Review of a series of 180 blind diabetic patients who had received guide dogs from the Seeing Eye, Inc., over a 17-year period included 85 deceased and 95 living diabetic patients. The average age at onset of diabetes in the entire group was 14.6 years, and the mean age at onset of severe blindness was 31.4 years. Each group of diabetic patients, the living and the deceased, had used its guide dogs an average of 3.5 years. Of the 85 deceased diabetics in this series, the average lifespan after the onset of severe blindness due to diabetic retinopathy was 5.8 years. This suggests that the life expectancy of a diabetic is very poor after the onset of blindness due to severe retinopathy.
Berkow JW, Shugarman RG, Maumenee AE, Patz A. A Retrospective Study of Blind Diabetic Patients. JAMA. 1965;193(11):867–870. doi:10.1001/jama.1965.03090110005001