To date, there is no cure for Stargardt's disease. Stem cell treatment does appear to offer some promises for the future; however, currently, it is not a viable treatment alternative. At this time, all treatment modalities are geared towards obtaining the most vision that the eyes will offer. This includes a very precise refraction by a low vision specialist (ask your local ophthalmologist for a referral for this type of specialist) and certain magnifying aids for better reading acuity.
I encourage you to inquire with the closest university-based ophthalmology department. It is in this setting, where most cutting edge research is being performed. It is possible to become enrolled in research projects where the latest treatment alternatives are being explored, including stem cell treatment.
I hope this is helpful and good luck and you deal with this condition...