Incidence and Risk Factors for Progression of Pachychoroid Subtype

The incidence and determinants of progression across the pachychoroid subtype remain incompletely characterized, limiting risk stratification and follow-up strategies.

To evaluate progression, diagnostic transitions, and associated risk factors in eyes with pachychoroid subtype.

This prospective, multicenter, observational cohort study included participants with pachychoroid subtype, defined by subfoveal choroidal thickness (SFCT) of 300 µm or greater measured beneath the foveal center point, recruited at centers in Asia. Participants underwent standardized clinical assessment and multimodal imaging and were followed up for 2 years. The study was conducted between July 2020 and November 2023, and data analysis was performed from November 2023 to February 2026.

Baseline pachychoroid subtype phenotype and imaging characteristics.

The primary outcome was diagnostic progression within the pachychoroid subtype spectrum over 2 years. Secondary outcomes included incident neovascularization, treatment initiations, and changes in best-corrected visual acuity (BCVA) and SFCT.

A total of 205 eyes from 125 participants (mean [SD] age, 59.0 [8.8] years; 32 female participants [25.6%]) completed 2-year follow-up. At baseline, 39 eyes had uncomplicated pachychoroid (UP), 102 had pachychoroid pigment epitheliopathy (PPE), 47 had central serous chorioretinopathy (CSCR), and 17 had pachychoroid neovasculopathy (PNV). Mean (SD) changes from baseline in BCVA and SFCT were 0.13 (0.18) logMAR (approximate Snellen equivalent, 20/25) to 0.11 (0.24) (20/25; difference, -0.02 logMAR [approximately 1 letter]; 95% CI, -0.05 to 0.02; P = .33) and from 419 (83) µm to 424 (90) µm (difference, 6 µm; 95% CI, -5 to 16; P = .32), respectively. Eyes with CSCR and PNV had worse baseline BCVA compared to eyes with UP and PPE. Progression occurred in 15 eyes (7.3%; 95% CI, 4.5%-11.6%), including 7 eyes with neovascularization, all of which had shallow, irregular retinal pigment epithelium elevation at baseline, among 116 eyes at baseline with such elevation.

In this study among a relatively small cohort of 4 different levels of pachychoroid subtype, progression to a worse level was infrequent, as was worsening of visual acuity or choroidal thickening. Neovascularization was unusual and occurred exclusively in eyes with shallow, irregular retinal pigment epithelium elevation, suggesting the importance of this imaging feature if confirmed in subsequent studies.