Correlation between central foveal thickness as measured by OCT andHbA1c level in diabetes retinopathy

Objectives: To evaluate the correlation between Glycosylated Haemoglobin (HbA1c) level and central foveal thickness measured by Optical coherence tomography (OCT) in patients with type 2 diabetes mellitus.Materials and methods:This was a retrospective single center study of 6 month duration including patients of pre-proliferative stage of type 2 diabetes mellitus. Clinically significant macular oedema (CSME) was diagnosed by using OCT. OCT examination by ‘RT optovue, Fremont, CA’ and HbA1c measured by specific high-pressure liquid chromatography methods. If patient have both eye macular oedema, eye with thicker macular oedema was used for statistical analysis. Exclusion of patients who received intraocular surgery, cataract surgery,pars plana vitrectomy, Severe vitreous haemorrhage,etc.Results:One hundred four eyes of 104 patients were included in this cross-sectional study. The mean Age ±SD was 62.3±8.1 years (range, 40–77 years). Mean value of HbA1c was 7.8%±1.4% (range, 5.1%–12.1%). Mean DM duration was 11.2±5.5 years (range, 1–30 years). Mean central retinal thickness was 257.1±79.3 μm (range, 151–526 μm). Univariate analysis was significant with HbA1C level (7 or over) (P=0.005). Not statistically significant with Sex (P=0.78), Right or left eye (P=0.59). Conclusion:Patients with HbA1c of 7% or above had an increase in macular thickness as measured by OCT in shorter DM duration (< 10 years). Its association with macular oedema is statistically significant. Good sugar control decreased the risk of diabetic macular oedema.