Orbital Vascular Inflammation in Ischemic Optic Neuropathy and Giant Cell Arteritis
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 122
- 试验地点
- 1
- 主要终点
- Orbital vascular inflammation on PET/MRI
研究概览
简要总结
Giant cell arteritis (GCA) is an inflammation of the blood vessels. A dangerous complication is sudden vision loss due to insufficient blood supply to the optic nerve. However, it is often difficult to distinguish acute vision loss due to GCA from a similar condition of insufficient blood supply to the optic nerve, called NAION. Quick treatment with anti-inflammatory medication is needed in case of GCA to prevent vision loss on the eye and other serious complications. Patients with NAION have no benefit of the medication, but can have serious side effects, why it is very important to differentiate between these conditions.
In this project, the investigators will use FDG PET/MRI with Black Blood (BB) sequences and OCT-imaging to study patients with GCA and/or ischemic optic nerve disease. The investigators will look for signs of inflammation in and around the small vessels of the orbit using PET/MRI and study subtle retinal changes using OCT images.
The investigators want to answer the following research questions:
Do patients with ischemic optic nerve disease and GCA show signs of inflammation in the orbital vessel wall on PET/MRI-scans, that are not present in patients with NAION?
Do GCA patients without vision loss, but with signs of orbital vessel wall inflammation on PET/MRI-scans, have a higher risk of later vision loss than GCA patients without?
Can subtle changes in the retina, detectable through OCT, help distinguish between GCA-related vision loss and NAION?
This will, to our knowledge, be the first study to systematically use FDG PET/MRI BB-scans to illuminate vascular changes in the orbit of patients with GCA and/or ischemic optic nerve disease. The results may improve diagnosis and treatment of GCA and NAION in the future. The investigators hope that this will help prevent blindness and other serious complications in patients with GCA, while also avoiding unnecessary treatments for patients with NAION.
详细描述
Rationale and problem statement:
Giant cell arteritis (GCA) is an immune-driven inflammatory condition affecting the walls of blood vessels. Untreated, GCA can cause vessel wall thickening severe enough to reduce blood flow to various organs. One of the most feared complications is arteritic anterior ischemic optic neuropathy (A-AION), where the anterior part of the optic nerve loses its blood supply, resulting in sudden and often permanent vision loss.
It is crucial to distinguish A-AION from the much more common non-arteritic AION (NAION), since the correct diagnosis directly determines treatment. High-dose corticosteroids must be started immediately when GCA is suspected, in order to reduce the risk of vision loss in the other eye and other severe complications such as stroke or aortic dissection. In contrast, corticosteroid treatment does not benefit patients with NAION and should be avoided because of its significant short- and long-term side effects. However, it remains clinically very difficult to distinguish between A-AION and NAION, even with current diagnostic tools. Furthermore, fundamental knowledge about the vascular changes underlying ischemic optic neuropathy is still lacking.
Imaging background:
18F-Fluorodeoxyglucose (FDG) is a radiolabeled sugar analogue that highlights areas with increased metabolic activity, including inflammatory processes. Previous studies have shown increased FDG uptake in the walls of large and medium-sized arteries in the trunk and skull of GCA patients, but not in the small orbital vessels that supply the eye and optic nerve. Vessel wall inflammation also causes endothelial leakage and thickening, which can be visualized by Magnetic Resonance Imaging (MRI). Prior studies using orbital MRI with Black Blood (BB) sequences have demonstrated thickening and contrast enhancement of orbital vessels in GCA patients.
研究设计
- 研究类型
- Observational
- 观察模型
- Cohort
- 时间视角
- Prospective
入排标准
- 年龄范围
- 50 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •For AION group:
- •Clinical suspicion of newly onset ischemic optic neuropathy (A-AION or NA-AION), defined by ipsilateral findings of: Papilledema; Relevant visual impairment measured by visual acuity and/or visual field; Relative afferent pupillary defect (RAPD), except if mydriatic agents have been administered or if bilateral optic neuropathy is present.
- •Age ≥ 50 years
- •For GCA group:
- •Clinically- and ultrasound-confirmed, newly diagnosed GCA
- •Absence of visual changes related to GCA in one or both eyes, including: Transient vision loss; permanent vision loss; transient double vision; permanent double vision
- •Age ≥ 50 years
排除标准
- •Ferromagnetic implants
- •Severe renal impairment with eGFR < 30 mL/min/1.73m²
- •Allergy to MRI contrast agents
- •Severe claustrophobia
- •Pregnancy or breastfeeding
- •Previously documented ipsilateral optic neuropathy or giant cell arteritis
- •More than 5 days of treatment with prednisolone prior to inclusion
结局指标
主要结局
Orbital vascular inflammation on PET/MRI
时间窗: 2 years
To investigate whether there is increased FDG uptake, increased endothelial permeability, and thickening of the vessel wall in the direct vascular supply to the eye and optic nerve, as signs of orbital vascular inflammation, among patients with ischemic optic neuropathy.
Risk of vision loss in GCA
时间窗: 2 years
To investigate whether GCA patients without visual symptoms, but with signs of orbital vascular inflammation, have a higher incidence of GCA-related eye disease after 6 months compared to GCA patients without signs of orbital vascular inflammation (and possibly again after 2 years).
Retinal biomarkers in AION
时间窗: 2 years
To characterize the occurrence of subtle retinal changes, with a focus on paracentral acute middle maculopathy (PAMM; band-like hyperreflective changes in the middle retinal layers) and intra- and subretinal fluid (IRF/SRF; fluid in or beneath the retina) among patients with ischemic optic neuropathy.
Orbital vascular inflammation on PET/MRI
时间窗: 2 years
To investigate whether there is increased FDG uptake, increased endothelial permeability, and thickening of the vessel wall in the direct vascular supply to the eye and optic nerve, as signs of orbital vascular inflammation, among patients with ischemic optic neuropathy.
Risk of vision loss in GCA
时间窗: 2 years
To investigate whether GCA patients without visual symptoms, but with signs of orbital vascular inflammation, have a higher incidence of GCA-related eye disease after 6 months compared to GCA patients without signs of orbital vascular inflammation (and possibly again after 2 years).
Retinal biomarkers in AION
时间窗: 2 years
To characterize the occurrence of subtle retinal changes, with a focus on paracentral acute middle maculopathy (PAMM; band-like hyperreflective changes in the middle retinal layers) and intra- and subretinal fluid (IRF/SRF; fluid in or beneath the retina) among patients with ischemic optic neuropathy.
次要结局
- Orbital pathophysiologic changes in NAION(2 years)
- Retinal biomarkers to diagnose A-AION vs NAION(2 years)
- Correlation with final clinical diagnosis(2 years)
- Occurence of orbital vascular inflammation in GCA without vision loss(2 years)
- Eye examination biomarkers of orbital vascular inflammation(2 years)
- Vascular inflammation outside of the orbit(2 years)
- Correlation with final clinical diagnosis(2 years)
- Occurence of orbital vascular inflammation in GCA without vision loss(2 years)
- Eye examination biomarkers of orbital vascular inflammation(2 years)
- Vascular inflammation outside of the orbit(2 years)
- Orbital pathophysiologic changes in NAION(2 years)
- Retinal biomarkers to diagnose A-AION vs NAION(2 years)
研究者
Steffen Hamann
Clinical Professor
Rigshospitalet, Denmark