After a fruitless ER visit when my husband was experiencing severe pain in his side along with lethargy he was referred to a gastroenterologist. The next day my husband went suddenly blind. It was our opthalmologist who sent us to ER for testing for GCA. A temporal biopsy confirmed but too late as my husband is now permanently blind. Most of what we have learned about GCA and PMR has been thru this forum and a book I bought on Amazon Good luck and go immediately to ER if you experience any vision problems