[Renal lesions in patients with Fabry's disease]

Optical Coherence Tomography Angiography for the Evaluation of Retinal Vasculature in Fabry Disease: Our Experience and Review of Current Knowledge

Purpose: Optical coherence tomography angiography (OCTA) is a non-invasive and objective tool for the evaluation of the retinal microvascular changes in Fabry disease (FD). We investigated changes in retinal vasculature in FD patients, and the possible correlation with systemic parameters, by using OCTA, and reviewed the current status of literature.

Methods: Thirteen FD patients (eight females, five males, mean age 49.85 ± 14.7 years) were compared with 13 age- and sex-matched healthy controls. OCTA 3 × 3 mm macular scans were performed in all subjects. We evaluated the vessel density and vessel perfusion in distinct macular areas (whole, inner, and outer) of both the superficial capillary plexus (SCP VD and SCP VP) and of the deep capillary plexus (DCP VD and DCP VP). We also evaluated the foveal avascular zone (FAZ) metrics (area, perimeter, and circularity), and correlation between systemic and OCTA parameters. A literature review on the current understanding of OCTA in FD is then presented.

Results: FD patients showed significantly lower SCP VD values in the whole area (17.37 ± 2.08 mm⁻¹ vs. 18.54 ± 1.21 mm⁻¹; p-value 0.022), as well as in the outer area (17.46 ± 2.10 mm⁻¹ vs. 19.08 ± 1.14 mm⁻¹; p-value 0.002), but not in the inner. Even the DCP VD was significantly lower in all the imaged areas: whole (17.75 ± 3.93 mm⁻¹ vs. 19.71 ± 1.20 mm⁻¹; p-value 0.024), outer (18.25 ± 4.17 mm⁻¹ vs. 20.33 ± 1.20 mm⁻¹; p-value 0.023), and inner (19.54 ± 4.17 mm⁻¹ vs. 21.96 ± 1.55 mm⁻¹; p-value 0.011). There were no significant differences in vessel perfusion parameters (both SCP VP and DCP VP ones) and FAZ. No significant correlations were found between the OCTA parameters and systemic parameters (maximal left ventricular wall thickness and glomerular filtration rate) in FD patients.

Conclusions: OCTA can be considered as a promising non-invasive tool, which enables a quantitative evaluation of retinal vascular involvement in FD, despite the varying data reported in literature. Our results support the use of OCTA as an objective tool to evaluate retinal vascular abnormalities in FD. The utility of OCTA in FD needs to be validated by longitudinal studies taking into account the overall progression of the disease.

Macular Impairment in Fabry Disease: A Morpho-functional Assessment by Swept-Source OCT Angiography and Focal Electroretinography

Purpose

Fabry disease (FD) is a multiorgan X-linked condition characterized by a deficiency of the lysosomal enzyme alpha-galactosidase A, resulting in a progressive intralysosomal deposit of globotriaosylceramide. The aim of this study was to evaluate the macular ultrastructure of the vascular network using optical coherence tomography angiography (OCTA) and to evaluate macular function using focal electroretinography (fERG) in Fabry patients (FPs).

Methods

A total of 20 FPs (38 eyes, mean age 57 ± 2.12 SD, range of 27-80 years) and 17 healthy controls (27 eyes, mean age 45 years ± 20.50 SD, range of 24-65 years) were enrolled in the study. Color fundus photography, swept-source optical coherence tomography (SS-OCT), OCTA and fERG were performed in all subjects. The OCTA foveal avascular zone (FAZ), vasculature structure, superficial and deep retinal plexus densities (images of 4.5 × 4.5 mm) and fERG amplitudes were measured. Group differences were statistically assessed by Student's t-test and ANOVA.

Results

In the FP group, the FAZ areas of the superficial and deep plexuses were enlarged (P = 0.036, t = 2.138; P < 0.001, t = -3.889, respectively), the vessel density was increased in the superficial plexus, and the fERG amplitude was reduced (P < 0.001, t = -10.647) compared with those in healthy controls. No significant correlations were found between the structural and functional data.

Conclusions

OCTA vascular abnormalities and reduced fERG amplitudes indicate subclinical signs of microangiopathy with early retinal dysfunction in FPs. This study highlights the relevance of OCTA imaging analysis in the identification of abnormal macular vasculature as an ocular hallmark of FD.