Doctor's opinion? my question is if diabetic retinopathy is effected due to diabetes, is it curable totally or can we prevent further damage?

Diabetic retinopathy: (dr) is reversible to some extent. Vision can be preserved or improved with proper treatment. Once microvascular damage has occurred and pericyte death has occurred, the threat of recurrent edema (fluid) and/or ischemia (low oxygen) is always present. Thus to say treatments always cure dr is not accurate. In short, dr treatment is successful in most treated patients.

Key is early. : Ophthalmic manifestations of diabetes are dependent on the severity of long term damage caused to the small blood vessels in the eye. If visually significant manifestations are seen early, then there is good prognosis with treatment. Some diabetics will require mild treatment and remain stable, while others may require extensive treatment and still have continued damage. Key: dilated exam yearly.