Background: This study is aimed to find out the correlation between change in macular volume on optical coherence tomography (OCT) in patients with uncontrolled HbA1c levels . Methods: It is a observational study. Patients with diabetes mellitus for over 5 years were included in the study. Only one eye of each patient was selected for analysis. Eyes with proliferative diabetic retinopathy were not included in the study. Chronic HBA1c level was defined as mean HbA1c value in last one year duration. Central Subfield Volume (CSV) , Central Subfield Thickness (CST) and Total Macular Volume (TMV) were all measured by OCT. Results: 50 eyes from 50 patients (22 women and 28 men ; mean age 63.5 years ). Mean duration of Diabetes Mellitus (DM) being 10.5 years. 6 patients had Type 1 DM and 44 patients had Type 2 DM. Of these , 19 eyes (38 % ) had no diabetic retinopathy (DR) and 31 eyes (62 % ) had non proliferative diabetic retinopathy. In statistical analysis , CST ( mean 188.82 ± 27.62 µm , p = 0.03 ) , CSV ( mean 0.148 ± 0.022 mm3 , p = 0.03 ) and TMV ( mean 6.495 ± 0.717 mm3 , p = 0.003 ), all positively correlated with chronic HBA1c level (8.95 ± 1.40 % ). Conclusion: There is a positive correlation between chronic HbA1c and macular volume in patients with DM > 5 years duration without Macular oedema. Our studies suggest that there are changes in values of subclinical macular volume or thickness before onset of diabetic macular oedema (DMO) becomes clinically significant. Strict glycaemic control ( HbA1c levels below 6 ) is needed in case of diabetic patients to prevent development and further deterioration of macular function prior to development of DMO .