Adult-onset vitelliform macular dystrophy (AVMD) is an eye disorder that can cause progressive vision loss. AVMD affects an area of the retina called the macula, which is responsible for sharp central vision. The condition causes a fatty yellow pigment to accumulate in cells underlying the macula, eventually damaging the cells. AVMD usually begins after age 40. Some people remain without symptoms throughout their life. Other people with AVMD may slowly develop blurred and/or distorted vision, that can progress to central vision loss over time. In the past, AVMD was believed to be mainly a genetic disorder caused by mutations in the PRPH2, BEST1, IMPG1, and IMPG2 genes; however, recent studies focused on genetic testing suggest that the genetic cause for most cases of AVMD has not been found. Sometimes AVMD clearly runs in families in an autosomal dominant manner, but the inheritance is suspected to be more complicated in the majority of cases.

Studies have revealed much variability in the signs, symptoms and progression of this condition. Some people with AVMD do not have any visual symptoms throughout their life. Others may experience ongoing visual loss, but for most people the vision loss is not severe. In general, the long-term outlook (prognosis) is usually good, but loss of central visual function is possible.

Currently known genetic causes include mutations in the PRPH2, BEST1, IMPG1, and IMPG2 genes. It is additionally suspected that AVMD might be associated with a single-nucleotide polymorphism (variant DNA sequence) in the HTRA1 gene. Single-nucleotidepolymorphisms in the HTRA1 gene are additionally associated with age-related macular degeneration.

The inheritance pattern of AVMD can be confusing as not all individuals with AVMD have a family history and not all individuals who inherit a causative gene mutation develop symptoms.

CNV is sometimes associated with adult-onset vitelliform macular dystrophy because macular degeneration can damage the retinal layers. When this happens, the vascular layer of the eye between the sclera and the retina known as the choroid may produce new blood vessels (neovascularization) which grow up through the damaged layers and leak or bleed into the retina. This can cause vision loss on its own. If CNV does develop, anti-VEGF therapy such as Ranibizumab or Bevacizumab can control and even reverse the CNV. However anti-VEGF therapy does not stop or reverse the vision loss caused by adult-onset vitelliform macular dystrophy, only the extra vision loss that is due to also developing CNV.

Although vision loss is usually slow, when vision is impaired significantly, people with adult-onset vitelliform macular dystrophy may be referred for low vision testing and rehabilitation. Low vision rehabilitation can help maintain and optimize reading ability and improve overall quality of life.