Purchase this article with an account.
G. Vizzeri, C. Bowd, M. Balasubramanian, R. N. Weinreb, F. A. Medeiros, P. A. Sample, L. M. Zangwill; Determinants of Agreement Between the Heidelberg Retina Tomograph (HRT) Topographic Change Analysis (TCA) and Standardized Assessment of Glaucomatous Progression in the Diagnostic Innovations in Glaucoma Study (DIGS). Invest. Ophthalmol. Vis. Sci. 2009;50(13):2248.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To estimate the agreement of HRT TCA with assessment of stereophotographs and standard automated perimetry (SAP) for detecting glaucomatous change and to identify factors associated with agreement between methods.
HRTII series (≥ 4, mean follow-up 4 years), stereophotographs and SAP results from 246 eyes of 167 DIGS glaucoma patients, suspects and ocular hypertensives were included in the analysis. 36/246 eyes (14.6%) were classified as progressors by masked stereophotograph assessment or SAP Guided Progression Analysis (GPA, "likely progression"). 15 (6.1%) progressed by stereophotographs only, 18 (7.3%) progressed by GPA only and 3 (1.2%) progressed by both. TCA progression was determined for 3 previously described parameters (CSIZEdisc, number of progressed superpixels in the largest cluster; CAREAdisc, area of progressed superpixels in the largest cluster; and CVOLdisc, volume of progressed superpixels in the largest cluster; all 3 within the disc margin) at each of 3 previously determined specificity cut-offs (99%, 95%, 90%)1. Agreement between progression by each TCA parameter, stereophotographs and GPA was assessed using the Kappa test. ANOVA with post-hoc analysis was applied to identify factors including image quality (standard deviation of the mean topography), disc size and disease severity (PSD and cup area) associated with agreement/non-agreement between methods.
Agreement was generally poor regardless of the TCA parameter and specificity cut-offs applied. For the parameters with the strongest agreement, CSIZEdisc and CAREAdisc, Kappa values were 0.14 (72.8%, agreement on 165 non-progressing eyes and 14 progressing eyes) at 95% cut-off and 0.15 (63.8%, agreement on 135 non-progressing eyes and 22 progressing eyes) at 99% cut-off. Most of the factors evaluated were not significantly associated with agreement/non-agreement between methods (all p>0.11). However, SAP PSD was greater in the progressors by stereophotograph only group compared to the progressors by TCA only group (5.8±4.6 and 2.7±2.3, respectively p=0.001 for CSIZE disc at 95% specificity and 5.3±4.6 and 2.6±2.3, respectively p=0.003 for CAREA disc at 99% specificity).
Agreement between TCA, stereophotography and SAP GPA is poor. However, longer follow-up may result in better agreement among methods. Progressors by stereophotography tended to have more advanced disease at baseline than progressors by TCA only.1. Bowd C et al, IOVS Oct 3 2008 Epub.
This PDF is available to Subscribers Only