When there is going to be retina regrow cure ?

Stem Cell trials: Currently there are several stem cell trials being conducted to replace retinal tissue. Summary of phase 1 trial results have been posted online and can be found by searching. Going to clincaltrials.Gov will help you find current trials in place and the status of recruitment.

Not soon: Retina light receptor cells do not divide after birth so what you have at that point is all you will get. Some investigators think stem cells offer some promise. Others are working on reversing the turning off of the DNA that prevents dividing. We have a long way to go so don't hold your breath.