1,721,107 research outputs found
collirio a base di liposomi e suo uso per la valutazione in vivo dell'efficacia farmacologica della terapia medica e chirurgica anti-glaucoma
No full text
Near-Infrared Fluorescence Imaging of Aqueous Humor Outflow Structures
No full textThe aim of this study has been to visualize the aqueous outflow system in patients affected by primary open angle glaucoma. A solution of indocyanine green (ICG) plus high viscosity viscoelastic solution was injected into the Schlemm canal during surgery in 10 glaucomatous patients undergoing canaloplasty. Soon after injection of the dye the borders of the scleral flap were completely stained due to partial reflux caused by the intrachannel resistance; progression of the dye along the Schlemm canal starting from the site of injection was then visualized. The filling of the collector channels was observed only in the patent portions of the Schlemm canal. The only noticeable aqueous veins were located in correspondence of the quadrant in which both the Schlemm canal and the collectors were patent. Lastly, a retrograde filling, of glomerular-shaped structures, deepest to the Schlemm canal was observed in the quadrants where the pathway was functioning. Our findings show that injection of a mixture composed of ICG and viscoelastic solution into the Schlemm canal allows a clear visualization of the functioning portions of the conventional outflow pathway. In addition, a retrograde filling of structures presumably located into the iris was also recorded. Clinical Trial Registration. Our study is registered in ISRCTN registry, number 54005880, DOI 10.1186/ISRCTN54005880
Using Canalography to Visualize the In Vivo Aqueous Humor Outflow Conventional Pathway in Humans
No full text
Thermodynamic properties and photodegradation kinetics of indocyanine green in aqueous solution
No full textAqueous solutions of indocyanine green (ICG) are spectrophotometrically and fluorimetrically studied as a function of the dye concentration. The integral absorbance concept is introduced to minimize uncertainties due to the use of only a point. This new method, provides a value of the equilibrium constant consistent with those obtained, by a different method, for safranine and thionine. The influence of ICG concentration on its fluorescence spectrum is determined. When ICG is exposed to white light degrades through the formation of free radicals. The overall kinetics of degradation is monitored spectrophotometrically and studied in an unconventional way. The results exhibit a power law, regardless of the initial concentration of dye. An apparent order of 1.5 suggests a complex mechanism where the collision between radicals is very important whilst a lifetime of 4 h it is indicative of a rapid degradation kinetics
Corneal epithelial wound healing promoted by verbascoside-based liposomal eyedrops
Full text linkDifferent liposomal formulations were prepared to identify those capable of forming eyedrops for corneal diseases. Liposomes with neutral or slightly positive surface charge interact very well with the cornea. Then these formulations were loaded with verbascoside to heal a burn of corneal epithelium induced by alkali. The cornea surface affected involved in wound was monitored as a function of time. Experimental results were modeled by balance equation between the rate of healing, due to the flow of phenylpropanoid, and growth of the wound. The results indicate a latency time of only three hours and furthermore the corneal epithelium heals in 48 hours. Thus, the topical administration of verbascoside appears to reduce the action time of cells, as verified by histochemical and immunofluorescence assays
Fractal dimension as a new tool to analyze optic nerve head vasculature in primary open angle glaucoma
No full textAim: To investigate the features of optic nerve head (ONH) microvasculature in primary open angle glaucoma using fractal geometry analysis. Patients and Method: ONH blood flow was analyzed at the level of the lamina cribrosa by means of confocal scanning laser Heidelberg Doppler flowmetry (HRF) in medically-controlled early and advanced glaucoma. Fractal dimension D of vasculature map was calculated using the Box Counting. Results: Our data demonstrated that, in patients with advanced glaucoma, fractal dimension D was significantly lower than in controls, whereas, in the early stage of disease, its value was similar. Fractal dimension D of microcirculation was significantly and negatively correlated with the cup-disk area ratio in both early and advanced glaucoma groups, whereas linear cup-disk ratio of the disk, cup shape measure and nerve fiber layer thickness, where correlated only in advanced stage of the disease. Conclusion: These findings demonstrate that fractal dimension D of ONH appeared significantly reduced in advanced glaucoma and correlated with the optic disc damage
Some Physicochemical Remarks on Spontaneous Emulsification of Vitreal Tamponades
Full text linkThe importance of gravitational instability in determining the emulsification of vitreal tamponades is discussed. Theoretical results and numerical simulations indicate that the spontaneous formation of water-silicon oil is a rare event and that the very low concentration of surface active agents cannot justify the systematic formation of emulsions. The gravitational instabilities seem to play the main role. Our theoretical results seem in agreement with the experimental evidences; furthermore they indicate a future research line for the improvement of endotamponades. Indeed, the use of biodegradable antifoam may avoid the formation of bubbles and delay the formation of emulsions
- …
