Biopsy of the superficial temporal artery provides vital confirmation of the diagnosis of giant cell arteritis. The vessel splits into 2 main branches: frontal and parietal. It is unknown which branch is most likely to yield a positive biopsy finding or, indeed, whether arteritis is ever confined to a single branch.
Correspondence: Dr Horton, Beckman Vision Center, University of California, San Francisco, 10 Koret Way, San Francisco, CA 94143 (hortonj@vision.ucsf.edu).
Financial Disclosure: None reported.
Funding/Support: This work was supported by grants EY10217 (Dr Horton) and EY02162 (Beckman Vision Center) from the National Eye Institute and by Research to Prevent Blindness.