What is the immediate management for suspected Giant Cell Arteritis (GCA) with vision loss?

Immediate Management of Vision Loss in Giant Cell Arteritis (GCA)

For patients with suspected GCA and threatened vision loss, immediate treatment with intravenous (IV) pulse glucocorticoids (methylprednisolone 0.25-1g/day for 3 days) is conditionally recommended over high-dose oral glucocorticoids. 1

Initial Assessment and Treatment

• GCA with visual symptoms is a medical emergency requiring immediate treatment even before diagnostic confirmation due to the imminent risk of permanent vision loss 2
• Visual loss occurs in 15-35% of patients with GCA, primarily before initiation of therapy 2
• If one eye is affected, risk for losing vision in the second eye is as high as 50% without treatment 2

First-Line Treatment

• Administer IV pulse methylprednisolone 250-1000 mg/day for 3 days 1, 3
• Do not delay oral glucocorticoid treatment while arranging for IV therapy - start oral prednisone immediately if IV administration will be delayed 1
• Treatment should be initiated immediately upon suspicion of GCA with visual symptoms, even before diagnostic confirmation 2

Follow-up Treatment

• After IV pulse therapy, transition to high-dose oral prednisone (1 mg/kg/day, up to 60-80 mg daily) 1, 3, 4
• Consider adding tocilizumab as a glucocorticoid-sparing agent 1, 2
• Add daily aspirin for patients with critical or flow-limiting involvement of vertebral or carotid arteries 2

Monitoring and Precautions

• The greatest risk of visual deterioration is in the first 6 days despite high-dose IV methylprednisolone 4
• Visual deterioration can occur in approximately 27% of eyes despite high-dose IV therapy 4
• Contralateral vision loss can occur 1-12 days following treatment initiation (median 2 days), with cases reported up to 12 days after starting treatment 5
• Monitor visual acuity, visual fields, and inflammatory markers (ESR, CRP) closely during the initial treatment period 3

Diagnostic Workup (Concurrent with Treatment)

• Obtain ESR, CRP, and CBC immediately 3
• Arrange for temporal artery biopsy as soon as possible, ideally within 2 weeks of starting glucocorticoids 1
• Consider noninvasive vascular imaging to evaluate large vessel involvement 1

Important Caveats

• Do not delay treatment while awaiting biopsy results - vision loss can be permanent 2, 3
• Visual recovery is uncommon in patients who have already lost vision from GCA (only 15% show improvement in visual acuity and only 5% have corresponding improvement in visual field) 4
• Studies investigating the effect of IV pulse glucocorticoids in patients with GCA and cranial ischemia have demonstrated conflicting results, but the risk of permanent vision loss justifies aggressive treatment 1
• Intravenous megadose steroid therapy has not been definitively proven more effective than oral therapy in preventing visual deterioration, but is still recommended for threatened vision loss 6, 1

Tapering Strategy

• Maintain high-dose glucocorticoids until both ESR and CRP have reached their lowest stable levels (typically about 2 weeks) 6
• Then gradually taper prednisone to 15-20 mg/day within 2-3 months and to ≤5 mg/day after 1 year 1
• Tapering should be guided by clinical symptoms and normalization of inflammatory markers 2