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Repeatability in and interchangeability between the macular and the fast macular thickness map protocols: a study on normal eyes with Stratus optical coherence tomography
Author(s) -
Eriksson Urban,
Alm Albert
Publication year - 2009
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2008.01345.x
Subject(s) - repeatability , intraclass correlation , optical coherence tomography , coefficient of variation , reproducibility , limits of agreement , ophthalmology , mathematics , medicine , optometry , nuclear medicine , statistics
. Purpose: To collect a normal material and to compare the macular and the fast macular thickness map protocols regarding normal values and repeatability. Methods: Sixty‐seven individuals underwent three repeated scans with the macular thickness protocol; 45 of them also had three scans with the fast thickness protocol in Stratus optical coherence tomography (OCT). The maps were divided into nine ETDRS fields, where thickness values were presented. The repeatability was calculated as intraclass correlation coefficient (ICC), coefficient of variance (CV) and coefficient of repeatability (CR). For comparison between the two protocols, limits of agreement were determined according to Bland–Altman. Results: Normal values for the two protocols were very close. Repeatability was high. ICC for all areas was 0.92–0.98. CV was less than 1% and CR was 6–8 μm for both protocols, with the exception of the fovea in the fast protocol (where CV was 1.44% and CR 12.4 μm). Limits of agreement between the two protocols were less than 10 μm as a rule. Conclusion: Normal values for the protocols are equal and they both have excellent repeatability. The fast macular map is a good alternative with the possible exception of the fovea, where variation is twice that of the macular thickness map.