Stargardt disease, or fundus flavimaculatus, is an inherited juvenile macular degeneration that causes progressive vision loss usually to the point of legal blindness. The progression usually starts between the ages of six and twelve years old and plateaus shortly after rapid reduction in visual acuity.
It can be associated with several different genes:
STGD1: The most common form of Stargardt disease is the recessive form caused by mutations in the ABCA4 gene. It can also be associated with CNGB3.
STGD3: There is also a rare dominant form of Stargardt disease caused by mutations in the ELOVL4 gene.
STGD4: Associated with PROM1.
The classification “STGD2″ is no longer used.
Stargardt disease is the most common form of inherited juvenile macular degeneration.
Those with Stargardt disease are sensitive to glare; overcast days offer some relief. Vision is most noticeably impaired when the macula (center of retina and focus of vision) is damaged, leaving peripheral vision more intact. Symptoms usually appear before age 20. Symptoms include wavy vision, blind spots, blurriness, impaired color vision, and difficulty adapting to dim lighting.
Some patients are able to drive. Many patients use magnifiers to help them see, and wear sunglasses to slow the development.
The genetic defect is manifest in the visual phototransduction cycle. The ATP-binding cassette transporter is defective and leads to a build up of a toxic metabolite lipofuscin.
Some doctors have recommended colored lenses that filter out wavelengths shorter than 600 nm; the light wavelengths that stimulate rod vision.
There are no clinical trials to provide evidence for ways in which sufferers can slow the progression of the disease. Therefore the advice provided is based on theoretical models of the disease, and includes avoiding bright sun light where possible, and wearing a broad brimmed hat and sunglasses where appropriate.
Currently undergoing trials, AREDS2 is a supplement containing lutein and zeaxanthin thought to slow progression of the disease. Different from AREDS, AREDS2 contains no vitamin A, which Stargardt’s patients should avoid.
The disease was discovered in 1909 by Karl Stargardt, an ophthalmologist in Berlin.
In 1997, it was discovered that mutations in the ABCA4 gene cause Stargardt. The mutations cause the production of a dysfunctional protein that cannot perform energy transport to and from photoreceptor cells in the retina. The photoreceptor cells then degenerate, causing vision loss.
Stem Cell Therapy
On November 22, 2010, it was announced that Advanced Cell Technology received United States Food and Drug Administration clearance to immediately initiate a Phase I/II multicenter clinical trial using retinal cells derived from human embryonic stem cells (hESCs) to treat patients with Stargardt’s Macular Dystrophy. This is the first ever human trials of this nature as an approach to treat Stargardt’s Macular Dystrophy.
In Sept 2011 ACT announced they were beginning the next stage of treatment for SMD, and Dry AMD as the first stage proved to be safe by an independent board of experts.