Eye Health Among Islet Cell Transplant Recipients With Long-duration Type 1 Diabetes

Diabetic retinopathy (DR) is the commonest cause of blindness among people with type 1 diabetes (T1D) and can progress over time. In Australia, islet cell transplantation (ICT) is available for adults with T1D experiencing recurrent severe hypoglycemia. Rapid improvement in glycemia, which can occur post-ICT, may lead to "early worsening" of DR and warrants investigation. This study explored eye health outcomes among ICT recipients.

This retrospective study examined all ICT recipients at a single tertiary institution in Victoria, Australia, 2007-2022 inclusive. Recipients of successful ICT, with available eye health information pre- and posttransplantation, were included. Eye health outcomes were assessed relative to ICT for changes in DR and other major retinal pathologies.

Sixteen recipients (30 eyes) with T1D duration median 31 y (interquartile range, 26-44) were followed up for 5 y (interquartile range, 4-9). At 12 mo post-ICT, hemoglobin A_1c improved by -1.2 percentage points (-1.9 to -0.5; P < 0.001). Pre-ICT, 9 of 16 recipients (56%) had DR, with 4 recipients having proliferative DR. During follow-up post-ICT, 4 of 16 recipients (25%) had worsening eye outcomes; there were no new cases of proliferative DR. Four recipients had "early worsening" signs, not associated with progression of DR. Recipients experiencing worsening eye outcomes post-ICT exhibited higher hemoglobin A_1c and lower C-peptide levels during 12 mo compared with recipients who had stable eye outcomes (P = 0.02 and P = 0.01, respectively).

These findings highlight the potential positive impact of ICT to stabilize eye health among a small group of ICT recipients with long-duration type 1 diabetes. An extended systematic evaluation of eye health pre- and post-ICT is required to monitor both short-term and long-term eye health among transplant recipients.