What Causes Young Age Cataract And Retina Detachment?

My brother is 45 yers old, healthy, no medical problem but he developed cataract in his left eye, got it operated and after a week, his retina was detached. He went under an emegency operation but retina got detached again and this happened 5 times. They filled his eye with silicone oil. All this was happening in one eye that all of a sudden for no apperent reason his right eyes retina got detached too. Right now, he has silicone oil in his right eye, lense removed from the left eye and vision in left eye is almost gone. He has started having neovascularization in his left etye. They also tried Avastin but it didn't work. I think unless they find out the root/original cuase of the problem that lead to this young age cataract development, nothig would help him. Is here anything that can be done for him? I can email all of his reports if needed. Thanks a lot!!