Purpose: To compare macular thickness values in normal subjects and diabetic patients without diabetic macular edema (DME) using optical coherence tomography (OCT).
 
Methods :comparative  prospective case control study was conducted on 150 eyes with varying stages of diabetic retinopathy compared with 50 normal control.
We  used the Topcon,3D OCT-2000 machine to perform the fast macular scan which gives 3 concentric circles : 1 , 3 and 5 mm. centered on the fovea . The mean ± standard deviation of macular thickness by area in these eyes were analyzed and compared. 
 
Results: OCT findings demonstrated that the macula in the diabetic patients with no diabetic retinopathy group was significantly thinner than that of the control group with mean (233.34±29.15) and (221.38±24.26) respectively.
In addition, our findings showed that the macular thickness with mean (221.38±24.26) ,(231.30±29.34) and (256.48 ±39.62)gradually increased with the duration of DM with mean (5.48±4.39) ,(13.96±4.93) and (14.70±4.17) respectively probably because of an increase in vascular permeability in the diabetic retinas .
 
Conclusion: OCT will allow the detection of early changes and designing a personalized, noninvasive treatment .the role of neurodegeneration in the pathogenesis of DR is a solid basis for proposing neuroprotection as an effective strategy for preventing or arresting DR.