Purpose: To evaluate the correlation between glycosylated haemoglobin (HbA1c) and central foveal thickness as measured by optical coherence tomography (OCT) in patients with diabetes.
Methods: Retrospectively review of medical records of central foveal thickness as measured by OCT and laboratory data of glycosylated haemoglobin. HbA1c was compared with foveal thickness measured by OCT within the preceding 3 months. Clinically significant macular oedema (CSME) was diagnosed if central foveal retinal thickness was greater than 325 mum in OCT.
Results: One hundred and two eyes of 102 patients were included in this cross-sectional study. Univariate analysis revealed that the CSME diagnosed by OCT in diabetes was not statistically significant with sex, right or left eye, DM duration over 10 years or not, and AC sugar level (over 140 or not). The HbA1C level (8 or over) and age (50 or less) showed a significant (P=0.005 and 0.006, respectively) and positive association with macular thickness in OCT. A trend towards higher risk was seen for factors of age <or=50 and HbA1c >or=8%.
Conclusions: Patients with HbA1c of 8 or above had an increase in macular thickness in type 2 diabetic eyes and there was a statistical significant correlation between younger age, shorter DM duration and thicker macular thickness. Strict sugar control decreased the risk of diabetic macular retinopathy, and OCT could be an excellent detector of early diabetic macular oedema.