Retinal Vasculitis vs Choriovasculitis: Key Distinctions
Retinal vasculitis is inflammation of the retinal blood vessels (arteries, veins, or capillaries), while choriovasculitis refers to inflammation of the choroidal vessels—these are anatomically and clinically distinct entities affecting different vascular layers of the eye. 1
Retinal Vasculitis: Definition and Characteristics
Anatomic Location and Pathophysiology
- Retinal vasculitis involves inflammation of vessels within the neurosensory retina itself, affecting retinal arteries, veins, or capillaries 1, 2
- The inflammation is characterized by inflammatory cell infiltration and/or necrosis of retinal vessel walls 3
- Active disease presents with exudates around retinal vessels, resulting in white sheathing or cuffing of affected vessels visible on ophthalmoscopy 4
Clinical Presentation
- Patients present with visual symptoms ranging from asymptomatic peripheral disease to severe vision loss depending on location and severity 3
- Fundoscopic findings include vascular sheathing, retinal hemorrhages, cotton-wool spots, and macular edema 1
- Fluorescein angiography (FA) confirms diagnosis by demonstrating vascular leakage, staining of vessel walls, and areas of capillary nonperfusion 4
Classification by Vessel Type
- Can be classified as arteritis (affecting retinal arteries), phlebitis (affecting retinal veins), or capillary vasculitis 1
- Further categorized as occlusive (with vessel closure and ischemia) or non-occlusive 1
- Infectious retinal vasculitis typically exhibits ischemic areas, arterial or venous sheathing or occlusion, while noninfectious forms predominantly show capillary vasculitis 5
Choriovasculitis: Definition and Characteristics
Anatomic Location
- Choriovasculitis involves inflammation of the choroidal circulation, which lies posterior to the retina and external to Bruch's membrane 6
- The choroid is part of the uveal tract and has a distinct vascular supply separate from the retinal circulation 6
Clinical Context
- Choriovasculitis is typically seen in the context of posterior uveitis or choroiditis rather than as an isolated entity 6
- Conditions like Vogt-Koyanagi-Harada disease demonstrate choroidal inflammation with early hyperfluorescence on indocyanine green angiography (ICGA), distinct from retinal vascular patterns 6
- White dot syndromes show hypofluorescent changes on late-phase ICGA, reflecting choroidal vascular involvement 6
Critical Diagnostic Differences
Imaging Characteristics
- Retinal vasculitis: Fluorescein angiography shows retinal vascular leakage, staining, and capillary dropout in the retinal circulation 4
- Choriovasculitis: ICGA is superior for detecting choroidal vascular inflammation, showing hypofluorescent or hyperfluorescent patterns depending on the disease 6
Associated Findings
- Retinal vasculitis: Often accompanied by retinal hemorrhages, cotton-wool spots, and may lead to vitreous hemorrhage, neovascular glaucoma, or tractional retinal detachment 1
- Choriovasculitis: Typically presents with choroidal thickening, serous retinal detachment, and outer retinal changes on OCT 6
Systemic Associations
- Retinal vasculitis: Strongly associated with Behçet's disease, sarcoidosis, systemic lupus erythematosus, and infectious etiologies 1, 3
- Choriovasculitis: More commonly seen in Vogt-Koyanagi-Harada disease, posterior scleritis, and white dot syndromes 6
Treatment Implications
Retinal Vasculitis Management
- Requires differentiation between infectious and noninfectious etiologies, as treatment differs fundamentally 2
- Noninfectious cases require high-dose corticosteroids and immunosuppressive therapy, potentially including biological agents 1
- Occlusive disease may require anti-VEGF injections and laser photocoagulation to prevent neovascular complications 1
Choriovasculitis Management
- Treatment focuses on the underlying inflammatory condition (e.g., Vogt-Koyanagi-Harada disease, posterior scleritis) 6
- Systemic corticosteroids and immunosuppressive medications are mainstays of therapy 6
- Local corticosteroids may be used for acute inflammation control 7
Common Pitfall to Avoid
Do not confuse retinal phlebitis (a form of retinal vasculitis affecting veins) with retinal vein occlusion—while retinal phlebitis may be associated with branch retinal vein occlusion, the latter is primarily a thrombotic/embolic process rather than a primary inflammatory vasculitis 6. Retinal vein occlusions show venous dilation, tortuosity, and hemorrhages but lack the inflammatory vessel wall changes (sheathing/cuffing) characteristic of true vasculitis 4.