Retrobulbar blood flow changes in eyes with diabetic retinopathy a 10 year follow up study

Abstract

PurposeWe sought to assess long-term changes in the flow parameters of retrobulbar vessels in diabetic patients.MethodsThe retrobulbar circulation of 138 eyes was evaluated between 1994 and 1995 and 36 eyes were reevaluated between 2004 and 2008 (study group). They were divided into four groups: eyes of diabetic patients without diabetic retinopathy (DR), eyes with nonproliferative DR, eyes with proliferative DR, and eyes of nondiabetic patients (controls). Color Doppler imaging was used to assess the flow velocities in the major retrobulbar vessels. The resistive index (RI) was calculated and compared among the groups and between the two time periods.ResultsRI values of the central retinal artery and posterior ciliary artery had increased in the two non-DR groups and in the nonproliferative DR group, with a surprising decrease measured in eyes with proliferative DR (P= nonsignificant [NS]). Combining the nonproliferative DR and proliferative DR groups resulted in a milder increase of the RI of the posterior ciliary artery (P= NS) and the central retinal artery (P=0.02) in the DR group compared to the other groups.ConclusionOur results demonstrate that an increase of the resistance in the retrobulbar vessels, as a part of DR, can lessen over time and may even be reversed.

Assessment of Retinal Blood Flow in Diabetic Retinopathy Using Doppler Fourier-Domain Optical Coherence Tomography

“…20–21 TRBF was significantly lower in eyes with severe NPDR and PDR compared to normal eyes. The decrease in TRBF in eyes with severe NPDR compared to normal eyes was in accordance with the previously published results by Neudorfer 25 et al, who showed that the resistive index of the central retinal artery and posterior ciliary artery increased in eyes with NPDR in comparison to healthy control eyes, indicating that blood vessel resistance increased in eyes with NPDR. Since vascular resistance is inversely proportional to blood flow, retinal blood flow decreased in eyes with NPDR.…”

“…10–12 However, other studies have shown increased blood flow in PDR compared to normals. 25 There was no significant difference in the total cross-sectional areas of either veins or arteries between the eyes with DR and the normal eyes. Of note, there was no significant difference in mean TRBF between eyes with severe NPDR and those with PDR.…”

Evaluation of retrobulbar circulation in type 2 diabetic patients using color Doppler imaging

“…It has been suggested that the decrease in resistance reflects the beginning of an increase in retinal blood flow with the progression of DR due to the short-circuiting of the obstructed retinal capillary network. [ 28 ] This is supported by histopathologic studies, which have shown areas of capillary closure being traversed by preferential dilated anastomotic channels. [ 29 ]…”

“…evaluated the long-term changes in the retrobulbar circulation of 138 eyes of diabetic subjects at a 10-year follow-up. [ 28 ] Patients were divided into four groups, namely, nondiabetic controls, diabetics without DR, nonproliferative DR, and proliferative DR. RI values of CRA and PCA had increased in the two no retinopathy groups and in the nonproliferative DR group, with a surprising nonsignificant decrease in the proliferative DR group. The authors have concluded that an increase of resistance in the retrobulbar blood vessels due to DR can decrease over time and may even be reversed.…”

Effect of Single Intravitreal Bevacizumab on Ophthalmic and Middle Cerebral Arterial Blood Flow in Retinopathy of Prematurity

“…Ocular blood flow (OBF) analysis by Doppler imaging has been carried out in several ocular conditions as a repeatable, noninvasive and safe procedure [9,10,11,12]. Studies investigated the effect of IVB treatment on retrobulbar hemodynamics in different ophthalmic disorders and demonstrated that IVB causes prominent changes in ocular perfusion [13,14].…”