This disease goes through several stages linked with progressive deterioration of vision.
The more severe changes, usually, happens in individuals older than 40 years.
Various studies have shown that most individuals retain reading and driving vision in at least 1 eye into adulthood (88% have 20/40 or better vision)
In other words, the deterioration of vision usually is very slow and is not significant in most individuals until after age 40 years.
Some patients will never have progression beyond the earliest stages of the disease.
Your sister when says injected dye, means about test performed to detect a complication of this disease, known as choroidal neovascularization (new blood vessel develop and are associated with severe worsening in central vision, and this usually happens in the last stage, atrophic stage of best's disease).
The eyes check ups are usually done every 6 month.
Continue to be a worrier!
Best wishes!
Marija
