Fundus autofluorescence in patients with pseudoxanthoma elasticum

To characterize changes in fundus autofluorescence in patients with pseudoxanthoma elasticum (PXE). Fundus autofluorescence intrinsically derives from lipofuscin, and the degree of autofluorescence is thought to indicate the degree of retinal pigment epithelium (RPE) metabolic activity.

Twelve eyes of 6 patients (2 men, 4 women) with PXE were studied with a confocal scanning laser ophthalmoscope. Patient age ranged from 42 to 62 years. The autofluorescence of abnormal retinal areas was compared digitally with that of neighboring, presumed healthy control areas. When the average gray level of a fundus region was 2 SDs above or below the average gray level of a control area, autofluorescence of the fundus region was considered abnormal.

In all 12 eyes, some segments of the angioid streaks showed decreased fundus autofluorescence, and other segments of the streaks showed normal autofluorescence. Areas of peripapillary chorioretinal atrophy seen in 2 eyes and of disciform scarring seen in 3 eyes showed decreased autofluorescence. Solitary or multiple drusen-like spots showed increased autofluorescence in all 12 eyes.

Atrophic and degenerative RPE regions showed decreased fundus autofluorescence in areas of chorioretinal atrophy and in some segments of the angioid streaks. Some drusen-like spots showed increased autofluorescence. The characteristic changes in autofluorescence that we observed in PXE patients suggest that the content of the drusen-like substance differs from that of senile drusen and that the drusen-like lesions are similar to the sub-RPE deposits seen in macular dystrophy.