What are the various etiologies of retinal vasculitis?

Etiologies of Retinal Vasculitis

Retinal vasculitis can be broadly classified into infectious and noninfectious etiologies, with noninfectious causes including systemic vasculitic disorders, connective tissue diseases, inflammatory conditions, and idiopathic disease, while infectious causes encompass bacterial, viral, fungal, and parasitic pathogens. 1, 2

Noninfectious Etiologies

Systemic Vasculitic Disorders

• Behçet's disease represents a major association with retinal vasculitis and is one of the most common systemic causes 1
• Granulomatosis with polyangiitis (formerly Wegener's granulomatosis) can produce retinal vasculitis as part of its systemic manifestations 3, 4
• Polyarteritis nodosa may cause inflammatory retinal vessel involvement 3
• Eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) is associated with retinal vasculitis 3
• Microscopic polyangiitis can manifest with retinal vascular inflammation 3
• Kawasaki disease (primarily affecting children) may involve retinal vessels 3

Connective Tissue Diseases

• Systemic lupus erythematosus is a well-established cause of retinal vasculitis and should be considered in the differential diagnosis 3, 1, 4
• Rheumatoid arthritis can be associated with retinal vascular inflammation 3, 4
• Relapsing polychondritis may produce retinal vasculitis 3

Inflammatory Disorders

• Sarcoidosis represents a major systemic inflammatory condition associated with retinal vasculitis 3, 1, 4

Drug-Induced Vasculitis

• Methamphetamine, intravenous immunoglobulins, opioids, hydralazine, antifibrotics, antibiotics, and leukotrienes can all cause drug-induced vasculitis affecting retinal vessels 3

Malignancy-Associated Vasculitis

• Retinal vasculitis may occur secondary to underlying malignancies 3, 4

Idiopathic

• Isolated ocular retinal vasculitis without systemic disease association 1, 5

Infectious Etiologies

Viral Causes

• Herpes simplex virus (HSV) can produce retinal vasculitis with immunologically mediated infiltrates 3, 2
• Varicella-zoster virus (VZV) causes retinal vascular inflammation 3, 2
• Epstein-Barr virus may produce retinal vasculitis 3
• Cytomegalovirus is an important viral cause, particularly in immunocompromised patients 2

Bacterial Causes

• Bacterial infections can cause retinal vasculitis through direct infection or immune-mediated mechanisms 2, 5
• Tuberculosis represents an important bacterial etiology globally 2
• Syphilis should be considered in the differential diagnosis 2

Fungal Causes

• Fungal pathogens can produce retinal vasculitis, particularly in immunocompromised hosts 2, 5
• Candida species are common fungal causes 2

Parasitic Causes

• Toxoplasmosis is one of the most common parasitic causes of retinal vasculitis, causing retinochoroiditis 3, 2
• Onchocerca (nematode) may cause retinal vascular inflammation 3

Key Clinical Distinctions

Infectious retinal vasculitis tends to exhibit ischemic areas, arterial or venous sheathing or occlusion, and is usually associated with retinal or choroidal involvement, while noninfectious retinal vasculitis is predominantly associated with capillary vasculitis. 2

Geographic Variations

• The prevalence and spectrum of infectious etiologies show significant geographical variations 2
• Toxoplasmosis genotypes in Central and South America cause more severe inflammatory responses compared to other regions 3

Common Pitfalls

• Retinal vasculitis may be asymptomatic initially, particularly when peripheral retinal disease is present, requiring systematic retinal examination in patients with verified rheumatic disease 4
• Giant cell arteritis (GCA) represents an ophthalmologic emergency and must be excluded promptly in appropriate clinical contexts, as it can cause central retinal artery occlusion with retinal vascular inflammation 3
• Retinal vasculitis can be the presenting or first manifestation of active, potentially lethal systemic disease in patients with nonspecific presentations 4