It’s an exciting time for ophthalmology and the search for a cure for blindness. In the last month alone, three separate reports came out of the scientific world claiming that researchers have found either a cure or a potential cure for the condition. That’s big news, but that doesn’t mean everyone’s vision is in the clear yet. Blindness is caused by a number of factors, and some forms of it are easier to cure than others.
Here’s what the science world has been reporting in the last month when it comes to the exciting advancements in curing blindness.
British Doctors Successfully Cure Blindness Caused by Age-Related Macular Degeneration
The first of three potential cures is for age-related macular degeneration, which is the most common cause of vision loss in people older than 60 years. There are two forms of AMD: dry and wet. The dry form is characterized by the presence of yellow deposits (drusen), whereas the wet form is characterized by the growth of abnormal blood vessels from the choroid underneath the macula.
Surgeons at London’s Moorfields Eye Hospital used a new treatment to successfully transplant eye cells received through stem cells into a patient with wet AMD. The transplanted cells are used to replace diseased cells at the back of the eye. The surgeons believe that the treatment can apply for patients with dry AMD as well.
The surgery was performed on a 60-year-old female patient—who is the first of 10 others who are scheduled to take part in the trial—and there have been no complications since. With hopes that the procedure will fully restore the patient’s vision, the final outcome of her results will be determined by early December 2015.
“The reason why we are so excited is that we have been able to grow a perfect copy of the eye,” said Professor Lyndon Da Cruz, a surgeon at Moorfields. He added that he was optimistic that the patient’s sight would be restored. “Having got this far, we feel it will work,” Prof Cruz said.
Using Green Algae Protein to Cure Blindness
In degenerative diseases of the eye such as retinitis pigmentosa and macular degeneration, the rods and cones are destroyed, but the messenger cells stay intact. This is what gives scientists hope for the next potential cure for blindness using channelrhodopsin-2, a light-sensitive protein found in green algae.
Channelrhodopsin-2 is placed into the retina using gene therapy, bypassing the rod-and-cone system entirely, giving the eye’s ganglion cells the ability to sense light on their own. Some levels of colorblindness may persist in patients, even after successful treatment, but it is theorized that the brain can potentially make adjustments to make up for this.
The technique was discovered in 2006 when Zhuo-Hua Pan, PhD, placed channelrhodopsin-2 into blind mice and found that it restored their vision almost immediately. Almost 10 years later, the protein is on track to be part of human trials. RetroSense Therapeutics is expected to begin testing on 15 patients by the end of 2015.
Spark Therapeutics’ Gene Therapy
The third potential cure for blindness that lit up headlines this month comes from another gene therapy by Spark Therapeutics Inc. The therapy, SPK-RPE65, targets mutations in a gene known as RPE65 that are associated with retinal dystrophies in patients.
Patients with these rare mutations progressively lose the ability to see in dim light and ultimately experience complete vision loss. Through eye surgery, the new therapy delivers a functional copy of the RPE65 gene to replace the mutated version causing the vision loss.
“We saw substantial restoration of vision in patients who were progressing toward complete blindness,” said Albert Maguire, MD, professor of ophthalmology at the University of Pennsylvania’s Perelman School of Medicine and principal investigator in the trial. “The majority of the subjects given SPK-RPE65 derived the maximum possible benefit that we could measure on the primary visual function test, and this impressive effect was confirmed by a parallel improvement in retinal sensitivity.”
- Age-related macular degeneration. WebMD website. http://www.webmd.com/eye-health/macular-degeneration/age-related-macular-degeneration-overview. Reviewed April 26, 2015. Accessed October 22, 2015.
- Austin H. British doctors hail ‘cure for blindness’ with successful treatment of age-related macular degeneration. Independent website. September 29, 2015. http://www.independent.co.uk/news/science/british-doctors-hail-cure-for-blindness-with-successful-treatment-of-age-related-muscular-a6671106.html. Accessed October 22, 2015.
- First patient receives potential new treatment for wet age-related macular degeneration in London Project to Cure Blindness. Moorfields Eye Hospital website. September 29, 2015. http://www.moorfields.nhs.uk/news/new-trial-wet-amd. Accessed October 22, 2015.
- Kaye B. Scientists may have found a cure for blindness. UPROXX website. September 21, 2015. http://uproxx.com/gammasquad/2015/09/algae-cure-for-blindness. Accessed October 22, 2015.
- Tirrell M. Spark Therapeutics gene therapy hits goals in blindness study. CNBC website. October 5, 2015. http://www.cnbc.com/2015/10/05/spark-therapeutics-gene-therapy-hits-goals-in-blindness-study.html. Accessed October 22, 2015.