Angiography of Peripapillary Retina in Retinal Vasculitis with 70 kHz Spectral OCT

Abstract

 

Purpose

 

To compare peripapillary retinal perfusion between normal and retinal vasculitis subjects using a commercially available optical coherence tomography (OCT) system

 

Methods

 

Each study participant was imaged using a 3x3 mm angiography scan by a high-speed (70 kHz) 840 nm spectrometer-based OCT system. The split-spectrum amplitude decorrelation angiography (SSADA) algorithm was used to compute angiograms. The peripapillary retinal flow index and vessel density were calculated in the 700µm wide annulus extending outward from the optic disc boundary. The flow index was defined as the average decorrelation value on the retinal angiogram in the annulus region. The peripapillary retinal vessel density was defined as the percentage area occupied by vessels. Mann-Whitney test was used to compare these perfusion variables between vasculitis patients and normal subjects

 

Results

 

The study included 7 normal(7 eyes) and 4 retinal vasculitis patients(5 eyes). In the normal eye, a dense microvascular network around disc was visible on OCT angiography (Fig. B). This network was visibly attenuated in the vasculitis eyes, and focal capillary dropout was detected (Fig. E, F). In normal participants, the population variability of peripapillary retinal flow index and vessel density was 6.5% and 1.5% coefficient of variation (CV) respectively. In the vasculitis participants, the peripapillary retinal flow index was 0.085 ± 0.005 (mean ± SD), which was significantly less (P<0.05) than that of the normal group (0.094 ± 0.006). The vessel density in the vasculitis participants was 85.2% ± 1.3% (mean ± SD), which was significantly less (P<0.01) than that of the normal group (90.9% ± 1.3%)

 

Conclusions

 

High quality OCT angiograms of peripapillary retina could be obtained in both normal and retinal vasculitis participants. Retinal vasculitis reduction in peripapillary perfusion could be visualized as focal defects and quantified as flow index and vessel density. OCT angiography could be useful in the clinical evaluation of retinal vasculitis.  

 

Results from a normal eye(A, B) and a retinal vasculitis eye(C,D,E,F). The 3x3mm peripapillary En face OCT angiogram(E) of the region indicated by the red square in C and D, the microvasular network was reduced compared with normal eye(B). The supranasal OCT angiograms(F) of the region indicated by the yellow square in D, the yellow arrow shows focal capillary dropout in the vasculitis eye(F)