Photodynamic therapy of pigmented choroidal melanomas using a liposomal preparation of benzoporphyrin derivative.
OBJECTIVE
To evaluate the effectiveness of photodynamic therapy of pigmented choroidal melanoma using a liposomal preparation of benzoporphyrin derivative monoacid (BPD), verteporfin.


METHODS
Pigmented choroidal melanomas were established in 25 New Zealand albino rabbit eyes. The animals were treated with daily injections of cyclosporine, and tumor growth was monitored with funduscopic examination and ultrasonography. Fifteen minutes after intravenous injection of BPD (2 mg/kg), the tumors were irradiated at 692 nm through an argon-pumped dye laser with the delivered fluence ranging between 40 and 150 J/cm2. Control animals were treated with light only, photosensitizer only, or observation only. Tumor growth was monitored by indirect ophthalmoscopy, fundus photography, fluorescein angiography, and ultrasonography. Histologic examination was performed.


RESULTS
Eighteen tumor-bearing rabbits were treated with light and BPD; 16 were followed up for 1 month, and two were killed immediately for histologic examination. Tumors regressed in all eyes treated with 60 J/cm2 or more. With fluence of 40 J/cm2, tumor regrowth was observed in one animal within 10 days of treatment. In the three control groups, all animals showed continuous tumor growth. Histologic examination of the eyes treated with photosensitizer and light immediately after treatment showed prominent vascular occlusion throughout the full thickness of the tumor. One month after treatment, tumor necrosis and infiltration of mononuclear cells and pigment-laden macrophages were the predominant findings.


CONCLUSIONS
Photodynamic therapy with BPD may have a role in the treatment of pigmented choroidal melanomas.
Young
L H
LH
Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, USA.
Howard
M A
MA
Hu
L K
LK
Kim
R Y
RY
Gragoudas
E S
ES
D000818:Animals; D002830:Choroid Neoplasms / Q000188:drug therapy* / Q000473:pathology; D004195:Disease Models, Animal; D004337:Drug Carriers; D005260:Female; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D008081:Liposomes; D008546:Melanoma, Experimental / Q000188:drug therapy* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011166:Porphyrins / Q000627:therapeutic use*; D011817:Rabbits; D000077362:Verteporfin
D004337:Drug Carriers; D008081:Liposomes; D017319:Photosensitizing Agents; D011166:Porphyrins; D000077362:Verteporfin