# Combined Therapy Versus Fortified Anti-VEGF Monotherapy in Type C Polypoidal Choroidal Vasculopathy: Long-Term Outcomes and Exploratory Biomarker Insights

## TL;DR

This study compares treatment options for type C polypoidal choroidal vasculopathy and finds that while anatomical improvements are achieved, functional outcomes remain challenging, with biomarker insights suggesting new therapeutic possibilities.

## Contribution

The study introduces fortified anti-VEGF dosing and explores biomarker differences among PCV, CSCR, and nvAMD, suggesting potential roles for HIF-1α inhibitors.

## Key findings

- Combined therapy reduced treatment burden and achieved significant anatomical improvement but did not improve visual outcomes.
- Biomarker analysis revealed shared hypoxia-related mechanisms between PCV and CSCR, with elevated HIF-1α compared to nvAMD.
- Differential expression of VEGF, PlGF, β-catenin, and HIF-1α highlights potential therapeutic targets for future interventions.

## Abstract

While standard anti- vascular endothelial growth factor (VEGF) therapy, with or without photodynamic therapy (PDT), is effective for patients with polypoidal choroidal vasculopathy (PCV), not all achieve optimal visual outcomes. This study aimed to compare fortified (double the dose and the volume of the standard one) anti-VEGF combined with PDT versus fortified anti-VEGF monotherapy and to investigate biomolecular profiles and disease relationships among PCV, neovascular age-related macular degeneration (nvAMD), and central serous chorioretinopathy (CSCR). The goal was to identify novel pathways to inform future therapeutic strategies, including hypoxia-inducible factors (HIF)-1α inhibitors. This retrospective cohort study included 23 eyes with indocyanine green-confirmed type C PCV. One eye treated with transpupillary thermotherapy was not included in the following two groups. Patients received either combined therapy (PDT + fortified-dose anti-VEGF; n = 12) or fortified-dose anti-VEGF monotherapy (n = 10). Primary outcomes were changes in best-corrected visual acuity (BCVA) and central retinal thickness (CRT). Secondary outcomes included injection burden and recurrence. Exploratory analyses examined aqueous biomarkers, including VEGF, placental growth factor (PlGF), β-catenin, HIF-1α, and Wnt1 across PCV, CSCR, and nvAMD to identify novel therapeutic targets. Significant (p = 0.003/p = 0.005) median CRT reduction was similar (p = 0.468) between groups (combined/monotherapy: 137.5 µm/106.5 µm). BCVA (median [Q1, Q3]) change in logarithm of the minimum angle of resolution (LogMAR) was not statistically significant (p = 0.279), with 0.25 [0.00, 0.98] in the combined group versus 0.00 [−0.03, 0.28] in the monotherapy group. Treatment burden of anti-VEGFs per person per year was lower with combined therapy (1.16 ± 0.47# PDT + 2.81 ± 0.92# anti-VEGF injections) compared with monotherapy (4.61 ± 1.49# injections). Six eyes demonstrated recurrence at a mean of 15.5 months. Incomplete regression of polyps and branching vascular networks was observed in all eyes. Exploratory biomarker analysis revealed significantly (p < 0.05) higher VEGF and PlGF levels in nvAMD compared with PCV. nvAMD also demonstrated significantly (p < 0.05) higher β-catenin and lower HIF-1α levels relative to PCV and CSCR, while no significant biomarker differences were observed between PCV and CSCR. Combined therapy or monotherapy with fortified anti-VEGFs reduced treatment burden and achieved significant anatomical improvement but did not yield superior functional outcomes, highlighting the therapeutic difficulty of type C PCV. Biomarker profiling revealed shared hypoxia-related mechanisms between PCV and CSCR, with elevated HIF-1α compared to nvAMD indicating a “preliminary” possible role for HIF-1α inhibitors. Differential expression of these biomarkers highlights additional molecular pathways that may inform future targeted interventions.