gms | German Medical Science

Purpose: To describe the progression of type 1 macular neovascularization (MNV) in pachychoroid neovasculopathy (PNV) into pachychoroid aneurysmal type 1 macular neovascularization (PAT1)/polypoidal choroidal vasculopathy (PCV).

Methods: Patients diagnosed with PNV who had received multimodal imaging for ≥2 years were reviewed for the presence of MNV, aneurysms within the MNV, and subfoveal choroidal thickness (SFCT).

Results: In total, 37 eyes of 32 patients with PNV with a mean follow-up of 3.3±1.1 years (range, 2.0–5.2) were included in the study. At PNV diagnosis, the mean age was 59.7±8.7 years (range, 38.5–78.0 years) and mean SFCT was 357±92 µm (185–589). During the follow-up, 5 (13.5%) eyes developed aneurysms after a mean 3.4±0.8 years (2.3–4.2), defining PAT1/PCV. The risk of PAT1/PCV conversion was 7.4% at year 3, 13.6% at year 4, and 30.7% at year 5. A mean of 5.2±4.0 to 7.9±3.6 intravitreal anti-VEGF injections were given per year, resulting in a significant reduction of SFCT to 317±104 µm (122–589) (P = 0.0007). The age at diagnosis of PNV was significantly lower in eyes that later went on to develop PAT1/PCV (54.0±5.6 [45.9–60.5] vs. 61.2±8.4 [38.5–78.0] years; P = 0.025). At the end of the follow-up, SFCT had on average decreased by -14.0%±17.6% (-55.9% to 23.1%) in the PNV group, whereas it had increased by mean 6.9%±4.4% (0.00%–10.8%) in the PAT1/PCV conversion group (P = 0.0025).

Conclusions: PNV can develop aneurysms within its type 1 MNV, defining the conversion to PAT1/PCV. In this study, Kaplan–Meier estimates of risk for conversion of 7.4% at year 3, 13.6% at year 4, and 30.7% at year 5. A similar process of type 1 MNV to PCV progression should be investigated in age-related macular degeneration.