Pachychoroid pigment epitheliopathy: long-term structural changes and risk factors for disease evolution

Pachychoroid pigment epitheliopathy (PPE) is an early, often asymptomatic stage of the pachychoroid disease spectrum that may progress to central serous chorioretinopathy (CSC), pachychoroid neovasculopathy, or polypoidal choroidal vasculopathy. This study evaluated longitudinal changes in retinal pigment epithelium (RPE) lesions in PPE and identified baseline predictors.

Retrospective cohort study.

Forty-five eyes (45 patients) with PPE.

All patients underwent multimodal imaging, including near-infrared reflectance, optical coherence tomography (OCT), blue fundus autofluorescence, and OCT angiography. RPE alteration areas were quantified by projecting OCT B-scan delineations onto near-infrared images. Central subfield thickness (CST) and central choroidal thickness (CCT) were measured, along with choroidal thickness at four quadrants 500 µm and 1000 µm from the foveal centre.

Change in total RPE lesion area at 1-year follow-up and baseline predictors of lesion progression.

At 1 year, total RPE lesion area increased significantly (median 0.81 mm² vs. 0.71 mm² at baseline; p < 0.001), with a median percentage increase of 10.5%. The number of discrete lesions remained unchanged. CST and CCT showed no significant longitudinal changes. Preliminary 2-year data (n = 13) demonstrated similar trends. Multivariable regression identified greater baseline CCT as independently associated with increased RPE lesion progression, whereas smaller baseline RPE areas were associated with a greater relative increase.

PPE demonstrates progressive RPE alterations over time despite stable retinal and choroidal thickness. Greater baseline choroidal thickness and limited initial RPE involvement predict faster lesion expansion, supporting PPE as an active and evolving condition requiring regular multimodal monitoring.