Infrared fundus angiography

Utilization of indocynanine green fluorescent imaging (ICG-FI) for the assessment of microperfusion in vascular medicine

Intraoperative valuation of organ and tissue microperfusion is always a current topic in different surgical situations. Although indocyanine green fluorescent imaging (ICG-FI) has turned to be a more and more common technique to evaluate organ perfusion, only few studies tried to quantitatively validate the technique for microperfusion assessment. The aim of the following manuscript is to present the results of our interdisciplinary research confirming additional quantitative assessment tools in different surgical conditions. Thus, we are implementing the background-subtracted peak fluorescent intensity (BSFI), the slope of fluorescence intensity (SFI), and the time to slope (TTS) using ICG-FI in several regions of interest (ROI).

Fundus Angiography with Fluorescein-Labelled Peptide Fraction from Bovine Factor Viii: Correlation with Histologic Findings

A peptide fraction (VUEFFE) obtained from bovine factor VIII, with a high affinity for vessel endothelium, was bound to fluorescein and used for angiography in rabbits. Several eyes had undergone laser photocoagulation on the retina. The location of the dye was studied histologically with fluorescence microscopy on the enucleated, freeze-dried eyes. The angiographic and histologic findings were compared with findings obtained using sodium fluorescein. Fluorescein-labelled VUEFFE gave a longer lasting fluorescence of the retinal vessels with histologic evidence of dye deposition on the vessel wall. It also showed marked affinity for the photocoagulated tissues, giving intense and prolonged staining of the laser burns. Possible clinical applications are discussed.

Indocyanine green angiography in posterior uveitis

Literature review for indocyanine green angiography and evaluate the role of indocyanine green angiogram (ICGA) in patients with posterior uveitis seen at a tertiary referral eye care centre. Detailed review of the literature on ICGA was performed. Retrospective review of medical records of patients with posterior uveitis and dual fundus and ICGA was done after institutional board approval. Eighteen patients (26 eyes) had serpiginous choroiditis out of which 12 patients had active choroiditis and six patients had healed choroiditis, six patients (12 eyes) had ampiginous choroiditis, six patients (12 eyes) had acute multifocal posterior placoid pigment epitheliopathy, eight patients (10 eyes) had multifocal choroiditis, four patients (eight eyes) had presumed ocular histoplasmosis syndrome, four patients (eight eyes) had presumed tuberculous choroiditis, two patients (four eyes) had multiple evanescent white dot syndrome and two patients (four eyes) had Vogt Koyanagi Harada (VKH) syndrome. The most characteristic feature noted on ICGA was the presence of different patterns of hypofluorescent dark spots, which were present at different stages of the angiogram. ICGA provides the clinician with a powerful adjunctive tool in choroidal inflammatory disorders. It is not meant to replace already proven modalities such as the fluorescein angiography, but it can provide additional information that is useful in establishing a more definitive diagnosis in inflammatory chorioretinal diseases associated with multiple spots. It still needs to be determined if ICGA can prove to be a follow up parameter to evaluate disease progression.

Digital indocyanine-green angiography in chorioretinal disorders

The authors performed digital indocyanine-green angiography in 37 patients with chorioretinal disorders. Eighteen patients had choroidal neovascularization, 7 patients had atrophic age-related maculopathy, and 12 patients had uncommon choroidal and retinal disorders. A Topcon indocyanine-green camera was integrated with a digital (1024-line resolution) angiography system. Compared with conventional video or photographic indocyanine-green angiography, this technique offers enhanced image resolution, the possibility of direct qualitative comparison with fluorescein angiography, image archiving, hard-copy generation, and tracing capabilities to plan laser treatment strategies and monitor the adequacy of laser therapy after surgery.

Indocyanine green videoangiography of choroidal neovascularization

Choroidal neovascular membranes often are poorly defined on fluorescein angiography because of rapid or indistinct fluorescein leakage or because of blockage of hyperfluorescence by overlying hemorrhage, lipid, turbid fluid, or pigment. Indocyanine green (ICG) is a high protein-bound dye with peak absorption (805 nm) and peak fluorescence (835 nm) in the near infrared portion of the spectrum. At these wavelengths, penetration through overlying pigments is increased. Using an infrared videoangiography system, the authors obtained ICG angiograms of 32 eyes with suspected choroidal neovascularization. Compared with fluorescein angiography, ICG improved visualization of the choroidal circulation and enhanced visualization of some membranes that were poorly defined with fluorescein. In addition, after clearance of the dye from the retinal and choroidal circulations, ICG remained in and around the neovascular tissue. The authors conclude that ICG videoangiography may aid in the evaluation of selected patients with poorly defined membranes on fluorescein angiography.