Abstract
Purpose :
Interventional therapies like low-dose photodynamic therapy (PDT) are implemented successfully in patients with chronic central serous chorioretinopathy (CSCR). It is assumed that low-dose PDT induces short-term choriocapillaris hypoperfusion which leads to long-term choroidal vascular remodeling and subsequent reduction of vascular hyperpermeability and leakage. However, it remains unclear whether the hypoperfusion completely returns to normal.
The aim of the study is to analyze the choroidal flow signal after treatment with low-dose PDT by optical coherence tomography angiography (OCTA) and to examine its morphological effects on the choroidal thickness.
Methods :
16 eyes (12 men, 3 women, mean age 57 years) with a total of 19 treated areas were included. All patients underwent SD-OCT and fluorescein angiography for treatment planning reasons, with visual acuity and metamorphopsia examined before treatment and again 10 months on average after treatment. Moreover, the areas treated with low-dose PDT were scanned with SD-OCT, EDI-OCT and OCTA (Optovue).
Analyzed parameters were: choroidal flow signal within a defined area of 0,25 mm radius both in the PDT-treated area and in a nontreated reference area located in near proximity with similar distance to the center of the fovea (eccentricity); choroidal thickness measured with EDI-OCT in both the treated area and the reference area, morphological changes, metamorphopsia and visual acuity before and after PDT treatment.
Results :
OCTA results show a mean reduction of 33 % of the choroidal flow signal in the treated area compared to the reference area. EDI-OCT results show that the choroidal thickness decreased by 71 µm on average. In the long term, 8 out of 11 patients suffered from metamorphopsia despite the low-dose PDT; however, visual acuity was improved significantly by the treatment.
Conclusions :
Thanks to OCTA, it was shown that at the choriocapillaris level, hypoperfusion persists in spite of low-dose PDT, thus the choroidal vascular remodeling is not able to completely compensate for the hypoperfusion induced by thrombosis.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.