Predictors of the early pneumatic displacement effect of submacular haemorrhage secondary to polypoidal choroidal vasculopathy

Purpose To identify baseline predictors of early submacular haemorrhage (SMH) displacement following intravitreal injection of C3F8, recombinant tissue plasminogen activator (rt-PA), and ranibizumab in patients with polypoidal choroidal vasculopathy (PCV). Methods In this retrospective case-control study, swept-source OCT scans were analysed before and one week after treatment. SMH displacement was classified as incomplete (Group 1) or complete (Group 2) based on fundus photography and OCT. Clinical characteristics and OCT-derived parameters were evaluated for associations with displacement status. Results Fifty-one eyes from 51 PCV patients were included. All eyes demonstrated some degree of SMH displacement after treatment, with 33 eyes showing incomplete displacement (residual SMH under the fovea: 80–768 μm) and 18 eyes showing complete displacement. Group 2 had better baseline visual acuity, and baseline LogMAR BCVA was negatively correlated with displacement grade. Group 2 also exhibited larger initial SMH volume and lower contrast-to-noise ratio (CNR), both associated with greater displacement. Although baseline PED volumes were similar, PED regression was more pronounced in Group 2. Conclusion Complete SMH displacement was associated with better baseline vision, lower CNR, larger haemorrhage volume, and greater PED regression. Baseline BCVA, CNR, and SMH volume may serve as predictive factors for early SMH displacement following treatment.