[1] In terms of the first description of the disease,[2] it follows an autosomal recessive inheritance pattern, which has been later linked to bi-allelic ABCA4 gene variants (STGD1).
However, there are Stargardt-like diseases with mimicking phenotypes that are referred to as STGD3 and STGD4, and have a autosomal dominant inheritance due to defects with ELOVL4 or PROM1 genes, respectively.
Symptoms typically develop before age 20 (median age of onset: ~17 years old),[4] and include: wavy vision, blind spots, blurriness, loss of depth perception, sensitivity to glare, impaired colour vision,[4] and difficulty adapting to dim lighting (delayed dark adaptation).
[citation needed] Historically from Stargardt's first description of his eponymous disease until recently, the diagnosis was based on looking at the phenotype using examination and investigation of the eye.
Importantly, the exact genotype (i.e., combinations of both ABCA4 variants along with the presence of additional genetic modifiers[5]) is highly prognostic for the age of onset and disease progression.
In STGD4, a butterfly pattern of dystrophy is caused by mutations in a gene that encodes a membrane bound protein that is involved in the elongation of very long chain fatty acids (ELOVL4)[15] Diagnosis is firstly clinical through history and examination usually with a Slit-lamp.
If characteristic features are found the investigations undertaken will depend on locally available equipment and may include Scanning laser ophthalmoscopy which highlights areas of autofluorescence which are associated with retinal pathology.
In one study, 35% of patients diagnosed with Stargardt Disease through physical ophthalmic examination were found to be misdiagnosed when subsequent genetic testing was done.
There are no prospective clinical trials to support these recommendations, but they are based on scientific understanding of the mechanisms underlying the disease pathology.
There are three strategies doctors recommend for potential harm reduction: reducing retinal exposure to damaging ultraviolet light, avoiding excess Vitamin A with the hope of lowering lipofuscin accumulation and maintaining good general health and diet.
[17] Reasons for improvement may include transfer of organelles (mitochondria, lysosomes), enhanced clearing of toxic Vitamin A byproducts, and neuroprotection of photoreceptors.
On the other hand, the consumption of oily fish, in a diet similar to that which doctors recommend for age related macular degeneration, can be used to slow the progression of the disease.
[citation needed] Advances in technology have brought devices that help Stargardt patients who are losing their vision maintain their independence.
Low-vision aids can range from hand lenses to electronic devices and can allow those losing their vision to be able to carry out daily activities.
The long-term prognosis for patients with Stargardt disease is widely variable and depends on the age of onset and genetic alleles.
[21] Some patients, usually those with the late-onset form, can maintain excellent visual acuities for extended periods and are therefore able to perform tasks such as reading or driving.
In 1909 he described 7 patients with a recessively inherited macular dystrophy, now known as Stargardt's disease, being described as a progressive and severe reduction of central vision, which develops in the first and second decade of life.