New Retinitis Pigmentosa Treatment Explored

new retinitis pigmentosa treatment

In the quest for effective treatments of retinitis pigmentosa, a research team recently completed a study in which they were able to restore some visual ability to mice who had inherited advanced retinal degeneration. Based on the results of this study, the authors noted that their approach “warrants consideration as a method for restoring vision in advanced retinal degeneration.”

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Retinitis pigmentosa is a group of inherited conditions in which individuals experience progressive peripheral vision loss and problems with night vision and eventual loss of central vision. Vision loss is associated with the degeneration of the light receptors (cones and rods) in the retina.

Retinitis pigmentosa is a major cause of blindness around the world. It affects about one of every 4,000 people and is slightly more prevalent among people ages 45 to 64 (1 in 3,195). Currently there is no known cure, but researchers have been exploring a number of avenues (see Related Articles below).

New retinitis pigmentosa study
In the new study, a team of scientists at the University of Manchester conducted a study in which they treated blind mice with a human protein called rod opsin. This protein, which is light sensitive, was placed into the undamaged cells of the animals’ retina, which allowed them to turn into cells called photoreceptors (the rods and cones), which enable sight.

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According to the researchers, the treated mice gained an ability to distinguish flickering light and spatial patterns. The use of a human protein is better than previous attempts to use a non-human protein, noted the study’s leader, Rob Lucas, GSK Professor of Neuroscience, because it is easy to produce and is less damaging.

Overall, the scientists concluded that “Given the inherent advantages in employing a human protein, the simplicity of this intervention, and the quality of vision restored, we suggest that rod opsin merits consideration as an optogenetic actuator for treating patients with advanced retinal degeneration.” In other words, this treatment approach should be explored further as a possible treatment option for people who have retinitis pigmentosa.

Related Articles: Artificial retina restores vision in retinitis pigmentosa
Update on artificial retina for retinitis pigmentosa
Retinitis pigmentosa cure found using gene therapy in dogs
Valproic acid may stop vision loss in RP

Source
Cehajic-Kapetanovic J et al. Restoration of vision with ectopic expression of human rod opsin. Current Biology 2015 Aug 17; 25(16): 2111-22

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Comments

My son has Retinitis Pigmentosa and so I follow these articles very closely. He is 30 and has relatively good vision 20/40 in one eye and 20/60 in the other. His field of vision has been reduced to about 30 degrees and he is completely night blind. I would consider his vision to be bad and is almost to the point where he will not be able to drive and he can't at night right now. However, a number of clinical trials are going on in the US and elsewhere that are designed to "retain" what vision a person has left but not necessarily improve it dramatically. In my son's case he does not qualify for these clinical trials since his vision is not bad enough. This seems counter-productive to have a treatment that is hoped to retain what vision a person has but is not allowed to be used on someone until there vision becomes bad enough that it is not worth saving that much. I understand that these are clinical trials but still they should be applied to those people you would hope to help the most which is to diagnose and treat the vision problem early and retain the vision when people still have a significant amount to retain. Is there something that I am missing from this?
Mike: Thank you for your comment. I am not a medical professional, so I can only offer my personal thoughts. I agree, it does seem unfair for clinical trials to often accept only those who are not yet "bad enough." There are probably numerous factors that play a role in these decisions, including funding, available resources, success of previous research on which new trials can be based, current knowledge base on which to justify new trials, etc. I wish I had a more satisfying response for you and your son. I wish you both the best.
this study sounds much promising. One thing I am not clear about is, does it restore the lost cells? If so, are the subjects supposed to possess too bad vision? Please let me know
Varun: Thank you for your question. Since I am not a medical professional, I can adequately answer your question. Based on the results of this study, it seems that adding the protein to the damaged area allows new cells to be formed. As for the quality of vision restored, I would think more research is necessary before that can be determined.
Hi Varun. I'm one of the co-authors of this paper. The treatment does not generate new cells as such. Instead it targets healthy surviving cells which are not able to respond to light and provides them with the proteins necessary for converting light into visual responses. I.e. it makes non-vision cells into vision cells. Whilst these findings are significant and certainly promising it is still rather early when considering clinical trials. One advantage of our technique however is that there are are few barriers to clinical trial, due to the fact that all the proteins used are human proteins.
Wow, thank you Rob!
Thank you so much, Rob!
Rob: Thank you so much for a providing this clarification. I, for one, look forward to the results of future studies utilizing these proteins.
That's a great news. Thanks, Rob!!