I am not familiar with the specifics of diabetic retinoplasty, but I think I would speak for the most of people here at curezone, if I would suggest improving health overall rather than chasing symptoms as there is no magic bullet for anything. One has to have diabetes to have diabetic retinoplasy, correct? So, digging deeper, there are also underlying causes for diabetes - virtually 100% of the time it is the lifestyle - poor dietary choices, reliance on drugs, little movement, Depression - in that order. To help your mother (and enjoy radiant health yourself) you would have to address these issues first - if you do, you would find out that these are the only issues that need to be addressed. Nothing in your body works in isolation, especially eyes. There are plenty of information on this forum (see under "Foods" and "Cleansing") that should help you get started. One site that I found very helpful some time ago was reading all the chapters in http://www.thedoctorwithin.com.
I hope this helps!