Optical coherence tomography angiography findings in Susac’s syndrome: a case report

[Effects of Susac syndrome on the central vascular structure of the retina-An optical coherence tomography angiography study]

BACKGROUND

Susac syndrome (SS) describes an endotheliopathy of vessels in the central nervous system. Retinal involvement plays a central role in the manifestation of the disease.

OBJECTIVE

This case-control study investigated the macular microvasculature in patients with chronic SS compared to controls using optical coherence tomography angiography (OCTA).

MATERIAL AND METHODS

12 eyes of 12 patients with SS were compared with age-matched healthy control subjects with regard to their OCT angiographic parameters. The flow density (FD) of different macular layers, foveal avascular zone (FAZ) parameters and central retinal thickness and volume values were compared between the two groups.

RESULTS

The FD of the choriocapillaris was reduced in Susac patients compared to healthy controls. The FD values of the superficial and deep capillary plexus of the inner retina, parameters of the FAZ as well as central retinal thickness and volume showed no significant differences between the two groups.

DISCUSSION

Treated chronic SS does not appear to significantly affect the vascular and structural composition of the central inner retina; however, differences in the choriocapillaris indicate changes in deeper, highly vascularized capillary layers.

RETINAL FLUORESCEIN ANGIOGRAPHY IN SUSAC SYNDROME: A SHIFTING PATTERN OF ARTERIOLAR WALL HYPERFLUORESCENCE-A REPORT OF TWO CASES

BACKGROUND

Susac syndrome consists of the triad of encephalopathy, branch retinal artery occlusion, and hearing loss and is believed to be an immune-mediated endotheliopathy. Arteriolar wall hyperfluorescence (AWH) on retinal fluorescein angiography (FA) has been described in the literature as a classic ophthalmic sign for Susac syndrome. In this article, we report a pattern of distally shifting segments of AWH on FA over time that was observed in two cases.

METHODS

Two cases of Susac syndrome are presented with an emphasis on FA findings, obtained at frequent intervals during follow-up.

RESULTS

In both cases, FA displays a shifting pattern of segments of AWH distal to the localization of the AWH observed on the previous FA.

CONCLUSION

In patients with Susac syndrome, FA plays an important role in aiding diagnosis and monitoring the efficacy of treatment and disease activity during follow-up. In these two cases, the angiography revealed how the AWH can migrate along the vessel over time. This is the first published report showing an evolving distally shifting pattern of AWH in patients with Susac syndrome.

Susac's syndrome - A new ocular finding and disease outcome

BACKGROUND

Susac's syndrome, a rare autoimmune vasculo-occlusive disease, may pose a diagnostic challenge and result in a devastating ocular and systemic outcome. Our study identifies a new retinal finding and evaluates disease outcome. We aimed to assess clinical and imaging findings, systemic manifestations and disease outcome in patients with ocular Susac's syndrome under immunosuppressive/immunomodulation therapies.

METHODS

Retrospective tertiary center study including patients with a diagnosis of Susac's syndrome with >12 months follow up. Medical record review including ocular, neurological and auditory clinical and imaging findings, and treatment modalities. Main outcome measures were clinical manifestations and disease outcome.

RESULTS

Seven patients (14 eyes) with a mean age of 34.1 years were included. Mean follow-up was 31.9 months (12.4-72.4). All had bilateral ocular disease. Retinal microaneurysms, a new ocular finding, were demonstrated in 5 patients and persisted at the final visit. In 5 eyes, they further extended during follow-up. All were treated with immunosuppressive drugs and 5/7 additional immunomodulation therapy. At last examination, best corrected visual acuity was >20/40 in all eyes, 1/10 eyes had visual field deterioration, no eye had active ocular disease, all patients achieved neurological stability, and 1 patient had auditory deterioration.

CONCLUSION

Retinal microaneurysms, a new ocular finding in Susac's syndrome, were present in most of our patients, indicating ischemic retinal damage. Immunosuppressive and immunomodulation therapies seem to be highly effective in the control of disease activity.

A Novel Quantitative Assessment Method of Disease Activity in Susac's Syndrome Based on Ultra-Wide Field Imaging

PURPOSE

Susac's syndrome (ScS) is a rare, potentially life-threatening auto-immune disease. Ophthalmic imaging can depict characteristic branch retinal arteriolar occlusions (BRAO) and arterial wall hyperfluorescences that form one of the three diagnostic pillars of this condition. We aim to demonstrate that ophthalmological ultrawide-field (UWF) imaging allows for a qualitative and quantitative assessment in ScS, with application in diagnostics, monitoring of treatment response, and titration of therapy.

METHODS

In seven ScS patients (♀:♂ = 2:5), with a median age of 36 years, range 18 to 57 years, serial ultrawide-field fluoresceine angiography (UWF-FA) studies were performed, with adjunctive wide-field optical coherence tomography angiography analyses (WF-OCTA) in five patients. Mean follow-up was 12.5 months, range 1 to 46 months.

RESULTS

In all seven patients, BRAO and arterial wall hyperfluorescences were present in UWF-FA and calculated as a quantitative score of disease activity in fluorescein angiography (DA-FA) during follow-up visits. Treatment response was accessible in follow-up imaging as partial reperfusion of retinal vessels, resolution of arterial wall hyperfluorescences and consequently, in reduction of DA-FA score. While qualitative analysis of WF-OCTA provided further information about retinal micro-perfusion, quantitative analysis did not demonstrate a vectored treatment response as it was accessible in FA.

CONCLUSION

DA-FA score, as a comprehensive disease activity parameter in ScS has potential to facilitate optimal communication between subspecialties and thereby treatment success.

Multimodal Imaging in Susac Syndrome: A Case Report and Literature Review

Susac syndrome (SS) is a rare microangiopathy that involves arterioles of the brain, retina, and cochlea. Diagnosis is extremely difficult because of the rarity of the disease and because the signs and symptoms often occur at different times. Multidisciplinary approaches and multimodal images are mandatory for diagnosis and prompt therapy. In this report, we describe a case of SS and the application of multimodal retinal imaging to evaluate the ophthalmologic changes and to confirm diagnosis. Early diagnosis and therapy based on the associations of steroids and immunosuppressants are necessary to limit the sequelae of the disease.

Use of ultra-wide field retinal imaging and optical coherence tomography angiography in the diagnosis of incomplete Susac syndrome

PURPOSE

To describe clinical findings through ultra-wide field (UWF) images and optical coherence tomography angiography (OCT-A), in Susac's syndrome (SS).

METHODS

SS patients were retrospectively analyzed in a single center. Clinical features, ultra-wide-field retinographies (UWF-PR), UWF fluorescein angiographies (UWF-FA), and optical coherence tomography angiography & en face (OCT-A/EF) were reviewed.

RESULTS

Twelve eyes from six patients with a mean follow-up of 35.66 months ± SD 36.88 were included. UWF-PR showed areas of retinal whitening and cotton-wool spots in all the eyes after acute attack. Segmentary mid peripheral arteriolitis could be observed in five eyes by UWF-FA in acute and convalescent stages. OCT-A revealed capillary density changes in all of the affected eyes. During the acute phase there was a well-preserved superficial capillary network, while deep retinal plexus showed a lower density in the affected areas. OCT-A/EF revealed deep retinal plexus drop-out and surrounding edematous retina in acute attacks, becoming atrophic over time. Conversely, superficial plexus was much less affected. Perifoveal reperfusion was seen in seven eyes after the acute attack.

CONCLUSIONS

UWF-PR/FA and OCT-A/EF might be helpful to stablish an early diagnosis and to monitor SS progression.

Comparison of vascular parameters between normal cynomolgus macaques and healthy humans by optical coherence tomography angiography

BACKGROUND

The metabolic activity of retina is higher than other human tissues and is crucial to the vision. Cynomolgus macaques is widely used in ophthalmic disease research. The evaluation and comparison of macular and optic disc vascular circulation parameters between normal adult cynomolgus macaques and healthy adult humans using OCT-A can promote better use of nonhuman primate models in studies of ophthalmic vascular disease.

METHODS

Twelve normal adult cynomolgus macaques with a mean age of 4.91 ± 0.43 years were studied for data collection. The macula of 28 adult healthy humans (14 males and 14 females), with a mean age of 25.11 ± 6.21 years and the optic discs of 9 adult healthy humans (4 males and 5 females) with a mean age of 28.56 ± 6.78 years were measured. The vessel density (VD) was measured using an RTVue XR with AngioVue. The scan sizes of the macular and optic discs were 3 × 3 mm and 4.5 × 4.5 mm, respectively.

RESULTS

OCT-A can image the superficial and deep capillary plexuses and radial peripapillary capillary network. In RPC layer of the optic disc, the VD in the nasal quadrant was lower than the VD in the inferior temporal quadrant. Similarities and significant differences in VD between healthy humans and cynomolgus macaques were obtained using OCT-A.

CONCLUSIONS

This study provides normal vascular parameters for adult cynomolgus macaques using OCT-A to help establish an optical parameter database for cynomolgus macaques and compare VD between healthy humans and cynomolgus macaques to promote choroid-retinopathy research.

TRIAL REGISTRATION

Current Controlled Trials NCT03692169 , retrospectively registered on 26 sept 2018.

Widefield OCT angiography and ultra-widefield multimodal imaging of Susac syndrome

The aim is to present the changes in ultra-widefield and widefield multimodal imaging, including optical coherence tomography angiography of a 33-year-old woman diagnosed with Susac syndrome, over 1 year of follow-up. Fundus examination and multimodal imaging revealed bilateral arterial occlusion of multiple vascular branches with retinal ischemia. Over 1 year follow-up, best-corrected visual acuity improved while retinal ischemia gradually resolved. Widefield optical coherence tomography angiography showed reperfusion of macular large vessels, but not of the small capillaries. Despite anatomical improvement, functional defects of the visual field persisted. In conclusion, widefield and ultra-widefield imaging provided high-resolution details of the central and peripheral damages in Susac syndrome.