Color Doppler Imaging of Retrobulbar Circulation in diabetics – A predictor of progression of Diabetic Retinopathy

• Dr. Thanuja G Pradeep,  
• Dr Rachana Kotian,*  
• Raghav Venkatesh

Abstract

PURPOSE : To record the peak systolic velocity (PSV), end-diastolic velocity ( EDV ), and resistivity index ( RI), in the retrobulbar circulation and predict the progression of diabetic retinopathy (DR) using these parameters . MATERIALS AND METHOD: Forty with and without diabetes attending the ophthalmology OPD were enrolled following which they 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 and the PSV, EDV, and RI readings were recorded from the ophthalmic artery (OA), central retinal artery (CRA), and the posterior ciliary artery (PCA). RESULT: A Significant reduction in PSV and EDV with the progression of DR and an increase in RI was noted in the parameters recorded from OA. The indices recorded from CRA showed a clinically significant reduction in PSV and EDV with the progression of DR. RI showed an initial increase with the onset of DR followed by a significant reduction from severe NPDR to PDR. Parameters of PCA showed a reduction in PSV and EDV with the progression of DR, a significant reduction in RI was noted. CONCLUSION: 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 increase with the progression of DR. These could be useful to predict individuals at higher risk for developing severe DR or PDR.

Keywords

Diabetic retinopathy, color Doppler imaging, retrobulbar circulation,Peak systolic velocity,end-diastolic velocity,resistivity index,ophthalmic artery (OA), central retinal artery (CRA), and the posterior ciliary artery (PCA)