Retinal blood flow detection in diabetic patients by Doppler Fourier domain optical coherence tomography

Wang, Yimin; Fawzi, Amani A.; Tan, Ou; Gil-Flamer, J. H.; Huang, David

doi:10.1364/oe.17.004061

Cited by 79 publications

(78 citation statements)

References 35 publications

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“…13,14 Doppler OCT measurements made with the newer semi-automated DOCTORC software agreed closely with the results of manual measurements that we published previously. [1][2][3][4][5] The difference between DOCTORC measurements and manual measurements in individual cases, as measured by CV, is similar to inter-grader differences. This indicates that the difference was primarily associated with subjective portion of the grading process, and not the difference between software.…”

Section: -5supporting

confidence: 52%

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Doppler Optical Coherence Tomography of Retinal Circulation

Tan

Wang

Konduru

et al. 2012

JoVE

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Noncontact retinal blood flow measurements are performed with a Fourier domain optical coherence tomography (OCT) system using a circumpapillary double circular scan (CDCS) that scans around the optic nerve head at 3.40 mm and 3.75 mm diameters. The double concentric circles are performed 6 times consecutively over 2 sec. The CDCS scan is saved with Doppler shift information from which flow can be calculated. The standard clinical protocol calls for 3 CDCS scans made with the OCT beam passing through the superonasal edge of the pupil and 3 CDCS scan through the inferonal pupil. This double-angle protocol ensures that acceptable Doppler angle is obtained on each retinal branch vessel in at least 1 scan. The CDCS scan data, a 3-dimensional volumetric OCT scan of the optic disc scan, and a color photograph of the optic disc are used together to obtain retinal blood flow measurement on an eye. We have developed a blood flow measurement software called "Doppler optical coherence tomography of retinal circulation" (DOCTORC). This semi-automated software is used to measure total retinal blood flow, vessel cross section area, and average blood velocity. The flow of each vessel is calculated from the Doppler shift in the vessel cross-sectional area and the Doppler angle between the vessel and the OCT beam. Total retinal blood flow measurement is summed from the veins around the optic disc. The results obtained at our Doppler OCT reading center showed good reproducibility between graders and methods (<10%). Total retinal blood flow could be useful in the management of glaucoma, other retinal diseases, and retinal diseases. In glaucoma patients, OCT retinal blood flow measurement was highly correlated with visual field loss (R 2 >0.57 with visual field pattern deviation). Doppler OCT is a new method to perform rapid, noncontact, and repeatable measurement of total retinal blood flow using widely available Fourierdomain OCT instrumentation. This new technology may improve the practicality of making these measurements in clinical studies and routine clinical practice. Video LinkThe video component of this article can be found at http://www.jove.com/video/3524/ Protocol 1. Protocol Text 1. Patients are scanned by RTVue Fourier-domain optical coherence tomography (OCT) system (Optovue Inc., Fremont, CA, USA) using the circumpapillary double-circular scan (CDCS) and the 3D optic disc scan. 1. The CDCS pattern consists of two concentric circles around the optic nerve head. The inner ring diameter is 3.40 mm and the outer ring diameter is 3.75 mm. This pattern transects all branch retinal arteries and veins emanating from the optic nerve head. The double circles are performed 6 times in a single scan to cover about 2 cardiac cycles. To calculate Flow velocity, Doppler shift and Doppler will be estimated on vessel detected in the OCT image. (Figure 1a, Figure 1b) 2. A "dual angle" protocol is used to acquire Doppler OCT scans. In the "dual-angle" protocol, 3 scans are obtained with the OCT beam passing through the superona...

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Section: -5supporting

confidence: 52%

“…[6][7][8][9][10] Volumetric measurement of retinal blood flow gives valuable information about the disease process. [4][5][6]11,12 DOCTORC provides a practical way to estimate total retinal blood flow based on the measurements in individual vessels determined by Doppler OCT using the double circle scan pattern.…”

Section: Discussionmentioning

confidence: 99%

Doppler Optical Coherence Tomography of Retinal Circulation

Tan

Wang

Konduru

et al. 2012

JoVE

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“…Metabolic dysfunction increased by high glucose level and other signalling pathways activation leads to DR progression. At present, DR represented by glycemic control which is the most effective medical treatment (Hudson, 1996;Aiello, 2003;Porta and Allione, 2004;Wang et al, 2009). There are Studies which showed that blood sugar level control is more important (Schaumberg et al, 2005;Kilpatrick et al, 2006).…”

Section: Proliferative Retinopathy (Pdr)mentioning

confidence: 99%

Current and Emerging Therapies for the Management of Diabetic Retinopathy

2017

J App Pharm Sci

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Diabetes Mellitus (DM) has many complications, in which Diabetic Retinopathy (DR) is the major one. Blindness among working age people was due to DR. Retinal angiogenesis and retinal vascular permeability is the pathogenesis behind vision loss. Polyol pathway, protein kinase C (PKC) activation, renin angiotensinaldosterone system (RAAS), oxidative stress etc are the pathophysiological pathways which are discussed in this review for better understanding. PKC inhibitors, anti-inflammatory agents, RAAS blockers, anti-vascular Endothelial growth factor (VEGF) agents, antioxidants and fibrates which are the used for the better treatment for DR is also elaborated in this review.

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“…Since the real eye optical system is complex, 18,19 factors such as multiple refracting surfaces from the cornea and ocular lens, among others, complicate the blood flow rate calculation. As a preliminary study, we employed a simplified optical model of the eye as used by other groups.…”

Section: Introductionmentioning

confidence: 99%

“…As a preliminary study, we employed a simplified optical model of the eye as used by other groups. 11,13,18 We simplified the multiple refracting ocular surfaces into a single ocular lens, and assumed the single ocular lens can focus a collimated beam perfectly onto the retina. We also assumed that the simplified ocular lens would not modify the preset incident angles.…”

Section: Introductionmentioning

confidence: 99%

Measuring retinal blood flow in rats using Doppler optical coherence tomography without knowing eyeball axial length

Liu

Chen

et al. 2015

Medical Physics

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Purpose: Doppler optical coherence tomography (OCT) is widely used for measuring retinal blood flow. Existing Doppler OCT methods require the eyeball axial length, in which empirical values are usually used. However, variations in the axial length can create a bias unaccounted for in the retinal blood flow measurement. The authors plan to develop a Doppler OCT method that can measure the total retinal blood flow rate without requiring the eyeball axial length. Methods: The authors measured the retinal blood flow rate using a dual-ring scanning protocol. The small and large scanning rings entered the eye at different incident angles (small ring: 4• ; large ring: 6• ), focused on different locations on the retina, and detected the projected velocities/phase shifts along the probing beams. The authors calculated the ratio of the projected velocities between the two rings, and then used this ratio to estimate absolute flow velocity. The authors tested this method in both Intralipid phantoms and in vivo rats. Results: In the Intralipid flow phantom experiments, the preset and measured flow rates were consistent with the coefficient of determination as 0.97. Linear fitting between preset and measured flow rates determined the fitting slope as 1.07 and the intercept as −0.28. In in vivo rat experiments, the measured average total retinal blood flow was 7.02 ± 0.31µl/min among four wild-type rats. The authors' measured flow rates were consistent with results in the literature. Conclusions: By using a dual-ring scanning protocol with carefully controlled incident angle difference between the two scanning rings in Doppler OCT, the authors demonstrated that it is feasible to measure the absolute retinal blood flow without knowing the eyeball axial length. C 2015 American Association of Physicists in Medicine. [http://dx

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Retinal blood flow detection in diabetic patients by Doppler Fourier domain optical coherence tomography

Cited by 79 publications

References 35 publications

Doppler Optical Coherence Tomography of Retinal Circulation

Doppler Optical Coherence Tomography of Retinal Circulation

Current and Emerging Therapies for the Management of Diabetic Retinopathy

Measuring retinal blood flow in rats using Doppler optical coherence tomography without knowing eyeball axial length

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