Author: Jorge Simão (Portugal)
Co-authors: Catarina Silva, Cláudia Farinha, João Pedro Marques, Maria Luz, João Figueira, Rufino Silva
Polypoidal choroidal vasculopathy (VPC) is a chorioretinal pathology that is defined by the presence of an anomalous neovascular network associated with aneurysmal dilations, which develops between the choriocapillary and the retinal pigment epithelium (EPR), and which has traditionally been associated with sero-hemorrhagic detachments at the posterior pole. Concomitant choroidal changes, once present, can also affect the fellow eye, lacking characterization especially in Caucasian populations. Thus, this work aims to perform, in a sample of Caucasian patients with unilateral PCV, the multimodal imaging characterization of unaffected fellow eyes.
Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal (tertiary center, university hospital); Association for Innovation and Biomedical Research on Light and Image (AIBILI), Coimbra, Portugal.
Multicenter retrospective cohort study with a sample of 55 unaffected fellow eyes from patients diagnosed with unilateral PCV confirmed by Indocyanine Green Angiography (AVI). The sample was characterized in the baseline by color fundus photography, spectral domain optical coherence tomography (SD-OCT), fluorescein angiography and with indocyanine green. Morphological characteristics of both the retina and the choroid were evaluated in multimodal scope. The SD-OCT of the last follow-up visit was also evaluated in order to exclude evolution to VPC / choroidal neovascularization.
From our initial sample (77 patients), 11.7% of patients had bilateral PCV. The 55 patients included had a median age of 74±15 years. After 15.5±6.4 months of follow-up, only one developed disease (1.9%). Soft drusen were present in 32.7% of the fellow eyes, hard drusen in 27.3%, reticular pseudodrusen in 5.4% and pachydrusen in 23.6%. Pigmentary changes were also present in 29.1% of the cases. The thickness of the central retina was 273.4±37.0um, subfoveal choroid thickness was 238.3±83.0um, with signs of pachychoroid (both focal and diffuse) present in 47.2% of the sample. We identified the double layer sign in 36.4% of the cases, elevation due to detachment of the retinal pigmented epithelium in 5.4%, disruption of the EPR due to epitheliopathy / pigmentary changes in 16.4% and presence of fluid in 9.1% of the cases. EPR atrophy was present in 10.9% of the sample. In AVI, choroidal vascular dilation was present in 63.6% of patients, diffuse hyperfluorescence in 49.1%, punctiform hyperfluorescence in 52.7%, anastomoses in the posterior pole occurred in 18.2% of cases and late geographic hyperfluorescence in 16.4%. Branching vascular network was identified in only 1.8% of cases.
The pachychoroid signs in the OCT and AVI were present in more than half of the cases and the double layer sign in more than a third. They are very relevant findings for the better characterization of this pathology and for the understanding of its pathogenesis, being able to translate different phases of its progression.