Three-Dimensional Morphometric Analysis of Exfoliative Material Using Ultrahigh-Resolution OCT in Exfoliation...

Exfoliation syndrome (XFS), characterized by the accumulation of fibrillar extracellular material in the anterior segment, is a leading cause of secondary glaucoma worldwide. This study aimed to characterize the three-dimensional morphology of exfoliative material on the anterior lens surface in XFS eyes using ultrahigh-resolution optical coherence tomography (UHR-OCT).

We imaged 17 eyes with lens photography and acquired volumetric UHR-OCT using radial scanning. We fine-tuned the Segment Anything Model to automatically identify the anterior lens capsule and surface. The exfoliative material was segmented and categorized as deposited (thickened epithelium layer), peeling-off, or detached, as well as central versus peripheral. Volumetric quantification of each category was also performed to assess the distribution of exfoliative material.

Compared to lens photography, UHR-OCT resolved greater microscopic pathological features on the anterior lens surface in XFS, including a thickened capsular layer with small/grainy material and exfoliative material peeling-off or detached from the lens surface. En face OCT images showed the scattered hyperreflective deposits across central and peripheral regions of the lens capsule, as well as diffused, thickened capsular layers. From volumetric analysis, the average volume of exfoliative material was 10.9 ± 4.0 × 107 µm3, consisting of deposited (9.0 ± 4.3 × 107 µm3), peeling-off (1.6 ± 1.1 × 107 µm3), and detached (0.3 ± 0.6 × 107 µm3). The peripheral band had slightly more exfoliative material than the central disc (5.5 ± 3.7 × 107 µm3 vs. 5.4 ± 2.8 × 107 µm3).

UHR-OCT clearly visualizes the heterogeneous appearance of exfoliative material in XFS, enables quantitative analysis, and can potentially be used to monitor its deposition over time.