I Think your child is having gyrate atrophy of choroid .these problem comes under retinal and macular dystrophy.See THESE PROBLEM DOESNOT HAVE ANY treatment.

Only thing we can do is that you have to counsel ur child to adapt lifestyle,career options according to vision.For further consultation its better to go good eye institute like LVPEI in hyderabad,Sankar nethralaya in chennai,Aravind eye hospital in madurai.in these institute they are having good retinal examination and have low vision clinic which can give ur child some low visin aids.