Abstract
Purpose :
The aim of this study is to evaluate the change in flow after treatment in patients with retinal angiomatous proliferation lesions (RAP, type 3 choroidal neovascularization) using optical coherence tomography angiography (OCT-A), and to compare photodynamic therapy (PDT) and bevacizumab as initial treatment.
Methods :
A prospective observational cohort study of treatment-naïve patients diagnosed with RAP. Patients were imaged with a 1040 nm swept-source phase resolved Doppler system and Spectralis OCT-A (Heidelberg Engineering) at week 0, 2 and 4. Patients were treated with intravitreal bevacizumab (Avastin) at week 0 followed by PDT at week 2 (‘Avastin first’ patients) or vice versa (‘PDT first’ patients). RAP lesions were subjectively scored as unchanged, increased, decreased or resolved with respect to the previous measurement, and objectively analyzed by calculating the size of the lesion on OCT-A en-face images using ImageJ (Spectralis only, figure 1). The flow signal within a fixed perimeter was plotted as pixel2. A change of more than 5% was considered significant.
Results :
18 patients with a median age of 84 years (range 68-95) were included. One patient was excluded due to inability to fixate. There were 11 ‘Avastin first’ patients and 6 ‘PDT first’ patients. Figure 2a and b show the effect of treatment for both the subjective and objective analysis. Subjective analysis (figure 2a) showed that in most lesions flow was ‘decreased’ or ‘resolved’ from week 0 to 2 and from week 2 to 4. More lesions were resolved in the ‘PDT first’ group compared to the ‘Avastin first’ group from week 0 to 2 (20% and 9% respectively), and week 2 to 4 (83% and 50% respectively). We were not able to score a lesion as ‘resolved’ with the objective analysis (figure 2b), but it did show more decreased lesions in the ‘PDT first’ group compared to the ‘Avastin first’ group from week 2 to 4 (67% and 25% respectively). However, from week 0 to 2 the ’Avastin first’ group showed a higher percentage of decreased flow (56% vs. 33% in the ‘PDT first’ group).
Conclusions :
The highest percentage of resolved lesions (subjective analysis) were seen in the ‘PDT first’ group, suggesting that initial treatment of RAP with PDT followed by Avastin on a PRN schedule is most beneficial. Objective results from week 2 to 4 support this suggestion.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.