Colour Doppler imaging of the ocular circulation in diabetic retinopathy

MacKinnon, Jane R.; McKillop, Graham; O’Brien, Colm; Swa, Kenneth; Butt, Zahida; Nelson, Patricia

doi:10.1034/j.1600-0420.2000.078004386.x

Cited by 56 publications

(70 citation statements)

References 21 publications

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“…Our finding of an increased resistivity index in the ophthalmic artery and central retinal vein is similar to that reported by MacKinnon et al [11]. The finding that the resistivity and pulsatile indices of the central retinal artery, posterior ciliary artery, and ophthalmic artery in patients with and without retinopathy are significantly greater than those of healthy individuals is also in agreement with certain other studies [6,[25][26][27].…”

Section: Discussionsupporting

confidence: 93%

“…In contrast, studies using color Doppler imaging reported a reduced blood flow velocity in patients with diabetes which appeared to become further reduced as retinopathy progressed [6,25]. Two other studies evaluated the blood flow velocities of the ophthalmic artery, central retinal artery, and posterior ciliary artery and found decreased PSV and EDV in the central retinal artery in patients with retinopathy [9,11]. Similar results were reported by Mendivil et al, who analyzed 25 type 1 and type 2 diabetes patients with proliferative retinopathy and 30 non-diabetic controls [5].…”

Section: Discussionmentioning

confidence: 99%

“…These studies focused only on some of the orbital vessels and measured indices and velocities in specific diabetic or control groups. They were usually of limited sample size, and the results produced were inconsistent [3][4][5][6][7][8][9][10][11][12].…”

Section: Discussionmentioning

confidence: 99%

“…However, the role of hemodynamics in DR has not been clearly defined [2]. There have also been conflicting reports of impaired hemodynamics in the orbital vessels in patients with DR [3][4][5][6][7][8][9][10][11][12][13][14]. Orbital blood flow velocities were increased in some studies [3], but decreased in others [4, 9-11, 13, 14], or unchanged [15].…”

Section: Introductionmentioning

confidence: 99%

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Orbital Doppler Evaluation of Blood Flow Velocities in Patients with Diabetic Retinopathy

Karami

Janghorbani²,

Dehghani³

et al. 2012

Rev Diabet Stud

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■ Abstract BACKGROUND:There have been conflicting results in relation to impaired ocular hemodynamics in the orbital vessels of patients with diabetic retinopathy (DR). Clarification of the early signs of retinopathy in diabetic patients is urgently needed. AIMS: We aimed to evaluate orbital blood flow velocities using Doppler and gray-scale sonography in patients with DR, and to compare the results with those of their non-diabetic and diabetic peers without retinopathy. METHODS: Orbital Doppler and gray-scale sonography were performed in 123 patients aged 29-77 who had been divided into 3 groups: non-diabetic controls (n = 25), diabetes and impaired glucose tolerance with minimal clinical retinopathy (n = 74), and diabetes with untreated nonproliferative retinopathy (n = 24). Retinopathy was diagnosed by an ophthalmologist on the basis of fundoscopic examination. The peak systolic (PSV) and end-diastolic (EDV) blood flow velocities, and the resistivity and pulsatile indices, of the ophthalmic artery, central retinal artery, posterior ciliary artery, and central retinal vein were measured. RE-SULTS: Compared with healthy controls, the age-adjusted resistivity and pulsatile indices of the ophthalmic artery were significantly higher in patients with DR (p < 0.05). PSV and EDV of the posterior ciliary arteries were significantly lower in diabetic patients with DR. After further adjustment for age, gender, HbA1c, fasting plasma glucose, blood pressure, BMI, cholesterol, HDL, LDL, and triglycerides, only the resistivity index of the ophthalmic artery and the central retinal vein remained significantly higher in patients with DR compared with healthy controls (p < 0.005 after Bonferroni adjustment). CONCLUSIONS: Resistivity index alteration of the ophthalmic artery and central retinal vein may be prevalent among patients with early changes in DR.

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Section: Discussionsupporting

confidence: 93%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Orbital Doppler Evaluation of Blood Flow Velocities in Patients with Diabetic Retinopathy

Karami

Janghorbani²,

Dehghani³

et al. 2012

Rev Diabet Stud

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“…It is an ultrasonographic method that has been employed for the evaluation of the circulatory status in much ocular pathology, but is most used for the investigation of the circulatory status in retinal vascular disorders and in glaucoma. [1][2][3] Ultrasound imaging (sonography) is accomplished with a pulse-echo technique. Pulses of ultrasound (generated by a transducer) are sent into the patient where they produce echoes at organ boundaries and within tissues.…”

Section: Imagingmentioning

confidence: 99%

Colour Doppler Imaging of Ocular and Orbital Blood Vessels in Retinal Diseases

Dimitrova¹

2011

European Ophthalmic Review

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ImagingColour Doppler Imaging (CDI) is an established method for investigation of the ocular and orbital blood flow characteristics. It is an ultrasonographic method that has been employed for the evaluation of the circulatory status in much ocular pathology, but is most used for the investigation of the circulatory status in retinal vascular disorders and in glaucoma. [1][2][3] Ultrasound imaging (sonography) is accomplished with a pulse-echo technique. Pulses of ultrasound (generated by a transducer) are sent into the patient where they produce echoes at organ boundaries and within tissues. These echoes then return to the transducer, they are being detected and then displayed. Colour-flow imaging extends the use of the pulse-echo imaging principle. Echoes returning from stationary tissues are detected and presented in greyscale in appropriate locations along the scan line. The depth is determined by the echo's arrival time and the brightness is determined by the echo's amplitude. If a returning echo has a different frequency than what is emitted a frequency change has occurred because the echo-generating object was moving. If the motion is towards or away from the transducer, the Doppler shift is positive or negative, respectively. Along with the transducer, the colour-flow instrument consists of a pulser, a beam-former, a receiver, a memory and a display (see Figure 1).In ophthalmology, CDI is most often used to study the circulatory parameters in the retrobulbar blood vessels -the central retinal artery, central retinal vein, ophthalmic artery and the short and long posterior ciliary arteries. However, intraocular blood vessels have also been studied, such as vortex veins, blood vessels in the intraocular tumours, in detached retina, etc. The measurement is usually obtained through closed eyelids in a supine or in a seated position. Nagahara et al.patented a device for CDI measurement in seated subjects that increased the reproducibility of the measurement by 50% (see Figure 2). 4 The reflected ultrasound from the moving cells in the measured blood vessels is recorded by the CDI device and represented as a velocity wave. Two such velocity waves from the central retinal artery and the central retinal vein are presented in Figure 3.Several blood flow parameters can be obtained from the velocity wave, such as peak systolic blood velocity (PSV), end-diastolic blood velocity (EDV), mean blood velocity (MV), resistivity index (RI) and pulsatility index (PI): RI is calculated as (PSV-EDV)/PSV; PI is calculated as (PSV-EDV)/MV.Although the CDI device is equipped for measurement of blood vessel diameter, the dimension of the retrobulbar blood vessels is too small to obtain a reliable estimation of their diameter. Therefore, total blood flow cannot be evaluated in the retrobulbar blood vessels using CDI.The recording of the blood flow parameters of the central retinal artery and vein is obtained inside the optic nerve, a few millimetres away from the lamina cribrosa (see Figure 3). A specific finding of the blood flo...

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Microcirculation of the Ocular Fundus

Riva

Schmetterer

2008

Comprehensive Physiology

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Colour Doppler imaging of the ocular circulation in diabetic retinopathy

Cited by 56 publications

References 21 publications

Orbital Doppler Evaluation of Blood Flow Velocities in Patients with Diabetic Retinopathy

Orbital Doppler Evaluation of Blood Flow Velocities in Patients with Diabetic Retinopathy

Colour Doppler Imaging of Ocular and Orbital Blood Vessels in Retinal Diseases

Microcirculation of the Ocular Fundus

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