Recent advances in fluorescein fundus angiography

Since MacLean and Maumenee (I960) first examined the fundus of patients with slit-lamp and indirect ophthalmoscopy after the injection of 5 per cent. intravenous sodium fluorescein, and Novotny and Alvis (I96I) made the first successful photographs of the passage of dye through the retinal, vessels with a modified fundus camera, fluorescein fundus angiography (FFA) has come to occupy a unique position in the diagnosis and understanding of numerous fundus lesions. The technique has made great strides in a comparatively short time because of the enthusiasm with which it has been received by ophthalmologists-both clinical and research. It is impossible to review all the recent advances and literature in such a broad field, and I therefore propose to concentrate mainly on the aspects which I consider most important, and those which interest me. FFA, like all other investigations, unless properly conducted and interpreted, is bound to produce erratic results. With the sudden explosion of enthusiasm for this technique, it is not uncommon to find that it is being performed with inadequate knowledge of the right equipment and technique and indeed of basic facts; moreover, many abbreviated and inadequate versions have been advocated. Too many ophthalmologists assume that they are able to interpret FFA, not realizing that a correct interpretation of these angiograms, like that of x rays, requires a good deal of experience and expertise. These factors have often produced disappointing results which have been attributed to the inadequacies of FFA. It is not uncommon to find two extreme views on FFA: one of expecting miracles and an answer to every fundus problem; the other (held even by a few in high places!) that FFA has no significant contribution to make in clinical ophthalmology. Many factors are involved in obtaining satisfactory rapid-sequence fluorescein angiograms. These include a good fundus camera and accessories, the right combination of filters, correct films and processing, a competent person doing the angiography, good dilatation of the pupils, clear ocular media, good co-operation from the patient, the patient's circulation time, and the concentration, quantity, mode, and site of injection of the fluorescein. A defect in any of these results in imperfect pictures. Over the years a good deal of attention has been devoted to improving the quality of fluorescein angiograms, and some of the recent advances in instrumentation and technique are mentioned below.