Aitchison RT, Kennedy GJ, Shu X, et al. - In the present study, the researchers sought to use swept-source optical coherence tomography (SS-OCT) to measure foveal thickness and macular volume in diabetic patients without cystoid macular oedema, and in non-diabetic people, and relate these measures to participants’ glycaemic control. The diabetic group consisted of type 1 (n = 7) and type 2 (n = 20) diabetic individuals who were matched for duration of diabetes and whose glycaemic control was comparable. The only way to measure macular thickness in vivo is SS-OCT. Compared with nondiabetic people, diabetic individuals en bloc had higher centre point thickness (CPT). In addition, HbA _1c level significantly predicted CPT in the diabetic group. The findings indicate that subclinical thickening in diabetes may occur in the fovea before cystoid macular oedema becomes clinically apparent. This could provide early warning of disease progression to diabetic patients and motivate them to improve control of their diabetes, with a view to avoiding the need for intra-vitreal injections with their associated risks.