This study aims to systematically assess the retest reliability and ability to detect a change of new visual function tests and ophthalmological imaging methods for observing the natural course of pseudoxanthoma elasticum (PXE).

Inclusion Criteria:

• Adult patients with Pseudoxanthoma elasticum according to the Plomp criteria or adult patients with a PXE-mimicking phenotype (angioid streaks and peau d'orange [e.g., ENPP1 or GGCX-associated disease])
• Best-corrected visual acuity (BCVA): ≤1.0 LogMAR

Exclusion Criteria:

• Inability to give informed consent
• Claustrophobia
• Prior surgery (other than anti-VEGF injections, cataract surgery, YAG laser capsulotomy, or laser retinopexy) that - according to the investigator's judgment - may affect visual function assessments (e.g., retinal detachment surgery, glaucoma filtration surgery, or a history of a corneal transplant in the study-eye)
• Concurrent ophthalmic conditions in the study eye that (according to the investigator's judgment) may contribute to loss of vision, such as clinically significant opacification of the ocular media (corneal dystrophies, cataract), other retinal diseases, or disease of the optic nerve head and visual pathway (including amblyopia)
• Major surgery planned or other events that (according to the investigator's judgment) could hinder follow-up examinations (e.g., knee replacement)

The study will include subjects with PXE and PXE-mimicking ocular phenotypes.