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BioMed Research International
Volume 2015, Article ID 729392, 6 pages
http://dx.doi.org/10.1155/2015/729392
Clinical Study

Repeatability and Reproducibility of Retinal Nerve Fiber Layer Parameters Measured by Scanning Laser Polarimetry with Enhanced Corneal Compensation in Normal and Glaucomatous Eyes

1Department of Ophthalmology, Miguel Servet University Hospital, Aragon Health Sciences Institute, 50009 Zaragoza, Spain
2Department of Surgery, Gynecology and Obstetrics, University of Zaragoza, 50009 Zaragoza, Spain
3Department of Family Medicine, Seminario Primary Health Care Center, 50009 Zaragoza, Spain
4Department of Neurosciences, University of Pisa, 56100 Pisa, Italy
5Department of Ophthalmology, University of Siena, 53100 Siena, Italy

Received 7 September 2014; Accepted 4 March 2015

Academic Editor: Alfredo García-Layana

Copyright © 2015 Mirian Ara 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.

Abstract

Objective. To assess the intrasession repeatability and intersession reproducibility of peripapillary retinal nerve fiber layer (RNFL) thickness parameters measured by scanning laser polarimetry (SLP) with enhanced corneal compensation (ECC) in healthy and glaucomatous eyes. Methods. One randomly selected eye of 82 healthy individuals and 60 glaucoma subjects was evaluated. Three scans were acquired during the first visit to evaluate intravisit repeatability. A different operator obtained two additional scans within 2 months after the first session to determine intervisit reproducibility. The intraclass correlation coefficient (ICC), coefficient of variation (COV), and test-retest variability (TRT) were calculated for all SLP parameters in both groups. Results. ICCs ranged from 0.920 to 0.982 for intravisit measurements and from 0.910 to 0.978 for intervisit measurements. The temporal-superior-nasal-inferior-temporal (TSNIT) average was the highest (0.967 and 0.946) in normal eyes, while nerve fiber indicator (NFI; 0.982) and inferior average (0.978) yielded the best ICC in glaucomatous eyes for intravisit and intervisit measurements, respectively. All COVs were under 10% in both groups, except NFI. TSNIT average had the lowest COV (2.43%) in either type of measurement. Intervisit TRT ranged from 6.48 to 12.84. Conclusions. The reproducibility of peripapillary RNFL measurements obtained with SLP-ECC was excellent, indicating that SLP-ECC is sufficiently accurate for monitoring glaucoma progression.