Analysis of progression of reticular pseudodrusen by spectral domain-optical coherence tomography

To analyze reticular pseudodrusen progression using spectral domain-optical coherence tomography (SD-OCT).

Thirty-three consecutive patients (48 eyes) underwent SD-OCT using the eye-tracked follow-up protocol 24 ± 2 months after baseline examination. Each pair of B-scans (only one per eye was evaluated among those showing pseudodrusen progression) was compared with respect to pseudodrusen appearance and retinal layer structure. Stage 1 pseudodrusen was defined as granular material between the RPE and the inner segment/outer segment (IS/OS), stage 2 as mounds of material sufficient to alter the contour of the IS/OS, stage 3 as thicker material adopting a conical appearance and breaking through the IS/OS, and stage 4 as fading of the material because of reabsorption and migration within the inner retinal layers.

A total of 78 pseudodrusen (detected on the 48 analyzed B-scans, and counting for a mean of 2.3 pseudodrusen per scan) showed progression over a mean of 23.9 ± 1.2 months. All 58 pseudodrusen (100%) graded as stage 1 at baseline examination progressed to stage 2. Thirteen of 16 pseudodrusen (81.3%) graded as stage 2 at baseline examination progressed to stage 3, and three (18.7%) progressed to stage 4. All four pseudodrusen (100%) graded as stage 3 at baseline examination progressed to stage 4. Among pseudodrusen that were stage 3 or 4 at follow-up (n = 20), 100% had IS/OS disruption whereas 12.1% (n = 7) had IS/OS disruption at stage 1 or 2 (n = 58) (OR, 1.736; 95% CI, 1.02-2.43).

The frequency of stage changes over time suggest that reticular pseudodrusen are dynamic pathologic structures.