Analysis Of Hemodynamic Changes Of Ocular Vascular In Diabetic Patients By Color Doppler Ultrasonography

ObjectiveDiabetic retinopathy(DR) is the serious complication of diabetes melllitus.Micrangium hemodynamic changes play the central role in the pathogenesis of DR. The development of DR is close connected with ischemia and hypoxia of retina. Since early DR is reversible and functional,so early intervention has important meaning with reducing morbidity. To understand the correlation between the ocular and the development of diabetic retinopathy in type 2 diabetic patients, and to investigate the applicative value of color Doppler ultrasonography, we measured the the ocular hemodynamic changes of central retinal artery (CRA),posterior ciliary artery (PCA) and ophthalmic artery (OA) with color Doppler ultrasonography.Data and methods108 diabetic patients with different stages of DR were prospectively included in this investigation. Diabetes mellitus was diagnosed on the clinical presentation and features according to WHO standard. Following ophthalmoscopy or fundus photography,DR was classified according to Clinical Classification Standard of Diabetic Retinopathy issued by the Chinese Ophthalmological Association. We divided the 216 eyes of 108 diabetic patients into 3 groups:NDR(92 eyes without DR),NPDR(70 eyes with non-proliferative DR), PDR(54 eyes with proliferative DR).We also included 106 eyes of 53 healthy subjects by the way of health control group(HC group). They were without diabetes mellitus, hypertension and ocular pathyology.Ocular blood flow velocity was determined by CDI of CRA,PCA and OA using the Sequioa 512 by Siemens and iE33 by PHILIPS with a high frequency probe.The subjects assumed a supine position and the probe was applied to the closed eyelids. Angle correction was applied to the pulsed Doppler recording to minimize errors in the measured velocities. With CDI we measured the peak systolic velocity(PSV), end diastolic velocity(EDV) and resistant index (RI) of blood flow of the artery.ResultsNormal CRA, PCA and OA has typical arterial blood flow frequency spectrum. With the progression of diabetic retinopathy, PSV and EDV of CRA,PCA and OA decreased and RI increased significantly. Systolic accelerated time extend gradually. In proliferative DR, PSV of CRA is only amount to 50% of normal systolic velocity. Statistical analysis (ANOVA) indicated differences in the PSV, EDV and RI of CRA,PCA and OA among the four groups (P<0.05). Follow-up SNK-q test show that between NDR and normal control group, there was no statistical deference PSV of CRA, PCA and OA (P>0.05), there was statistical deference in EDV and RI of CRA, PCA and OA. There was statistical deference of hemodynamic parameter in group NPDR and PDR compared with normal control group (P<0.05). In group PDR, PSV and EDV of CRA, PCA and OA is lowest, RI is highest. Compared with NPDR and NDR, there was statistical deference of hemodynamic parameter (P<0.05).ConclusionIn the present investigation we assess the changes of ocular hemodynamic in DR with Doppler. The results of our investigation indicated a significant decrease in PSV and EDV in the CRA,PCA and OA of diabetics with DR and an increase in RI. The results show that DR lead to the increase of circulation resistance in the retina and choroid. The reason maybe is diabetes mellitus-associated microvascular damage.We found the of flow velocity and resistance index in the CRA, PCA and OA of diabetics with NDR. In early diabetes melllitus, before we found the damage by fundus examination, retina and choroid have been pathological condition. The hemodynamic abnormality have appeared before the change of vessel form. Vascular changes and consequently ocular changes play the central role in the pathogenesis of DR.In conclusion, color Doppler ultrasonography can reflect accurately the change of diabetic retinopathy. It also has important value for detecting early retinal hemodynamic changes.