Abstract
Purpose :
Swept-Source Optical Coherence Angiography (SS-OCTA) allows wide-field imaging for visualization of choroidal structures. In patients undergoing verteporfin photodynamic therapy (vPDT) for central serous chorioretinopathy (CSCR), the choroid is the main treatment target. Change in subfoveal choroidal thickness (SCT) on spectral domain OCT (SD-OCT) is an accepted quantitative biomarker for vPDT treatment success. We hypothesized that the punctual nature of this read out may underestimate treatment response. Here we evaluate the effect of vPDT on choroidal volume (CV) with a novel algorithm within the Zeiss Advanced Retinal Imaging (ARI) Network.
Methods :
Retrospective case series of chronic CSCR patients with or without secondary MNV undergoing a single half-dose vPDT treatment in one eye. The fellow eye served as control. Inclusion criteria were availability of high signal to noise ratio 12x12mm SS-OCTA (Plex Elite 9000, Zeiss) with minimal artefacts at baseline prior to PDT and at 6-8 weeks (range: 4 -12) follow up in both eyes. CV was calculated using the choroid quantification v1.2 algorithm (ARI Network). Central macular thickness (CMT, ETDRS) and SCT data were extracted from corresponding SD-OCTs (Spectralis, Heidelberg Engineering). Primary outcome parameters were the change in CV and SCT, secondary outcome parameters were CMT and best corrected visual acuity (BCVA).
Results :
A total of 16 patients (13 male, 3 female, mean age 53 years) with an average of 53 days between vPDT and follow-up examination were included. In all treated eyes, the mean CV was 49.1 mm3 prior to PDT, compared to 44.7 mm3 at follow-up (9.6% reduction) – correspondingly, mean SCT decreased from 426.4 to 381.9 µm (10.4%). In control eyes, mean CV and SCT were similar at vPDT and follow-up examination (45.2 vs. 45.3 mm3 and 361.6 vs. 366.0 µm, respectively). Mean CMT decreased from 351.4 to 295.4 µm (15.9%) in treated eyes, opposed by a slight increase in mean CMT in reference eyes (314.7 to 343.5 µm). Visual acuity changed from 0.31 to 0.24 logMAR in vPDT eyes.
Conclusions :
vPDT treated CSCR eyes showed similar changes in CV using wide-field SS-OCTAand SD-OCT B-scan based SCT, whereas no change was observed in control eyes. Future work will analyze regional characteristics of CV and average CT change, as well as correlation of CV and average CT change with SCT and CMT.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.