Abstract
Purpose: :
To evaluate the sensitivity and specificity of measurements of central macular thickness (CMT) thickness in diabetic macular edema using Stratus time-domain and Cirrus spectral-domain optical coherence tomography (OCT; Carl Zeiss Meditec, Dublin, CA).
Design: :
Evaluation of diagnostic technology.
Methods: :
36 eyes from 19 patients with clinically significant diabetic macular edema (DME) were included. All participants underwent Cirrus HD-OCT and Stratus OCT examinations on the same day with a maximum of 3 consecutive scans per patient on each machine. The sensitivity/specificity of retinal thickness measurements was calculated from published normative data. Agreement was calculated using Bland-Altman method. Interclass and intersessional repeatability were calculated for each device. The receiver operating characteristic curves (ROC) and areas under the ROC were plotted.
Results: :
The mean difference between the Cirrus HD-OCT and Stratus OCT in the central foveal zone was 49.89µm. Bland-Altman analysis confirmed that the retinal thickness measurements had poor agreement. Intrasessional repeatability studies indicate the coefficient of variation being 0.9833 and 0.833 using Stratus and the Cirrus HD-OCT respectively. The areas under the ROC for retinal thickness measurements were 0.88 using Cirrus HD-OCT and 0.94 with Stratus.
Conclusions: :
In patients with DME, the Cirrus HD-OCT gives a higher reading than Stratus OCT with poor agreement between the devices in most regions within the nine subfield zones. The sensitivity and specificity of the Stratus OCT was comparable to the Cirrus.
Keywords: diabetic retinopathy • retina • imaging/image analysis: clinical