Ciliary muscle thickness profiles derived from optical coherence tomography images: erratum

Abstract

We recently reported on a novel semi-automatic method to study the morphological changes of the ciliary muscle during accommodation using optical coherence tomography [Biomed. Opt. Express 9, 5100 (2018)]. Here we present an erratum concerning the calculation of the displacement of the ciliary muscle apex vs. the scleral spur, which affects the data described in Section 3.3 but not the main findings of our publication.

We recently reported on a novel semi-automatic method to study the morphological changes of the ciliary muscle during accommodation in near-emmetropic subjects using optical coherence tomography [1]. In Section 2.4.3, we described the calculation of the ciliary muscle apex’ displacement relative to the scleral spur’s position. This description needs to be corrected: The tangent line to the upper ciliary muscle border passing through the scleral spur was defined, not the tangent line to the sclera. We then plotted the perpendicular to this tangent line, called q, and thereafter the perpendicular to q passing through the ciliary muscle apex. In the source code used to receive the results in Section 3.3, the ciliary muscle apex was accidentally taken as the reference point for plotting a perpendicular to the ciliary muscle’s upper border, instead of taking the scleral spur as described in the Methods section. Thus, the shift of the scleral spur against the ciliary muscle apex’ position was erroneously calculated and presented. Using the scleral spur as the reference point, the correct values of the ciliary muscle apex’ shift are on average −0.51 ± 0.20 mm and −0.36 ± 0.15 mm for 0 D and 3 D accommodation demand, respectively. The minus sign indicates the direction of the shift, which is in both conditions to the left from q. As the ciliary muscle apex is positioned closer to q during near vision, these values confirm the muscle’s forward movement during accommodation. The displacement of the ciliary muscle apex was still significantly different during far vs. near vision (Wilcoxon test, S = 33.50, p = 0.017, two-tailed). We emphasize that this correction does not affect the main findings of our publication.

Funding

Sandra Wagner acknowledges support from the Hector Fellow Academy. Eberhart Zrenner was supported by the German Research Council in the Excellence Center Program (EXC307).