ObjectiveTo observe the clinical effect of subretinal injection and intravitreal injection of conbercept in the treatment of polypoid choroidal vasculopathy (PCV). MethodsA prospective, randomized double-blind controlled study. From June 2022 to January 2023, 35 patients of 35 eyes with PCV diagnosed at Affiliated Eye Hospital of Nanchang University were included in the study. All patients were first-time recipients of treatment. Best corrected visual acuity (BCVA), optical coherence tomography (OCT), and indocyanine green angiography (ICGA) were performed in all affected eyes. BCVA was performed using an international standard visual acuity chart and converted to logarithmic minimum resolved angle (logMAR) visual acuity for statistical purposes. Enhanced depth imaging with OCT instrument was used to measure the macular retinal thickness (MRT), subfoveal choroidal thickness (SFCT), and pigment epithelium detachment (PED) height. Randomized numerical table method was used to divide the patients into subretinal injection group (group A) and vitreous cavity injection group (Group B), 18 cases with 18 eyes and 17 cases with 17 eyes, respectively. Comparison of age (t=0.090), disease duration (t=−0.370), logMAR BCVA (t=−0.190), MRT (t=0.860), SFCT (t=0.247), and PED height (t=−0.520) between the two groups showed no statistically significant difference (P＞0.05). The eyes of group A were given one subretinal injection of 10 mg/ml conbercept 0.05 ml (containing conbercept 0.5 mg), and subsequently administered on demand (PRN); eyes in group B were given intravitreal injection of 10 mg/ml conbercept 0.05 ml (containing conbercept 0.5 mg). The treatment regimen was 3+PRN. Lesions were categorized into active and quiescent according to the results of post-treatment OCT and BCVA. Active lesions were treated with intravitreal injection of conbercept at the same dose as before; stationary lesions were followed up for observation. BCVA and OCT were performed at 1, 2, 3, 6 and 9 months after treatment; ICGA was performed at 3, 6 and 9 months. BCVA, MRT, SFCT, and PED height changes before and after treatment were compared and observed in the affected eyes of the two groups. Independent sample t-test was used to compare between the two groups. ResultsWith the prolongation of time after treatment, the BCVA of the affected eyes in groups A and B gradually increased, and the MRT, SFCT, and PED height gradually decreased. Compared with group B, at 2, 3, 6, and 9 months after treatment, the BCVA of group A was significantly improved, and the difference was statistically significant (t=−2.215, −2.820, −2.559, −4.051; P＜0.05); at 1, 2, 3, 6, and 9 months after treatment, the MRT of the affected eyes in group A (t=−2.439, −3.091, −3.099, −3.665, −5.494), SFCT (t=−3.370, −3.058, −3.268, −4.220, −4.121), and PED height (t=−3.460, −4.678, −4.956, −5.368, −6.396) were significantly reduced, and the differences were statistically significant (P＜0.05). No complications such as intraocular inflammation, high intraocular pressure, or vitreous hemorrhage occurred in any of the affected eyes during or after treatment. ConclusionCompared with the intravitreal injection of conbercept, the subretinal injection of conbercept can more effectively reduce the height of MRT, SFCT, PED height, and improve the visual acuity of the affected eyes with PCV.