Photodynamic therapy for corneal neovascularization using topically administered ATX-S10 (Na)

BACKGROUND AND OBJECTIVE: We investigated the effect of photodynamic therapy (PDT) using topically administered ATX-S10(Na) on corneal neovascularization (CoNV). MATERIAL AND METHODS: Rabbit eyes with induced CoNV were treated with ATX-S10(Na) eye drops (10 mg/mL) every 5 minutes, 5 to 25 times. Five to ninety minutes after topical administration, the CoNV were irradiated with a diode laser using a wavelength of 670 nm. RESULTS: The CoNV were occluded fluorescein angiographically in 7 of 16 treated eyes. The eyes having occluded, CoNV were irradiated using fluence of 510-1019 J/cm2 within 20 minutes of eye-drop administration. However, the effect was more variable than what we found using systemic administration in our previous investigation. CONCLUSIONS: Experimental CoNV was occluded by photodynamic therapy using topically administered ATX-S100(Na), suggesting this modality as a possible treatment for CoNV avoids the side effects found with systemic administration of the dye. Further efforts to improve the eye drops in terms of pH and osmotic pressure are needed to achieve increased dye accumulation.     

Effect of photodynamic therapy with ATX-S 10 (Na) on experimental choroidal neovascularization

PURPOSE: To evaluate an appropriate irradiative condition for selective occlusion of experimental choroidal neovascularization(CNV) with photodynamic therapy (PDT) using ATX-S 10 (Na). METHODS: Experimental CNV was induced in monkey eyes by laser photocoagulation. PDT(dose of irradiative energy 40 to 80J/cm2) was performed after 3.5 mg/kg of body weight intravenous injections of ATX-S 10(Na). CNV and retinal vessel occlusion induced by PDT was evaluated by fluorescein angiography (FA) at 1 and 7 days after irradiation. If FA showed no fluorescein dye leakage from CNV at 1 and 7 days after irradiation, CNV was evaluated by histopathological analysis at 7 days after irradiation. RESULTS: Within 30 to 33 minutes after ATX-S 10(Na) injection and irradiation with 50 to 60 J/ cm2, FA showed no fluorescein dye leakage from CNV and no closure of retinal vessels at 1 and 7 days after irradiation. Light micrographs showed occluded CNV, and retinal vessels remained patent and there was no apparent change in the inner layer of the retina. CONCLUSIONS: Irradiative condition of ATX-S10 (Na) 3.5 mg/kg was appropriate 30 to 33 minutes after ATX-S 10(Na) injection and irradiation with 50 to 60 J/cm2.     

Accumulation of photosensitizer ATX-S10 (Na) in experimental corneal neovascularization

PURPOSE: To determine the most appropriate time for laser irradiation to produce selective occlusion of new corneal vessels by photodynamic therapy (PDT) with a new photosensitizer, ATX-S10(Na). METHODS: The time course of the plasma levels of ATX-S10(Na) and the degree of dye accumulation in the corneal neovascularization after intravenous administration was determined in rabbit eyes. Plasma concentration of ATX-S10(Na) was analyzed by a spectrophotometer. The amount of ATX-S10(Na) in the new corneal vessels was measured by nitrogen-pulsed laser spectrofluorometry. Frozen sections of neovascularized cornea and iris were observed by fluorescence microscopy. RESULTS: Plasma ATX-S10(Na) concentration was highest 5 minutes after dye injection and rapidly decreased and reached almost zero at 24 hours, indicating its prompt excretion from the body. The amount of ATX-S10(Na) in the new corneal vessels as measured by nitrogen-pulsed laser spectrofluorometry increased and reached maximal level at 2 to 4 hours. Under fluorescence microscopy, the dye was more abundantly localized in the wall of new corneal vessels than in the normal tissue at 2 to 4 hours. CONCLUSION: These results indicate that laser irradiation between 2 and 4 hours after dye injection is appropriate for selective PDT with ATX-S10(Na) for the occlusion of new corneal vessels.     

应用血啉单醚光动力疗法治疗角膜新生血管的研究

目的观察应用血啉单醚行光动力疗法(PDT)治疗角膜新生血管的效果。设计前瞻性随机对照实验。研究对象成年有色兔18只。方法制作碱烧伤角膜新生血管模型。血啉单醚5mg/kg静脉注射,不同能量密度(7.6￣152.8J/cm2)的氩绿激光照射角膜新生血管根部,不注射血啉单醚只单纯行同等能量密度的激光照射组作为对照组。主要指标PDT的能量密度,行角膜新生血管荧光素造影观察新生血管封闭情况。结果PDT后3天,角膜新生血管荧光素血管造影显示:应用61.2J/cm2及以上的能量,有67%以上的眼角膜新生血管被完全封闭,33%的眼部分有效。PDT后1周,61.2J/cm2及以上组仍有66.7%(16/24眼)的眼角膜新生血管完全封闭。激光后1个月5/24眼无新生血管出现,其余眼再次出现新生血管。结论采用激光能量密度在(61.2￣152.8)J/cm2照射的PDT治疗能完全或部分封闭兔碱烧伤角膜新生血管模型中的角膜新生血管,但有新生血管再生。(眼科,2006,15:180-183)     

PDT to monkey CNV with ATX-S10(Na): inappropriateness of early laser irradiation for selective occlusion

PURPOSE: There is controversy about which mode of laser irradiation, early irradiation with low-dose photosensitizer or late irradiation with high-dose, benefits the selective occlusion of choroidal neovascularization (CNV) in photodynamic therapy (PDT). In this study, using an amphiphilic photosensitizer, 13,17-bis (1-carboxypropionyl) carbamoylethyl-8-etheny-2-hydroxy-3-hydroxyiminoethylidene-2,7,12,18-tetraethyl porphyrin sodium (ATX-S10(Na); Photochemical Inc., Okayama, Japan), photodynamic and adverse effects of early irradiation on CNV-bearing monkey eyes were investigated. METHODS: Experimentally induced CNV lesions and normal retina were irradiated with a diode laser (670-nm wavelength) at a dose of 1 to 90 J/cm(2) at 1 to 19 minutes after intravenous injection of 2 mg/kg body weight of ATX-S10(Na). Vascular occlusion and CNV recurrence were evaluated by fluorescein and indocyanine green angiography and histologic analysis, until 4 weeks after irradiation. RESULTS: Of 45 different conditions, 23 did not induce CNV closure, 20 provided both CNV occlusion and retinal vessel damage, and 2 achieved selective CNV occlusion without retinal vascular injury. Recurrence of CNV was induced in 19 of 22 CNV-occluding conditions. ATX-S10(Na) angiography showed that dyes were similarly distributed between normal vessels and CNV at early time periods after injection, whereas they were preferentially accumulated in CNV after 30 minutes. CONCLUSIONS: In PDT with ATX-S10(Na), irradiation within 20 minutes of dye injection failed to induce selective CNV occlusion, probably because there is no significant difference in the biodistribution of dye between CNV and retinal vessels. It also caused frequent CNV recurrence after extensive inflammation in the irradiated retina.     

光动力学疗法治疗角膜新生血管后角膜的光电镜改变

目的观察应用国产光敏剂行光动力学疗法(PDT)治疗角膜新生血管后角膜的组织学改变。方法碱烧伤有色兔角膜制作角膜新生血管模型。血啉单醚5mg/kg自耳缘静脉注射,不同的能量密度61.2-52.8J/cm2的氲绿激光照射角膜新生血管根部,不注射血啉单醚并单纯行同等能量密度的激光照射组作为对照组,PDT治疗后3h、1周、1个月行角膜光电镜检查。结果PDT后3h可见角膜急性炎症反应,有大量中性粒细胞浸润和少量嗜酸性白细胞浸润,虹膜组织无损伤。PDT后1周角膜炎症反应大部分消失,可见新生血管腔内有无定形物质填塞和许多影子血管。透射电镜显示:PDT组角膜新生血管内皮细胞内线粒体显示出空泡样变,细胞形态不完整。结论血啉单醚作为光敏剂,应用氩绿激光对角膜新生血管行PDT治疗,导致新生血管内皮细胞损伤,能有效封闭角膜新生血管,对周围组织无明显损伤。     

维替泊芬介导的光动力疗法治疗兔眼角膜新生血管

目的:旨在探讨和评估光敏剂维替泊芬(vertporfin)介导的光动力疗法(PDT)对角膜新生血管(CoNV)治疗的效果。方法:新西兰白兔随机分为2组:两组采用角膜基质层缝线的方法诱导CoNV形成。Ⅰ组行vertporfin-PDT治疗CoNV,verteporfin以1.5mg/kg静注。Ⅱ组不治疗,为阳性对照。治疗后裂隙灯显微镜观察CoNV变化并记录面积,取处理组及对照组的角膜、虹膜睫状体组织,行组织病理学检查,免疫组织化学(SABC法)检测血管内皮生长因子(VEGF)在角膜组织中的表达。结果:治疗后3d;1,2wk,Ⅰ组CoNV面积均明显小于Ⅱ组(P<0.01)。组织病理学检查显示,Ⅰ组CoNV管壁破坏,形成血栓。VEGF的表达Ⅰ组明显低于Ⅱ组(P<0.01)。结论:Vertporfin-PDT对兔模型眼CoNV有明显的抑制作用,不损伤邻近的正常血管及组织。     

Experimental photodynamic effects of hypocrellin A on the choriocapillaris

OBJECTIVE: To investigate the use of the photosensitizer hypocrellin A as a photodynamic agent to occlude the choriocapillaris in the eyes of pigmented rabbits. METHODS: Hypocrellin A (500 microg/kg) incorporated into liposomes was injected intravenously in pigmented rabbits. Ten to 15 minutes later, the retinas were irradiated with a dye laser (spot size, 2 mm; 10-60 mW; 10-60 seconds; fluences 3.2 to 95.5 J/cm2) at two wavelengths: yellow (568 nm) and red (647 nm). Fluorescein angiography was performed 2 and 24 hours later. Parallel controls were irradiated without a photosensitizer. Histology was performed immediately after the 24-hour angiogram. observed 24 hours after PDT in eyes subjected to yellow laser irradiation at 20 mW for 60 seconds (fluence, 38.2 J/cm2) and at higher powers for lesser durations: 30 mW for 40 seconds (fluence, 38.2 J/cm2), 40 mW for 20 seconds (fluence, 25.4 J/cm2), and 50 and 60 mW for 10 seconds (fluences, 15.9 and 19.1 J/cm2, respectively). Light microscopy showed occlusion of the choriocapillaris in all eyes with angiographic responses. Control eyes and eyes irradiated with the red laser revealed no angiographic or histologic changes. CONCLUSION: Photodynamic therapy using liposomal hypocrellin A and the yellow laser of 568 nm was effective in occluding the choriocapillaris of pigmented rabbits.     

兔眼脉络膜黑色素瘤的第二代光敏剂光动力治疗

目的 观察第二代光敏剂CASPc（chloroaluminum su lfonated phthalocyanine,CASPc）对B16F10黑色素瘤动物模型的光动力治疗（PDT）作用 。 方法 38只新英格兰大白兔经免疫抑制后种植B16F10黑色素瘤碎片于脉络膜下腔，B型超声、间接检眼镜随访肿瘤生长至2.0 ~3.8 mm厚时30只兔眼给予PDT治疗。耳静脉注射CASPc 5 mg/kg, 24 h后给予氩-染料激光照射，激光波长675 nm, 输出功率600 nm/cm2，激光照射剂量20~70 J/cm2；8只对照组兔眼只给予激光或光敏物质。治疗后观察6~8周。 结果 38只兔眼建模成功。30只PDT治疗兔眼中21只眼肿瘤得到控制，9只眼未能控制；对照组兔眼肿瘤治疗后2周充满整个玻璃体。 结论 第二代光敏剂CASPc对实验性眼B16F10黑色素瘤具有一定的PDT治疗作用。 （中华眼底病杂志，2004，20：67-132）     

Photodynamic therapy of experimental choroidal neovascularization with a hydrophilic photosensitizer: mono-L-aspartyl chlorin e6

PURPOSE: To demonstrate the selective localization of the hydrophilic photosensitizer mono-L-aspartyl chlorin e6 (NPe6) in experimental choroidal neovascularization in nonhuman primate eyes. METHODS: Sixty-seven experimental choroidal neovascular lesions (CNV) were created in the fundi of Macaca monkeys using the modified Ryan's model and documented by fluorescein and indocyanine green angiography. To determine the biodistribution of NPe6 and the optimal timing of laser irradiation after dye administration, NPe6 angiography and fluorescence microscopy with NPe6 were performed. Photodynamic therapy (PDT) was performed at various dye doses (0.5-10.0 mg/kg) and laser fluences (7.5-225.0 J/cm2) on the CNV and on 10 areas of normal retina and choroid. Treatment outcomes were assessed by fluorescein and indocyanine green angiography and confirmed by light and electron microscopy. RESULTS: NPe6 fluorescence microscopy demonstrated intense fluorescence of CNV and retinal pigment epithelial cells. Choroidal vessel walls and outer retina adjacent to CNV fluoresced moderately; retinal vessel walls and microcapillaries had trace fluorescence. The fluorescence of CNV lesions on fluorescein angiography became stronger than that of retinal vessels 20-60 minutes after dye injection. Choroidal neovascular lesion closure was achieved with NPe6 PDT without significant damage to the sensory retina. Histology demonstrated necrosis of CNV endothelial cells with minimal damage to surrounding tissues. CONCLUSIONS: NPe6 PDT selectively localizes to experimental CNV in nonhuman primates, resulting in occlusion of CNV with sparing of the neurosensory retina.     

Photodynamic therapy with verteporfin in a rabbit model of corneal neovascularization

PURPOSE: To determine the efficacy of photodynamic therapy (PDT) with verteporfin (Visudyne; Novartis AG, Basel, Switzerland) for treatment of corneal neovascularization in a rabbit eye model. METHODS: Corneal neovascularization was induced in Dutch belted rabbits by placing an intrastromal silk suture near the limbus. Verteporfin was administered by intravenous injection at a dose of 1.5 mg/kg, and the pharmacokinetics of verteporfin distribution in the anterior segment or PDT-induced (laser energy levels 17, 50, and 150 J/cm(2)) regression of corneal blood vessels were then determined. To assess PDT-induced toxicity of the anterior segment, corneal and iris/ciliary body histology, and IOP were evaluated after PDT. RESULTS: Verteporfin accumulation in vascularized regions of the cornea and the iris/ciliary body tissue were time dependent and maximum levels achieved at 60 minutes after injection. In rabbits, PDT of corneal vessels using laser energy of 17 or 50 J/cm(2) resulted in 30% to 50% regression of corneal neovascularization; however, in these animals, a rapid regrowth of new blood vessels occurred between 3 and 5 days. In the rabbits receiving PDT using laser energies of 150 J/cm(2), the mean vessel regression was 56%. During the nine days of the laser therapy follow-up period, no vessel regrowth was observed in these rabbits. Histologic examination of the anterior segment after PDT (150 J/cm(2)) showed localized degeneration of the corneal blood vessels without observable change in other anterior segment structures. CONCLUSIONS: These results provide evidence that PDT can produce significant regression of neovascular corneal vessels with no observable toxicity to the anterior segments. However, the optimal laser energy necessary to induce long-term regression (150 J/cm(2)) was three times that used to treat choroidal neovascularization.     

Dynamic observation of selective accumulation of a photosensitizer and its photodynamic effects in rat experimental choroidal neovascularization

PURPOSE: The authors investigated the selective accumulation of a photosensitizer, ATX-S10(Na), in experimental choroidal neovascularization (CNV) in rats using a highly sensitive colorchromatic charge coupled device (CCD) camera. METHODS: To detect the development of experimental CNV in 30 rats, the animals were followed weekly with simultaneous fluorescein and indocyanine green angiography. After injecting ATX-S10(Na), the authors detected fluorescence from the photosensitizer using a highly sensitive color CCD camera. The camera was connected to a surgical microscope, under which rat fundi were observed through a coverglass in contact with the cornea. The retinas were excited with 405-435 nm light, and the light emitted from the photosensitizer passed through a 680-nm bandpass filter before being detected by the CCD camera. RESULTS: Immediately after injection, fluorescence appeared in the retinal vessels and then the entire retina. Thirty minutes postinjection, the intensity of the fluorescence was still strong from the whole retina, and the CNV was not detected. One hour after injection, retinal fluorescence was weak but still observable; 1.5 hours postinjection, retinal fluorescence was undetectable but fluorescence was strong from the CNV. Under the optimum therapeutic conditions, CNV was effectively occluded. CONCLUSION: ATX-S10(Na) selectively accumulates in the CNV in rats. The optimum therapeutic timing is approximately 1.5 hours postinjection of the dye in this CNV model.     

Application of femtosecond ultrashort pulse laser to photodynamic therapy mediated by indocyanine green

BACKGROUND/AIMS: To evaluate treatment with high peak power pulse energy by femtosecond ultrashort pulse laser (titanium sapphire laser) delivered at an 800 nm wavelength for corneal neovascularisation using photodynamic therapy (PDT) mediated by indocyanine green (ICG). METHODS: Using a gelatin solid as an in vitro corneal model, the safety of laser power was studied to determine if it degenerated gelatin with or without ICG. The authors then induced corneal neovascularisation in rabbit eyes by an intracorneal suturing technique. Fluorescein angiography was used to evaluate occlusion before PDT and 0, 1, 3, and 10 days after PDT. The authors performed light microscopy with haematoxylin eosin staining and transmission electron microscopy to determine thrombosis formation in the neovascular regions. RESULTS: The threshold of peak laser power density ranged from 39 to 53 W/cm(2). Laser irradiation was started 30 seconds after a 10 mg/kg ICG injection, and all irradiated segments were occluded at 0, 1, 3, and 10 days at 3.8 J/cm(2). Light and electron microscopy documented thrombosis formation in the neovascular region. CONCLUSION: Femtosecond pulse laser enhanced by ICG can be used for PDT. Because of effective closure of corneal neovascularisation at a low energy level, the high peak power pulse energy of the femtosecond pulse laser might be more efficacious than continuous wave laser for use with PDT.     

Evaluation of the new photosensitizer Tookad (WST09) for photodynamic vessel occlusion of the choroidal tissue in rabbits

PURPOSE: To determine the efficacy of Tookad (WST09; Negma-Lerads, Magny-Les-Hameaux, France) photodynamic therapy (T-PDT) by evaluating the angiographic and histologic closure of choroidal vessels at different radiance exposures, drug dosages, and intervals between photosensitizer injection and laser application in a rabbit model. METHODS: Chinchilla Bastard rabbits were injected intravenously with three different dye concentrations (2.5, 5, and 10 mg/kg) before application of light. In every group T-PDT was performed at four different times after injection: 5, 15, 30, and 60 minutes with different radiance exposures ranging from 200 to 3 J/cm2. Fundus photographs and fluorescein angiograms were obtained 90 minutes after injection. Follow-up angiographies were performed at days 1, 3, 7, and 14 after initial treatment. Histology was performed in selected cases immediately after treatment and on days 1, 3, and 7. RESULTS: Immediately after irradiation, most of the visible lesions were angiographically hyperfluorescent due to damaged vessel endothelium and associated RPE damage. Lesions from high-radiance exposures revealed immediate hypofluorescence, indicating vessel closure. Hypofluorescent lesions appeared mainly during day 1 (all lesions angiographically visible, some hypofluorescent) to day 3 (all lesions hypofluorescent) after treatment. At day 7, ophthalmoscopically visible hyperpigmentation took place in all lesions. ED50 thresholds for angiographic hypofluorescence determined at day 3 after treatment with 2.5 mg/kg were 18.8 J/cm2 (5 minutes), 62.0 J/cm2 (15 minutes), and >100 J/cm2 (30 minutes); with 5 mg/kg, 8.4 J/cm2 (5 minutes), 22.8 J/cm2 (15 minutes), 54.5 J/cm2 (30 minutes), and >100 J/cm2 (60 minutes); and with 10 mg/kg, 11.7 J/cm2 (30 minutes) and 54.1 J/cm2 (60 minutes). Histology of the angiographically hypofluorescent lesions revealed vessel thrombosis in all groups 1 hour after PDT up to 7 days after treatment. Sparing of photoreceptors indicated selectivity of T-PDT; however, slight damage was partly observable. After 7 days, localized proliferation of the RPE cells was noted and was enhanced 14 days after treatment. CONCLUSIONS: T-PDT has the potential to achieve selective choroidal vessel occlusion with proper parameter selection, such as (1) 2.5 mg/kg, 5 minutes, 100 J/cm2; (2) 5 mg/kg, 5 minutes, 25 J/cm2; or (3) 5 mg/kg, 15 minutes, 50 J/cm2; however, slight damage to the photoreceptors cannot be ruled out. RPE proliferation indicates primary RPE damage due to PDT, also described with the use of all other photosensitizers.     

Mechanism of photodynamic occlusion using liposomal Zn(II)-phtalocyanine

PURPOSE: To evaluate the potential of liposomal Zinc(II)-phthalocyanine (ZnPc) to selectively target subretinal vasculature. METHODS: Photodynamic therapy (PDT) with liposomal Zinc(II)-phtalocyanine was used to induce choroidal occlusion in eyes of pigmented rabbits. Drug doses of 0.16, 0.24, 0.32, and 0.4 mg/kg body weight were administered. Photosensitization was performed at a wavelength of 671 nm and an irradiance of 100 mW/cm2 applying fluences of 5, 10, 20, and 50 J/cm2. RESULTS: Using liposomal ZnPc, occlusion of choroidal vessels was achieved without damage to the overlying neurosensory retina. A tight dose correlation was found with a drug dose of 0.32 mg/kg and a light dose of 10 J/cm2 inducing a selective thrombosis of the subretinal capillary layer. Histology revealed a selective intravascular alteration of the endothelial cells. CONCLUSIONS: PDT using liposomal ZnPc allows occlusion of subretinal vasculature with maintenance of neuroretina and RPE. The destructive effect on choroidal vascular endothelium is intensive.     

Evaluation of the new photosensitizer Stakel (WST-11) for photodynamic choroidal vessel occlusion in rabbit and rat eyes

PURPOSE: To evaluate the photodynamic potential of a new hydrosoluble photosensitizer (WST-11, Stakel; Steba Biotech, Toussus-Le-Noble, France), for use in occlusion of normal choroidal vessels in the rabbit eye and CNV (choroidal neovascularization) in the rat eye. METHODS: Occlusive and nonocclusive parameters of Stakel and verteporfin photodynamic therapy (PDT) were investigated in pigmented rabbits. Eyes were followed by fluorescein angiography (FA) and histology at various intervals after PDT. RESULTS: When occlusive parameters (fluence of 50 J/cm(2), 5 mg/kg drug dose and DLI [distance to light illumination] of 1 minute) were used, Stakel PDT was efficient immediately after treatment without associated structural damage of the RPE and retina overlying the treated choroid in the rabbit eye. Two days later, total occlusion of the choriocapillaries was seen in 100% of the treated eyes, along with accompanying histologic structural changes in the overlying retina. When the occlusive parameters (fluence, 100 J/cm2; drug dose, 12 mg/m2; and DLI, 5 minutes) of verteporfin PDT were used, occlusion of the choriocapillaries was observed in 89% of the treated eyes. Histology performed immediately after treatment demonstrated structural damage of the overlying retina and RPE layer. Weaker, nonocclusive Stakel PDT parameters (25 J/cm2, 5 mg/kg, and DLI of 10 minutes) did not induce choriocapillary occlusion or retinal lesions on FA or histology. Weaker, nonocclusive verteporfin PDT parameters (10 J/cm2, 0.2 mg/kg, and DLI of 5 minutes) did not induce choriocapillary occlusion. However, histology of these eyes showed the presence of damage in the retinal and choroidal tissues. Moreover, preliminary results indicate that selective CNV occlusion can be achieved with Stakel PDT in the rat eye. CONCLUSIONS: Unlike verteporfin PDT, Stakel PDT does not cause direct damage to the RPE cell layer or retina. These observations indicate that Stakel PDT may have a high potential for beneficial therapeutic outcomes in treatment of AMD.     

Photodynamic therapy for corneal neovascularization using polymeric micelles encapsulating dendrimer porphyrins

PURPOSE: To investigate the accumulation of new photosensitizers (PSs), dendrimer porphyrin (DP, free DP), and DP encapsulation into polymeric micelles (DP-micelle) and the efficacy of photodynamic therapy (PDT) in an experimental corneal neovascularization model in mice. METHODS: Corneal neovascularization was induced by suturing 10-0 nylon 1 mm away from the limbal vessel in C57BL6/J mice. To determine the accumulation of free DP and DP-micelle, 10 mg/kg free DP or DP-micelle was administered by intravenous injection 4 days after suture placement. Mice were killed 1, 4, 24, and 168 hours after the injection of PS. Twenty-four hours after the administration of free DP or DP-micelle, mice were treated with a diode laser of 438-nm wavelength at 10 or 50 J/cm(2). Fluorescein angiography was performed before and 7 days after irradiation, and the area of corneal neovascularization was quantified. RESULTS: Free DP and DP-micelle accumulated in the neovascularized area 1 hour to 24 hours after administration. Fluorescence of DP was weaker than that of DP-micelle. Neither DP-micelle nor DP could be detected in normal limbal vasculature. In the PDT experiments using PS, mean residual rates of corneal neovascularization were 10.1% in the mice treated with DP-micelle and 21.6% in the mice treated with free DP at 10 J/cm(2) (P < 0.01). At 50 J/cm(2), mean residual rates of corneal neovascularization were 10.6% in the mice treated with DP-micelle and 13.7% in the mice treated with free DP (P > 0.05). Although corneal neovascularization in PDT-treated mice exhibited significant regression compared with the control group, significant energy-related vessel regression with increasing laser energy could not be observed. CONCLUSIONS: PDT with DP-micelle and free DP can provide efficacious treatment of corneal neovascularization.     

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.     

光动力疗法治疗CNV的术后早期改变(2)

目的：观察光动力疗法治疗黄斑中心凹下脉络膜新生血管性疾病后1wk的早期变化,并比较两种不同的光动力治疗方法在术后1wk有无差别。 方法：经诊断有黄斑中心凹下脉络膜新生血管者16例19眼,随机分为两组,13眼接受维替泊芬标准光动力疗法(维替泊芬剂量为6mg/m²体表面积,静脉推注的速度为3mL/min,药物开始注射15min后开始激光照射,波长689nm,光照密度为600mW/cm²,光照时间为83s,光能量为50J/cm²);6眼接受快速推注低能量照射光动力疗法(维替泊芬剂量为6mg/m²体表面积,静脉推注的速度为6mL/min,药物开始注射15min后开始激光照射,保持光照强度为600mW/cm²,波长689nm,光照时间为42s,光剂量25 J/cm²)。在术前及术后1wk分别行最佳矫正视力（BCVA）、ETDRS视力、OCT及眼底检查,利用OCT自带软件分别测量层间厚度（Tf）、神经上皮厚度（Nf）、外层高反光带厚度（T）、视网膜下液（SF）等观测值。比较患者术前及术后1wk各个观察指标的变化,并比较两组间观察指标有无差别。 结果：不同参数光动力疗法术后1wk视力及OCT图像中Tf,Nf,T,SF等差别无统计学意义（P>0.05）。术后1wk,标准光动力疗法和快速推注低能量光动力疗法之间各指标的差异无统计学意义（P>0.05）。 结论：标准参数光动力疗法和快速推注低能量照射光动力疗法在术后1wk对视网膜结构的影响无差异,两种治疗方法之间疗效无差异。 "     

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.