Acute Increase in Ocular Microcirculation Blood Flow Upon Cholesterol Removal. The Eyes Are the Window of the Heart

Tiziana Sampietro; Beatrice Dal Pino; Federico Bigazzi; Francesco Sbrana; Andrea Ripoli; Enrica Fontanelli; Mascia Pianelli; Roberta Luciani; Antonio Lepri; Giacomo Calzetti

doi:10.1016/j.amjmed.2022.08.016

Acute Increase in Ocular Microcirculation Blood Flow Upon Cholesterol Removal. The Eyes Are the Window of the Heart

Am J Med. 2023 Jan;136(1):108-114. doi: 10.1016/j.amjmed.2022.08.016. Epub 2022 Sep 21.

Affiliations

¹ Lipoapheresis Unit, Reference Center for Diagnosis and Treatment of Inherited Dyslipidemias, Fondazione Toscana Gabriele Monasterio, Pisa Italy. Electronic address: tiziana.sampietro@gmail.com.
² Lipoapheresis Unit, Reference Center for Diagnosis and Treatment of Inherited Dyslipidemias, Fondazione Toscana Gabriele Monasterio, Pisa Italy.
³ Bioengineering Department, Fondazione Toscana Gabriele Monasterio, Pisa, Italy.
⁴ Institute of Ophthalmology, University of Pisa, Italy.
⁵ Institute of Molecular and Clinical Ophthalmology Basel, Basel, Switzerland; Ophthalmology Unit, University Hospital of Parma, Parma, Italy.

PMID: 36152804
DOI: 10.1016/j.amjmed.2022.08.016

Abstract

Background: Lipoprotein apheresis acutely increases coronary microvascular blood flow. However, measurement techniques are time-consuming, costly, and invasive. The ocular vasculature may be an appropriate surrogate and an easily accessible window to investigate the microcirculation. Recent advances in ocular imaging techniques enable quick, noninvasive quantification of ocular microcirculation blood flow. The insights from these techniques represent a significant opportunity to study the short-term changes in optic disk blood flow after lipoprotein apheresis for inherited hypercholesterolemia.

Methods: This study was performed at the Italian Reference Center for Inherited Dyslipidemias in Tuscany. The study sample was comprised of 22 patients with inherited hypercholesterolemia who were previously studied for coronary microcirculation. Laser speckle flowgraphy (LSFG) was used to measure optic disk blood flow before and after lipoprotein apheresis. The main outcomes measures were average tissue blood flow (referred to as mean tissue) and arteriolar/venular average blood flow (referred to as mean vessel). Eyes were divided into 2 groups based on pre-lipoprotein apheresis optic disk blood flow values. P < .05 was considered statistically significant.

Results: After each lipoprotein apheresis treatment resulting in the reduction of plasma lipids, there was a concurrent increase in all optic disk microcirculatory parameters. The increase was statistically significant in eyes with lower pre-apheresis optic disk blood flow values (mean tissue +7.0%, P < .005; mean vessel +7.2%, P < .05).

Conclusions: A single lipoprotein apheresis session resulted in a statistically significant short-term increase in optic disk blood flow. These findings together with previous coronary microcirculation data suggest a similar ocular and coronary blood flow response to lipoprotein apheresis. Ocular microcirculation may represent a versatile biomarker for evaluating systemic microcirculatory health, including coronary microcirculation. Hence, it is plausible that plasma lipoprotein levels may influence optic disk blood flow.

Keywords: Lipoprotein apheresis; Microcirculation; Ocular blood flow.

MeSH terms

Cholesterol*
Humans
Lipoproteins*
Microcirculation

Substances

Cholesterol
Lipoproteins