Abstract
Purpose: :
Pseudoxanthoma elasticum (PXE) is a systemic disease which frequently leads to a loss of vision due to ocular involvement. Typical findings include angioid streaks, peau d’orange and salmon spots. The retinal pigment epithelium (RPE) has been suggested to be of importance in the progression of disease and the occurrence of visual loss. To assess the integrity of the RPE-photoreceptor complex fundus autofluorescence (FAF) imaging and spectral domain optical coherence tomography (SD-OCT) were performed in a large cohort of PXE patients.
Methods: :
The diagnosis of PXE was confirmed by clinical examination, ABCC6 gene mutation screening and skin biopsies. Retinal imaging techniques included digital fundus photography, fluorescein angiography (FAG), FAF imaging and SD-OCT (HRA SPECTRALIS, Heidelberg Engineering). Findings were described and classified into several categories related to the disease stage (early changes, presence of CNV or fibrovascular scar) and appearance on FAF.
Results: :
Mean age of the 46 patients (92 eyes) analyzed was 50 years (SD 13.8, range 13 - 74) and mean best-corrected distance visual acuity (BCVA) 20/125 (LogMAR mean 0.8, SD 0.69). PXE-typical fundus changes were present in all eyes. Angioid streaks were visible in all eyes in all imaging modalities and showed abnormal layering of the RPE-photoreceptor complex in SD-OCT. Focal spots of increased FAF alongside angioid streaks, consisting of pigmentations visible on fundus photography, constitute the parastreak phenomenon. Peau d’orange was - contrary to salmon spots - not visible on FAF and SD-OCT but detectable by infrared reflectance imaging. Further findings such as drusen of the optic nerve head (5 eyes) and pattern dystrophies (8 eyes) were observed in a subset of patients.
Keywords: retinal degenerations: hereditary • imaging/image analysis: clinical • retinal neovascularization