This work are devoted our experience with photodynamic therapy (PDT) with <<Photosens>> for patients
with choroidal neovascularization (CNV). 18 patients with subfoveal CNV in age-related macular degeneration
(AMD), 24 patients with subfoveal CNV in pathological myopia (PM) and 4 patients with subfoveal CNV
associated with toxoplasmic retinochoroiditis were observed. CNV was 100% classic in all study patients.
Standardized protocol refraction, visual acuity testing, ophthalmologic examinations, biomicroscopy, fluorescein
angiography, and ultrasonography were performed before treatment and 1 month, 3 months, 6 months, and 1 year
after treatment; were used to evaluate the results of photodynamic therapy with <<Photosens>> (0.02% solution of
mixture sulfonated aluminium phtalocyanine 0.05 mg/kg, intravenously). A diode laser (<<Biospec>>, Inc, Moscow)
was used operating in the range of 675 nm. Need for retreatment was based on fluorescein angiographic evidence of
leakage at 3-month follow-up intervals.
At 3, 6, 9 month 26 (56.5%) patients had significant improvement in the mean visual acuity. At the end of
the 12-month minimal fluorescein leakage from choroidal neovascularization was seen in 12 (26.1%) patients and
the mean visual acuity was slightly worse than 0.2 which was not statistically significant as compared with the
baseline visual acuity. Patients with fluorescein leakage from CNV underwent repeated PDT with <<Photosens>>. 3D-mode
ultrasound shown the decreasing thickness of chorioretinal complex in CNV area.
Photodynamic therapy with <<Photosens>> can safely reduce the risk of severe vision loss in patients with
predominantly classic subfoveal choroidal neovascularization secondary to AMD, PM and toxoplasmic
retinochoroiditis.
Choroidal metastasis (CM) are more and more spreading type of eye's neoplasma. The frequency of CM is
increasing with prolonging of cancer patients' life. And it makes worse the quality of their life because blindness.
Photodynamic therapy (PDT) is very delicate modality, which can be used for this purpose. The aim of this work was to
open the possibility and to determine the efficacy of photodynamic therapy (PDT) in the treatment of patients with CM.
PDT was performed simultaneously with standard chemotherapy in 8 oncological patients with CM. We used
photosensitizer Photosens in doses of 0.3 mg/kg and light doses 150 J/cm2 (675 nm). PDT was performed in the some
stances. Its are ranged from 7 to 10. Complete tumor regression was achieved in 6 cases. The high retina ablation was
developed in one case. And in one case effect was not complete: tumor size reduced from 5 mm to 3 mm of thickness.
We didn't notice any recurrence for 6-18 months follow-up. PDT is modality that could to be used in the in the
combined treatment of the CM.
The new aqueous gel compositions based on 5-aminolevulinic acid (ALA) for fluorescent diagnostics and
photodynamic therapy of superficial diseases have been elaborated. Biodegradable polymer was used as gel-forming
component and some additives - solubilizer, emulgator etc - were used to improve distribution uniformity and
penetration ability. These new compositions represent colorless and transparent gels which are long-term stable at the
storage temperature of ≤5°C.
The effectiveness of aqueous gels as ALA delivery systems is demonstrated. After topical administration of the gel
at the skin with Ehrlich tumor inoculated subcutaneously, ALA effectively induces the synthesis of protoporphyrine IX
(PPIX) in the skin and in the tumor. Intensity of ALA-induced PPIX fluorescence grows with increasing ALA
concentration in the gel and time of gel application. The deepness of ALA penetration in the tumor reaches 5-6 mm after
4 h gel application.
A distribution of ALA-induced PPIX in mouse tumor tissue after 4 h gel application depends on ALA concentration
in gel. Intensity of PPIX fluorescence in deep-located part of tumor was substantially higher with gel containing 20%
ALA than with ones containing 10% or 5% ALA.
14 patients with transional-cell bladder cancer in stage T1N0M0G2 after transurethral bladder resection were
offered adjuvant treatment with PDT. Adjuvant PDT was performed 1-1.5 months after transurethral bladder resection
for superficial bladder cancer. Prior to PDT conventional and fluorescent cystoscopy were performed. In the absence of
inflammation and after full epitalisation of postoperative wound a session of therapy was performed. 24 hours prior to
PDT-session photosensitizer Photosens was injected intravenously in the dose of 0.8 mg per kg of body weight. Prior to
PDT local anesthesia of urethra with lidocain-gel was performed. Cystoscopy was carried out. PDT was performed with
diode laser "Biospec" (675 nm). During the session the place of standing diffuser and the volume of a bladder were
controlled.
After 7 months of observation no tumor recidivists were observed. Registered side effects were not life-threatened.
5 patients had pain or discomfort in suprapubic area, ceasing spontaneously or requiring administration of
analgetics. No systemic side-effects or allergic reactions were observed. The method can be used in out-patient practice.
Absence of early recidivists shows efficiency of PDT in the treatment of superficial bladder cancer. Further study is
necessary to estimate optimal regimen of PDT. The further controlling of condition on the patients in this group is
required.
At the laboratory animals' experiment, we conducted the explorations devoted to the influence of the photodynamic effect at the prostate's tissues.
Cytotoxical effect of a pulsed laser irradiation in presence of nanoparticles of carbon black, sulphuretted carbon and
fullerene-60 on death of human uterus nick cancer HeLa and mice lymphoma P 388 cells was studied in vitro. Bubbles
formation as result of "microexplosions" of nanoparticles is one of possible mechanisms of this effect. Other possible
mechanism is cytotoxical products formation in result of pyrolysis of nanoparticles and biomaterial which is adjoining.
The cytotoxical effect of addition of a supernatant from the carbon nanoparticles suspensions irradiated by the pulsed
laser was studied to test this assumption. Analysis using gas chromatograph determined that carbon monoxide is
principal gaseous product of such laser pyrolysis. This is known as cytotoxical product. Efficiency of its formation is
estimated.
Photodynamic therapy (PDT) with topical 5-aminolevulinic acid (ALA) was tested for the treatment of acne vulgaris. Patients with acne were treated with ALA plus red light. Ten percent water solution of ALA was applied with 1,5-2 h occlusion and then 18-45 J/cm2 630 nm light was given. Bacterial endogenous porphyrins fluorescence also was used for acne therapy. Treatment control and diagnostics was realized by fluorescence spectra and fluorescence image. Light sources and diagnostic systems were used: semiconductor laser (λ=630 nm, Pmax=1W), (LPhT-630-01-BIOSPEC); LED system for PDT and diagnostics with fluorescent imager (λ=635 nm, P=2W, p=50 mW/cm2), (UFPh-630-01-BIOSPEC); high sensitivity CCD video camera with narrow-band wavelength filter (central wavelength 630 nm); laser electronic spectrum analyzer for fluorescent diagnostics and photodynamic therapy monitoring (LESA-01-BIOSPEC). Protoporphyrin IX (PP IX) and endogenous porphyrins concentrations were measured by fluorescence at wavelength, correspondingly, 700 nm and 650 nm. It was shown that topical ALA is converted into PP IX in hair follicles, sebaceous glands and acne scars. The amount of resulting PP IX is sufficient for effective PDT. There was good clinical response and considerable clearance of acne lesion. ALA-PDT also had good cosmetic effect in treatment acne scars. PDT with ALA and red light assist in opening corked pores, destroying Propionibacterium acnes and decreasing sebum secretion. PDT treatment associated with several adverse effects: oedema and/or erytema for 3-5 days after PDT, epidermal exfoliation from 5th to 10th day and slight pigmentation during 1 month after PDT. ALA-PDT is effective for acne and can be used despite several side effects.
The efficiency of photodynamic therapy (PDT) using 5- aminolevulinic acid (5-ALA) is essentially determined by an optimal choice of sensitization means, among which the application method is one of the most perspective due to high permeability of a skin for 5-ALA. The aim of present work is optimization of sensitization process with ALA. We have used the possibility of 5-ALA transparency in applicator (outside of tissue) while protoporphyrin-IX, formed in sensitized tissue, has sufficient absorption for providing PDT. We have developed 5-ALA containing applicator on the basis of transparent biodegradable polymers, which serve as a programmed source of 5-ALA in the zone of their contact with pathological tissue. The investigations carried out on mice with the solid form of leucosis p-388, have shown that developed applicator provides effective sensitization of pathological tissue, supporting high concentration of photosensitizer in tissue during the whole time of application (up to week). The experiments in vivo have demonstrated high efficiency of PDT. The preliminary clinical researches allow to draw a conclusion about its perspectivity for photodynamic treatment of skin malignancies.
It is well known that sulphophthalocyanines induce in process of PDT photochemical reaction of II type with generation of cytotoxic agent -- singlet oxygen. The combination of phthalocyanine and exogenic reductant -- sodium ascorbate may also induce other reactions, involving the formation of free radicals, and thus intensify the antitumor effect. The mechanism of action of the ascorbate may be connected also with the direct tumor cells damage (apoptosis) and with the stimulation of antiblastome resistance. We conducted the experimental study on 150 white mice with Erlich carcinoma. Macroscopic and microscopic data showed that ascorbate significantly increases the effect of PDT in comparison with control group due to the higher tumor damage, inhibition of its growth and stimulation of antitumor desmoplastic reaction.
A coherent optics technique of obtaining heart beats time series is presented. The method uses a dependence of properties of speckle-structures formed by focused coherent light field diffraction from a rough surface on the surface statistics and movement parameters. Computer simulation was applied to analyze different components of skin surface vibration and their influence on speckles dynamics was investigated.
We have determined the efficacy of PDT and depth of necrosis for advanced tumors. Clinical results of PDT have shown that it is possible to get the depth of tumors necrosis till 20 mm using lasers providing high power density of laser irradiation. One of the possible models can be enlightenment of sensitizer during laser irradiation.
The comparative study of the photosensitizers with different chemical, spectral-luminescent and photophysical properties (phthalocyanines -- photosense, di- and trisulphonated zinc (II) phthalocyanines; chlorines -- chlorine p6, desvinyl-3- formyl-chlorine p6 and 3-desvinyl-3-acetyl-chlorine p6; xanthenes --rhodamine 123, rhodamine 6G-chloride, rhodamine 6G-acetate, rhodamine 6G-iodide; arylamines -- oxazinne perchlorate, oxazine-1 zinc salt, 9-diethylamino-5- ethylaminobenzophe-nothiazonium acetate, methylene blue) was performed. The cyto- and the phototoxicity of these compounds were studied on the cells of two human tumor cell lines (Raji B-cell lymphoma and A-549 lung adenocarcinoma) by MTT-test. It was shown that phthalocyanines and chlorines were not cytotoxic, whereas xanthenes and arylamines possessed dark toxicity. On the basis of the IC50 (the substance concentration, which induced 50% inhibition of cell proliferation in the cell culture) the rows of phototoxicity of the compounds of various classes were set out: in phthalocyanines: ZnPcS2 greater than Photosence greater than ZnPcS3; in chlorines: 3dV-3F-Chl p6 greater than 3 dV-3Ac Chl p6 greater than Chl p6; in xanthenes: R6G- Ac greater than R6G-Cl greater than R6G-I greater than R 123; in arylamines: Meth B greater than or equal to 9-DE-B- Ac greater than Ox1-1/2ZnCl42- very much greater than Ox1-ClO4-. Phototoxicity of the studied compounds depended on the nature of the substitutes and of the counter ions in photosensitizers molecules as well as on the concentration of the photosensitizer, on the light doses and on the regimes of irradiation. The fractionation of the light doses increased the efficiency of the phototoxic effect of the dyes on the tumor cells significantly. It was shown by the luminescent microscopy that the dynamics and the intensity of the accumulation of the rhodamines derivatives in lung adenocarcinoma cells depended on the nature of the counter ion in the photosensitizer molecule and correlated with their cyto- and pho-toxicity. Thus, photosense, di- and trisulphonated zinc phthalocyanines, 3- desvinyl-3-formyl-chlorine p6, rhodamine 6G-acetate and methylene blue turned out to be promising for their further study as photodynamic agents and efficient modifiers of chemoradiotherapy and of PDT.
A method of small-amplitude biovibrations detection is presented in the paper. The method uses a dependence of properties of speckle-structures formed by focused coherent light field diffraction from rough surfaces on the statistics and movement parameters of the surface. With the help of computer modeling the different components of skin surface vibration were analyzed and their influence on speckles dynamics was studied. Human vocal chord oscillations spectrum was monitored using the developed technique.
The paper describes a method and an experimental setup for biovibrations monitoring using coherent fields diffraction. The results of in-vivo human pulse wave measurements are presented. The computer modeling of the considered processes was carried out. The proposed measuring system output characteristics were analyzed. The sensor designed allows to perform a direct recording of a pulse beating.
The application of laser speckle and speckle-interferometric methods to cardiovibrations measurements is presented. The homodyne and heterodyne measuring techniques that use the Michelson mterferometer are compared. As shown, the space-time projections of the mterferometer output signal can be useftil for analysis of biovibrations. New diffraction methods based on speckles dynamics with a small number of scatterers are suggested that allow pulse waves to be sensed and recorded without distortion.
Keywords: speckles, interferometiy, cardiovibrations, pulse waves
The paper presents an analysis of the optical technique for low frequency biovibrations sensing. The suggested method makes use of dynamics of speckles induced by focused coherent fields diffraction from vibrating surface. Computer simulation of strongly focused coherent beams scattering from a vibrating skin surface has been carried out for cases of in- plane and angular vibrations. The dependence of output characteristics of the developed speckle-using vibration sensor on vibration type and relations between the amplitude of surface oscillations, illuminating beam waist size and the scale of the surface inhomogeneities has been analyzed. Results of biovibration monitoring using the proposed technique are presented.
In the paper the focused Gaussian beams diffraction from random surfaces which obey first- order Gaussian statistics is considered. The analytical expressions describing the probability density function and the correlation function of dynamic speckles intensity fluctuations and phase for different relations between the surface and the coherent beam parameters have been derived. The results of numerical simulation of focused coherent beam scattering for a small number of scatterers are discussed. The range of parameters, when the scattered field complex statistics are close to Gaussian ones, has been determined. Dependence of statistical characteristics of diffracted radiation on the correlation length and the standard deviation of random screen phase fluctuations has been studied.
The paper describes two practical works in Optics Laboratory of undergraduates to whom the courses on Statistical Optics, Diffraction Methods in Biomedicine and Physical Principles of Laser Measurements are taught. The first work belongs to a training course on Numerical Methods and Computing. Through it the undergraduates can analyze the regularities of speckles forming at coherent beams scattering in random media. The set of educational training software enables students to model the process of strongly focused Gaussian beams and focuses speckle fields scattering from moving phase screen and to investigate the statistical characteristics of scattered field. Another practical work, designed on the base of two-coordinate robot with aerodynamic suspension and a linear pitch drive, is a scanning laser profilometer used for an analysis of the first and second order statistics of statistically inhomogeneous speckles and for examining the profilometer's output signal as well.
The report presents a circulation plan of the course of Diffraction Methods in Biomedicine. When teaching the course, the special attention is drawn to an analysis of strongly focused Gaussian beams diffraction in random media. Original materials included in lectures provide the most complete study of the question. The diffraction fundamentals are taught in accordance with Rytov, Kravtsov and Tatarsky's book under the title of 'Introduction in Statistical Radiophysics'. Delivering lectures is combined with practical undergraduate training in speckle optics problems and seminars. The seminars are organized as scientific conferences. Along with theoretical course the laboratory training is foreseen. In particular, the paper describes two set-ups designed for investigations of human pulse waves, cardiovibrations and for measurements of white rats lymph and blood flows in vivo.
The process of the focused Gaussian beams diffraction from the surfaces with both small and large-scale relief inhomogeneities is considered. The analytical expressions describing the probability function of dynamic speckles intensity fluctuations have been derived. The numerical modeling of focused coherent beam scattering with a small number of scatterers has been conducted. As shown, this case corresponds to non-Gaussian scattered radiation statistics. The range of parameters, when the scattered field statistics are close to Gaussian ones, has been determined. The analysis of probability density function of amplitude fluctuations shows that speckle fields formed when the number of scatterers is small are statistically inhomogeneous ones. It was established how the statistical characteristics of a diffracted radiation depend on the correlation length and the standard deviation of random screen phase fluctuations.
The possibility of using strongly focused coherent fields diffraction for cardiovibration measurements is considered on the basis of a numerical modeling of light scattering by vibrating rough surface. The optical scheme for cardiovibration measurements is suggested. The forming of the output signal of the measuring system has been studied. The region of parameters when the system considered operates in the linear regime has been determined. The influence of profile statistics on investigated system output characteristics has been analyzed.
The possibility of using strongly focused coherent Gaussian beams diffraction for cardiovibration measurements is considered on the basis of a numerical modeling conducted for this type of light scattering from the vibrating rough surface. The optical scheme for cardiovibration measurements is suggested. The forming of output signal of the measuring system has been studied. The region of parameters when the considered system operates in linear regime has been determined. The influence of profile statistics on investigated system output characteristics has been analyzed.
A new type of semiconductor photosensor has been suggested and designed. Its major feature is that the size and configuration of the photosensitive region on the working surface, as well as the value of its photosensitivity to registered light, are governed by control light flux. This allows us to use the new device in optical data processing systems for various important fields, such as image signal forming, determination of light spot center position, and others. The photodetector is based on a new effect of photoinduced reversible local electric field redistribution due to the space charge of free photocarriers. On the basis of field redistribution measurements the suitable semiconductor structures were found and the first samples of the light controlled photodetector were realized. They have demonstrated rather high detectability at the control light intensity about 10-2 W/cm2, spatial resolution up to 5 lines/mm, and speed of 105 cycles/s.
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