Differential diagnosis between the primary total choroidal vascular atrophies.

Mlany descriptions of the primary chorio-retinal degenerations have been reported (Sosbry, Franceschetti, Joseph, and Davey, 1952; Waardenburg, I 959; Waardenburg, Franceschetti, and Klein, i96i, I963; Franceschetti, FranSois, and Babel, I963). Earlier diagnostic methods of distinguishing these disorders were limited to genetic investigation, general examination, objective ocular examination, functional ocular examination, and investigation of development (Fran.ois, 1958). Further histological (McCulloch, I969; Vogel, 1972) and fluorescein angiographic studies (Krill, Newell, and Chishti, I968; Amalric, I969; Hyvarinen, Mlaumenee, George, and Weinstein, I969) gave fresh insight into the nature of many of these conditions. A clear-cut classification of the choroidal atrophies based on fluorescein angiographic and functional studies was described by Krill and Archer (I97I), but even this does not offer a precise method for differential diagnosis between the primary chorio-retinal degenerations in all cases. In our earlier study (Simell and Takki, 1973), a constant relationship between gyrate atrophy of the choroid and retina and hyperornithinaemia was found. This offers