Abstract
Abstract: :
Purpose: To determine the within–visit repeatability and between–visit reproducibility of the optical coherence tomographer (OCT) 3 (Model 3000, Carl–Zeiss Ophthalmic Systems Inc, Humphrey Division, Dublin, CA). Methods: Macular thickness measurements were obtained at each of two visits using multiple radial line scans, 6mm in length, centred through the fixation point of 20 normal control subjects (58.9 ±13.1 years) and 20 diabetic patients (60.1 ±9.4 years) diagnosed with diabetic maculopathy. Retinal thickness analysis software produced a circular map comprising 9 sectors depicting average retinal thickness. Coefficient of repeatability (CoR 1) and coefficient of variation (CoV) were used to determine the repeatability of measures within a visit, while coefficient of reproducibility (CoR 2) and intraclass correlation coefficients (ICC) were used to determine the reproducibility of measures between visits. Results: The within–visit CoV was 1.62% for normal subjects and 1.57% for diabetic patients. The CoR (1) was 1.64 ±0.39 for normal subjects and 1.58 ±0.29 for diabetic patients. The between–visit CoR (2) was 2.87 ±1.12 for normal subjects and 2.6 ±1.33 for diabetic patients. ICC’s for between–visit reproducibility ranged from 77% to 97% and mean ICC was 91% for normal subjects; ICC’s ranged from 67% to 98% and mean ICC was 91% for diabetic patients. Conclusions: Measurements of macular thickness made with the OCT 3 are repeatable and reproducible for both normal and diabetic patients. OCT 3 provides quantitative measurements of retinal structure and can be used to monitor the progression of disease over a period of time allowing more effective management and treatment of disease.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • retina • diabetic retinopathy