Abstract
Purpose :
The aim of this prospective observational cohort study was to explore the response of type 3 neovascularization due to AMD to combination therapy with intravitreal bevacizumab (IVB) and photodynamic therapy (PDT) using optical coherence tomography angiography (OCT-A) imaging. Additionally, we compared two different sequences of the combination therapy.
Methods :
Thirty eyes of 29 treatment-naïve patients with new-onset type 3 neovascularization based on conventional diagnostic imaging were included. They were treated with a combination of IVB and PDT 2 weeks apart. Treatment sequence for each patient, i.e. starting with IVB (IVB-first group) or starting with PDT (PDT-first group), was based on logistics. We performed OCT-A imaging (Spectralis OCTA, Heidelberg Engineering; Doppler OCT) at week 0 (baseline), 2, 4 and 18. Two independent medical retina specialists graded vascular and structural characteristics of the lesion over time based on OCT-A images as: increased, unchanged, decreased or resolved with respect to the baseline image. Primary parameters were intraretinal flow (IRF; vascular) and intraretinal cysts (IRC; structural). Best corrected visual acuity (BCVA in LogMAR) was measured at week 0 and 18. Non-parametric tests were used for statistical analysis (binominal, Wilcoxon Signed-Ranks and Mann-Whitney U tests).
Results :
Seventeen eyes were in the IVB-first group (12 female, median age 83 years), and 13 in the PDT-first group (8 female, median age 82 years). Seven eyes were excluded for OCT-A analysis (4 from IVB-first group), and 1 eye for BCVA analysis (from IVB-first group). Analysis of all patients together revealed that most lesions were decreased or resolved after 2, 4 and 18 weeks based on the IRF and IRC scores (figure 1; p≤0.001). Median BCVA improved with 0.14 LogMAR after 18 weeks (p=0.04). Although not statistically significant, IRF and IRC were slightly more often resolved in the PDT-first group than in the IVB-first group (figure 2; p>0.05). Also, the median BCVA improved slightly more in the PDT-first group from baseline to week 18 (0.24 LogMAR) than in the IVB-first group (0.14 LogMAR; p=0.22).
Conclusions :
Both the vascular, structural (OCT-A) and functional (BCVA) parameters improved after combination therapy with IVB and PDT in patients with type 3 neovascularization. Initial therapy with PDT tended to be most beneficial in our study.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.