Abstract
Purpose: :
Intravitreal bevacizumab (IVTB) is an effective treatment for choroidal neovascularization (CNV) in age-related macular degeneration (ARMD), often resulting in stabilization and/or improvement of visual acuity in most patients. Photodynamic therapy (PDT) can lead to disease stabilization and regression through localized inflammatory damage of abnormal CNV vessels, though visual acuity results are less optimal. We report our experience with combined IVTB and PDT for the treatment of CNV in ARMD in a particular subset of patients with significant resistance to IVTB monotherapy.
Methods: :
Charts of all ARMD patients with CNV treated with IVTB were retrospectively reviewed. 11 patients were treated with combined PDT and IVTB (1.25mg/ 0.05ml) administered consecutively within a period of 3-7 days. Indication for treatment was a failed response to IVTB, defined as persistent and/or recurrent fluid on OCT; and failure to discontinue treatment without recurrence. Response to therapy was determined by findings on OCT and visual acuity (VA).
Results: :
VA at the time of presentation ranged from 20/25 to CF, with a median of 20/60. Final VA ranged from 20/40 to CF with a median of 20/50. Most lesions were occult (6/11), one was minimally classic, and the rest were fibrovascular (4/11). All patients failed IVTB at intervals of 4 to 6 weeks, with a mean of 10 injections. 5 patients had failed multiple other treatment modalities, including PDT with or without intravitreal kenalog (IVTK), intravitreal pegabtanib sodium, intavitreal ranibizumab, and combined IVTB/IVTK. All patients responded to combined PDT/IVTB with complete resolution of retinal fluid on OCT. 6 patients achieved a sustained response without recurrence and with stabilization of VA, and some continued therapy with maintenance IVTB at 2 month intervals for an additional 2-5 doses (mean 3). 5 patients experienced recurrence of retinal fluid within 6-16 weeks (mean 10 weeks), one of whom achieved complete resolution with repeat PDT/IVTB.
Conclusions: :
Intravitreal anti-VEGF therapy can be successful at inducing regression of immature abnormal vessels. Studies have shown, however, that this therapy can fail in the treatment of lesions with more established vessels. Paradoxically, dependence on this form of treatment can often result. PDT can destabilize these well established vessels, making them more responsive to anti-VEGF therapy. Our case series shows that, even in cases resistant to multiple treatment modalities and longstanding therapy with IVTB, combined PDT/IVTB can often be successful.
Keywords: age-related macular degeneration • choroid: neovascularization • photodynamic therapy