Stargardt disease is an inherited form of macular degeneration that gradually impairs central vision over time. A genetic mutation in ABCA4 creates lipofuscin buildup under the macula, leading to gradual loss.

Symptoms

Stargardt disease is an inherited form of macular degeneration affecting the macula of the retina and leading to progressive loss of central vision while leaving peripheral vision unaffected. ABCA4 gene mutations that provide instructions for producing lipofuscin transport proteins from retinal cells cause its accumulation, damaging retinal pigment epithelial cells and eventually leading to damage and gradual decline of central vision and color perception over time.

Stargardt disease symptoms include a gray or black spot in the center of vision, difficulty reading or driving, glare or shadows on objects and gradual loss of central vision for children with this disorder; they may struggle with reading letters and numbers and recognizing pictures; they may have trouble following moving objects or adapting to dark environments after going outdoors on bright days.

Children and teens diagnosed with Stargardt disease must understand its progression and seek support services immediately. An ophthalmologist specializing in retinal diseases should be seen for diagnosis, as well as connecting with others affected by Stargardt and seeking counseling if needed.

Stargardt’s disease may not have a cure, but there are treatments that may slow its progression and enhance visual acuity. A regular intake of vitamins C and E, zinc, lutein, and zeaxanthin may protect the eyes from UV damage while wearing sunglasses with wide brim hats is important when spending time outdoors.

Topical cholinergic medication like echothiophate iodide may help slow the progression of Stargardt’s disease by blocking certain chemicals found within the eye that degrade retinal pigment epithelial cells. Patients living with Stargardt’s should discuss this option with their ophthalmologist for an evaluation.

Diagnosis

Stargardt disease is an inherited disorder characterized by progressive central vision loss while maintaining peripheral vision, most often in young adults and children. Its cause lies in genetic mutations found in ABCA4 gene and typically follows a recessive inheritance pattern. Macular degeneration often results from accumulation of fatty deposits on retinal pigment epithelium (RPE).

As this disease advances, the central region of the macula becomes clouded and difficult to differentiate details, leading to decreased color vision and loss. Usually first signs appear during childhood or adolescence and remain mild in severity.

Eye examinations can detect symptoms of the disease. Your physician may order an electrodiagnostic test to examine retinal function; other possible tests include visual acuity tests, Amsler grid exams and fluorescein angiography to view macula.

Stargardt disease will typically require the expertise of a specialist such as an ophthalmologist, retinal specialist or geriatrician familiar with macular degeneration in older people. An ophthalmologist will typically inquire into family histories related to this form of degeneration before making their diagnosis.

Genetic testing is vital for patients living with Stargardt’s disease. A DNA test can be performed to ascertain whether either parent has the recessive gene for Stargardt’s, as well as to locate any ABCA4 mutations present within their genomes.

Stargardt’s disease does not currently have any FDA-approved treatments; however, low vision specialists can help patients adjust to living with it by providing low vision aids such as magnifiers, special lights and telescopes as well as providing alternative techniques for performing everyday tasks such as reading and writing.

An ongoing clinical trial to treat Stargardt’s disease caused by mutations to ABCA4 gene is known as ACDN-01 and employs an innovative gene editing technique called RNA exon editing to address it. The Foundation Fighting Blindness is funding this trial and researchers plan to enroll 30 participants with either clinical or genetic diagnoses of Stargardt’s disease for participation.

Treatment

Patients with Stargardt disease who still possess adequate central vision may benefit from wearing protective sunglasses and wearing a wide-brimmed hat outdoors to minimize UV damage, and limiting the use of vitamin A supplements which could increase the risk of macular degeneration.

Most cases of Stargardt’s are linked to sequence variants in the ABCA4 gene, which provides instructions for producing a protein called retinaldehyde that converts light into electrochemical signals in the retina. When this gene does not function as expected, an accumulation of lipofuscin forms within retinal pigment epithelial cells which leads to central vision loss.

Though no cure exists yet for Stargardt’s, the Foundation Fighting Blindness Clinical Research Institute (FFBCRI) has conducted multiple studies in an attempt to find possible treatments. One such study, ProgStar, is the world’s largest international multi-center natural history study on monogenic retinal degenerative disease ever undertaken.

This study involves retrospective and prospective data collection as well as an analysis of the natural progression of Stargardt’s disease. To participate, patients must have been diagnosed with Stargardt caused by a pathogenic variant in ABCA4 gene as well as having confirmed Stargardt phenotype. Furthermore, at least six-year old children must cooperate during eye exams as well as provide informed consent for using medical record information from them.

Participants of the STARLIGHT study received MCO-010, an oral medication which prevents retinal axons and dendrites from breaking down, to treat Stargardt’s patients over time. Three patients predominantly displayed macular atrophy while three exhibited pan-retinal disease phenotype. Overall, patients demonstrated a mean improvement of 10 ETDRS letters in mean BCVA when wearing wearable magnifiers at baseline and longitudinally; additionally they achieved improved performance on Octopus Visual Field Perimetry as well as Multi-Lumennce Shape Discrimination Test (MLSDT).

As valuable as an increase in BCVA was, the primary purpose of the study was its ocular and systemic safety. The most frequent adverse reaction of the drug was nausea; however, this could easily be managed using anti-nausea medication or acetaminophen as necessary.

Prevention

Stargardt disease is an inherited condition that results in progressive central vision loss, caused by accumulation of lipofuscin within the retinal pigment epithelium (RPE). The RPE converts light into visual signals for transmission to the brain; mutations of ABCA4 cause malfunction of this process and build-up of excess lipofuscin which collects in the macula area over time, blurring or distorting vision over time.

Central vision begins to deteriorate first, impairing reading or driving abilities as well as distinguishing colors and fine details. Because these symptoms could easily be mistaken for dry age-related macular degeneration, early diagnosis by an ophthalmologist is crucial.

Your ophthalmologist may diagnose your condition with a fundus photo. This allows them to spot the presence of fatty deposits underneath the macula and assess disease progression. They’ll also conduct a dilated eye exam and test peripheral vision.

Always wear sunglasses when outdoors as UV rays can hasten degeneration of your eyesight. Furthermore, it is wise to adhere to the daily allowance for vitamin A as too much can lead to choroidal neovascular membrane (CNVM) formation.

If your family history includes Stargardt disease, genetic testing should be considered in order to confirm its diagnosis and determine your risk for developing late-onset forms of the condition.

Research is ongoing into potential gene replacement or stem cell therapies for Stargardt disease. Meanwhile, eating well-balanced meals featuring leafy green vegetables and fish as well as omega fatty acid supplements like docosahexanoic acid (DHA) may also be beneficial in maintaining eye health.

At present, no treatment can stop the progression of Stargardt disease. Some patients with Stargardt may require laser treatment to seal off leaky blood vessels in their retina, though this won’t stop its progression; low vision aids are recommended instead to maximize use of remaining peripheral and central vision.