Professor Stitt is known for his research in ophthalmology, particularly in the pathogenesis of diabetic retinopathy and age-related retinal disease. His research efforts established the role of advanced glycation endproducts (AGEs) and their receptors in the progression of retinal vascular diseases and his work has uncovered several inter-related pathways involved in neuroglial and microvascular dysfunction in the diabetic and ageing retina. This research has led to the development and testing of several drugs that have progressed to clinical trials in diabetic retinopathy and diabetic macular oedema.