A Comparison Among Different Automatically Segmented Slabs to Assess Neovascular AMD using Swept Source OCT Angiography

Abstract

Purpose

We systematically compare the intermodality and interreader agreement in age-related macular degeneration(AMD)-associated neovascularization assessment for optical coherence tomography angiography (OCTA) images obtained using different slabs.

Methods

We collected data from 48 patients (50 eyes) with type 1 or 2 neovascularization (NV) and AMD. Subjects were imaged with a swept source (SS)-OCTA system. For each eye, three OCTA en face images generated from three different slabs were exported: (1) the outer retina to choriocapillaris (ORCC) image, (2) the choriocapillaris (CC) image, and (3) the retinal pigment epithelium (RPE)-RPE fit image. Each image was graded by two readers to assess interreader variability and a single image for each modality was used to assess the intermodality variability.

Results

In the assessment of type 1 NV, mean absolute interreader difference between measured NV areas was 0.19, 0.30, and 0.16 mm ² for ORCC, CC, and RPE-RPE fit images, respectively. Similarly, the coefficient of repeatability (CR) and intraclass correlation coefficient (ICC) indicated that the RPE-RPE fit assessment was characterized by the highest interreader reproducibility. Type 1 NV size was 0.58 mm ² (0.30–1.60 mm ²) on ORCC images, 0.00 mm ² (0.00–0.36 mm ²) on CC images ( P = 0.002 vs. ORCC), and 0.62 mm ² (0.31–2.03 mm ²) on RPE-RPE fit images ( P < 0.0001 vs. CC, P = 0.041 vs. ORCC).

Conclusions

The RPE-RPE fit OCTA images have the highest interreader agreement and deliver larger measurements in type 1 lesions.

Translational Relevance

OCTA imaging may be used in ongoing trials of potential novel treatments for NV.