Reproducibility of Quantitative Optical Coherence Tomography Subanalysis in Neovascular Age-Related Macular Degeneration

PURPOSE. To determine the intergrader reproducibility for computer-assisted grading of optical coherence tomography (OCT) images in eyes with neovascular age-related macular degeneration (AMD), by using a standardized grading procedure. METHODS. Sixty OCT image sets (of six radial lines each) were independently analyzed by two graders using validated custom software (OCTOR) to draw boundaries manually on OCT B-scans. Spaces delineated by these boundaries included retina, subretinal fluid, subretinal tissue, and pigment epithelial detachments (PEDs). Volume measurements for the nine Early Treatment of Diabetic Retinopathy Study (ETDRS) subfields and the mean foveal center point (FCP) thickness were calculated by the software and compared by using weighted K statistics and intraclass correlation coefficients (ICCs). RESULTS. Intergrader comparison of the foveal central subfield (FCS) volume, total volume, and mean FCP thickness showed a high level of agreement and strong correlation between measurements for all spaces (K weighted = 0.72-0.97; ICC = 0.92-0.99). The best agreement was observed for total volume of the combination of all four graded spaces (K weighted = 0.97, mean difference = 0.31 mm 3 , or 2.51%). The highest ICCs were seen for FCP thickness measurements. The poorest agreement was found for grading of subretinal tissue. Eyes with advanced choroidal neovascularization (CNV) and poor visibility of the retinal pigment epithelium (RPE) band appeared to show the greatest intergrader discrepancies. CONCLUSIONS. Analysis of OCT images by trained graders using computer-assisted grading software allows for highly reproducible quantitative measurements, even in eyes with complex diseases such as neovascular AMD. Quantitative subanalysis may be useful in studying the differential morphologic effect of therapies on various anatomic components.