Intra- and Intergrader Agreement for Detection of OCT Angiographic Characteristics Associated With Type 3...

To examine the intra- and intergrader agreement on morphologic characteristics of type 3 neovascularization on optical coherence tomography angiography (OCT-A).

OCT-A images of 22 eyes from 21 patients with a new-onset, treatment-naive type 3 neovascularization were included in this cross-sectional retrospective agreement study. Each image was graded three times by two independent medical retina specialists to assess intra- and intergrader agreement. The graders scored the presence or absence of the following vascular and structural features: intraretinal neovascularization (IRN), subretinal neovascularization, sub-retinal pigment epithelium (RPE) neovascularization (SRPEN), retinal choroidal anastomosis (RCA), intraretinal cysts, subretinal fluid, and pigment epithelial detachment. Agreement was analyzed for each feature using Gwet's AC₁, к statistics, and percentage of agreement.

The best agreement (AC₁) was found for intraretinal neovascularization (within_grader1: 0.94; within_grader2: 0.93 and between: 1.00) and intraretinal cysts (within_grader1, 1.00; within_grader2, 0.97 and between, 1.00). The poorest intragrader agreements were observed for SRPEN (within_grader1, 0.54 and within_grader2, 0.36) and RCA (within_grader1, 0.45 and within_grader2, 0.52), and the poorest intergrader agreement was found for SRPEN, RCA, and pigment epithelial detachment (0.18, 0.37, and 0.15, respectively).

Although the agreement values were high for intraretinal features, considerable grader variability was found for the vascular and structural features in the deeper retina or under the RPE. Clinicians should be careful to base therapeutic decisions on qualitative OCT-A assessment, because even well-trained specialists show a considerable grader variation in their subjective evaluation.

The clinical value of OCT-A imaging largely depends on the agreement of subjective evaluations by ophthalmologists.