Quantitative Evaluation of Retinal Vessel Density in Central Serous Chorioretinopathy after Half-dose Photodynamic Therapy.

Purpose To determine vessel changes in retinochoroid with optical coherence tomographic angiography (OCT angiography) and spectral-domain OCT (SD-OCT) of patients with central serous chorioretinopathy (CSC) after half-dose photodynamic therapy (hd-PDT). Methods A prospective observational study of 62 eyes of 58 patients undergoing hd-PDT was followed for 3 months. Fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) were performed at baseline; best corrected visual acuity (BCVA), fundus photography, OCT angiography and SD-OCT were performed at baseline, 1-month, and 3-month follow-up visits. Results The mean vessel density of inner retina (VDIR) layer was 50.72 ± 3.17 at baseline, then decreased to 48.97 ± 4.34 at 1-month follow-up (p < 0.001), and partially recovered to 49.00 ± 4.28 at 3-month follow-up (p < 0.001); the mean area of foveal avascular zone (FAZ) was 0.303 ± 0.107 mm2 at baseline, and then increased to 0.339 ± 0.121 mm2 and 0.342 ± 0.125 mm2 at 1-month and 3-month follow-up after hd-PDT (p < 0.001, p < 0.001). The mean diameters of choroidal big vessels (DCV) was 309.66 ± 72.24 microns at baseline, then decreased to 300.13 ± 69.38 microns at 1-month and 293.39 ± 69.92 microns at 3-month after treatment (p < 0.001, p < 0.001). Conclusions Currently common applied hd-PDT for patients with CSC has significantly impact on both retinal and choroidal vessels. The retinal capillary flow decreased, therefore optimizing PDT parameters for treating CSC may still be necessary in the future.