Aim: To assess the correlation between Hba1c and central macular thickness in diabetic patients with or without diabetic retinopathy. Material and Methods: This observational cross sectional study was conducted involving the 50 patients with and without signs and symptoms of diabetic retinopathy who are attending the Outpatient Department of Ophthalmology at Maharishi Markandeshwar Institute of Medical Science and Research. All patients underwent SD OCT, and central macular thickness was assessed regardless of the presence or absence of diabetic retinopathy. The HBA1C test was performed the same day as the ophthalmic examination, and its results were correlated with the central macular thickness. Results: The study subjects were divided 66% male and 34% female. The mean CMT was 192.16±10.78, 247.08±13.99, 283.11±22.84, and 289.4±17.82 for the participants with no DR, mild NPDR, moderate NPDR, and severe NPDR, respectively. It was revealed that the mean CMT was highest in individuals with a HbA1c >7 and lowest in those with a HbA1c >7.8%. Conclusion: There was a strong positive association found between the levels of CMT and HbA1c. Increased retinal thickness was seen in patients with HbA1c > 8% and longer-term diabetes, as well as in patients with proliferative and severe non proliferative DR.