.04 x RE + 3.08, r = -0.76). No association was observed between age and AL, nor between CR and RE.


CONCLUSIONS
The IOLMaster provides high repeatability in AL measurement in myopic children. The associations between AL and each refractive component found in this study were consistent with those in previous studies that used the ultrasound A-mode method, except for slightly higher AL/CR ratios in our study.
Kimura
Shuhei
S
Department of Ophthalmology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Hasebe
Satoshi
S
Miyata
Manabu
M
Hamasaki
Ichiro
I
Ohtsuki
Hiroshi
H
D000293:Adolescent; D001699:Biometry; D002648:Child; D005123:Eye / Q000473:pathology*; D005260:Female; D006801:Humans; D007368:Interferometry / Q000379:methods*; D008027:Light; D008297:Male; D009216:Myopia / Q000473:pathology*; D015203:Reproducibility of Results