Abstract
Purpose: :
Pseudoxanthoma elasticum (PXE) is an inherited disorder of the elastic tissue affecting mainly the skin, the cardiovascular system and the eyes. Funduscopic findings include angioid streaks (AS), peau d’orange, pattern dystrophy like changes, comet tail lesions and secondary choroidal neovascularisations. The functional relevance of fundus alterations characteristic for PXE remains largely unknown. Herein, microperimetry was used to analyze structure-function correlations with findings on fundus photography and fundus autofluorescence (FAF) in patients with PXE.
Methods: :
36 eyes of 29 patients underwent microperimetric assessment (Microperimeter MP1, Nidek). The diagnosis of PXE was confirmed by skin biopsy, mutation analysis of the ABCC6 gene, or by characteristic clinical presentation. Retinal sensitivity in areas of AS, pattern dystrophy- like changes and regions with increased FAF surrounding atrophic areas were analyzed. The t-test for independent samples was used for statistical analysis (SPSS 17, SPSS Inc., Chicago, Illinois, USA).
Results: :
The retina overlying AS visible on FAF (n=22) showed a strong loss of the mean light sensitivity of 5.8 ± 4.9 dB. Areas of AS not visible on FAF (n=6) were considerably less affected showing a mean sensitivity of 13.5 ± 4.4 dB (p=0.03). Corresponding retinal locations in eyes with (n=5) or without (n=7) pattern dystrophy-like changes revealed a mean sensitivity of 4.4 ± 4.5 dB and 17.6 ± 1.9 dB, respectively (p<0.01). Areas of increased FAF surrounding atrophic areas of the central retina had a mean sensitivity of 3.5 ± 3.4 dB compared to 17.6 ± 1.9 dB in patients without central alterations beyond AS (p<0.001).
Conclusions: :
AS with atrophy of the retinal pigment epithelium as detected by FAF, areas of pattern dystrophy-like alterations and regions of increased FAF surrounding retinal atrophy lead to a topographically related decrease in retinal sensitivity. These fundus alterations may have prognostic relevance for visual function in patients with PXE. Thus, FAF imaging may aid in the prognosis of visual function in patients with PXE.</b>
Keywords: retinal degenerations: hereditary • imaging/image analysis: clinical • degenerations/dystrophies