The role of Red cell characteristics, Angiogenesis, Viscosity and Oxygenation in the pathophysiology of Sickle cell related retinopathy (RAVOS study)

The role of Red cell characteristics, Angiogenesis, Viscosity and Oxygenation in the pathophysiology of Sickle cell related retinopathy (RAVOS study) - RAVOS study

Status

Active, not recruiting

Phases

Unknown

Study type

Observational

Source

NL-OMON

Registry ID

NL-OMON53639

Enrollment

Registered

2022-07-22

Start date

2023-06-13

Completion date

Unknown

Last updated

2025-09-15

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

sickle cell disease related retinal damage sickle cell retinopathy

Interventions

None listed

Eligibility

Age

18 Years to 99 Years

Inclusion criteria

Inclusion criteria: In order to be eligible to participate in this study, a subject must meet all of the following criteria: • Minimum age of 18 years • HbSC or HbSS genotype • Recent ophthalmologic examination (up to 2 years prior) or (willingness to attend) upcoming examination

Exclusion criteria

Exclusion criteria: A potential subject who meets any of the following criteria will be excluded from participation in this study: • Age below 18 years • Genotype other than HbSC or HbSS • No recent ophthalmologic examination and no intention to visit the outpatient clinic for ophthalmic and hematologic examination • Participation in trials with either crizanlizumab, voxelotor or mitapivat.

Design outcomes

Primary

Measure	Time frame
1. The difference in red blood cell characteristics (point of sickling) between patients with and without (P)SCR in both genotypes 2. The difference in plasma levels of parameters representing the level of systemic angiogenesis activity (CD105, VEGF, CTGF and angiopoietin-2) between patients with and without P()SCR in both genotypes 3. The difference in oxygenation of the retina by assessing the vessel density with angio-OCT and by assessing the oxygen saturation in the retinal arterioles and venules with the oxymap scan in patients with and without (P)SCR in both genotypes 4. The difference in whole blood viscosity between patients with and without (P)SCR in both genotypes	—

Measure

Time frame

1. The difference in red blood cell characteristics (point of sickling) between patients with and without (P)SCR in both genotypes 2. The difference in plasma levels of parameters representing the level of systemic angiogenesis activity (CD105, VEGF, CTGF and angiopoietin-2) between patients with and without P()SCR in both genotypes 3. The difference in oxygenation of the retina by assessing the vessel density with angio-OCT and by assessing the oxygen saturation in the retinal arterioles and venules with the oxymap scan in patients with and without (P)SCR in both genotypes 4. The difference in whole blood viscosity between patients with and without (P)SCR in both genotypes

—

Secondary

Measure	Time frame
1. Association between retinal vessel density assessed by OCT-angiography, oxygen saturation assessed by an Oxymap scan and red blood cell characteristics (deformity, adhesion and point of sickling upon hypoxia) 2. Association between sex, age, and genotype and the biomarkers of angiogenesis 3. Association between hemoglobin, and HbF and biomarkers of angiogenesis 4. Associations between whole blood viscosity and genotype	—

Measure

Time frame

1. Association between retinal vessel density assessed by OCT-angiography, oxygen saturation assessed by an Oxymap scan and red blood cell characteristics (deformity, adhesion and point of sickling upon hypoxia) 2. Association between sex, age, and genotype and the biomarkers of angiogenesis 3. Association between hemoglobin, and HbF and biomarkers of angiogenesis 4. Associations between whole blood viscosity and genotype

—

Countries

Netherlands

Outcome results