Change in Outer Retinal Layer Thickness in Subjects with Reticular Pseudodrusen

Abstract

Purpose: To evaluate the thickness of the outer retinal layers in subjects with reticular pseudodrusen.

Methods: Thirty four eyes of 34 subjects with reticular pseudodrusen (RPD) and 39 eyes of 39 subjects with early non-neovascular age-related macular degeneration without RPD were enrolled in this prospective study at three clinical sites (Belfast, Coimbra, Milan). These subjects been fallowed up for one year. Spectral domain optical coherence tomography (SD-OCT) volume scans was collected in 3 clinical sites from Belfast, Coimbra and Milan using Spectralis HRA+OCT (Heidelberg Engineering, Heidelberg Germany). Detailed manual segmentation of outer retinal layers was performed using custom designed and validated grading software 3D OCTOR. Thickness measurements were derived for retina, photoreceptor outer segments, RPE+Drusen complex and Choroid layers in both the study cohorts.

Results: was no significant difference in retinal thickness and photoreceptor outer segments thickness between study groups. There was significant (p=0.004) difference in RPE+Drusen complex layer thickness in RPD subjects (30.6 ± 3.69 (±SD) µm) compared to those without RPD (28.21 ± 2.35 µm). In contrast, the choroid was significantly thinner (p = 0.04) in RPD subjects with a thickness of149.78 ± 33.56 compared with 162.42 ± 36.24 µm in subjects without RPD. Longitudinal analysis, revealed a small but significant (p = 0.04) thinning (25.53 ± 3.71 µm at baseline vs 24.03 ± 4.32 µm at month 12) in RPD subjects, compared to no significant change over time in subjects with no RPD.

Conclusions: The RPE+ Drusen complex layer is significantly thicker and the choroid is significantly thinner in subjects with reticular pseudodrusen. The photoreceptor outer segments appear to thin over time in eyes with RPD.