Dunedin Hospital consultant eye surgeon and also University of Otago ophthalmology consultant Dr Francesc March said that diabetic retinopathy (DR) was the most common microvascular complication from diabetes, and it was also a leading cause of blindness.
Landmark diabetes studies had identified high HbA1c (blood-glucose levels), long duration of type-1 diabetes, kidney disease and high diastolic blood-pressure as the greatest risk factors for rapid progression of DR.
Other risk factors included the frequency of severe hypoglycemia (low blood-sugar levels) and diabetic ketoacidosis (high blood acidity).
"Currently, the recommended intensive therapy option for people with type-1 diabetes is automated insulin delivery (AID).
Dr March said all AID systems had demonstrated benefits for glycemia (blood-sugar levels), and research on individuals with very unhealthy glycemia suggested that dramatic and rapid improvements were possible for many.
"Given this potential for rapid improvements in glycemia with AID systems, concerns have been raised that this may lead to early worsening of diabetic retinopathy (EWDR) — often defined as DR progression during the first year after rapid improvement in glycemia.
"It is still unclear which pathophysiological mechanisms may cause EWDR, but variations in the somatotropic axis and higher retinal concentrations of angiogenic factors have been suggested."
While the health benefits of intensively improving glycemia clearly outweighed the risks of EWDR in the long term, Dr March said a greater understanding was required to monitor and manage these risks.
For the first time, Otago researchers led by Professor Ben Wheeler and Dr March have demonstrated the new AID technology is safe for the eyes.
"We looked at the short-term effects of diabetic retinopathy in people aged 13 and older with type-1 diabetes after using automated insulin delivery systems for more than six months," Dr March said.
"We included 165 people and we demonstrated that most participants, 79%, saw improvements or no change in their diabetic retinopathy, with younger age being a protective factor.
"In this study, stable or improved DR grades were evident in most who had recently commenced AID."
