Reduced Duration Photodynamic Therapy (PDT) Combined With Dexamethasone and Ranibizumab Intravitreal Injection in the Treatment of Exudative Age-Related Macular Degeneration

Abstract

Purpose: : The pharmacotherapy of age-related macular degeneration (AMD) is evolving rapidly, and different therapeutic regimens are being explored. Ranibizumab has shown clinical efficacy in all forms of neovascular AMD. However, this anti-angiogenic therapy has no known endpoint, and regular injections are required to maintain visual improvements. Although intravitreal triamcinolone combined with verteporfin photodynamic therapy (PDT) reduced the need for repeated treatments, this regimen was associated with increased risk of cataract and glaucoma, and with minimal visual improvements. This prospective, non-comparative, interventional case series evaluated verteporfin PDT followed by intravitreal dexamethasone and ranibizumab for treatment of AMD.

Methods: : Forty treatment-naïve patients with occult, predominantly classic or minimally classic neovascular AMD received reduced-duration verteporfin PDT (42 seconds at 600 mW/cm² at a light dose of 25 J/cm²), followed by dexamethasone (0.8 mg) within 48 hours, and ranibizumab (0.5 mg) 4-6 days after verteporfin PDT. Ranibizumab was repeated every 4 weeks if central retinal thickness (CRT) increased by >75 µm, visual acuity decreased, there was evidence of fluid on optical coherence tomography (OCT), or there was evidence of new blood. Triple therapy was repeated if leakage was noted on fluorescein angiography (FA).

Results: : At the 12-month follow-up, there was a mean 2.4-line improvement in visual acuity. Overall, 78% of patients exhibited no leakage on FA and their CRT remained flat on OCT; therefore, they received a single triple therapy with a single ranibizumab booster in 8 patients. Only 22% of patients received one additional triple therapy re-treatment, of whom 5 received a single ranibizumab booster.

Conclusions: : A regimen of reduced-duration verteporfin PDT followed by intravitreal dexamethasone and ranibizumab may offer a balance of clinically meaningful outcomes and acceptable safety in the treatment of AMD. Extended follow-up will be reported and further clinical investigation of this treatment regimen is warranted.

Keywords: age-related macular degeneration • photodynamic therapy • vascular endothelial growth factor