Comparison of Retinal Thickness Measurements Between Three-dimensional and Radial Scans on Spectral-Domain Optical Coherence Tomography

PURPOSE: To compare retinal thickness (RT) measurements between traditional 6 radial line scans and three. dimensional OD) scans using spectral-domain optical coherence tomography (SD-OCT). DESIGN: Prospective, consecutive case series. METHODS: Twenty eyes of 17 patients with macular diseases and 8 healthy subjects were scanned using 2 different methods OD scan and 6 radial line scan) using 2 different SD-OCT devices (Topcon OCT,1000 [Top, con Inc, Paramus, New Jersey, USA] and Canon SPOCT [(Canon/Optopol Inc, Depew, New York, USA]) by an experienced OCT operator. In 16 eyes, the data of TD-OCT were also obtained for comparison. The RT in 9 regions based on Early Treatment Diabetic Retinopathy Study areas were analyzed and compared. Bland, Altman plots were used to evaluate agreement. RESULTS: In the eyes with macular diseases, there was no significant difference in the RT between 3D and 6 radial line scans except the center subfield (P = .011) on the Topcon OCT-1000, and inner inferior (P = .031) and outer nasal (P = .014) areas on the Canon SPOCT. In the healthy subjects, there was no significant difference between the different scans on both SD-OCT devices. The 95% limit of subjects was 3.2 to 30.6 mu m and 16.7 to 28.3 mu m in the eye with macular diseases on OCT-1000 and SPOCT, respectively, and 6.7 to 13.6 mu m and 10.8 to 32.3 mu m in healthy subjects on OCT 1000 and SPOCT, respectively. CONCLUSIONS: Preliminary results suggest the RT obtained by the 2 different scan patterns, 3D scan and 6 radial line scan, did not differ significantly on SD-OCT. (Am J Ophthalmol 2009;148:431-438. (C) 2009 by Elsevier Inc. All rights reserved.)