benzoporphyrin-d and Choroid-Neoplasms

Photocoagulation, cryotherapy and radiotherapy have been used to treat angiomatous lesions. Depending on the location of the angioma, these treatments can cause additional, significant functional damage. Photodynamic therapy (PDT) however, allows a selective occlusion of vascular lesions without damaging adjacent retinal structures.. Two patients with isolated choroidal hemangiomas involving the posterior pole were treated with PDT. Treatments were performed using a diode laser at 692 nm, a light dose of 100 J/cm2 and 6 mg/m2 body surface area verteporfin (BPD-MA). PDT was applied in two courses in one eye and in four in the other eye at 1-4 months intervals. Patients were followed up for 9-12 months with visual acuity measurements and dilated ophthalmoscopy. Ultrasound, indocyanine green angiographic and fluorescein angiographic images were evaluated at each visit.. Tumor heights were 3.3 and 4.6 mm on pretreatment ultrasound. After therapy, patients with isolated choroidal hemangioma showed total regression of the lesion and improved visual acuity due to resorption of retinal edema. Serous retinal detachment and cystoid macular edema resolved. Ultrasound demonstrated a progressive decrease in tumor height after each PDT application, with complete disappearance of the lesion. Retinal vessels were not affected by the treatment, and retinal function recovered in areas with previous tumor involvement.. PDT allows selective treatment of large intraocular angiomatous lesions. Without optimized parameters, complete regression of choroidal hemangiomas, resolution of secondary complications and improvement of visual acuity were documented.

Topics: Adult; Choroid Neoplasms; Female; Fluorescein Angiography; Hemangioma; Humans; Indocyanine Green; Lasers; Male; Middle Aged; Photochemotherapy; Photosensitizing Agents; Porphyrins; Treatment Outcome; Visual Acuity

Photodynamic therapy (PDT) with its potential for precise localization and absence of severe side effects such as radiation retinopathy may be particularly appropriate for the treatment of intraocular tumors. Benzoporphyrin (BPD), a potent photosensitizer currently in clinical trial, absorbs light at 692 nm, thus allowing sufficient tissue penetration due to minor light absorption in melanin and hemoglobin. The efficiency and selectivity of BPD are significantly pronounced through preassociation with low-density lipoprotein (LDL), since proliferating cells exhibit an increased metabolism of lipoproteins. As an experimental model Greene's melanomas were implanted either into the iris or choroid of albino rabbits. Irradiation at a radiation energy of 80 for iris and 100 J/cm2 for choroidal tumors 3 h after the i.v. injection of BPD-LDL (2 mg/kg) was administered via a laser arrangement with argon-pumped dye-laser, using the slit-lamp. Angiographies and LM/EM histologies were done immediately, and 1, 3, and 14-21 days post-exposure. All 16 treated tumors demonstrated complete regression with a remaining avascular, fibrotic scar. Immediate vascular occlusion within the tumor was seen angiographically, suggesting a direct vascular mechanism. Histologically, two primary mechanisms could be detected: destruction of neovascular endothelial cells and intracellular tumor cell damage. These results indicate that PDT using BPD-LDL complexes may provide an efficient and selective modality for the management of intraocular neoplasms. The availability of new and potent photosensitizers may also lead to broader clinical applications.

Topics: Animals; Choroid; Choroid Neoplasms; Hematoporphyrin Photoradiation; Iris; Iris Neoplasms; Lipoproteins, LDL; Melanoma, Experimental; Porphyrins; Rabbits; Radiation-Sensitizing Agents

Benzoporphyrin derivative monoacid (BPD) is a new photosensitizer currently undergoing clinical trial for cutaneous malignancies. Compared with the clinically most frequently used sensitizer, Photofrin, BPD may offer higher tumor phototoxicity, better tissue penetration, and absence of significant skin sensitization. Low-density lipoprotein (LDL) carriers heighten efficiency and selectivity of BPD because neovascular and tumor cells express an increased number of LDL receptors. Hence, in addition to the vaso-occlusive effects similar to most other photosensitizers, LDL-BPD also has been shown to cause direct tumor cell damage.. Benzoporphyrin derivative monoacid was complexed with human LDL and used in photodynamic treatment of choroidal melanomas experimentally induced in eight albino rabbits. Five rabbits served as controls. Three hours after intravenous injection of 2 mg/kg body weight of LDL-BPD, eight tumors were irradiated at 692 nm and 100 J/cm2 via an argon-pumped dye laser coupled into a slit lamp.. Angiography and histologic findings showed immediate photothrombosis after disintegration of endothelial membranes. After complete necrosis of tumor cells within 24 hours, a small fibrotic scar slowly developed. No tumor regrowth was noted up to 6 weeks when animals were killed.. These data suggest that photodynamic treatment with LDL-BPD may be a promising modality for multiple clinical applications, including tumors and neovascularizations II.

Topics: Animals; Choroid Neoplasms; Drug Carriers; Fundus Oculi; Injections, Intravenous; Laser Therapy; Lipoproteins, LDL; Melanoma; Neoplasms, Experimental; Photochemotherapy; Porphyrins; Rabbits; Radiation-Sensitizing Agents