ObjectiveTo evaluate the spectral domain optical coherence tomography (SD-OCT) characteristics of polypoidal choroidal vasculopathy (PCV) and its correlation with the visual acuity after photodynamic therapy (PDT) combined with intravitreal ranibizumab. MethodsTwenty-six eyes of 26 patients with PCV diagnosed by indocyanine green angiography (ICGA) were enrolled in this study. All the patients were examined for best corrected visual acuity (BCVA), slit lamp microscope, SD-OCT, fundus fluorescein angiography (FFA) and ICGA before and 1, 3 months after treatment. The mean baseline BCVA was (31.46±16.87) letters, mean central retinal thickness (CRT) was (581.19±309.05) μm, and mean subfoveal choroidal thickness (SFCT) was (248.92±95.45) μm. Patients were divided into 2 groups according to the final visual improvement after 6 month of treatment: GR or sensitive Group (17 eyes) and PR or non-sensitive Group (9 eyes). GR group included 12 males and 5 females, with a mean age of (65.24±7.03) years, a mean CRT of (619.06±335.07) μm and a mean SFCT of (271.24±106.61) μm. There were 4 eyes with subretinal hemorrhage (SRH), 2 eyes with interface retinal fluid (IRF), 13 eyes with subretinal fluids (SRF) and 15 eyes with pigment epithelial detachment (PED). PR group included 8 males and 1female, with a mean age of (64.00±7.02) years, a mean CRT of (509.67±255.21) μm and a mean SFCT of (271.24±106.61) μm. There were 6 eyes with subretinal hemorrhage (SRH), 5 eyes with interface retinal fluid (IRF), 6 eyes with subretinal fluids (SRF) and 8 eyes with pigment epithelial detachment (PED). The difference of sex, age, CRT and SFCT between these two groups was not significant (P>0.05). The relationship of baseline SD-OCT and post-treatment BCVA was analyzed. ResultsOn 1, 2, 3, 6 months after treatment, the BCVA were (38.46±19.81), (40.04±20.80), (42.96±21.63), (43.77±20.91) letters respectively. On 6 months after treatment, the mean CRT in GR and PR group were (360.71±276.54), (341.44±193.68) μm respectively (P>0.05). 64.71% (11/17) eyes in GR group and 22.22% (2/9) eyes in PR group had a SFCT thicker than 263μm. The difference was statistical significant between two groups [odds ratio (OR):0.052, 95% confidence interval (CI):0.005-0.533; P=0.013]. Logistic regression analysis showed that existence of IRF (OR=9.375, 95% CI: 1.299-67.645; P=0.026) or SRH (OR=6.500, 95% CI: 1.094-38.633; P=0.040) at baseline was negative prognostic factor to treatment. ConclusionThick SFCT is a protective factor, however, existence of IRF or SRH at baseline is negative prognostic factor of final visual improvement.