Purchase this article with an account.
Y Ding, A Loewenstein, B Azmon, P Pianka, R Zeimer, S Vitale; Reproducibility of Retinal Thicknes Summary Parameters in Eyes with Diabetic Macular Edema . Invest. Ophthalmol. Vis. Sci. 2002;43(13):539.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: The goal of this study was to determine, in diabetic eyes, the reproducibility (standard error of measurement (Se)) of retinal thickness measurements assessed by the Retinal Thickness Analyzer (RTA, Talia Technologies, Ltd, Neve Ilan, Israel). The reproducibility is important in determining when a patient can be said to have a significant change in retinal thickness. Reproducibility of the RTA has been studied in normal and in glaucomatous eyes, but not in eyes with diabetic macular edema. We assessed the intra- and inter-operator reproducibilities (IaOR, IeOR) of foveal and parafoveal retinal thickness (RT) summary parameters in 26 eyes of 20 diabetic patients. Methods: The RTA is a scanning laser technology to obtain digital optical cross-sections over the macular region. An automated algorithm computes a RT map and summary parameters within regions of interest. RTA scans were obtained two times in the same day by two independent operators (total of 4 scans per eye) and independently aligned by an independent operator. RT summary parameters studied were mean foveal RT (FAV: 600-mm-radius circle), mean foveolar RT (VAV: 300-mm-radius circle), and mean parafoveal RT (PFAV: 6x6mm2 area excluding FAV). Results: In eyes with mild-to-moderate edema (RT values £ 300 mm (1.5x normal)), IaOR was about 1.5 times that of normal eyes (Se for FAV, VAV, PFAV:13.4, 15.9, 7.3 mm) for both operators. For mild-to-severe edema (RT values £ 500 mm (2.5x normal)), IaOR for operator 2 was similar: Se for FAV, VAV, and PFAV: 13.9, 12.8, and 5.9 mm. Operator 1's IaOR was dramatically worse for mild-to-severe edema (Se for FAV, VAV, and PFAV: 48.0, 34.0, 15.2 mm). IeOR was similar for mild-to-severe edema (Se for FAV, VAV, and PFAV: 13.5, 16.2, 10.3 mm). For eyes with very severe edema (RT values ≷ 500 mm (≷ 2.5x normal, usually associated with extensive cysts), IeOR was poor (Se for FAV, VAV, and PFAV: 191, 197, 147 mm). Conclusions: Change of 27 (9%), 33 (11 %), and 21 (7%) mm or more, in FAV, VAV, and PFAV, respectively, would constitute significant change for eyes with for mild-to-severe edema at baseline. In the early stages of macular edema, relatively small changes can be detected. These findings will allow more accurate characterization of significant changes in studies of new treatments for macular edema.
This PDF is available to Subscribers Only