Conversion of Stratus optical coherence tomography (OCT) retinal thickness to Cirrus OCT values in age-related macular degeneration

Abstract

Stratus OCT and Cirrus OCT use a different posterior reference line within the hyper-reflective band of the outer retina. Therefore a conversion formula is necessary to compare Stratus and Cirrus OCT CRT values, and this has been determined in our study.

A randomised double-masked trial comparing the visual outcome after treatment with ranibizumab or bevacizumab in patients with neovascular age-related macular degeneration

“…BCVA was tested with ETDRS charts at 4 m distance. For OCT examinations, either Stratus OCT or Cirrus OCT or Spectralis OCT could be used; central retinal thickness (mean value of retinal thickness within the central area with a diameter of 100 µm) values were converted as previously described 19 20…”

Non-responders to treatment with antagonists of vascular endothelial growth factor in age-related macular degeneration

“…To assess the activity of a lesion the OCT scans were explored, and increased activity in the OCT scans and automatically recorded central retinal thickness (CRT) were used to identify non-responders. CRT values of Stratus OCT were converted to Cirrus OCT levels to provide comparable data 6. The fluorescein angiograms were performed with the Heidelberger Retina Angiograph (Heidelberg engineering, Heidelberg, Germany) at baseline and thereafter at the discretion of the examiner (in cases of new blood or new choroidal neovascularisation, and loss of distance acuity).…”

Macular ischemia and outcome of vitrectomy for diabetic macular edema

“…CST was defined as the mean macular thickness within a central circle of 1-mm diameter and was measured automatically. Conversion formulas derived from prior studies were applied to determine the Stratus OCT equivalents of the thickness values measured on the Spectralis OCT (Spectralis, Heidelberg Engineering, Vista, CA, USA) or Cirrus OCT (Carl Zeiss Meditec Inc., Dublin, CA, USA) [26,27]. Refractory DME was defined as biomicroscopically and tomographically confirmed persistent CSME that showed no response to at least one treatment modality among macular grid/focal photocoagulation, two sessions of intravitreal injection of bevacizumab, and intravitreal and posterior sub-Tenon injection of triamcinolone acetonide, all being performed at least 3 months before vitrectomy.…”