Effect of light-activated tin ethyl etiopurpurin (SnET2) on normal rabbit choriocapillaries

The aim of this study was to investigate the use of photodynamic therapy (PDT) using tin ethyl etiopurpurin (SnET2) for occluding the choriocapillaris in the eyes of pigmented rabbits. Following intravenous injection of SnET2 (0.5 and 1.0 mg/kg) or lipid emulsion alone, the fundus of pigmented rabbits was irradiated within 5 - 15 minutes of photosensitizer injection using 664 nm light at a fluence of 300 mW/cm2 and light doses of 5 - 20 J/cm2. Fundoscopy, fluorescein angiography (FA), and histology were performed at 1, 14 and 28 days after PDT. Following PDT, closure of choriocapillaris was achieved with light doses as low as 5 J/cm2 (17 seconds). Control eyes of rabbits demonstrated no effect to light irradiation at the parameters tested. PDT with SnET2 was effective in this animal model using low levels of activating light for the treatment of choriocapillaris.

[1]  J. Duker,et al.  The photodynamic occlusion of choroidal vessels using benzoporphyrin derivative. , 1994, Current eye research.

[2]  N. Bressler,et al.  Clinical characteristics of choroidal neovascular membranes. , 1987, Archives of ophthalmology.

[3]  S. Kimel,et al.  Vascular damage during PDT as monitored in the chick chorioallantoic membrane. , 1991, International journal of radiation biology.

[4]  T J Flotte,et al.  Photodynamic therapy of experimental choroidal neovascularization using lipoprotein-delivered benzoporphyrin. , 1995, Archives of ophthalmology.

[5]  C. Puliafito,et al.  Retinal and choroidal vessel closure using phthalocyanine photodynamic therapy , 1994, Lasers in surgery and medicine.

[6]  E. Ben-hur,et al.  The endothelium and red blood cells as potential targets in PDT-induced vascular stasis. , 1991, International journal of radiation biology.

[7]  Argon laser photocoagulation for neovascular maculopathy. Three-year results from randomized clinical trials. Macular Photocoagulation Study Group. , 1986, Archives of ophthalmology.

[8]  R Birngruber,et al.  Vascular targeting in photodynamic occlusion of subretinal vessels. , 1994, Ophthalmology.

[9]  C J Gomer,et al.  THE EVOLUTION OF PHOTODYNAMIC THERAPY TECHNIQUES IN THE TREATMENT OF INTRAOCULAR TUMORS , 1987, Photochemistry and photobiology.

[10]  R. Keck,et al.  New photosensitizers for photodynamic therapy: combined effect of metallopurpurin derivatives and light on transplantable bladder tumors. , 1988, Cancer research.

[11]  J V Jester,et al.  Hematoporphyrin derivative photoradiation induced damage to normal and tumor tissue of the pigmented rabbit eye. , 1984, Current eye research.

[12]  M W Berns,et al.  Photodynamic therapy for antifibrosis in a rabbit model of filtration surgery. , 1997, Ophthalmic surgery and lasers.

[13]  T. Dougherty,et al.  HOW DOES PHOTODYNAMIC THERAPY WORK? , 1992, Photochemistry and photobiology.

[14]  T. Dougherty.  Photodynamic therapy. , 1993, Photochemistry and photobiology.

[15]  I G Pallikaris,et al.  Phthalocyanine mediated photodynamic thrombosis of experimental corneal neovascularization: Effect of phthalocyanine dose and irradiation onset time on vascular occlusion rate , 1994, Lasers in surgery and medicine.

[16]  J D Gass,et al.  Pathogenesis of disciform detachment of the neuroepithelium. , 1967, American journal of ophthalmology.

[17]  C. Puliafito,et al.  Phthalocyanine photodynamic therapy: New strategy for closure of choroidal neovascularization , 1994, Lasers in surgery and medicine.