Abstract
Purpose :
To study the intra- and peripapillary capillary density (CD) using optical coherence tomography angiography (OCTA) in eyes treated with plaque radiotherapy for choroidal melanoma.
Methods :
Five patients treated with plaque radiotherapy for unilateral choroidal melanoma without radiation papillopathy or retinopathy clinically and by optical coherence tomography (OCT) were imaged with OCTA. Comparison of optic nerve head (ONH) and radial peripapillary capillary (RPC) level CDs between irradiated and fellow non-irradiated eyes was performed for regions [whole image, inside disc/intrapapillary, and peripapillary] and quadrants [nasal, inferior nasal, inferior temporal, superior temporal, superior nasal, and temporal] as defined by preset parameters on the Angiovue software [version 2016.1.0.26] (Figure 1).
Results :
Overall, imaging was performed at mean 14 months after radiation. Mean age was 65 years (median: 61, range: 54-78), all were Caucasians (5/5, 100%), and majority were female (3/5, 60%). One patient had diabetes mellitus, 4 had controlled hypertension, and none had glaucoma. Tumor was located superiorly (3/5, 60%), temporal (1/5, 20%), and in the macula (1/5, 20%). Mean radiation dose to optic disc and foveola were 32 Gy (median: 29, range: 22-49), and 37 (median: 32, range: 12-69) Gy, respectively. By OCT, mean central macular thickness between irradiated eyes and fellow non-irradiated eyes was 257 um vs 229 um (p=0.25), respectively. OCTA analysis by region showed there was significant decrease in whole image (p=0.01 and p=0.03), intrapapillary (p=0.01 and p=0.02), and peripapillary (p=0.01 and p=0.02) CD of irradiated eyes in both ONH and RPC, respectively (Table 1). Analysis by quadrant showed only significant CD reduction in the inferotemporal quadrant in ONH (p=0.02), and inferonasal quadrant in RPC (p=0.03) (Table 1).
Conclusions :
OCTA allows quantitative analysis of ONH and RPC CD. There appears to be significant reduction in intrapapillary and peripapillary CD in irradiated eyes even before clinical or OCT evidence of radiation papillopathy and maculopathy.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.