Impact of Reticular Pseudodrusen on Choriocapillaris Flow Deficits and Choroidal Structure on Optical Coherence Tomography Angiography

Abstract

Purpose To examine the impact of reticular pseudodrusen (RPD) on choriocapillaris blood flow and choroidal structure in individuals with intermediate age-related macular degeneration (AMD). Methods Individuals with bilateral large drusen underwent optical coherence tomography (OCT), color fundus photography, near-infrared reflectance, and fundus autofluorescence imaging to determine the presence of RPD. These participants also underwent swept-source OCT angiography (SS-OCTA) imaging to determine (1) choriocapillaris flow deficit (FD) parameters, including the percentage, mean size, and number of FDs present; and (2) choroidal structural parameters, including mean choroidal thickness and choroidal vascularity index. Differences in these parameters between eyes with and without coexistent RPD were examined with and without adjustment for potential key confounders such as drusen volume from the SS-OCTA scans and age. Results This study included 102 eyes from 51 individuals with bilateral large drusen, and the analyses showed that there were no significant differences in the choriocapillaris FD parameters ( P ≥ 0.062 for all) and choroidal structural parameters ( P ≥ 0.059 for all), with or without adjustment for potential confounders in this cohort. However, the percentage of FDs and the mean FD size were both significantly greater with increasing drusen volume ( P ≤ 0.038 for both). Conclusions The coexistence of RPD in eyes of individuals with intermediate AMD was not associated with significant impairments in choriocapillaris blood flow and choroidal vascular structural changes, with or without adjustment for key confounders. These findings suggest that macular changes in these vascular parameters may not be associated with the presence of RPD.

Integrity of the Hyperreflective Layer in the Inner Choroid in Eyes with Drusen

“…Furthermore, a focal defect in the choriocapillaris overlying pachyvessels was also suggested to be related to pachydrusen [ 32 ]. While previous studies on the relationship between flow deficit in the choriocapillaris/choroid and the phenotype of drusen have been presented [ 14 , 15 ], it is still not clear why soft drusen are uncommon in Asians with darker pigmentation [ 3 ]. The finding of the current study that depigmentation in the inner choroid is more frequent in eyes with soft drusen may provide a new perspective on the role of stroma in the development of AMD.…”

“…A linear reduction in choroidal blood flow with aging has been reported in many studies with volunteers [ 6 , 11 ]. While early studies on age-related choroidal changes have focused on the choriocapillaris and choroidal flow [ 12 – 15 ], in addition to vessels, the choroid is composed of stroma, such as various cells and neurons. Aging changes in choroidal stroma have also been reported in various studies [ 16 , 17 ].…”

Optical Coherence Tomography Angiography: A 2023 Focused Update on Age-Related Macular Degeneration

“…Therefore, RPD development in AMD could be the result of a choroidal perfusion impairment, as also proved by other similar workgroups [ 45 , 46 ]. On the contrary, Wu et al reported no relevant differences in CC FD and mean choroidal thickness, suggesting that RPD did not alter vascular parameters in intermediate AMD [ 47 ].…”

Current Perspectives on Type 3 Macular Neovascularization due to Age-Related Macular Degeneration

“…However, the period between MNV3 diagnosis and fellow-eye neovascularization was significantly shorter in eyes with RPD than in eyes without [61]. Both RPD and MNV3 patients reportedly share common features such as a high rate of bilaterality, associations with older age and arterial hypertension, a decreased choroidal thickness, and possibly altered CC flow characteristics [62‒67]. In summary, RPD is a striking phenomenon in MNV3 patients, but its cause remains largely unexplained to date.…”