The Natural History of the Progression of Atrophy Secondary to Stargardt Disease Type 4: PROM1-Related Macular Dystrophy

Inclusion Criteria: 1. Provide a signed informed consent form and authorization allowing the disclosure and use of protected health information. 2. The designated primary study eye must have at least one well-demarcated area of atrophy. The lesion size should not exceed the area to be tracked in the OCT mode (20x20 degrees). 3. Have at least one pathogenic mutation confirmed in the PROM1 gene and a Stargardt phenotype. 4. The primary study eye must have clear ocular media and adequate pupillary dilation to permit good quality FAF and sd-OCT imaging in the opinion of the investigator. 5. Be able to cooperate in performing the examinations. 6. Be willing to undergo ocular examinations once every 6 months for up to 24 months. 7. Be at least six years old. 8. Both eyes can be included if inclusion criteria are fulfilled for both eyes. Exclusion Criteria: 1. Ocular disease, such as choroidal neovascularization, glaucoma and diabetic retinopathy, in either eye that may confound assessment of the retina morphologically and functionally. 2. Intraocular surgery in the primary study eye within 90 days prior to baseline visit. 3. Current or previous participation in an interventional study to treat STGD such as gene therapy or stem cell therapy. Current participation in a drug trial or previous participation in a drug trial within six months before enrollment. The use of oral supplements of vitamins and minerals are permitted although the current use of Vitamin A supplementation shall be documented. 4. The site Principal Investigator may declare any patient at their site ineligible to participate in the study for a sound medical reason prior to the patient's enrollment into the study. 5. Any systemic disease with a limited survival prognosis (e.g. cancer, severe/unstable cardiovascular disease). 6. Any condition that would make adherence to the examination interfere with the patient attending their regular follow-up visits schedule of once every 6 months for up to 24 months difficult or unlikely, e.g. personality disorder, use of major tranquilizers such as Haldol or Phenothiazine, chronic alcoholism, Alzheimer's Disease or drug abuse. 7. Evidence of significant uncontrolled concomitant diseases such as cardiovascular, neurological, pulmonary, renal, hepatic, endocrine or gastro-intestinal disorders. 8. Patient is known to have one or more pathogenic mutation(s) in the ABCA4, RDS, or ELOVL4 genes.