Comparison of retrobulbar circulation in type 2 diabetics and non-diabetics using color Doppler imaging

: To record the resistivity index (RI), peak systolic velocity (PSV) and end-diastolic velocity (EDV) in the retrobulbar circulation and predict the progression of diabetic retinopathy (DR). : Forty patients with type 2 diabetes (DM) and forty non-diabetics patients attending the outpatient clinic for an eye examination were enrolled after informed consent. All study participants underwent a comprehensive ophthalmic examination including dilated fundoscopy. The diabetic patients were assigned to groups based on ETDRS grading of diabetic retinopathy. Color Doppler of the eye was performed on all the enrolled individuals. The peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistivity index readings were recorded from the ophthalmic artery(OA), central retinal artery (CRA), and the posterior ciliary artery (PCA). : The values acquired from OA showed a significant increase in RI and a significant decrease in PSV and EDV with the advancement of DR. The parameters PSV and EDV recorded from CRA, as were also decreased DR progressed. This decrease was clinically significant RI index recorded from CRA first displayed a rise with the appearance of DR and a notable decline from severe NPDR to PDR. As DR progressed, PCA parameters revealed a decrease in PSV and EDV and RI. Significant changes in the resistivity index and flow velocities were observed in the retrobulbar vessels of the two groups. In this study, the results of decreased flow velocity with the progression of diabetes support the rheological changes involved in the pathophysiology of diabetes. The resistance index shows an significant increase with the progression of DR. These could be useful to predict individuals at higher risk for developing severe DR or PDR.