Association of outer retinal and choroidal alterations with neuroimaging and clinical features in posterior cortical atrophy.

Background: Posterior cortical atrophy (PCA) is a rare condition characterized by early-onset and progressive visual impairment. Individuals with PCA have relatively early-onset and progressive dementia, posing certain needs for early detection. Hence, this study aimed to investigate the association of alterations in outer retinal and choroidal structure and microvasculature with PCA neuroimaging and clinical features and the possible effects of apolipoprotein E(APOE) ε4 allele on outer retinal and choroidal alterations in participants with PCA, to detect potential ocular biomarkers for PCA screening.

Methods: This cross-sectional study included PCA and age- and sex-matched healthy control participants from June 2022 to December 2023. All participants with PCA completed a comprehensive neurological evaluation. All participants were recorded baseline information and underwent an ophthalmic evaluation. Quantitative analyses were performed using swept-source optical coherence tomography (SS-OCT) and angiography (SS-OCTA). Adaptive optics scanning laser ophthalmoscopy (AO-SLO) was performed in some patients. In participants with PCA, the influence of APOE ε4 on outer retinal and choroidal alterations and the correlation of outer retinal and choroidal alterations with PCA neuroimaging and clinical features in participants with PCA were investigated.

Results: A total of 28 participants (53 eyes) with PCA and 56 healthy control participants (112 eyes) were included in the current study. Compared with healthy control participants, participants with PCA had significantly reduced outer retinal thickness (ORT) (p < 0.001), choriocapillaris vessel density (VD) (p = 0.007), choroidal vascular index (CVI) (p = 0.005) and choroidal vascular volume (CVV) (p = 0.003). In participants with PCA, APOE ε4 carriers showed thinner ORT (p = 0.009), and increased choriocapillaris VD (p = 0.004) and CVI (p = 0.004). The PCA neuroimaging features were positively associated with the ORT, CVI and CVV. Furthermore, differential correlations were observed of PCA clinical features with the CRT, CVV and CVI.

Conclusions: Our findings highlighted the association of outer retinal and choroidal alterations with PCA neuroimaging and clinical features in participants with PCA. Noninvasive SS-OCT and SS-OCTA can provide potential biomarkers for the diagnosis and management of PCA, improving awareness of PCA syndrome among ophthalmologists, neurologists, and primary care providers.