What Happens to Vision After Islet Cell Transplant? New Study Tracks Eye Health

Diabetic retinopathy—damage to blood vessels in the eye caused by high blood sugar—is the leading cause of vision loss in people with Type 1 diabetes. For patients considering islet cell transplantation, which is used to help control severe low blood sugar episodes, understanding how the procedure affects the eyes is important.

Islet cell transplants work by placing insulin-producing cells into the body, often leading to dramatic improvements in blood sugar control. However, researchers wondered whether this rapid improvement could trigger temporary worsening of existing eye damage, a phenomenon sometimes called "early worsening" of retinopathy.

A team in Australia reviewed eye health records for 16 people with Type 1 diabetes who received islet cell transplants between 2007 and 2022. On average, these patients had lived with diabetes for 31 years before transplant. Researchers tracked their eye health for up to 9 years after surgery.

Before transplant, more than half of the patients (56%) already had diabetic retinopathy, and four had the most advanced form called proliferative diabetic retinopathy. One year after transplant, blood sugar control improved significantly, with hemoglobin A1c dropping by about 1.2 percentage points.

During follow-up, four patients (25%) experienced some worsening of eye health. However, notably, no patients developed new cases of proliferative diabetic retinopathy. Four patients showed signs of temporary early worsening that did not progress into actual retinopathy.

Not all transplant recipients experienced eye changes. Patients whose eyes worsened tended to have two things in common: they maintained higher blood sugar levels in the first year after transplant, and they had lower C-peptide levels (a marker of how much insulin their own pancreas was producing).

This suggests that patients whose blood sugar control remained less stable, even after transplant, faced greater risk of eye complications. In contrast, patients with stable eye health after transplant generally had better blood sugar control and higher C-peptide production.

This research provides reassuring evidence that islet cell transplant recipients can generally maintain stable vision over years of follow-up. The study found no progression to the most severe forms of diabetic retinopathy and no new cases of proliferative disease.

The findings also highlight the importance of careful eye monitoring after transplant, especially in the first year when blood sugar changes are most dramatic. Some temporary vision changes may occur during the adjustment period, but these appear distinct from ongoing diabetic damage.

For people considering islet cell transplantation, particularly those with existing diabetic retinopathy, eye health should remain part of routine follow-up care alongside blood sugar monitoring.

Source: Transplantation direct. Evidence type: PubMed indexed literature. Type1Cure is an information and intelligence hub, not a medical advice service. This article summarizes published research and does not provide diagnosis, treatment, or personal medical guidance. Always talk to your own care team before changing anything about your Type 1 diabetes management.