COMMENTS ON BURCH's CRITICISM OF GITTER ET AL's ARTICLE

Abstract

To the Editor. —The angiographic differentiation between fluorescence and pseudofluorescence is often difficult and best made by observing the lesion over a period of time. True fluorescence or leakage of dye usually increases with time, whereas pseudofluorescence parallels normal background fluorescence for five to ten minutes and then begins to fade, as in Gass' article, Pathology of Disciform, Detachment of Neuroepithelium (Amer J Ophthal63:592, 1967). Figure 6 of our article shows a loss of overlying retinal pigment epithelium at the site of choroidal rupture without true fluorescence. Nevertheless, lesions of this type, ie, choroidal rupture or angiod streaks, as in Fig 9 and 10 of Smith et al's article (Brit J Ophthal48:517 [Oct] 1964), may demonstrate progressive staining with fluorescein, depending on whether or not there is extravascular leakage of dye from the choroidal vasculature. Pseudofluorescence is observed whenever the overlying pigment epithelium is thinned, thereby