PHOTODYNAMIC THERAPY OF SUBFOVEAL CHOROIDAL NEOVASCULARIZATION - CLINICAL AND ANGIOGRAPHIC EXAMPLES

Background: Conventional photocoagulation of subfoveal choroidal neova scularization (CNV) is often accompanied by visual loss due to thermal damage to adjacent retinal structures. Photodynamic therapy (PDT) all ows vascular occlusion by selective photochemical destruction of vascu lar endothelial cells only. In a pilot study we evaluated the use of P DT in CNV. Methods: In a clinical phase I/II trial, patients with subf oveal CNV were treated with PDT. Benzoporphyrin derivative monoacid ri ng A (BPD) was used as sensitizer at a drug dose of 6 mg/m(2) or 12 mg /m(2). Irradiation was performed via a diode laser emitting at 690 nm coupled into a slit lamp. Safe and maximum tolerated light doses were defined by dose escalation from 25 to 150 J/cm(2). Photodynamic effect s were documented ophthalmoscopically and angiographically.Results: Si xty-one patients received a single course of BPD-PDT. Preliminary resu lts suggest no damage to retinal structures within the treated area cl inically. Retinal perfusion was not altered, while CNV demonstrated im mediate absence of fluorescein leakage in the majority of lesions subs equent to PDT. At optimized parameters (6 mg/m(2) and 50 J/cm(2)) comp lete cessation of leakage from classic CNV occurred in 100% of cases a t 1 week and in 50% at week 4. In 70-80% of classic CNV, leakage reapp eared at week 12, but markedly less than before treatment. Conclusion: PDT allows temporary absence of leakage from CNV with preservation of visual acuity. The long-term prognosis of CNV secondary to age-relate d macular degeneration treated with repeated courses of PDT is being e valuated in a phase III trial.