Retinal Microvascular Changes in Familial Hypercholesterolemia: Analysis with Swept-Source Optical Coherence Tomography Angiography

Abstract

Familial hypercholesterolemia (FH) is a common but underdiagnosed genetic disorder affecting cholesterol metabolism, leading to atherosclerotic disease. The relationship between retinal microvascular changes and the presence of atheroma in patients with FH (FH group), and in comparison to volunteers without FH (CT group), needs further investigation. This cross-sectional study was conducted in a university hospital between October 1, 2020 and May 31, 2021. Cardiovascular data, including the Coronary Artery Calcium (CAC) score, were recorded for FH patients. Macula angiograms were acquired using swept-source optical coherence tomography angiography (SS OCT-A) to analyze both the superficial capillary plexus (SCP) and deep capillary plexus (DCP). A total of 162 eyes of 83 patients were enrolled in the FH group and 121 eyes of 78 volunteers in the CT group. A statistically significant association was found between the CAC score and both vessel density (β = −0.002 [95% CI, −0.004; −0.0005], p = 0.010) and vessel length (β = −0.00005 [95% CI, −0.00008; −0.00001], p = 0.010) in the DCP. The FH group had a significantly lower foveal avascular zone circularity index than the CT group in multivariate analysis (0.67 ± 0.16 in the FH group vs. 0.72 ± 0.10 in the CT group, β = 0.04 [95% CI, 0.002; 0.07], p = 0.037). Retinal microvascularization is altered in FH and retinal vascular densities are modified according to the CAC score.

The Observation of Retinal Microvascular Alterations in Familial Hypercholesterolemia Patients through Optical Coherence Tomography Angiography

“…We noticed that FAZ enlargement occurred in both the FH group and the HoFH group. This result was consistent with the previous observation of retinal ultrastructure changes in FH patients [8,19]. Other studies also revealed that the FAZ area is sensitive to ischemia and oxygen supply insu ciency in several retinal ocular diseases, such as retinal vein occlusion and diabetic retinopathy [21][22][23].…”

“…For the DCP, VDs in the DCP segment were signi cantly increased in some subsectors of the parafoveal area in FH patients. This result was consistent with Eid's study of retinal microvascular changes in FH patients [19]. As we noticed in our previous study, a phenomenon occurs in which there is a compensative increase in blood supply in the outer layer of the retina due to the capillary blood supply in the inner layer retina being insu cient, and the increase in the DCP VD may occur before a signi cant difference occurs [24].…”

“…Previous studies showed that the capillary endothelial cells of a rabbit hyperlipidemia model contain cholesterol deposits [7], and in hypercholesterolemia-inherited rats, irregular retinal capillary and constricted capillary networks were observed [9]. Recently, Eid's observation of macrovascular alterations in FH patients revealed that the SCP showed no signi cant differences compared with normal controls in FH patients, while DCP was signi cantly associated with the coronary artery calcium score [19]. The diversity of the results in our study and Eid's study may be due to the different patient characteristics and different statistical methods employed.…”

“…In a study of FH in 2019, Claudia Stefanutti found that FH patients had a larger fovea avascular zone (FAZ) area than normal controls, while the macular vascular densities (VDs) were not signi cantly different compared to the control group [8]. Another recent study observed deep capillary plexus (DCP) alterations in FH patients [19], but peripapillary capillary network alterations were not analyzed. In our study, the differences in macular VDs and peripapillary VDs between FH patients and homozygous FH (HoFH ) patients and normal controls were observed.…”

Early Retinal Microvascular Changes Assessed with Swept-Source OCT Angiography in Type 1 Diabetes Patients without Retinopathy

“…Second, as for many other OCT-A studies, we showed that age was a major confounding factor that must be considered when interpreting retinal microvascular changes [ 24 ]. Both groups showed similar demographic characteristics, limiting the impact of age on the OCT-A comparison, but many other systemic features can impact a retinal microvascular quantitative analysis such as hypertension, hypercholesterolemia, systemic neurovascular, or cardiovascular disease [ 31 , 32 , 33 ]. Third, the general health characteristics of the control group were self-reported.…”