Claim: Gene therapy improves sight in near-blind patients.
Verdict: SUPPORTS

Retrieved passages:
title: Gene therapy
text: results in independent clinical trials using gene therapy to treat the condition. In all three clinical trials, patients recovered functional vision without apparent side-effects. In September researchers were able to give trichromatic vision to squirrel monkeys. In November 2009, researchers halted a fatal genetic disorder called adrenoleukodystrophy in two children using a lentivirus vector to deliver a functioning version of ABCD1, the gene that is mutated in the disorder. An April paper reported that gene therapy addressed achromatopsia (color blindness) in dogs by targeting cone photoreceptors. Cone function and day vision were restored for at least 33 months in two

title: Choroideremia
text: choroideremia is an ideal candidate for gene therapy there are other potential therapies that could restore vision after it has been lost later in life. Foremost of these is stem cell therapy. A clinical trial published in 2014 found that a subretinal injection of human embryonic stem cells in patients with age-related macular degeneration and Stargardt disease was safe and improved vision in most patients. Out of 18 patients, vision improved in 10, improved or remained the same in 7, and decreased in 1 patient, while no improvement was seen in the untreated eyes. The study found "no evidence of

title: Gene therapy of the human retina
text: Gene therapy of the human retina Retinal gene therapy holds a promise in treating different forms of non-inherited and inherited blindness. In 2008, three independent research groups reported that patients with the rare genetic retinal disease Leber's congenital amaurosis had been successfully treated using gene therapy with adeno-associated virus (AAV). In all three studies, an AAV vector was used to deliver a functional copy of the RPE65 gene, which restored vision in children suffering from LCA. These results were widely seen as a success in the gene therapy field, and have generated excitement and momentum for AAV-mediated applications in retinal

title: Vision rehabilitation
text: related to vision cease translating faulty proteins. Gene therapy seems to be the most prominent field that might be able to restore vision through therapy. However, there are some problems with gene therapy which can lead to severe conditions such as death. For physical approaches to vision rehabilitation, most of the training is focused on ways to make environments easier to deal with for those with low vision. Occupational therapy is commonly suggested for these patients. Also, there are devices that help patients achieve higher standards of living. These include video magnifiers, peripheral prism glasses, transcranial direct current stimulation (tDCS),

title: Gene therapy of the human retina
text: for the treatment of choroideremia. Dr. Robert MacLaren of the University of Oxford, who lead the trial, co-developed the treatment with Dr. Miguel Seabra of the Imperial College, London. This Phase 1/2 trial used subretinal AAV to restore the REP gene in affected patients. Initial results of the trial were reported in January 2014 as promising as all six patients had better vision. Recent research has shown that AAV can successfully restore color vision to treat color blindness in adult monkeys. Although this treatment has not yet entered clinical trials for humans, this work was considered a breakthrough for the

title: Virotherapy
text: successful, faced considerable delays due to safety issues as the uncontrolled delivery of a gene into a host genome has the potential to disrupt tumour suppressing genes and induce cancer, and did so in two cases. Immune responses to viral therapies also pose a barrier to successful treatment, for this reason eye therapy for genetic blindness is attractive as the eye is an immune privileged site, preventing an immune response. An alternative form of viral gene therapy is to deliver a gene which may be helpful in preventing disease that would not normally be expressed in the natural disease condition.

title: Leber's congenital amaurosis
text: therapy to restore vision in LCA patients. In all three clinical trials, patients recovered functional vision without apparent side-effects. These studies, which used adeno-associated virus, have spawned a number of new studies investigating gene therapy for human retinal disease. The results of a phase 1 trial conducted by the University of Pennsylvania and Children’s Hospital of Philadelphia and published in 2009 showed sustained improvement in 12 subjects (ages 8 to 44) with RPE65-associated LCA after treatment with AAV2-hRPE65v2, a gene replacement therapy. Early intervention was associated with better results. In that study, patients were excluded based on the presence of

title: Visual impairment
text: encouraging for researchers. It is hoped that gene therapy may be even more effective in younger LCA patients who have experienced limited vision loss, as well as in other blind or partially blind individuals. Two experimental treatments for retinal problems include a cybernetic replacement and transplant of fetal retinal cells. Statements that certain species of mammals are "born blind" refers to them being born with their eyes closed and their eyelids fused together; the eyes open later. One example is the rabbit. In humans, the eyelids are fused for a while before birth, but open again before the normal birth

title: Gene therapy for color blindness
text: therapy should be feasible for humans as well. It is also theoretically possible for trichromats to be "upgraded" to tetrachromats by introducing new opsin genes. The goal of the gene therapy is to make some of the cones in the retina of a dichromat individual to express the missing photopigment. Although partial color blindness is considered to be a mild disability and even an advantage under certain circumstances (such as spotting camouflaged objects), it can pose challenges for many occupations such as Law Enforcement, Airline pilot, Railroad workers and military service. More generally, color codes in maps and figures may

title: Gene therapy for color blindness
text: of life will improve (or worsen) after the therapy. Gene therapy for color blindness Gene therapy for color blindness is an experimental gene therapy aiming to convert congenitally colorblind individuals to trichromats by introducing a photopigment gene that they lack. Though partial color blindness is considered only a mild disability and is controversial whether it is even a disorder, it is a condition that affects many people, particularly males. Complete color blindness, or achromatopsia, is very rare but more severe. While never demonstrated in humans, animal studies have shown that it is possible to confer color vision by injecting a

title: Retinal gene therapy using lentiviral vectors
text: Retinal gene therapy using lentiviral vectors Gene therapy using lentiviral vectors is being explored in early stage trials. In a Phase I clinical trial of three patients, two showed no improvement and one of them had some improvements. The study concluded further investigation is warranted for the use of the procedure to treat Leber's congenital amaurosis. Other early trials have been used to explore the treatments potential, including for therapeutic use of recombinant adeno-associated virus (rAAV) vectors. Many other possible viral vectors remain options for the treatment of various genetic disorders in the retina that lead to blindness. Retinal gene

title: Gene therapy for color blindness
text: in full sun), and a reduced visual acuity (generally 20/200 after correction). Moreover, the research may have strong implications toward genetic therapy of other cone diseases. Other cone diseases such as Leber's congenital amaurosis, cone-rod dystrophy, and certain types of maculopathies may be treatable using the same techniques as the gene therapy used for color blindness. There has been ongoing research for gene therapy to treat Leber's congenital amaurosis, a genetic disorder in photoreceptors that can lead to vision loss and blindness. These treatments use AAV vector and is delivered in much the same way as the gene therapy for

title: Gene therapy for color blindness
text: from red-violet, and have indeed gained trichromacy. The treated monkeys were also more successful when their color vision was tested with a modified Ishihara test. In 2007, Alexander JJ et al. used gene therapy to restore some of the sight of mice with achromatopsia. The results were positive for 80% of the mice treated. Moreover, a paper by Komáromy et al., published in 2010, deals with gene therapy for a form of achromatopsia in dogs. Cone function and day vision have been restored for at least 33 months in two young dogs with achromatopsia. However, this therapy was less efficient

title: Neuro-ophthalmology
text: and novel therapies are emerging to treat traditionally vision-devastating disease. For example, clinical trials began in February 2014 to use gene therapy to treat Leber hereditary optic neuropathy, which is one of the first uses of gene therapy in the central nervous system. Progress has also been made in understanding retinal ganglion cell regeneration and in re-establishing synaptic connections from the optic nerve to the brain, more than in other regions of the central nervous system. One of the goals of the National Institutes of Health is to use the visual system as a window to understand neural plasticity and

title: Gene therapy for color blindness
text: Gene therapy for color blindness Gene therapy for color blindness is an experimental gene therapy aiming to convert congenitally colorblind individuals to trichromats by introducing a photopigment gene that they lack. Though partial color blindness is considered only a mild disability and is controversial whether it is even a disorder, it is a condition that affects many people, particularly males. Complete color blindness, or achromatopsia, is very rare but more severe. While never demonstrated in humans, animal studies have shown that it is possible to confer color vision by injecting a gene of the missing photopigment using gene therapy. As

title: Choroideremia
text: trials for both choroideremia and Leber's congenital amaurosis (LCA) have produced somewhat promising results. Clinical trials of gene therapy for patients with LCA began in 2008 at three different sites. In general, these studies found the therapy to be safe, somewhat effective, and promising as a future treatment for similar retinal diseases. In 2011, the first gene therapy treatment for choroideremia was administered. The surgery was performed by Robert MacLaren, Professor of Ophthalmology at the University of Oxford and leader of the Clinical Ophthalmology Research Group at the Nuffield Laboratory of Ophthalmology (NLO). In the study, 2 doses of the

title: Gene therapy for color blindness
text: be difficult to read for individuals with color blindness. Because only a single gene codes for a photopigment and the gene is only expressed in the retina, it is a relatively easy condition to treat using gene therapy compared to other genetic diseases. However, there remains the question of whether the therapy is worthwhile, for an individual to undergo an invasive subretinal injection to temporarily treat a condition that is more of an inconvenience than a disorder. However, complete color blindness, or achromatopsia, is very rare but more severe. Indeed, achromats cannot see any color, have a strong photophobia (blindness

title: Gene therapy for color blindness
text: tritanopia can in principle be treated as well. For tritanopia, the S-opsin gene must be introduced instead of M-opsin gene. Despite the success in animals, there still remain challenges to conducting gene therapy on humans for treating color blindness. How to deliver the viral vector into the retina is probably the main obstacle to making gene therapy a practical treatment for color blindness. Because the virus has to be injected directly by using a needle to penetrate the sclera of the eye, the treatment may be highly unpleasant and is a risk for eye infection. Without a way to deliver

title: Retinitis pigmentosa
text: trials investigating the insertion of the healthy RPE65 gene in retinas expressing the LCA2 retinitis pigmentosa phenotype measured modest improvements in vision; however, the degradation of retinal photoreceptors continued at the disease-related rate. Likely, gene therapy may preserve remaining healthy retinal cells while failing to repair the earlier accumulation of damage in already diseased photoreceptor cells. Response to gene therapy would theoretically benefit young patients exhibiting the shortest progression of photoreceptor decline; thus, correlating to a higher possibility of cell rescue via the healthy inserted gene. The progressive nature of and lack of a definitive cure for retinitis pigmentosa contribute

title: Gene therapy
text: the treatment of blindness due to Leber's congenital amaurosis. The price of this treatment was 850,000 US dollars for both eyes. Speculated uses for gene therapy include: Athletes might adopt gene therapy technologies to improve their performance. Gene doping is not known to occur, but multiple gene therapies may have such effects. Kayser et al. argue that gene doping could level the playing field if all athletes receive equal access. Critics claim that any therapeutic intervention for non-therapeutic/enhancement purposes compromises the ethical foundations of medicine and sports. Genetic engineering could be used to cure diseases, but also to change physical