Abstract
Purpose :
Non-invasive structural retinal markers of disease activity are important to monitor treatment outcome in neovascular age-related macular degeneration (nAMD). We aimed to investigate if changes in the retinal vascular fractal dimension (FD) correlate with initial treatment outcome after intravitreal aflibercept therapy.
Methods :
Fifty-seven eyes of 57 patients with treatment-naïve nAMD received three intravitreal injections with 2.0 mg aflibercept and were followed for three months (3M). Swept source optical coherence tomography (DRI OCT Triton, Topcon, Tokyo, Japan) and fluorescein and indocyanine green angiography (Spectralis, Heidelberg Engineering, Heidelberg, Germany) was performed to verify the diagnosis of nAMD. The FD was measured at baseline and 3M using the semi-automated software Fractal Analyzer (Singapore Institute Vessel Assessment-Fractal image analysis software, Singapore) according to a standardized grading-protocol. At 3M, the eyes were divided into full and partial responders. Partial responders were defined as loss of ≥5 Early Treatment Diabetic Retinopathy Study letters or residual retinal fluid or macular hemorrhage.
Results :
At baseline, mean age was 79.4 years and 38.6% were male. Twenty nine point eight per cent were active smokers and 10.5% had diabetes. Twenty-six of 57 (45.6%) were full responders. These patients were older than partial responders (82.0 vs. 77.1 years, p=0.03), but did not differ at any time point according to sex, diabetes, smoking, intra ocular pressure, visual acuity or FD. In full responders, the FD decreased after treatment (1.5907 ±0.043 vs. 1.5714 ±0.0546, p=0.02), as opposed to partial responders (1.5877 ±0.037 vs. 1.577 ±0.041, p=0.07).
Conclusions :
The retinal vascular fractal dimension decreases after initial loading with intravitreal aflibercept in fully-responding, treatment-naïve patients with nAMD. This indicates structural changes in the retinal vasculature and could be a guidance for individualized treatment if confirmed in long-term studies.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.