Protective Effect of Intravitreal Bevacizumab and Sub-Tenon Triamcinolone Acetonide against Occlusion of Choriocapillaris Induced by Photodynamic Therapy

Abstract

Purpose: To evaluate the protective effect of intravitreal bevacizumab (IVB) and sub-Tenon triamcinolone acetonide (TA) against choriocapillaris occlusion induced by photodynamic therapy (PDT). Methods: This prospective, nonrandomized, consecutive study included 80 eyes of 80 patients with polypoidal choroidal vasculopathy who underwent an initial PDT. The posttherapeutic follow-up periods were more than 3 months (mean, 9.3 months). Patients were divided into three groups consecutively: the PDT group included 21 eyes of 21 patients treated with only PDT, the TA group included 32 eyes of 32 patients treated with PDT and a sub-Tenon injection of 20 mg TA, and the IVB group included 27 eyes of 27 patients treated with PDT and an intravitreal injection of 1.25 mg bevacizumab. Indocyanine green angiography (ICGA) was performed before and 3 months after PDT. The degree of choriocapillaris occlusion was assessed in the marginal zone of the PDT area based on the background hypofluorescence seen on ICGA quantified by densitometry (Imagenet). Results: ICGA at 1 and 5 min showed hypofluorescence in the marginal zone in all eyes 3 months after PDT. The hypofluorescence became indistinguishable from the background fluorescence 15 min after treatment in some eyes; however, the relative hypofluorescence persisted in some cases. The rates of fluorescence intensity in the marginal zone compared to those in the untreated area, i.e. the percentage of baseline fluorescence, were 0.60, 0.65 and 0.73 at 1, 5 and 15 min after dye injection in the PDT group, respectively, 0.64, 0.68 and 0.82 in the TA group, and 0.64, 0.73 and 0.90 in the IVB group. The intensity of the fluorescence was significantly (p < 0.05) higher in the TA group at 15 min and in the IVB group at 1, 5 and 15 min compared with the PDT group. Conclusions: IVB and TA reduced choriocapillaris occlusion after PDT. IVB appeared to have a stronger protective effect than TA in this therapeutic regimen.