Abstract
Purpose:
To compare the change of choroidal hyperpermeability after low-fluence photodynamic therapy (PDT) and intravitreal ranibizumab in the treatment of chronic central serous chorioretinopathy (CSC)
Methods:
Post-hoc analysis was performed in a randomized, controlled trial comparing low-fluence PDT versus intravitreal ranibizumab for chronic CSC, in which, the other treatment was available as salvage treatment if unsuccessful at 3 months. A commercially available image analysis software (Adobe® Photoshop® CS6 (Adobe Systems, Inc., San Jose, CA)) was used for quantification of change of choriodal hyperpermeability on indocyanine green angiography after low-fluence PDT or 3 consecutive intravitreal injections of ranibizumab. Post-treatment images were subtracted from pre-treatment images after adjustment to create images depicting the change of choroidal hyperpermeability with treatment. Integrated gray scale value per area in this image was used for analysis of change of choroidal hyperpermeability.
Results:
The calculated change in choroidal hyperpermeability represented by the integrated gray scale value per area was significantly greater in the low-fluence PDT group (18.53±7.55, 16 eyes) than in the ranibizumab group (6.78±5.03, 15 eyes) (P<0.001). All eyes in the low-fluence PDT group showed complete resolution of subretinal fluid, and no significant difference in change of choroidal hyperpermeability was found in eyes that received low-fluence PDT as primary or salvage treatment, (17.36±8.74, 9 eyes vs 20.04±6.01, 7 eyes, P=0.427). In the ranibizumab treated group, subretinal fluid resolution was accomplished in 8 eyes (56.25%), and these eyes showed a significantly larger decrease in choroidal hyperpermeability when compared with eyes showing poor response (10.31±4.00 vs. 2.74±2.16, P=0.005). In the successfully treated eyes of intravitreal ranibizumab, there was no significant difference in choroidal hypopermeability change when compared to low-fluence PDT (P=0.139).
Conclusions:
Using our novel method of analysis of change in choroidal hyperpermeability with treatment in chronic CSC, greater change was found in eyes with good response, and the superior outcome of low-fluence PDT over ranibizumab may be attributed to greater influence on choroidal hyperpermeability.