Retinal vascular impairment in Wolfram syndrome: an optical coherence tomography angiography study

Abstract

To evaluate differences in macular and optic disc circulation in patients affected by Wolfram Syndrome (WS) employing optical coherence tomography-angiography (OCTA) imaging. In this retrospective study, 18 eyes from 10 WS patients, 16 eyes of 8 patients affected by type I diabetes and 17 eyes from 17 healthy controls were enrolled. All patients were imaged through OCT and OCTA and vascular parameters, as perfusion density (PD) and vessel length density (VLD) were measured. OCTA showed reduced PD in WS patients at the macular superficial capillary plexus (SCP, 27.8 ± 5.3%), deep vascular complex (DVC, 33.2 ± 1.9%) and optic nerve head (ONH, 21.2 ± 9.1%) compared to both diabetic patients (SCP 33.9 ± 1.9%, P < 0.0001; DVC 33.2 ± 0.7%, P = 1.0; ONH 33.9 ± 1.3, P < 0.0001) and healthy controls (SCP 31.6 ± 2.5, P = 0.002; DVC 34.0 ± 0.7%, P = 0.089; ONH 34.6 ± 0.8%, P < 0.0001). Similarly, VLD was lower in WS patients at the SCP (10.9 ± 2.7%) and ONH levels (7.5 ± 4.1%) compared to diabetic patients (SCP 13.8 ± 1.2%, P = 0.001; DVC 13.8 ± 0.2%, P < 0.0001; ONH 13.0 ± 0.7%, P = < 0.0001), but higher in DVC (15.7 ± 1.2%, P < 0.0001). Furthermore, VLD was lower in WS patients in all the vascular parameters compared to controls (SCP 13.8 ± 1.5%, P < 0.0001; DVC 17.3 ± 0.6%, P < 0.0001; ONH 15.7 ± 0.5%, P < 0.0001). A significant microvasculature impairment in the macular SCP and ONH microvasculature was demonstrated in eyes affected by WS. Microvascular impairment may be considered a fundamental component of the neurodegenerative changes in WS.

Figure 1

Optic nerve head photography and OCTA images of the optic disc area, macular superficial and deep capillary plexus. Color fundus photography of the optic disc (a), optic nerve head (ONH; b), macular superficial capillary plexus (SCP; c) and deep vascular complex (DVC; d) imaged by optical coherence tomography-angiography (OCTA) in a patient affected by Wolfram Syndrome; color fundus photography of the optic disc (e), ONH (f) and macular SCP (g), DVC (h) in a young patient affected by type I diabetes; ONH color photography (i) and OCT-A acquisitions centered on the optic disc (j) and macula (k, l) in a healthy patient.

Figure 2

Explanatory case processed to obtain binarized and skeletonized images for perfusion density and vessel length density calculation. Optic nerve head (ONH; a), superficial capillary plexus (SCP; b) and deep vascular complex (DVC; c) imaged through optical coherence tomography angiography (OCTA) in a patient affected by optic atrophy in Wolfram Syndrome. The same panel after post-acquisition binarization (d; e; f) and skeletonization process (g; h; i).