Stargardt Macular Degeneration

By: Macular Degeneration In General

One of the more popular juvenile macular degeneration is the Stargardt Macular Degeneration. This category of macular degenerationi was first reported in 1901 by a German ophthalmologist, Karl Stargardt. It has the common feature of loss of central vision. In 1963, France ophthalmologist Adolphe Fransceschetti used the term Fundus flavimaculatus for a degenerative loss of central vision, but soon to be identified as Stargardt Macular Degeneration by Hadden and Gass in 1976.

This macular dystrophy affects about one in every 10,000 children. The problem may start anytime between the ages 6 and 20, but patients may not notice until they reach their 30s or 40s. First, the children may experience difficulty in reading, and complaining of some blind spots that are often gray, black or hazy at their central vision. They will need more time to adjust between the different lighting of the room too, between light and dark environments.
The dystrophy affects the retina, that sensitive tissue that lies at the back of the eye, focusing especially in the middle region called the macula. The macula is where focus is, that area that is highly sensitive and strong enough to give us the sharp central vision for tasks such as reading, driving and recognising faces.

Stargardt macular degeneration is similar to dry macular degeneration, with the build-up of abnormal yellow pigment substance called lipofuscin building up in cells underlying the macula. Patients will also experience problem with night vision, and it will be difficult for them to move around in places with low lighting. In some others, the patient may also experience colour impairment at advanced stages of the disease.

Vision loss is usually slow, until the 20/40 level. It may suddenly shoot right up to 20/200 where the patient is considered legally blind and forbidden from driving. In some cases, it may even deteriorate to 10/200 within a matter of months.

Genes are a big issue when it comes to Stargardt macular degeneration. A group of genes collectively known as the ABC genes, was found to be the culprit of this juvenile macular degeneration, a discovery made since 1997. The ABCA4 gene, responsible for the production of protein used as an energy transport to and from photoreceptor cells in the retina, mutates and produces dysfunctional protein that cannot perform such transport function. The useless ABCA4 protein then allows the accumulation of yellow, fatty material to accumulate in the retina, slowly covering the macularand ultimately causes the loss of vision. However, more studies had to be done to further understand how the mutated genes affect the biochemistry of the retina.
All is not lost for patients with Stargardt disease. It was found that patients may slow down the progression of vision loss by wearing UV protective sunglasses and avoid exposure to bright light. Although there is not yet any effective treatment for this form of macular degeneration at this moment, it is believed that the identification of the genes behind macular degeneration will help the search for new strategies and therapies. The latest is a study scheduled to begin in 2011, for the injection of embryonic stem cells into the eyes of twelve patients affected by the disease. The Advanced Cell Technology announced in November 2010 that the FDA had approved this injection and study.

Stargardt Macular Degeneration may be either autosomal or recessive trait type. A person may not have prior family history, but may have a recessive gene. If both parents carry a mutated gene, there is always a chance for the child to develop macular dystrophy. In fact, there may be more than one family member who gets Stargardt. For children who did not develop Stargardt, there is again the possibility of carrying the mutant gene, and pass on to their children instead. The chances will be 25%.
Three tests are used to check the presence of fundus flecks and the loss of cones to determine whether a patient has Stargardt Macular Degeneration. It may be fluorescein angiography, electroretinography or electrooculography. Since this problem is rare, it is not a widely studied subject. The discovery of genetic mutation in Stargardt may have encouraged the findings of genetic links for age-related macular degeneration, but further studies on the age-related macular degeneration may also become the contributing factor towards better understanding of Stargardt’s disease and its possible lead to new treatment. Whichever way it may be, it will always remain hopeful for parents and their affected children.