Comparison of spectral‐domain Cirrus optical coherence tomography and time‐domain Stratus optical coherence tomography for the evaluation of macular thickness in healthy subjects

Abstract

Purpose to compare Cirrus Fourier‐domain optical coherence tomograph (OCT) with Stratus Time‐domain OCT for acquiring retinal images and measuring retinal thickness. Methods Eighty five eyes from 85 healthy subjects, 26 men (30.6%) and 59 women (69.4%), aged 16 to 72 years were prospective and consecutively selected. All of them underwent three macular 512x128 volume cube scans with the Cirrus HD‐OCT system (Carl Zeiss Meditec, Inc.). The average of these three scans was calculated. With the Stratus OCT system (Carl Zeiss Meditec, Inc.) a fast macular scan was recorded. The nine areas corresponding to the Early Treatment Diabetic Retinopathy Study (ETDRS) macular protocol were compared between both devices. The reproducibility of macular thickness measurements using de Cirrus HD‐OCT was studied, and the variation coefficient (COV) of each parameter was assessed. Results Cirrus HD‐OCT macular thickness measurements were approximately 64.22 µm higher than those from Stratus OCT (266.40 µm vs 202.18 µm). The measurements in all nine ETDRS areas were statistically higher using the Cirrus HD‐OCT. Nasal inner area showed the highest value. Retinal thickness measurements using the 512x128 macular cube scan were highly reproducible for the nine ETDRS areas. Mean COV was 1.45 ± 1.11% (ranged from 0.98% to 2.49%). The lowest COV was found for the temporal inner ETDRS area (COV=0.98%) and the highest for the central ETDRS area (COV=2.49%). Conclusion Macular measurements using Cirrus HD‐OCT are clearly higher than those obtained by Stratus OCT.