Automated detection of Drusenoid Pigment Epithelial Detachments (DPEDs) on OCT’s in patients with Age related Macular Degeneration (AMD)

Abstract

Purpose : DPEDs in AMD appear as large yellowish mounds on stereoscopic examination. DPEDs are an important risk factor for progression to late AMD and vision loss. Spectral Domain OCT (SD-OCT) is an important imaging modality in the evaluation of retinal diseases. Automated detection of DPEDs on SD-OCT may help understand the pathophysiology of AMD progression and be useful for clinical trial screening.

Methods : 131 patients (294 eyes) enrolled in a longitudinal study of dark adaptation (NCT01352975) with a range of AMD severities from no AMD to eyes with advanced atrophic disease were imaged using both color fundus imaging (Topcon) and SD-OCT imaging (Heidelberg, Germany). Color fundus images were graded by the Wisconsin Reading Center and assigned AMD severity scores (AMDSC) of 0-10.
SD-OCT imaging consisted of a volumetric macular scan (30°x25°, 496×768×121 voxels). A 3D-UNet trained to segment the Retinal Pigment Epithelium (RPE) and Bruch’s membrane (BM) layers was used to contour all 294 macular volumes. The 6x6mm² region representing the grid centered around the fovea was considered for calculating the mean ± std of the maximum width (W) and maximum elevation (H) between the RPE and BM layers in eyes with DPEDs. The layer contours were screened to identify measures satisfying the requirements of distinct elevations (>50μm) in the RPE Drusen Complex region with minimum diameter (>433μm), defining a DPED.

Results : Out of 76 eyes with no AMD (AMDSC 0-1), 111 with early AMD (AMDSC 2-5), 96 with intermediate AMD (AMDSC 6-8), and 11 with Geographic Atrophy (GA) (AMDSC 9-10)- 12/329 (eyes/B-scans) in the intermediate AMD group (W=1168.48±598.19μm, H=143.85±56.62μm) and 4/81 (eyes/BScans) in the GA group (W=715.92±279.52μm, H=113.53±40.28μm) met the DPED criteria. These occurred in 1/27 (eyes/BScans) AMDSC-6, 10/269 AMDSC-7, 1/33 AMDSC-8, and 4/81 AMDSC-10, with no DPEDs identified in eyes with AMDSC 0-5.

Conclusions : Segmentation of RPE and BM layers by a 3D-UNet can subsequently be used for automated and objective detection of DPEDs on B-scans within the macular volume. Eyes with DPEDs are of special interest with some studies targeting this phenotype. By automating this process using OCTs, more quantitative and reproducible DPED detections are possible leading to more efficient clinical trial designs.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.