This 77YO female presented with vision of 20/20 OD and 20/30 OS and extensive bilateral subretinal drusenoid deposits.
Swept-source OCT shows numerous hyperreflective deposits in the outer retina located just above the RPE. En face OCT dramatically shows the extent of the dot-like drusenoid material.
Learning Points:
Subretinal drusenoid deposits (SDD) are polymorphous light-gray interconnected accumulations located above the RPE. They are present in about one-quarter of older adults with healthy maculas and in more than half of those with early- to intermediate-stage dry AMD. They can appear as an array of dots (as in our patient), interconnected reticular bands, or confluent lesions (Suzuki and Spaide, AJO 2014;157:1005-1012). The dot variant is associated with macular neovascularization (MNV) and the confluent variant with macular atrophy (Zhou et al, Ophthalmology 2016;123:1530-1540).
Clinically, they are often mistaken for conventional drusen and consist of a similar yet distinct lipid-rich material to that found in soft drusen. They are localized to rods, unlike typical soft drusen, which are more central and cone-based. As with drusen, SDDs are dynamic and can grow, shrink, resolve, or even recur.
Since they are located above the RPE, they are best visualized with blue or green illumination. On OCT, they appear in 3 stages (Zweifel et al, Ophthalmology 2010;117:303-312), growing upwards from the RPE towards the ELM (external limiting membrane): stage 1, diffuse deposition of granular hyperreflective material between the RPE and the EZ (ellipsoid zone), stage 2, material alters the EZ contour, and stage 3, conical appearance breaking through the EZ.
Rod function seems to be preferentially affected, and there is an associated increased risk of delayed dark adaptation, macular atrophy, and types 2 and 3 MNV. In fact, type 2 neovascularization in the setting of AMD occurs almost solely in eyes with subretinal drusenoid deposits.
