Relationship between the retinal thickness of the macula and the difference in axial length

The purpose of this study was to evaluate the relationship between the retinal thickness of the macula and the difference in axial length with A-scan ultrasonography (UD-6000) and partial coherence interferometry (IOLMaster).

In 38 eyes of 26 patients with macular edema (ME), we measured axial length using both instruments and the retinal thickness of the macula using optical coherence tomography (OCT). To compare the difference in axial length between both methods, the Wilcoxon signed-ranks test was used. In addition, the relationship between macula thickness and axial length difference was analyzed by Spearman's correlation coefficient.

There was a significant difference between axial-length measurements (p<0.001). In addition, the retinal thickness of the macula and the difference in axial-length measurements were positively correlated (correlation coefficient = 0.55, p=0.003).

The difference in axial length obtained by both methods was considered to be the difference in optical and acoustic reflection site. This study may suggest that IOLMaster is sufficient for measuring axial length in eyes with macular edema and reducing postoperative refractive errors.