Diabetic Retinopathy Treatment Care

My Mother is Diabetic[Insulin-dependant] for last 35 yrs with all the complications of it except nephropathyi.e Autonomic & peripheral neuropathy , retinopathy etc . One & half month ago , she had gangrene of small finger Lt.foot & amputation had to be done at MCP Joint . Now, the doctor says its not a favourite site for skin graft . What else i can do to accelerate the healing of this trophic Ulcer. Help appreciated.Please note that i live in PAKISTAN . So , mention products,drugs which can be obtained in my Country-Thanks a lot for dear help