Fluorescein fundus photography of angioid streaks.

The most characteristic ocular lesions in pseudoxanthoma elasticum are the angioid streaks which may be seen in about 85 per cent. of cases. The associated features in the fundus are a peculiar mottled appearance (Shimizu, I96I), peau d'orange (Smith, Gass, and Justice, I964), and yellowish-white spots (salmon spots). While most subjects showing angioid streaks have pseudoxanthoma elasticum, clinically and histologically indistinguishable angioid streaks are also seen in Paget's disease (osteitis deformans) (Shaffer, Copelan, and Beerman, 1957), and sometimes in sickle cell disease (Paton, I959; Geeraets and Guerry, I960), familial hyperphosphataemia (McPhaul and Engel, I96I), idiopathic thrombocytopenic purpura (Yatzkan, I957), and lead poisoning. The histopathological appearances of angioid streaks have been described by Hagedoorn (I939), Klien (I947), and Verhoeff (I948). Bruch's membrane takes up intense basophilic staining and shows evidence of deposition of metal salts such as calcium or iron. The membrane shows peripapillary cracks with radial extensions. Initially there is a thinning of the pigment epithelium. Later fibrovascular tissues fron the choroid invade the retina. The underlying choroid capillaries undergo degeneration. Many fluorescein fundus photographic studies have been made in cases of angioid streaks (Norton, Gass, Smith, Curtin, David, and Justice, I965; Ernest and Krill, I966; Tanenbaum and de Margerie, I966; Rosen, I968; Wessing and von Noorden, I958). There is a broad agreement on the fluorescein pattern, but the interpretation of the fluorescence phenomenon is neither uniform nor satisfactory.