Subtraction ICG angiography in Harada's disease.
BACKGROUND/AIM: The significance of indocyanine green (ICG) angiography (ICGA) in Harada's disease still awaits clarification in many respects. This study investigates the details of choroidal lesions observed in Harada's disease by the subtraction method. METHODS: Eight patients with Harada's disease were followed with ICGA. ICG angiograms were obtained with a Topcon high resolution digital fundus camera and processed with a Topcon IMAGEnet computer system. Image subtraction was conducted for analysing serial angiograms taken at about 2 second intervals during the dye transit phase and those taken in the early and middle phases of angiography. RESULTS: Standard ICG images of acute stage disease showed delayed choroidal filling in the early phase. Mid phase angiograms showed areas with bright fluorescence of variable intensity, indicating intrachoroidal ICG leakage. With image subtraction of angiograms with an interval of seconds the choroidal vessels could be imaged sequentially, with the choroidal arteries visualised first, followed by the definition of the choriocapillaris and then the choroidal veins. The choroidal veins with delayed filling were visualised as positive images in serial subtraction angiograms. Subtraction with an interval of minutes showed uneven background fluorescence and bright fluorescence corresponding to the areas of intrachoroidal ICG leakage. After the disease subsided with steroid therapy, angiography revealed an improvement in delayed choroidal filling. Image subtraction by the second allowed a clear visualisation of improved choroidal venous filling, while subtraction by the minute showed homogeneous background fluorescence, eliminating brighter areas. CONCLUSION: Subtraction ICGA demonstrated that delayed filling of the choroidal veins of varying severity occurs in association with hyperpermeability of the choroidal vessels in the course of Harada's disease. (+info)
Indocyanine green guided laser photocoagulation in patients with occult choroidal neovascularisation.
AIMS: To determine whether indocyanine green (ICG) guided laser photocoagulation of occult choroidal neovascularisations (OCNV) is beneficial for patients with occult choroidal neovascularisation secondary to age related macular degeneration (AMD). METHODS: A prospective pilot study was performed in 21 eyes with OCNV secondary to AMD that could be identified extrafoveolarly or juxtafoveolarly in an early ICG angiographic study. Laser photocoagulation was applied to the neovascular membrane identified in the early ICG angiographic study. RESULTS: Visual acuity ranged from 20/400 to 20/20 (logMAR 0.54 (SD 0.29) before and hand movements and 20/30 (logMAR 0.81 (0.69)) at the last follow up after laser photocoagulation. During the follow up (30 (13) months) vision improved in four eyes (two lines), in seven eyes the initial visual acuity could be stabilised (two lines), in five eyes vision dropped moderately (three to five lines), and in five eyes vision decreased severely (six or more lines). Recurrences (seven patients) or persistent CNV (six patients) was observed in 13 patients. CONCLUSION: This preliminary study of ICG guided laser photocoagulation of occult extrafoveal and juxtafoveal choroidal neovascularisations suggests that this technique may improve the visual prognosis of these patients. Further prospective controlled studies are necessary to confirm these data. (+info)
Photo-oxidative killing of human colonic cancer cells using indocyanine green and infrared light.
Despite of the approval of Photofrin in various countries, chemically defined sensitizers for photodynamic therapy (PDT) are still needed for the absorption of light in the infrared spectrum, which provides a maximal penetration of light into tissue. Therefore, both the efficacy and the mechanism of action of the clinically approved dye indocyanine green (ICG) and laser irradiation were investigated in vitro. For the investigation of phototoxic effects, HT-29 cells were incubated 24 h prior to irradiation by using different concentrations of ICG (10-500 microM). In each experiment, cells were irradiated using a continuous wave (cw)-diode laser (lambda(ex) = 805 nm, 30 J cm(-2), 40 mW cm(-2)). After laser irradiation, cell viability of dark control and of cells incubated with 500 microM ICG was 1.27+/-0.11 or 0.28+/-0.05 respectively. Using 100 microM ICG and D2O, cell viability was further decreased from 0.46+/-0.03 (H2O) to 0.11+/-0.01 (D2O). Using D2O and 100 microM ICG, the concentration of malondialdehyde, a marker of lipid peroxidation, increased from 0.89+/-0.10 nmol 10(-6) cells to 11.14+/-0.11 nmol 10(-6) cells. Using 100 microM ICG and laser irradiation sodium azide or histidine (50 mM), quenchers of singlet oxygen reduced the cell killing significantly. In contrast, when using mannitol, a quencher of superoxide anion and hydroxyl radical, cell killing was not inhibited. According to the present results, photoactivated ICG seems to kill colonic cancer cells due to the generation of singlet oxygen and the subsequent formation of lipid peroxides. Therefore, ICG might present a promising photosensitizer for PDT; first clinical results confirm these findings. (+info)
Effects of LPS on transport of indocyanine green and alanine uptake in perfused rat liver.
Lipopolysaccharide (LPS) initiates cholestasis. Whether this process is mediated by tumor necrosis factor-alpha (TNF-alpha) and whether the cholestatic response to LPS is associated with intrahepatic accumulation of possibly toxic substances are under debate. To study these questions the hepatic uptake and biliary excretion of indocyanine green (ICG) was examined in the isolated perfused rat liver 18 h after intravenous treatment of rats with either saline, 1 mg/kg body wt LPS, or LPS and intraperitoneal pentoxifylline (POF) (n = 6 in each group). POF inhibits TNF-alpha release after LPS administration. LPS induced a typical acute-phase response with increased mRNA for acute-phase proteins, reduced albumin mRNA, and increased hepatic uptake of alanine. Intrinsic hepatic clearance of ICG in controls (1.01 +/- 0.05 ml. min(-1). g liver(-1)) was similarly decreased by LPS alone (0.62 +/- 0.04 ml. min(-1). g(-1); P = 0.002 vs. control) or combined with POF (0.66 +/- 0.06 ml. min(-1). g(-1)). A kinetic analysis indicated that LPS reduced both uptake and excretion processes in a balanced manner, so that intrahepatic ICG content was unaffected or even slightly reduced, as confirmed by measurement of ICG contents in the perfused livers. In livers from parallel-treated nonperfused rats, mRNA for the organic anion transporting protein-1 (Oatp1, which is likely to mediate ICG uptake) was unaffected by LPS, whereas the concentration of Oatp1 protein was reduced. Thus LPS induced an acute-phase response that included downregulation of ICG uptake by reduction of Oatp1 protein concentration, possibly at a posttranscriptional level. TNF-alpha appears not to be the mediator because POF did not modify these LPS effects. (+info)
Glucose production during exercise in humans: a-hv balance and isotopic-tracer measurements compared.
The present study compared the arteriohepatic venous (a-hv) balance technique and the tracer-dilution method for estimation of hepatic glucose production during both moderate and heavy exercise in humans. Eight healthy young men (aged 25 yr; range, 23-30 yr) performed semisupine cycling for 40 min at 50.4 +/- 1.5(SE)% maximal O(2) consumption, followed by 30 min at 69.0 +/- 2.2% maximal O(2) consumption. The splanchnic blood flow was estimated by continuous infusion of indocyanine green, and net splanchnic glucose output was calculated as the product of splanchnic blood flow and a-hv blood glucose concentration differences. Glucose appearance rate was determined by a primed, continuous infusion of [3-(3)H]glucose and was calculated by using formulas for a modified single compartment in non-steady state. Glucose production was similar whether determined by the a-hv balance technique or by the tracer-dilution method, both at rest and during moderate and intense exercise (P > 0. 05). It is concluded that, during exercise in humans, determination of hepatic glucose production can be performed equally well with the two techniques. (+info)
Indocyanine green angiographic features prognostic of visual outcome in the natural course of patients with age related macular degeneration.
AIMS: To determine indocyanine green (ICG) angiographic features prognostic of visual acuity loss in eyes following a natural course of exudative age related macular degeneration (AMD). METHODS: 89 eyes of 72 patients (48 men, 24 women) aged between 50 and 87 years old (mean 69.5 (SD 8.8) years) with classic and/or occult choroidal neovascularisation (CNV) were reviewed. ICG angiographic features were classified as follows: type 1, well demarcated hyperfluorescence with late ICG leakage; type 2, well demarcated hyperfluorescence with no late dye leakage; type 3, poorly demarcated hyperfluorescence; type 4, no hyperfluorescence. Follow up ranged from 6 to 67 months (mean 19.2 (11.5) months). Logistic regression analyses were performed using change of visual acuity (worse or not) as the dependent variable, and patient age, sex, characteristics of fluorescein angiography (classic or occult CNV), location of CNV, and each ICG type as the independent variables. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. RESULTS: Type 1 CNV was associated with the highest risk for visual acuity loss (OR: 7.50, CI: 1.42-39.55, p = 0.018) among the present variables. In contrast, CNV having no ICG leakage (type 2, 3, and 4), represented no significantly increased risk. CONCLUSION: Well demarcated hyperfluorescence with late ICG leakage appears to be predictive of visual acuity loss in eyes with CNV. Thus, ICG angiography may offer a useful means of predicting visual outcomes in AMD. (+info)
Labeled carcinoembryonic antigen antibodies excitable by infrared rays: a novel diagnostic method for micro cancers in the digestive tract.
OBJECT: An indocyanine green derivative (ICG-sulfo-OSu) was used as the labeling substance for monoclonal antibody, and a fluorescence imaging system appropriate for ICG-sulfo-OSu excitable by infrared rays (IR) was developed. The goal of this study was to demonstrate antibody labeling at the tissue level using this new imaging system. MATERIALS AND METHODS: ICG-sulfo-OSu labeled mouse anti-human carcinoembryonic antigen (CEA) monoclonal antibody, a newly developed imaging system, and an infrared ray microscope were employed in this experiment. Paraffin sections of human colon cancer previously proven to have cross-reactivity to anti-CEA antibody were examined. RESULTS: Positive staining was seen as a brownish discoloration of oxidized 3,3'-diaminobenzidine tetrahydrochloride (DAB) in sections that reacted with ICG-sulfo-OSu-labeled anti-CEA antibody, and the fluorescence was well-matched with the oxidized DAB-positive sites. CONCLUSION: Specific antibodies labeled with ICG-sulfo-OSu have significant affinity to cancer cells and seem to reflect sufficient amounts of fluorescence by IR to be useful in a system for the endoscopic detection of micro cancers using the immunohistochemical staining method. (+info)
Effects of photodynamic therapy using verteporfin on experimental choroidal neovascularization and normal retina and choroid up to 7 weeks after treatment.
PURPOSE: To study the long-term effects of photodynamic therapy (PDT), using liposomal benzoporphyrin derivative (BPD) or Verteporfin, on experimental choroidal neovascularization (CNV) and on normal retina and choroid (with no CNV) in the cynomolgus monkey eye. METHODS: Photodynamic therapy was performed in 8 cynomolgus monkey eyes with experimental CNV induced by laser injury. The effect of PDT on normal retina and choroid (with no CNV) was studied in 9 monkey eyes. Liposomal BPD was administered intravenously (0.375 mg/kg) either as a bolus, as a slow infusion over 32 minutes, or as a fast infusion over 10 minutes. Photodynamic therapy was performed using light at a wavelength of 689 or 692 nm, with an irradiance of 600 mW/cm2 and fluence of 150 J/cm2. Follow-up studies, including fundus photography and FA, were performed at 24 hours after PDT and then weekly. Indocyanine green and BPD angiography were performed in selected cases. Tissues were examined with light and electron microscopy at the end of follow-up. RESULTS: Twenty-three of the 32 areas of CNV treated with PDT showed absence of angiographic leakage at 24 hours. Twenty-eight areas of CNV were followed for 4 weeks; 22 of 28 showed absence of angiographic leakage at 2 weeks; and 20 of 28 at 4 weeks of follow-up. Forty spots on the normal retina and choroid were treated with PDT and were followed for 4 to 7 weeks. These spots showed pigment-laden cells in the outer retina, variably pigmented retinal pigment epithelium (RPE) in the treated area, intact neurosensory retina, and reperfusion of the choriocapillaris. CONCLUSIONS: Photodynamic therapy leads to absence of angiographic leakage for at least 4 weeks in experimental CNV in the monkey model. In the normal monkey eye the RPE and choriocapillaris show generalized recovery with preservation of the neurosensory retina 7 weeks after PDT. (+info)