Growth Factor Responses of Human Iris Pigment Epithelial Cells to High Glucose Conditions

Diabetic eye disease is a leading cause of vision impairment and blindness around the world. In 2020, diabetic retinopathy—including macular oedema and the complications of neovascularisation—was responsible for 2.9 million cases of moderate and severe vision impairment and 0.9 million cases of blindness. As highlighted in the Global Burden of Disease Study, in contrast to other causes of avoidable blindness, the prevalence of diabetic retinopathy continues to increase globally. Understandably, substantial research effort has been invested over multiple decades to elucidate the pathogenic mechanisms of diabetic retinopathy, particularly the molecules that drive or limit its microvascular damage. This work has focused for the most part on the posterior segment of the eye, with limited attention directed at the involvement of anterior eye tissues. However, the pigment epithelium of the iris is a source of soluble growth factors, which have the potential to alter microvascular structure and function, including effects on angiogenesis. In this work, we sought to establish the response of human iris pigment epithelial cells to high glucose conditions.