High-Resolution, Motion-Corrected, Volume-Fused OCT for Investigating Longitudinal Changes in Subretinal Drusenoid Deposits in Intermediate AMD.

PURPOSE: To demonstrate high-resolution, motion-corrected, volume-fused optical coherence tomography (OCT) for assessing longitudinal changes in macular dot form subretinal drusenoid deposits (SDDs).

METHODS

Six consecutive isotropic volume raster scans over 6 × 6 mm (500 × 500 A-scans) were acquired using a high-resolution (2.7 µm axial resolution) spectral domain OCT prototype instrument. OCT volumes were computationally motion-corrected and fused. The distribution and longitudinal changes in dot SDDs were evaluated using en face OCT in a 50-µm-thick slab, from 27 µm above Bruch's membrane.

RESULTS

Computational motion correction and volume fusion methods improve visibility of small en face features and compensate for motion artifacts to facilitate longitudinal assessment. In total, 326 SDDs were identified in a representative series of four eyes from four patients with intermediate age-related macular degeneration (AMD) and assessed with a 3- to 12-month follow-up. Of the SDDs, 85.3% remained stable over the follow-up, while 9.8% regressed, 3.4% fused, and 1.5% new SDDs appeared.

CONCLUSIONS

Computational motion correction and volume fusion combined with high-resolution OCT B-scans and en face slabs facilitate visualization and longitudinal tracking of focal pathologies, such as SDDs.

TRANSLATIONAL RELEVANCE: The methods presented have the potential to improve OCT analysis of focal features, such as quantification of SDDs and other AMD biomarkers.