Abstract
Purpose: :
To describe the OCT grading system utilized in a large multicenter uveitis treatment trial, report the reproducibility of grading, and report pertinent findings in subjects at baseline.Background: The MUST trial is a large multi-center randomized clinical trial comparing the effectiveness and side-effects of standard systemic therapy versus fluocinolone acetonide intraocular implant for the treatment of severe non-infectious uveitis. Change in retinal thickness at the center of the macula as assessed by OCT is one of the secondary outcomes of the study.
Methods: :
OCT images of the fundus are obtained by certified photographers at study visits utilizing the Zeiss Stratus OCT3. Images are graded using standardized procedures at a Reading Center. An initial step in grading is the evaluation of scan quality. If automated thickness data is unreliable then manual measurement of retinal thickness is performed. Morphological features assessed include presence of cystoid spaces, subretinal fluid, and vitreoretinal interface abnormalities (epiretinal membrane and vitreomacular traction). A randomly selected subset of 78 images was regraded and compared with the original grade of record to determine reproducibility.
Results: :
450 eyes were assessed with OCT at baseline. 9.1% were manually measured for central retinal thickness. The mean central retinal thickness was 266.7 +/- 180. 1 um. 33% were categorized as clearly thickened, measuring > 240 um. 39% had cystoid spaces and 29.3% had a vitreoretinal interface abnormality. Quality control regrade of 78 images was performed. Intergrader agreement for categories of overall quality was 88%. The intraclass correlation coefficient for manually measured center point thickness was 0.99. Reproducibility for presence of cystoid spaces was 87% and for vitreoretinal interface abnormalities was 85%.
Conclusions: :
Retinal thickening, cystoid spaces, and vitreoretinal interface abnormalities are common findings in eyes enrolled in the MUST trial. The OCT grading system is highly reproducible for these features. This methodology will provide important secondary outcome information and will be useful in future uveitis clinical studies.
Clinical Trial: :
www.clinicaltrials.gov NCT00132691
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • uveitis-clinical/animal model • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials