What is the diagnostic approach towards retinal vasculitides?

Diagnostic Approach to Retinal Vasculitis

The diagnosis of retinal vasculitis requires clinical detection through dilated fundoscopic examination with confirmation by fluorescein angiography, supplemented by targeted systemic workup only when history or review of systems suggests underlying disease. 1

Initial Clinical Examination

Essential History Elements

• Duration and pattern of vision loss (acute vs. gradual, unilateral vs. bilateral) 2
• Specific systemic symptoms including headaches, scalp tenderness, jaw claudication (giant cell arteritis), oral/genital ulcers (Behçet's), joint pain, skin rashes, or constitutional symptoms (fever, malaise, weight loss) 2, 3
• Medication history particularly hydroxychloroquine, which can cause retinal toxicity 4
• Past medical history focusing on known autoimmune diseases (systemic lupus erythematosus, sarcoidosis, rheumatoid arthritis, Wegener's granulomatosis), infections, or malignancy 2

Physical Examination Components

• Visual acuity testing with best correction 4
• Relative afferent pupillary defect assessment to evaluate for ischemia and neovascularization risk 5, 4
• Slit-lamp biomicroscopy examining carefully for anterior segment inflammation (uveitis), iris neovascularization, and scleritis 5, 2
• Intraocular pressure measurement 5, 4
• Gonioscopy prior to dilation when elevated IOP or iris neovascularization is suspected 5

Dilated Fundus Examination

• Slit-lamp biomicroscopy with appropriate lenses for posterior pole and midperipheral retina evaluation 5
• Indirect ophthalmoscopy for far peripheral retina assessment 5
• Look specifically for:
  • Vascular sheathing or cuffing (white exudates around vessels indicating active inflammation) 1
  • Retinal hemorrhages, cotton wool spots, and vascular tortuosity 5, 2
  • Macular edema (often accompanies retinal vasculitis) 2
  • Neovascularization of disc or elsewhere 5
  • Vitreous cells or hemorrhage 5

Diagnostic Imaging

Primary Imaging Modalities

• Fluorescein angiography (FA) is the confirmatory test for retinal vasculitis, demonstrating vascular leakage, capillary nonperfusion, and distinguishing active inflammation from collateral vessels 5, 1
• Optical coherence tomography (OCT) to detect and quantify macular edema, assess vitreoretinal interface changes, and identify subretinal fluid 5
• Fundus photography for documentation of vascular sheathing, hemorrhages, and disease progression 5

Emerging Technologies

• OCT angiography (OCTA) can detect capillary nonperfusion and vascular abnormalities noninvasively, though currently limited by artifacts and field of view 5, 4
• Wide-field fluorescein angiography may reveal peripheral nonperfusion not visible on standard FA, though clinical utility remains under investigation 5

Systemic Workup Strategy

The Critical Decision Point

Order extensive laboratory testing ONLY if the review of systems suggests underlying systemic disease 3. In a retrospective study of 25 patients with primary retinal vasculitis, only 1 patient (4%) with positive review of systems had an underlying systemic disease (SLE), while 20.8% of patients without suggestive symptoms had false-positive results without subsequent disease development over 4-year follow-up 3.

When History/Symptoms Are Suggestive

If systemic symptoms are present, consider targeted testing based on clinical suspicion:

• Autoimmune workup: ANA, anti-dsDNA, ANCA, ACE level, chest imaging for sarcoidosis 2, 3
• Infectious workup: Based on specific risk factors and geographic location 2
• Inflammatory markers: ESR, CRP particularly if giant cell arteritis suspected 5

When History Is Negative

Minimal or no laboratory testing is warranted in patients without systemic symptoms, as extensive workups yield false-positives without diagnostic benefit 3.

Important Clinical Pitfalls

• Peripheral retinal vasculitis may be asymptomatic initially, requiring dilated examination in all patients with rheumatic diseases even without visual complaints 2
• FA must be performed with informed consent acknowledging rare but serious risks including death (1/200,000 patients), with emergency protocols in place 5
• Retinal vasculitis may be the first manifestation of life-threatening systemic disease, making thorough review of systems critical even when ocular findings appear isolated 2
• OCT thickness measurements don't always correlate with visual acuity, requiring clinical judgment beyond imaging metrics 5