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BioMed Research International
Volume 2015, Article ID 925217, 6 pages
Research Article

Repeatability, Reproducibility, and Comparability of Subjective and Objective Measurements of Intraocular Forward Scattering in Healthy Subjects

Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa 252-0374, Japan

Received 1 March 2015; Revised 10 May 2015; Accepted 7 June 2015

Academic Editor: Jose Manuel González-Méijome

Copyright © 2015 Ayaka Iijima et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Purpose. To assess the repeatability, reproducibility, and comparability of measurements of subjective and objective forward scattering in healthy subjects. Methods. We prospectively examined twenty eyes of 20 healthy volunteers (7 men and 13 women; ages, 28.4 ± 4.1 years). The logarithmic straylight value (log(s)) and the objective scattering index (OSI) were measured with a straylight meter (C-Quant) and a point-spread function meter (OQAS), respectively. Results. The 95% limits of agreement (LoA) between first and second measurements ranged from −0.211 to 0.207 for the C-Quant and from −0.302 to 0.477 for the OQAS. The intraclass correlation coefficients for the repeatability of the log(s) and OSI measurements were 0.815 and 0.926, respectively. The mean difference between examiners was −0.051 ± 0.133 (95% LoA; −0.311 to 0.209) for the C-Quant and 0.080 ± 0.307 (−0.522 to 0.682) for the OQAS. There was a modest, but significant, correlation between the log(s) and the OSI (Spearman correlation coefficient , ). Conclusions. The C-Quant and the OQAS provide good repeatability and reproducibility, although the OQAS measurement provides a slightly higher ICC than the C-Quant measurement. The subjective forward scattering may be to some extent expressed in the objective forward scattering in healthy subjects.