Endocrine Abstracts

This study describes the evolution of retinopathy 5 years after islet transplantation (IT) with the Edmonton protocol in type 1 diabetic patients. Before IT and then yearly for 5 years, 21 patients (13 islet-alone (ITA), 8 islet-after-kidney (IAK)) underwent monitoring of laboratory parameters, continuous 24 h mean blood pressure (24h BP) and 72 h glucose (CGM), as well as complete ophthalmologic examination. Ten of the 21 patients (48%) were insulin-independent 5 years post-IT (median (IQR) 5-year post-IT A1c: 6.9% (6.0–7.9); n=21; P<0.001). Four had lost their islet graft but were analyzed on an intention-to-treat basis. Before IT, 5/42 eyes were blind due to diabetes. A retinopathy was found in 26 of the remaining 37 eyes (70.3%) with panphotocoagulation in 19/37 eyes (51%). Five years post-IT, a stabilization of the retinopathy was found in 32/37 eyes (86%), and a mild worsening in 5/37 eyes (14%). No progression of a non-proliferative to a proliferative retinopathy was observed. Two vitreous bleeding occurred during the 1st year post-IT and spontaneously resolved in two different patients. Four patients required a photocoagulation during the 5-year follow-up period. There was no significant difference between ITA and IAK. The evolution of post-prandial blood glucose (P=0.0004), CGM-mean glucose (P=0.0053) and CGM–SD (P=0.002), but not of fasting blood glucose and C-peptide, ß score, GAD, lipids, blood pressure, diabetes duration, visual acuity, differed significantly between the groups worsening and stabilization. Five years post-IT, visual acuity (VA) had improved in 38% of the 37 eyes, stabilized in another 38% and worsened in 24%. Over the 5-year period, the mean VA did not change significantly in the whole group, but differed between ITA and IAK (P<0.0001), with a best and stable VA in ITA, and a greater benefit in IAK.

Conclusion: Islet transplantation enables to reach a 5-year insulin-independence rate close to 50% and a stabilization or improvement of retinopathy and visual acuity in 80% of cases.