Practice points for ophthalmologists from the 2020 British Society for Rheumatology Giant Cell Arteritis guidelines

Giant cell arteritis: reviewing the advancing diagnostics and management

Giant Cell Arteritis (GCA) is well known to be a critical ischaemic disease that requires immediate medical recognition to initiate treatment and where one in five people still suffer visual loss. The immunopathophysiology has continued to be characterised, and the influencing of ageing in the development of GCA is beginning to be understood. Recent national and international guidelines have supported the directed use of cranial ultrasound to reduce diagnostic delay and improve clinical outcomes. Immediate high dose glucocorticoids remain the standard emergency treatment for GCA, with a number of targeted agents that have been shown in clinical trials to have superior clinical efficacy and steroid sparing effects. The aim of this review was to present the latest advances in GCA that have the potential to influence routine clinical practice.

Is Erythrocyte Sedimentation Rate Necessary for the Initial Diagnosis of Giant Cell Arteritis?

Giant cell arteritis (GCA) is an ophthalmological emergency that can be difficult to diagnose and prompt treatment is vital. We investigated the sequential diagnostic value for patients with suspected GCA using three biochemical measures as they arrive to the clinician: first, platelet count, then C-reactive protein (CRP), and lastly, erythrocyte sedimentation rate (ESR). This retrospective cross-sectional study of consecutive patients with suspected GCA investigated platelet count, CRP, and ESR using diagnostic test accuracy statistics and odds ratios (ORs) in a sequential fashion. The diagnosis was established by experts at follow-up, considering clinical findings and tests including temporal artery biopsy. A total of 94 patients were included, of which 37 (40%) were diagnosed with GCA. Compared with those without GCA, patients with GCA had a higher platelet count (p < 0.001), CRP (p < 0.001), and ESR (p < 0.001). Platelet count demonstrated a low sensitivity (38%) and high specificity (88%); CRP, a high sensitivity (86%) and low specificity (56%); routine ESR, a high sensitivity (89%) and low specificity (47%); and age-adjusted ESR, a moderate sensitivity (65%) and moderate specificity (65%). Sequential analysis revealed that ESR did not provide additional value in evaluating risk of GCA. Initial biochemical evaluation can be based on platelet count and CRP, without waiting for ESR, which allows faster initial decision-making in GCA.

Giant Cell Arteritis Presenting as Bilateral Cotton Wool Spots

An 81-year-old Afro-Caribbean woman presented with a two-week history of a dull headache in her temples, jaw claudication especially when chewing food, and reduced vision in her eyes, more pronounced in the right eye. There was no past medical or family history of hypothyroidism or autoimmunity. On examination, the vision was counting fingers in the right eye and 6/36 in the left eye, best corrected. Dilated fundus examination revealed multiple peripapillary cotton wool spots in both eyes though more pronounced in the right. Her erythrocyte sedimentation rate (ESR) was 120 mm/h, and her C-reactive protein (CRP) level was 79 mg/L. A temporal artery ultrasound scan was undertaken immediately which demonstrated a halo sign around both temporal arteries and so a giant cell arteritis (GCA) diagnosis was made. The patient was commenced on daily high-dose IV methylprednisolone 1 g for three days and referred to the rheumatology team. Her vision improved to 1/60 right and 6/9 left eye best corrected at three days post-treatment. At 12 months after the initial presentation, her vision stabilized at 6/60 in the right and 6/6 with complete visual fields in the left eye. Cotton wool spots can be a sign of GCA. Their appearance with or without characteristic systemic symptoms should prompt urgent evaluation.

An update on the clinical approach to giant cell arteritis

Recent national and international guidance from rheumatology societies have reflected the advances in evidence for both the investigation and management of giant cell arteritis. Cranial ultrasound reduces diagnostic delay and improves clinical outcomes. Immediate high-dose glucocorticoids remain the standard treatment for giant cell arteritis. Randomised controlled trial evidence using tocilizumab, an interleukin-6 receptor antagonist, has been shown to have good clinical efficacy with glucocorticoid sparing effects. Overall patient outcomes appear to be improved by formalising pathways for diagnosis to include clinical experts' opinion early in decision making.