In this study we compared the effectiveness between half energy photodynamic therapy (PDT) and intravitreal bevacizumab (IVB) injection for chronic central serous chorioretinopathy (CSC).

Forty-five eyes of 42 patients diagnosed as chronic CSC from March 2008 to April 2011 were treated with half energy PDT or IVB injection. The subjects were chosen for a retrospective study and analysis was performed on changes in best corrected visual acuity and existence of subretinal fluid, recurrence rate and changes in central macular thickness.

Similar improvement of visual acuity was observed in both treatment groups 1 month after treatment and no meaningful difference was found in each stage for both groups ( p = 0.001, p = 0.0012, respectively). However, 6 to 12 months after the treatment, the half energy PDT group showed more improvement in visual acuity compared to the IVB injection group ( p = 0.019, p = 0.043, respectively). Nineteen out of 21 cases showed full recovery of subretinal fluid in the half energy PDT group with an average treatment period of 1.3 ± 0.8 months and 7 out of 24 cases showed full recovery in the IVB injection group with an average treatment period of 3.2 ± 2.8 months. There was a single case of recurrence in the half energy PDT group and 4 in the IVB injection group. The half energy PDT group showed a meaningful decline in central macular thickness at 1, 3, and 6 months after treatment ( p = 0.001, p = 0.005, p = 0.007, respectively) compared to the IVB injection group and showed numerous cases with decline in central macular thickness below the 2 standard deviation from normal values ( p = 0.002).

Both half energy PDT and IVB injection were effective for the treatment of chronic central serous chorioretinopathy. However, the half energy PDT group comparatively showed better anatomical and functional outcomes. The thinning of central macular thickness below normal value was also observed, thus careful choice of treatment is necessary for patients with chronic central serous chorioretinopathy.