A year ago, Canadian Taylor Binns was slowly going blind. Today, he's driving, reading and living a normal life because of a revolutionary stem-cell treatment.08 December 2012
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Dystrophies make the second largest group of eye diseases after inflammations. By clinical classification, dystrophies can be primary (no past history of ophthalmological diseases) and secondary (caused by inflammations and injuries).
Fetal stem cells offer gigantic potential for correction and inhibition/termination of dystrophy progression.
Eye tissue quality improvement triggered by capillary network growth, and optical nerve quality improvement after stem cell therapy result in long-term remissions of different retinal disorders (enzymopathies affecting cell quality, nucleotide/chromoprotein metabolism disorders, damage of neuroreceptors, retinal pigment epithelium and retinal ganglion cells).
Best’s and Stargardt’s diseases are hereditary primary pigmentary (tapetoretinal) dystrophies affecting mainly the macula (yellow spot). Hereditary central dystrophies (abiotrophies (“abiotrophy” - lack of vital capacity) develop at a certain age, affect several members of the same family, cause identical damage in both eyes, and they are triggered by a genetic defect causing impairment of enzyme systems and metabolic processes associated with them.
Stargardt’s disease is an autosomal recessive hereditary macular degeneration described by K. Stargardt in 1909-1913. Stargardt’s disease may occur in one of every 20,000 children over the age of 6 and is usually diagnosed before the age of 20. It gradually leads to marked vision loss. The process is localized in the macula and extends to the surrounding retina.
Stargardt’s disease is caused by heterozygosity of ABCA4 (used to be called ABCR) gene. In this disease, loss of central vision may be due to foveal cone degeneration caused by mutation of ABCA4 gene present in foveal and perifoveal cones.
There are 3 stages of the disease:
Stage I – photophobia (dread of light) for no apparent reason, visual acuity reduction to 0.5–0.6.
Ophthalmoscopic findings: optic disc and retinal arteries are normal; macular reflexes either disappear or become blurred; macula is grayish or grayish-reddish; retinal edema in macular region. Visual field borders, scotopic (dark) adaptation and color perception are normal.
Stage II – children complain of marked vision loss (0.1–0.2), photophobia.
Ophthalmoscopic findings: slight blurring of upper and lower borders of the optic disc due to edema of nervous fiber layer; dilution of the veins. Macular reflexes are blurred and polymorphic. Defects in central visual field are not usually found because fixation point is “floating”, color sensitivity threshold increases, and scotopic adaptation remains unchanged.
It is quite difficult to differentiate between stages II and III, and it usually takes around 6 months from stage II to progress to stage III.
Stage III – marked vision loss to 0.0.
Ophthalmoscopic findings: macular reflexes are blurred or absent; retinal pigment epithelium dystrophy with dust-like pigment deposits and multiple small grayish, though sometimes large, irregular lesions with metallic reflection. Scotomas in the visual field. Color sensitivity thresholds increase, mainly to red color, red-green dyschromatopsia. Scotopic adaptation remains unchanged, unless there is peripheral dystrophy.
Stargardt’s disease is usually treated with oxyribonucleic acid and taufonum derivatives.
Best’s Disease – egg-yolk (vitelliform) macular dystrophy described by Best in 1905. First symptoms of the disease appear at different age – from newborns to adults over 30. Best’s is autosomal dominant. Presently, abnormal genes are identified on chromosome 11, but the gene causing this condition is not yet known (since recently, VMD2 gene is associated with Best’s disease).
Best’s disease develops in stages and can be monolateral.
Stage I (“egg-yolk lesion”) – large cyst-like lesion with clear or yellowish content appears in the macula. This lesion has clear borders irradiating into the vitreous body. Both variants are possible within the same family: central scotoma is absent and normal or subnormal visual acuity.
Stage II (“scrambled egg”) – edema and aggregation of exudatation clots in the lesion, hemorrhages are also possible. Gradually, edema and hemorrhages disappear, and the cyst is substituted with flat atrophic yellowish focus “powdered” with fine pigment. Morphology: destruction of pigment epithelium in the macula, atrophy of choriocapillaries, thinning of Bruch’s membrane, partial destruction of neuroreceptors.
Visual acuity reduces to 0.0, seldom to 0.1-02. Preservation of relatively high visual acuity happens when the lesion is located behind neural epithelium.
Currently, there are no effective methods of Best’s disease treatment. Biostimulators provide some stabilization. In case of hemorrhages and exudation, the patient is usually prescribed resolving, dehydration and non-specific anti-dystrophy therapy. The patient should try to prevent focal infections.