Gene Therapy for Blindness

Jakarta, Blindness choroideraemia type (CHM) is a rare genetic disorder that causes progressive loss of vision due to degeneration of the choroid and retina. The disease is difficult to cure but to the findings there is hope for healing the sufferer.

Oxford University in collaboration with Imperial College London has conducted a study on the treatment of patients with a type of blindness that can not be cured using gene therapy for the first time. If research is successful, it can be applied to the treatment for choroideraemia (CHM).

CHM is a progressive form of blindness is genetically the first to appear in childhood and is estimated to affect more than 100,000 people worldwide. CHM is a retinal degenerative disease that leads to the degeneration of choriocapillaris, retinal pigment epithelium, and photoreceptors of the eye.

CHM is a rare genetic disorder, which causes a progressive loss of vision due to degeneration of the choroid and retina. In childhood, night blindness is the most common first symptoms occur. Along with the development of disease, vision loss can occur.

Vision loss often begins with an irregular ring pattern which gradually extends lead to central vision and out toward the extremes.

CHM only occurs in men and until now there has been no specific treatment for the disease. Diagnos disease is usually done in childhood when symptoms worsen.

The disease will cause blindness around the age of 40 years. The disease occurs because of lack of REP1 gene located on chromosome X.

"The disease has been recognized as a form of blindness that can not be cured since it was first identified more than a hundred years ago. I think that we have designed a genetic treatment that could potentially stop the disease with just one single injection," said Professor Robert MacLaren from University of Oxford, who led the study as reported from Epharmapedia, Wednesday (12/07/2011).

The study involved 12 patients who underwent surgery in which the therapeutic gene is injected into one eye. Other eye will then act as a control against which the eye had been injected with the gene. It aims to assess the effects of treatment.

The purpose of this study was primarily to assess safety, but also to obtain preliminary data on the effectiveness of treatment. The researchers estimate that, these observations will take 2 years to determine whether degeneration has been stopped completely by gene therapy or not.

Therapy is a new gene therapy that is designed to provide the missing genes in people with CHM. Therapy aims to stop the damage that gradually lead to blindness.

The therapy uses a virus, which is basically the viral DNA is used as a gene delivery agent is lost to the eye. The virus has been engineered to infect the light-sensitive cells in the retina, known as photoreceptors.

Then there are genes that are activated and genes become active. With a specific gene therapy, one-time treatment can provide a permanent correction to the disease. Because the gene is estimated to remain in the cells of the retina without limit.

"Treatment by gene replacement in patients with CHM is the ultimate goal of intensive research has been done for 20 years in my lab. The study is expected to fulfill the dream of all patients with CHM who want to look normal again. But there is still need to do further research to confirm and strengthen the results of this research, "says Prof. Seab