The impact of diabetes mellitus and hyperglycaemia on the refractive status of the eye

Purpose: Diabetes mellitus is a condition of considerable concern globally, which can affect the visual system in various ways, including changes to visual function, the integrity of the ocular surface and the retinal microcirculation. The aim of this article is to provide an overview on the perspectives around the relationship between diabetes and refractive status.
Material and Methods: Narrative literature review.
Results: The relationship between diabetes, hyperglycaemia and refractive error has been of interest to clinicians and researchers for more than a century. This review shows that research studies investigating the relationship have varied considerably in their design, methodology, their outcome measures used, as well as their reported results. While some uncertainty remains, there is evidence that short-term, drastic changes in blood glucose levels affect the refractive status of human eyes leading to fluctuating and blurred vision.
Conclusion: Patients starting glycaemic treatment or undergoing adaptation to a new treatment regime may present with considerable refractive changes and visual complaints. Before considering the prescription of spectacle lenses, clinicians should ideally monitor patients in whom glycaemic control has been initiated or is being adjusted until a stabilisation of blood glucose levels has been confirmed.