Feasibility of extracting velocity distribution in choriocapillaris in human eyes from ICG dye angiograms.

Indocyanine green (ICG) dye angiography has been used by ophthalmologists for routine examination of the choroidal vasculature in human eyes for more than 20 years. In this study, a new approach is developed to extract information from ICG dye angiograms about blood velocity distribution in the choriocapillaris and its feeding blood vessels. ICG dye fluorescence intensity rise and decay curves are constructed for each pixel location in each image of the choriocapillaris in an ICG angiogram. It is shown that at each instant of time the magnitude of the local instantaneous dye velocity in the choriocapillaris is proportional to both the slope of the ICG dye fluorescence intensity curve and the dye concentration. This approach leads to determination of the absolute value of blood velocity in the choriocapillaris, assuming an appropriate scaling, or conversion factor can be determined. It also enables comparison of velocities in different regions of the choriocapillaris, since the conversion factor is independent of the vessel location. The computer algorithm developed in this study can be used in clinical applications for diagnostic purposes and for assessment of the efficacy of laser therapy in human eyes.

[1]  R W Flower,et al.  Injection technique for indocyanine green and sodium fluorescein dye angiography of the eye. , 1973, Investigative ophthalmology.

[2]  R. Flower,et al.  Quantification of indicator dye concentration in ocular blood vessels. , 1977, Experimental eye research.

[3]  G J Klein,et al.  An image processing approach to characterizing choroidal blood flow. , 1990, Investigative ophthalmology & visual science.

[4]  R W Flower,et al.  Extraction of choriocapillaris hemodynamic data from ICG fluorescence angiograms. , 1993, Investigative ophthalmology & visual science.

[5]  J. Duker,et al.  Indocyanine green dye-enhanced diode laser photocoagulation of poorly defined subfoveal choroidal neovascularization. , 1994, Ophthalmic surgery.

[6]  E S Gragoudas,et al.  Ocular blood flow velocity in age-related macular degeneration. , 1995, Ophthalmology.

[7]  R W Flower,et al.  Variability in choriocapillaris blood flow distribution. , 1995, Investigative ophthalmology & visual science.

[8]  Selective visualization of choroidal neovascular membranes. , 1996, Investigative ophthalmology & visual science.

[9]  Computer Assisted Image Analysis Using the Subtraction Method in Indocyanine Green Angiography , 1996, European journal of ophthalmology.

[10]  H. Grossniklaus,et al.  Morphometric analysis of the choroid, Bruch's membrane, and retinal pigment epithelium in eyes with age-related macular degeneration. , 1996, Investigative ophthalmology & visual science.

[11]  A. Ho,et al.  Foveolar choroidal blood flow in age-related macular degeneration. , 1998, Investigative ophthalmology & visual science.

[12]  S. Wolf,et al.  Indocyanine green guided laser photocoagulation in patients with occult choroidal neovascularisation , 1999, The British journal of ophthalmology.

[13]  R P Danis,et al.  Color Doppler imaging discloses reduced ocular blood flow velocities in nonexudative age-related macular degeneration. , 1999, American journal of ophthalmology.

[14]  A C Bird,et al.  A fluorescein and indocyanine green angiographic study of choriocapillaris in age-related macular disease. , 1999, Archives of ophthalmology.

[15]  S. Orgül,et al.  Choroidal laser Doppler flowmetry in healthy subjects. , 2000, Archives of ophthalmology.

[16]  D. Weinberger,et al.  Comparison of fluorescein angiography and indocyanine green angiography for imaging of choroidal neovascularization in hemorrhagic age-related macular degeneration. , 2000, American journal of ophthalmology.

[17]  F. Shiraga,et al.  Evaluation of leukocyte dynamics in choroidal circulation with indocyanine green-stained leukocytes. , 2000, Investigative ophthalmology & visual science.

[18]  R. Flower,et al.  Theoretical investigation of the role of choriocapillaris blood flow in treatment of subfoveal choroidal neovascularization associated with age-related macular degeneration. , 2001, American journal of ophthalmology.

[19]  D P Holschneider,et al.  Fluorescence of indocyanine green in blood: intensity dependence on concentration and stabilization with sodium polyaspartate. , 2001, Journal of photochemistry and photobiology. B, Biology.

[20]  L. Kagemann,et al.  Ocular blood flow measurements and their importance in glaucoma and age-related macular degeneration. , 2001, The Israel Medical Association journal : IMAJ.

[21]  E. Vicaut,et al.  Analysis of retinal and choroidal circulation during central retinal vein occlusion using indocyanine green videoangiography. , 2001, Archives of ophthalmology.

[22]  K. Shiraki,et al.  Rapid injection of indocyanine green dye for evaluation of choroidal venous circulation. , 2001, Japanese journal of ophthalmology.

[23]  木村 眞一.  Indocyanine green elimination rate detects hepatocellular dysfunction early in septic shock and correlates with survival , 2001 .

[24]  S. Yoneya,et al.  AGING CHANGES OF THE CHOROIDAL DYE FILLING PATTERN IN INDOCYANINE GREEN ANGIOGRAPHY OF NORMAL SUBJECTS , 2001, Retina.

[25]  L. Kagemann,et al.  Choroidal perfusion perturbations in non-neovascular age related macular degeneration , 2002, The British journal of ophthalmology.

[26]  L. Schmetterer,et al.  Effects of isometric exercise on subfoveal choroidal blood flow in smokers and nonsmokers. , 2003, Investigative ophthalmology & visual science.

[27]  J. Detre,et al.  Spatiotemporal Quantification of Cerebral Blood Flow during Functional Activation in Rat Somatosensory Cortex using Laser-Speckle Flowmetry , 2004, Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism.

[28]  G. Michelson,et al.  Functional imaging of the retinal microvasculature by Scanning Laser Doppler Flowmetry , 2004, International Ophthalmology.

[29]  C. Prünte,et al.  Quantification of choroidal blood-flow parameters using indocyanine green video-fluorescence angiography and statistical picture analysis , 2005, Graefe's Archive for Clinical and Experimental Ophthalmology.