ObjectiveTo observe the efficacy and safety of vitrectomy combined with subretinal injection of alteplase (tPA) and intravitreal injection of Conbercept in the treatment of large area submacular hemorrhage (SMH) secondary to polypoidal choroidal vasculopathy (PCV). MethodsA retrospective clinical study. From January to September 2021, 32 eyes of 32 patients with massive SMH secondary to PCV diagnosed in the Affiliated Eye Hospital of Nanchang University were included in the study. Large SMH was defined as hemorrhage diameter ≥4 optic disc diameter (DD). There were 32 patients (32 eyes), 20 males and 12 females. The mean age was (72.36±8.62) years. All patients had unilateral disease.The duration from onset of symptoms to treatment was (7.21±3.36) days. All patients underwent best corrected visual acuity (BCVA) and optical coherence tomography (OCT) examination. BCVA examination was performed using the international standard visual acuity chart, which was converted to the logarithm of the minimum angle of resolution (logMAR) visual acuity during statistics. The central macular thickness (CMT) was measured by spectral domain-OCT. The average size of SMH was (6.82±1.53) DD. The logMAR BCVA 1.73±0.44; CMT was (727.96±236.40) μm. All patients were treated with 23G pars plana vitrectomy combined with subretinal injection of tPA and intravitreal injection of Conbercept. At 1, 3, 6 and 12 months after treatment, the same equipment and methods were used for relevant examinations before treatment. The changes of BCVA and CMT, the clearance rate of macular hemorrhage, and the complications during and after surgery were observed. BCVA and CMT before and after treatment were compared by repeated measures analysis of variance. ResultsCompared with before treatment, BCVA gradually increased at 1, 3, 6 and 12 months after treatment, and the differences were statistically significant (F=77.402, P＜0.001). There was no significant difference in BCVA between any two groups at different time points after treatment (P＞0.05). Correlation analysis showed that BCVA at 12 months after treatment was negatively correlated with the course of disease (r=－0.053, P=0.774). One week after treatment, macular hemorrhage was completely cleared in 30 eyes (93.75%, 30/32). The CMT was (458.56±246.21), (356.18±261.46), (345.82±212.38) and (334.64±165.54) μm at 1, 3, 6 and 12 months after treatment, respectively. Compared with before treatment, CMT decreased gradually after treatment, and the difference was statistically significant (F=112.480, P＜0.001). There were statistically significant differences in different follow-up time before and after treatment (P＜0.001). The number of treatments combined with Conbercept during and after surgery was (4.2±1.8) times. At the last follow-up, there was no recurrence of SMH, retinal interlamellar effusion and other complications. Conclusion Subretinal injection of tPA combined with intravitreal injection of Conbercept is safe and effective in the treatment of large SMH secondary to PCV, and it can significantly improve the visual acuity of patients.