gms | German Medical Science

Purpose: To identify a topographic relation of localized reticular pseudodrusen (RPD) to choroidal watershed zones (CWZ) and to changes in choroidal volumes (CV).

Methods: 30 eyes of 30 patients with RPD in an area <10 mm² and no other retinal alteration were included (76.7 ± 6.9 years). Patients underwent spectral-domain optical coherence tomography (SD-OCT), enhanced depth imaging (EDI) OCT, fluorescein video-angiography (vFA), indocyanine green video-angiography (vICG), confocal scanning laser ophthalmoscopy (cSLO). vICG was evaluated for the presence, localization and configuration of CWZ. Retinal areas affected by RPD were measured, and their localization was determined in relation to CWZ. CV was measured using a choroidal thickness map of the posterior pole and the ETDRS grid.

Results: In all study eyes, RPD could be clearly demonstrated in SDOCT, EDI-OCT, FA, ICG and cSLO. CWZ were identified in 25 eyes (83.3%). The area affected by RPD was 7.45 ± 2.25 mm². RPD area was fully or partly located within the CWZ in 22 eyes (88.0%). Mean CV in the full ETDRS grid area was significantly reduced (4.49 ± 1.44 mm³). Foveal CV and CV in the grid sector mostly affected by RPD were significantly diminished to 0.14 ± 0.05 mm³ and 0.85 ± 0.38 mm³, respectively.

Conclusions: The site of localized RPD seems to be related to presence and site of CWZ, suggesting that choroidal hypoxia may play a role in RPD pathogenesis. Reduced CV in eyes with localized RPD could be demonstrated and may be cause or consequence of RPD development.