Aitchison RT, Kennedy GJ, Shu X, et al. - Considering the possible value of a new ability to demonstrate a preclinical phase of accumulation of multiple pockets of fluid at the fovea, a complication of poor blood glucose control in diabetes which cause impairment of central vision, in enabling diabetic individuals to be alerted to the need to improve their glycaemic control, researchers sought to use swept-source optical coherence tomography (SS-OCT) to determine foveal thickness and macular volume in diabetic individuals without cystoid macular oedema, and in non-diabetic individuals, and correlate these estimates to participants’ glycaemic control. Using SS-OCT (DRI OCT Triton, Topcon, Tokyo, Japan), measurements of center point thickness (CPT) and total macular volume (TMV) were determined. Participants were 27 patients with diabetes [diabetic group; type 1 (n = 7) and type 2 (n = 20) diabetic individuals] and 27 patients without diabetes (non-diabetic group). Macular thickness can only be assessed in vivo using SS-OCT. Higher CPT was observed in diabetic individuals en bloc vs non-diabetic individuals. In addition, HbA1c level was significantly predictive of CPT in the diabetic group. Per results, sub-clinical thickening may occur at the fovea before cystoid macular oedema becomes clinically evident in diabetes. Diabetic individuals could consider this as an early warning of disease progression and should be encouraged to improve control of their diabetes, with a view to avoiding the need of intra-vitreal injections with their attendant risks.