[Experimental rationale for a transscleral approach to thermotherapy for intraocular tumors, by using a photosensitizer].

The authors present the results of an experimental study of the pattern of distribution of laser radiation at a wavelength of 810 nm in the normal and Photosens-photosensitized eye tissues and analyze the distribution of a temperature at the sclera/choroidea/ tumor border during transscleral radiation delivery. To further the goal, the authors have resorted to computer mathematical simulation. In convergent-beam radiation supply, the proportion of a scattered radiation component has been ascertained to be lower in the surface scleral layer than that in the layers adjacent to the choroidea and the base of a tumor. On entering the sclera, a splash of light decreases and power density and radiation-induced heating of the deeply located tissues increase. Thus, the major hyperthermic effects show themselves in the tumor rather than on the sclera.

[Photodynamic therapy in treatment of chorioid neovascularization].

The authors studied the effectiveness of photodynamic therapy (PDT) with Photosence, a Russian photosensitizer, in treatment of chorioid neovascularization (CNV) in cases of age-related macular degeneration (ARMD) and pathological myopia (PM). The subjects were 73 patients with CNV suffering from ARMD and PM. The efficiency of PDT and complex conservative therapy was compared using vision acuity measurement, retinal morphometry, and fluorescent eye ground angiography (FEGA), performed before treatment, immediately after treatment, and 1, 3, 6, and 12 months later. The study showed that PDT in patients with CNV, ARMD and PM was more efficient than pharmacotherapy. Vision acuity improved or stabilized, and the parameters of retinal morphometry and FEGA improved as well. The results of the study evidence high efficiency of PDT with Photosence in treatment of CNV with ARMD and PM.

[Role of fluorescence diagnosis using Photosens in patients with subretinal neovascular membrane].

The paper shows the capacity of fluorescence diagnosis (FD) in patients with subretinal neovascular membranes. Photosens was used as a photosensitizer (PS) (NIOPIK) in FD. The agent was intravenously injected in a dose of 0.05 mg/kg. To study the kinetics of tissue PS distribution, the authors employed a procedure of local fluorescence spectroscopy using a LESA-01-Biospek spectrometer, which was improved when applying the procedure for visual assessment of a visual fluorescence image. It was ascertained that the results of photodynamic therapy (PDT) should be compulsorily taken into account in processing its parameters. In some cases, PDT may be recommended on days 3, 5, and 7 after administration of an agent. By taking into account the pharmacodynamics of Photosens, 0.5 mg/kg, all patients should keep the light regime for 3 months.

[Feasibilities of photodynamic therapy in the treatment of corneal mycotic lesions: an experimental study].

The paper presents the results of studying the photofungicidal activity of a photosens (octacationic phthalocyanine) in the in vitro and in vivo systems. Cultured Candida guilliermondii were employed in in vitro investigations. The single combined action of octacationic phthalocyanine at a concentration of up to 1 microM and laser irradiation at a wavelength of 675 nm were established to allow the high activation (up to 100%) of yeast fungi to be achieved in the in vitro system. In vivo investigations were performed on 14 rabbits (28 eyes) with induced keratomycosis. In the first series, fluorescent diagnosis of photosens accumulation in the pathological corneal areas was made in 9 (18 eyes). Based on the data obtained in the second series of experiments, the authors examined the feasibilities of photodynamic therapy for corneal mycotic lesions with the above photosensitizer in 5 rabbits (10 eyes).

[Photodynamic therapy for subretinal neovascular membranes. Communication 2. Results of treatment for complicated myopia].

The efficiency of photodynamic therapy (PDT) versus drug therapy was evaluated in patients with subretinal neovascular membranes (SNM) in complicated myopia (CM). Photosens (aluminum phthalocyanine) was intravenously injected in a dose of 0.05 mg/kg. The irradiation conditions were as follows: a session was carried out, using a laser at a wavelength of 675 nm, in an exposure light dose of 120 J/cm2. The number of sessions ranged from 3 to 5 a week, depending on the clinical picture of SNM. The total light dose was not greater than 500 J/cm2. Twelve months after drug therapy and a course of PDT, reduced visual acuity was observed in 50% and only 20.8% of cases, respectively. Stabilization or increase of visual functions occurred in the remaining patients receiving a course of PDT.

[Photodynamic therapy for subretinal neovascular membranes. Communication 1. Results of treatment for age-related macular degeneration].

The purpose of the study was to assess the results of photodynamic therapy (PDT) for subretinal neovascular membranes (SNM) in age-related macular degeneration (ARMD), by using the Russian drug Photosens. According to the treatment performed, all the patients were divided into 2 groups: 1) 18 patients with the neovascular form of ARMD who received a course of PDT; 2) 14 patients with the same form who had drug therapy. Photosens (aluminum phthalocyanine) was intravenously injected in a dose of 0.05 mg/kg. The irradiation conditions were as follows: a session was carried out, using a laser at a wavelength of 675 nm, in an exposure light dose of 120 J/cm2. The number of sessions ranged from 3 to 5 a week, depending on the clinical picture of SNM. The total light dose was not greater than 500 J/ cm2. PDT showed a higher efficiency, as compared to drug therapy. PDT using Photosens increases and stabilizes visual acuity in 50% of cases, improves retinal functional activity (an increase in the mean value of a b-wave amplitude), and causes positive changes in the morphometric values of the mean neuroepithelial thickness above SNM and in the foveola.

[Experimental assessment of the capacities of use of photosense. Communication 1. Fluorescence diagnosis of epibulbar and choroid tumors].

Whether Photosense (PS) may be used in the fluorescence diagnosis (FD) of experimental epibulbar and choroid tumors is discussed. The fluorescent ability of Photosense in FD permits detection of advanced malignancies. The kinetics of concentration of PS and the selectivity of its accumulation in malignant versus normal tissues were investigated. PS is shown to be an effective photosensitizer in the FD and, possibly, photodynamic therapy of tumors.

[The first results of phase IIA of clinical studies of photodynamic therapy for subretinal neovascular membranes with photosense].

The subretinal neovascular membrane (SNM) is a common complication of diseases, such as senile macular degeneration, myopia, pseudohistoplasmic syndrome, and many others. There is no algorithm of treatment for this pathology in today's ophthalmological care; however, many authors have arrived at the conclusion that photodynamic therapy (PDT) plays a major role in solving this difficult problem. Fifteen (18 eyes) patients, including 8 (8 eyes) patients diagnosed as having senile macular degeneration and SNM and 7 (10 eyes) patients diagnosed as having complicated high-grade myopia, and 3 were diagnosed as having bilateral SNM. The Russian agent Photosense, 0.05 mg/kg, was used as a photosensitizer. PDT was performed on day 3 after administration of the agent according to the peak of accumulation and the maximum laser concentration gradient at a wavelength of 675 nm and a light dose of 120 J/cm2. Good functional and angiographic results may be observed after the first 3 months of a prospective controlled open-labeled study of the efficiency of PDT with Photosense; however, longer follow-ups and larger groups of patients are required to make a final assessment of this treatment.

[A device for fluorescence diagnosis and photodynamic therapy of eye diseases, by using photosense].

By having a high photodynamic effectiveness and an ability of fluorescence, a Photosense photosensibilizer provides a way of combining photodynamic therapy (PDT) and monitoring its control within a session, which enhances the efficiency of treatment for the subretinal neovascular membrane. A slit lamp-based apparatus complex has been developed to employ the methods of fluorescence diagnosis (FD) and PDT, by applying this photosensitizer. The complex comprises an optical adapter that focusing laser radiation on the fundus of the eye in a range of 100-1000 microm, a video adapter that includes color and high-sensitive monochromic video cameras, as well as a personal computer and software that processes video information from the high-sensitive camera and displays the obtained images in real time. The original system of filters provides an image of the eye fundus in the fluorescent and usual color light at once during a FR procedure. The spatial resolution of the developed apparatus was tested on the test object specially devised for these purposes, which was 10 microm. The sensitivity of the complex is sufficient to record slightly fluorescent objects on the fundus of the eye.