Background We undertook this study to evaluate the changes in macular edema of uncontrolled type 2 diabetes mellitus patients with the regulation of hyperglycemia. Methods The study population was comprised of 35 type 2 diabetes mellitus patients who had poorly regulated blood glucose values. Ophthalmic examinations including baseline and 6-month macular edema index values of patients by Heidelberg Retinal Tomography (HRT) macular module were done. Results Twenty four (68.6%) female patients and 11 (31.4%) male patients with a mean age of 50.7 ± 10.3 (mean ± SD) years and mean diabetic duration of 9.8 ± 7.5 years participated in the study. Twenty two (62.9%) did not have diabetic retinopathy (DR), whereas 13 (37.2%) had background DR with macular edema. There was a significant correlation between duration of diabetes and HRT-II macula edema index for the right and left eyes ( r = 0.40, p = 0.21 and r = 0.40, p = 0.22, respectively). Conclusions Macular edema did not change significantly by regulation of glycemic control in the study group.