High-Resolution Imaging of Retinal Vasculitis by Flood Illumination Adaptive Optics Ophthalmoscopy: A Follow-up Study

Adaptive Optics of Kyrieleis Plaques in Varicella Zoster Virus-Associated Posterior Uveitis: A Multimodal Imaging Analysis

Kyrieleis plaques (KP) represent a peculiar type of vasculitis affecting retinal arterial branches in a beaded segmental pattern that can be found in several posterior inflammatory ocular conditions. The nature and precise location of KP is unclear. Adaptive Optics (AO) provides an in vivo visualization of retinal vasculature on a microscopic level, thus permitting a more detailed characterization of KP as compared to traditional imaging techniques. This study aims to report AO imaging of KP in Varicella Zoster virus (VZV)-associated posterior uveitis and to correlate the findings with traditional imaging techniques. Three patients diagnosed with VZV posterior uveitis underwent adaptive optics (AO) imaging and traditional multimodal imaging techniques, including fundus photography, fluorescein angiography, indocyanine green angiography and optical coherence tomography. In all subjects, AO imaging revealed segmental hyporeflectivity confined to the vessel wall, with no evidence of arterial wall disruption or extravascular involvement. In our series, AO findings support the view that KP are localized within the inner arterial wall, possibly at the endothelial level.

Lower fractal dimension of retinal vessel for patients with Birdshot chorioretinopathy

PURPOSE

To identify the retinal vessel vasculature parameters associated with birdshot chorioretinopathy (BSCR).

METHODS

This retrospective observational study included 28 prevalent cases of BSCR with a median time from diagnosis of 6 years and 28 controls matched for age, arterial hypertension, diabetes and refraction. Forty-five-degree fundus images of both dilated eyes were acquired with a fundus camera (Canon CR-2, Tokyo, Japan). The summary diameter of the arterial retinal vessels (central retinal artery equivalent, CRAE), venous retinal vessels (central retinal vein equivalent, CRVE), vascular tortuosity and fractal dimension (FD) were measured using VAMPIRE software. Retinal vasculitis was characterized using fluorescein angiography and active choroiditis using indocyanine green angiography.

RESULTS

At baseline, BSCR was associated with lower FD compared with matched controls (mean difference, -0.04; 95% confidence interval [CI], -0.06 to -0.02, p < 0.001). No other VAMPIRE parameters (CRAE, CRVE, arterial and venous tortuosity) differed. Among BSCR patients, retinal vein vasculitis was associated with higher CRAE (mean difference, 21 μ; 95% CI, 2.6-40, p = 0.03), venous tortuosity (geometric mean ratio, 1.79; 95% CI, 1.18-2.72, p = 0.007) and FD (mean difference, -0.04; 95% CI, -0.06 to -0.01, p = 0.007). Resolution of retinal vein vasculitis during follow-up was paralleled by decrease in CRAE, CRVE and venous tortuosity values and increase in venous FD, respectively.

CONCLUSION

BSCR is associated with lower FD value, suggesting that chronic retinal inflammation induces microvascular remodelling. Efficient treatment of retinal vasculitis may reverse changes in retinal vascular parameters. Changes in retinal vascular parameters could be potentially useful for assessing patients with BSCR disease.