Abstract
Purpose :
To analyze the extent of signal reduction in choriocapillaris (CC) spectral domain optical coherence tomography angiography (OCT-A) caused by soft drusen due to age-related macular degeneration (AMD).
Methods :
10 eyes of 10 patients with soft drusen (76.1±10.9 years) underwent multimodal retinal imaging including central 3 mm2 OCT-A (AngioVue, Optovue). 30 soft drusen lesions were arbitrarily chosen and evaluated regarding height and diameter. Structural CC OCT en face images were graded regarding significant signal reduction in the individual drusen area. In cases without signal loss in structural CC OCT, CC decorrelation index was measured in OCT-A within a 30 µm slab in the exact area of drusen affection. Data were compared to mean CC decorrelation of a healthy control group (n=5, 81.2±2.6 y). CC OCT data and CC OCT-A data were correlated to morphological drusen parameters.
Results :
Mean best corrected visual acuity was 0.59±0.23. Mean SSI was 60.6±6.1. Mean drusen diameter and height was 281.0±112.5 µm and 96.6±22.5 µm. 25 drusen (83.33 %, mean diameter 297.4±110.2 µm, mean height 101.3±20.4 µm) showed a signal loss on the structural en-face CC OCT image. In 4 different patients (84.8±8.1 y), five drusen (16.67 %, 173.6±40.7 µm, p=0.003; 70.8±13.4 µm, p=0.001) were identified without signal loss in CC OCT and revealed a mean reduction in OCT-A CC decorrelation index compared to mean CC decorrelation of control eyes (76.4±7.1 µm versus 100.3±6.7 µm, p=0.009).
Conclusions :
In the presence of soft drusen, CC spectral domain OCT-A is mostly not evaluable regarding CC blood flow because of shadowing artifacts. If evaluable, CC decorrelation signal is reduced in drusen areas compared to healthy controls.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.