Structural alterations of macular inner retinal layers in patients with Fabry disease

Abstract

Purpose : Fabry disease (FD) is a rare X-linked lysosomal storage disorder characterized by the accumulation of globotriaosylceramide in various tissues, leading to renal, vascular, and neurological complications. Although structural changes in central and peripheral nervous system have been previously reported in FD, little is known on the alterations of retinal layers. This study aims to evaluate macular inner retinal layer changes in patients with FD using spectral domain optical coherence tomography (SD-OCT).

Methods : Twelve consecutive patients with FD and 12 age- and sex-matched healthy control participants were included in this cross-sectional study. The Mainz Severity Score Index (MSSI) was used to measure the severity of FD. All participants underwent SD-OCT (Heidelberg, Germany) imaging, and retinal layer segmentation was performed automatically. Total macular volume (TMV) and central macular thickness (CMT) were recorded, and the average thicknesses of nerve fiber layer (NFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL) and total inner retinal layers (IRL) were measured at the central fovea (1 mm) and four quadrants (superior, inferior, nasal, temporal) of the parafoveal region (1-3 mm).

Results : Intraretinal hyperreflective dots and increased retinal vessel tortuosity were observed in the OCT images of patients with FD (Figure 1). Compared to healthy control subjects, patients with FD had significantly reduced total IRL thickness at superior (P=0.005), inferior (P=0.016), temporal (P=0.005), and nasal (P=0.011) quadrants. Additionally, INL thickness was reduced at superior (P=0.038), temporal (P=0.006), and nasal (P=0.022) parafoveal regions. No significant differences were observed in TMV, CMT, NFL, GCL, and IPL thickness between patient and control groups. The MSSI inversely correlated with the thickness of INL at central (rho=-0.666; P=0.018) and inferior (r=-0.627; P=0.029) regions.

Conclusions : This study demonstrates significant structural alterations in the macular inner retinal layers in patients with FD. Further studies are required to identify potential pathophysiological mechanisms of inner retinal changes in FD.

This is a 2021 ARVO Annual Meeting abstract.

 

Figure 1. Representative OCT images of a patient with Fabry disease (top) and a healthy control subject (bottom), demonstrating increased retinal vascular tortuosity (red arrows) and multiple intraretinal hyperreflective dots (green arrows).