Importance of fluorescein angiography for differentiating between early papilledema and papillitis

Optic disc swelling poses a diagnostic challenge due to its multiple underlying pathological causes. This study aimed to investigate the use of fluorescein angiography (FLA) in combination with optical coherence tomography (OCT) as a diagnostic tool for differentiating between papilledema and papillitis in cases of optic disc swelling. A total of 12 patients were included in the study in whom both FLA and OCT of the optic disc were performed to evaluate the optic disc swelling in cases of papilledema (7 patients, 14 eyes) and papillitis (5 patients, 7 eyes). The fluorescence behavior of the optic disc during late phase FLA was examined in relation to papillary thickness measured by OCT. In the papilledema group OCT revealed a mean papillary thickness of 873 µm. In 6 patients FLA detected a ring-shaped papillary hyperfluorescence with papillary thicknesses ranging from 611 µm to 972 µm. Another patient with chronic and marked papilledema exhibited bilateral panpapillary leakage in FLA and papillary thicknesses of 1287 µm (right eye) and 1526 µm (left eye). In the papillitis group FLA showed panpapillary leakage in all cases. The mean papillary thickness was 865 µm (range 632-1195 µm). In acute optic disc swelling and a papillary prominence less than 1000 µm in OCT, a difference in FLA was noticeable between papilledema and papillitis. While acute and mild papilledema exhibited a ring-shaped hyperfluorescence, papillitis showed a panpapillary leakage in late phase FLA in the examined cases. This difference could not be seen in the case of papilledema with chronic and severe swelling.