Sir,

The authors would like to thank Dr Aristodemou for his interest in our study.1 All patients with giant cell arteritis who were included into the study fulfilled the inclusion criteria for acute arteritic anterior ischaemic optic neuropathy, which were a positive temporal artery biopsy showing the typical granulomatous inflammation with giant cells, an erythrocyte sedimentation rate markedly above the age-related normal value, an elevated C-reactive protein level in the serum, clinical symptoms with a sudden and marked loss in vision, headache often persisting for weeks and months, an acute optic disc swelling with an unsharp and prominent optic disc border, few haemorrhages, and often a rather whitish ischaemic appearance of the swollen neuroretinal rim. The authors agree with Dr Aristodemou that when a patient presents with these typical features of arteritic anterior ischaemic optic neuropathy, the diagnosis is usually not very challenging.

Since the study included only patients with acute arteritic anterior ischaemic optic neuropathy exhibiting the typical ophthalmoscopic and laboratory findings, the authors have unfortunately no ophthalmodynamometric data of patients with occult giant cell arteritis, although without doubt, it would clinically be helpful.2 As suggested by Dr Aristodemou, it may be the subject of a future study.