New treatment for patients with a form of congenital retinal blindness

Source: Scientific European

A new treatment for patients with a form of congenital retinal blindness has shown success in improving vision, according to new results.

“It was very dramatic to see one of the patients improve from only being able to differentiate light or dark to reading many letters on an eye chart at two months following the first injection,” 

“This therapy to repair the genetic defect in LCA10 is a breakthrough in treatment strategy and will open the door for clinical trials in other patients with this condition and other similar conditions that are currently untreatable,” 

“We performed an extreme form of personalized medicine where we targeted not just a specific gene but a specific mutation in a gene,” 

“It is gratifying to see clinical evidence supporting the action of this oligo predicted from basic science. In the future, we hope to evaluate patients carrying two identical splicing mutations to determine whether the efficacy of the injection might be even greater.”

• Children with retinal dystrophies can benefit from a definitive diagnosis and attentive follow-up, which may include corrective lenses, low vision aids and treatment of accompanying genetic conditions.
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• Identification of gene mutations as well as the availability of genetic testing has proven beneficial for patients and their families by allowing them to adjust to a future that includes visual disability.
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• Human trials that treat a mutation in the RPE65 gene, which causes some cases of Leber congenital amaurosis, have produced promising results.
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• Two drugs, fenretinide and isotretinoin, have shown promise in early animal studies for treating Stargardt macular dystrophy. Although they are not being pursued aggressively by the drug makers, isotretinoin was shown to suppress the buildup of the toxic pigment lipofuscin, which leads to loss of vision in Stargardt disease. Likewise, fenretinide interferes with the production and accumulation of the toxin A2E that leads to lipofuscin deposits. 
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• Clinical trials of fenretinide are in place for treating age-related macular degeneration, though none are planned for Stargardt. 
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• “It could possibly work in Stargardt disease, but we may never find out until we have clinical trials,” 

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• said Peter J. Francis, MD, PhD, associate professor of retinal and ophthalmic genetics at the Casey Eye Institute, Oregon Health & Science University in Portland. Dr. Francis noted as well that clinical trials of isotretinoin have not been initiated for Stargardt disease, and one possible reason is concern over the drug’s side effect profile.