From the Departments of Ophthalmology and Neurology of the University ofManchester

Fluorescein fundus photography is of value in the detection of early papilloedema (David, Heyman, and Hart, 1963; Miller, Saunders, and Ffytche, 1965). We have applied this technique to the serial study of patients with acute retrobulbar neuritis. This disorder is usually unilateral and the unaffected eye could be used as a control. Also, since papilloe-dema is not present at the onset of symptoms and the condition is self-limiting, it has been possible to follow in serial studies the evolution and resolu-tion of the disc oedema. Clinical papilloedema is detected in about half the patients with acute retrobulbar neuritis. Fluorescein photography might be expected to reveal abnormalities when there is no visible oph-thalmoscopic change and this has also been investi-gated. MATERUAL Ten patients were studied. They were unselected apart from having attended the hospital. They presented the characteristic clinical features of acute retrobulbar neuritis with pain, impaired visual acuity, and central scotoma. One patient developed a similar disturbance in the other eye while under observation. The age range was 20 to 47 years, with a mean of 29 years. There were seven females and three males. Three patients had clear evidence of associated disease of the nervous system indicating multiple sclerosis, and three others gave a history of neurological disturbance sugges-tive of demyelinating disease. The remaining four patients had no evidence of associated disease. METHOD Each patient was investigated after dilatation of the pupils with 5 % homatropine and 2 % cocaine. A Zeiss fundus camera with Zeiss-Siemens flash generator was used. Colour photographs of both discs were taken on Kodachrome II film at x 5 magnification. Stereoscopic photographs of the discs were taken by means of the 'successive exposure camera shift method'. The patient was given a single injection of 3 ml. 25% solution of sodium fluorescein into an antecubital vein. The camera was modified for fluorescein photography by the insertion of a fluorescence exciting filter, Ilford Bright Spectrum Blue 622, and a barrier filter, Koda