Researchers have developed a gene therapy to treat Best disease in canine models. The study was published in PNAS last week.

I sort of remember this but what is Best disease again?
You might recall the term “egg-yolk macula” from school. It’s a hereditary retinal dystrophy that involves the RPE and leads to a bilateral yellow egg-yolk appearance in the macula. The appearance of the lesion usually occurs in ages 3-15 but can also been seen later in life.

Tell me about the dog study.
The research team found that one underlying defect in Best disease is that the RPE doesn’t tightly connect to the photoreceptor layer, there is a slight separation. This gives a delay in communication and allows for build-up of metabolic waste giving the egg-yolk appearance.
In this study, they injected a working copy of the gene into the eye and found that the lesions actually improved and it restored the proper connection between the outer retina and the RPE. According to the study, the results have held for 5 years.
A lot needs to be done before conducting human trials but the work is a major step forward. (via)