Lessons to be learned: a case study approach--a case of temporal arteritis.

A 71-year-old male presented with a history of sudden partial visual loss in the right eye with an inferior visual field defect over the past 3-4 days. He had no history of headache or of facial pain. Clinical examination confirmed that vision on the right side was reduced to 6/18 and on the left to 6/12. The right eye showed a relative afferent pupillary defect. There was no other abnormality of the anterior segment of either eye. The right retina showed a pale swollen optic disc and a provisional diagnosis of anterior ischaemic optic neuropathy (AION) was made. An urgent erythrocyte sedimentation rate (ESR) was ordered and the patient was asked to return to the eye clinic in one month. However, 16 days later--when it was first recognised that his ESR was elevated to 75 mm in the first hour--the patient was recalled immediately in order to commence systemic steroid treatment; but regrettably, by this time, his right eye had become totally blind. In this case, although the attending doctor made a correct clinical diagnosis on presentation, he failed to act upon the result of the blood test.