Fluorescent Dots in Fluorescein Angiography and Fluorescein Leukocyte Angiography Using a Scanning Laser Ophthalmoscope in Humans

Yang, Yun-Sik; Kim, Sang-Duck; Kim, Jae-Duck

doi:10.1016/s0161-6420(97)30080-3

Cited by 29 publications

(23 citation statements)

References 21 publications

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“…Fluorescein is presently used in retinal imaging (13,14), but its absorption and emission spectra may be at short wavelengths, too short for transdermal measurements. Indocyanine green (IcG) absorbs and emits at wavelengths above 700 nm and is therefore suitable for transdermal measurements.…”

Section: Discussionmentioning

confidence: 99%

Polarization Sensing of Fluorophores in Tissues for Drug Compliance Monitoring

Gryczyński

Abugo

Lakowicz

1999

Analytical Biochemistry

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We used a new method, polarization sensing, to monitor the concentration of the fluorophore rhodamine 800 in an intralipid suspension and in chicken tissue. Rhodamine 800 (Rh800) could be excited at 648 nm using a laser pointer. We developed a simple device for measuring the combined emission from a highly polarized reference film and the unpolarized or orthogonally polarized emission of Rh800 from the scattering intralipid or tissue. The concentration of Rh800 in this medium was revealed by large changes in the polarization (P) with values of P ranging from 0.8 to -0.9. It is possible to vary the sensitive Rh800 concentration range by variation of the detected emission wavelengths, orientation of the excitation polarizer, or fluorophore concentration in the reference film. Polarization sensing of fluorophores in tissue requires only steady-state detection, and can be accomplished with simple and/or portable electronics. Such devices may find use in electronic detection of ingested medicines based on transdermal detection of nontoxic long-wavelength fluorophores.

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Section: Discussionmentioning

confidence: 99%

Polarization Sensing of Fluorophores in Tissues for Drug Compliance Monitoring

Gryczyński

Abugo

Lakowicz

1999

Analytical Biochemistry

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“…The velocity of leukocytes (V leuk ) has been measured by means of scanning laser ophthalmoscopy after tagging the cells with various dyes and tracking their motion in the retinal capillaries, veins and arteries on video images [28,29,30,31,32]. …”

Section: Noninvasive Techniques Used In Physiological and Clinical Rementioning

confidence: 99%

“…V leuk of leukocytes moving in perifoveal retinal capillaries (diameter 7–11 µm) measured by scanning laser ophthalmoscopy was reported to be 1.4 mm/s [31]. Using the blue-field simulation technique, which is based on the entoptic observation of one’s own leukocytes moving in the macular area of the retina, it is possible to determine quantitatively the number (N leuk ) , V leuk , and V leuk pulsatility of these particles [33].…”

Section: Noninvasive Techniques Used In Physiological and Clinical Rementioning

confidence: 99%

Retinal Blood Flow Evaluation

Pournaras

Riva

2012

Ophthalmologica

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Much of our basic knowledge of retinal blood flow regulation is based on data obtained from animal experiments through the use of invasive techniques. However, during the last decades, major developments in the field of optics and lasers have led to a variety of noninvasive techniques, which have been applied to the human eye for the investigation of retinal hemodynamics, and more specifically the regulation of retinal blood flow in response to a number of physiological and pharmacological stimuli. The Retinal Vessel Analyzer has markedly simplified the measurement of the diameter of retinal vessels, as well as the change in this diameter evoked by various physiological stimuli (dynamic measurements). Bidirectional laser Doppler velocimetry allows the measurement of absolute red blood cell centerline velocity, which, when combined with the diameter allows the calculation of retinal blood flow in the main retinal vessels. Laser Doppler flowmetry and laser speckle flowgraphy are techniques that measure the velocities of blood in discrete areas of the retinal tissue microcirculation. Adding a scanning capability, a spatial map of velocities across the retinal tissue is obtained. The blue-field simulation technique allows the quantification of the velocity, number and velocity pulsatility of leukocytes moving in the retinal capillaries of the macular region. With color Doppler imaging, the peak systolic and end-diastolic values of blood velocity in the ophthalmic and central retinal artery are measured, from which a resistivity index is obtained. These techniques may help better understand the role of altered retinal blood flow and its regulation in the pathogenesis of retinal diseases of vascular origin.

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“…1,4 Furthermore, investigating hemodynamics in the human retina provides potentially helpful information and clues for understanding the pathogenesis of retinal vascular disorders such as diabetic retinopathy, 5 glaucoma, 6 age-related macular degeneration, 7 retinal vein occlusion, 8 and collagen diseases. 9 Many approaches have been developed for evaluating blood vessels or dynamic blood flow, including the dye dilution technique, [10][11][12] blue field entoptic phenomenon, [13][14][15] laser Doppler velocimetry, [16][17][18][19] laser speckle phenomenon, 20 optical coherence tomography (OCT), 21 and adaptive optics scanning laser ophthalmoscopy (AO-SLO). [22][23][24][25] These techniques, except for blue field entoptic phenomenon and AO-SLO, evaluate the blood flow in the retina but do not monitor the blood corpuscles in the retinal capillary.…”

mentioning

confidence: 99%

“…36,37 AO-SLO images allow the noninvasive monitoring of leukocyte movements as bright particles flowing in dark parafoveal capillaries and the measurement of their velocities without the use of contrast dyes. [10][11][12] We previously reported that the bright particles moving in the dark vessel shadows may be reflections of the photoreceptor aggregates that pass through circulating transparent objects such as leukocytes or plasma gaps. Furthermore, we described the socalled dark tail, which could be seen as a region darker than the vessel shadow that occurred closely behind moving particles and might correspond to aggregated erythrocytes upstream of the leukocytes that block the AO-SLO laser (Fig.…”

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confidence: 99%

Noninvasive and Direct Monitoring of Erythrocyte Aggregates in Human Retinal Microvasculature Using Adaptive Optics Scanning Laser Ophthalmoscopy

Shigeta

Uji²,

Hangai³

et al. 2013

Invest. Ophthalmol. Vis. Sci.

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Citation: Arichika S, Uji A, Hangai M, Ooto S, Yoshimura N. Noninvasive and direct monitoring of erythrocyte aggregates in human retinal microvasculature using adaptive optics scanning laser ophthalmoscopy. Invest Ophthalmol Vis Sci. 2013;54:4394-4402. DOI:10.1167/ iovs.12-11138 PURPOSE. To investigate erythrocyte aggregates in parafoveal capillaries by adaptive optics scanning laser ophthalmoscopy (AO-SLO).METHODS. AO-SLO videos were acquired from the parafoveal areas of one eye in 10 healthy subjects. Erythrocyte aggregates were detected as ''dark tails'' that were darker regions than vessel shadows. The lengths of the dark tails were measured in target capillaries, and their time-dependent changes in length were analyzed using spatiotemporal images. The dark tail elongation rate was calculated as the change of dark tail length per unit length of the target capillary.RESULTS. The overall average dark tail length was 112.1 6 36.9 lm. The dark tail became longer in a time-dependent manner in every monitored capillary (P < 0.0001). The dark tail elongation rate and average velocity were 0.51 6 0.37 and 1.49 6 0.36 mm/s, respectively.CONCLUSIONS. AO-SLO can be used for noninvasive and direct monitoring of blood dynamics in the retinal microvasculature without dying agents. Erythrocyte aggregates were detected as dark tails and were elongated in a time-dependent manner in the parafoveal capillaries of normal subjects. Monitoring the characteristics of dark tails has promising potential for evaluating retinal hemodynamics.

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Fluorescent Dots in Fluorescein Angiography and Fluorescein Leukocyte Angiography Using a Scanning Laser Ophthalmoscope in Humans

Cited by 29 publications

References 21 publications

Polarization Sensing of Fluorophores in Tissues for Drug Compliance Monitoring

Polarization Sensing of Fluorophores in Tissues for Drug Compliance Monitoring

Retinal Blood Flow Evaluation

Noninvasive and Direct Monitoring of Erythrocyte Aggregates in Human Retinal Microvasculature Using Adaptive Optics Scanning Laser Ophthalmoscopy

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