Optical Coherence Tomography Angiography for Diagnosis of Choroidal Neovascularization in Chronic Central Serous Chorioretinopathy after Photodynamic Therapy

Abstract

The authors evaluated the proportion of choroidal neovascularization (CNV) detected by spectral-domain optical coherence tomography angiography (OCTA) in eyes with chronic central serous chorioretinopathy (CSC) (more than 3 months) with previous treatment via half-dose photodynamic therapy (PDT). All patients were followed up with at least twelve months. Macular angiograms were obtained using spectral-domain OCT (SD-OCT, RTVue XR; Optovue). CNV was defined as flow in the outer retinal slab between the outer plexiform layer and Bruch's membrane. Clinical characteristics were compared between CNV and non-CNV groups. Seventy eyes of 61 patients (51 male and 10 female) were included. The average age was 46.2 years old. The average duration of symptom was 32.9 months. All patients were treated with half-dose PDT initially. Eleven eyes (15.7%) received more than one session of PDT. CNV was diagnosed in 32 of 70 eyes (45.7%) based on OCTA. Only 6 of the 32 eyes (18.8%) needed intravitreal anti- vascular endothelial growth factor (VEGF) therapy for the exudative activity of CNV. Older age (p = 0.059), larger PDT spot size (p = 0.024), and thinner subfoveal choroidal thickness (p = 0.008) were noted in CNV group. The authors conclude that OCTA reveals high rates of CNV associated with chronic CSC after PDT. Patients in the CNV group had older age, larger PDT spot size, and thinner subfoveal choroidal thickness. OCTA may be considered as a first step in identifying CNV in chronic CSC following PDT.

Figure 1

A 55-year-old man had CNV in his left eye based on OCTA, which was located within the previous PDT area. Pre-PDT FA and ICGA (A,B), and post-PDT FA and ICGA (C,D) showed hyperfluorescence at macula. Pre-PDT OCT revealed PED and serous RD at macula (E). At 3 months after initial occurrence, half-dose PDT with spot size of 3900 μm was applied on the hyperfluorescence area in ICGA (whitish dotted circle in B and D). Post-PDT OCT disclosed resolution of SRF and persisted PED (F). At 44 months after half-dose PDT, a 3 × 3-mm OCTA image at deep retinal slab demonstrated tangled network, which was compatible with CNV and was located within the previous PDT area (G).