We thank Dr Chhablani for his interest and comments on our article. We agree that photodynamic therapy (PDT) has several disadvantages that can be minimized using indocyanine green angiography-guided treatment and concomitant intravitreal bevacizumab (IVB). We know that IVB stabilizes vision for a short period. However anti-vascular endothelial growth factor (VEGF) agents do not achieve the complete regression of polypoidal lesions. Patients have to receive intravitreal injection of expensive ranibizumab every month without knowing the end point of the treatment. We aimed to relieve the patients from the long-term repeated treatments and the economic burden.
Gomi and associates reported that IVB monotherapy reduced the subretinal fluid in polypoidal choroidal vasculopathy for 3 months of follow-up, but was ineffective for reducing the choroidal vascular changes. Kokame and associates reported stabilization of vision at 6 months with monthly intravitreal injections of ranibizumab in polypoidal choroidal vasculopathy. The polypoidal complexes on indocyanine green angiography decreased in 4 (33%) of 12 eyes. These results suggest that anti-VEGF monotherapy improves or stabilizes visual acuity for a short period, but does not eradicate the polypoidal lesions.
We agree that peripapillary polypoidal choroidal vasculopathy is contraindication for PDT. Such cases were not included in our series. The advantage of PDT is that it can occlude polypoidal lesions. We confirmed regression of the polypoidal vessels by indocyanine green angiography in 21 (72%) of 29 eyes after the first combined therapy. PDT and anti-VEGF agents have different mechanisms of action. Anti-VEGF therapy inhibits angiogenesis and vascular permeability. PDT occludes polypoidal lesions by selective endothelial uptake of a photoactivated compound. However, an immunohistologic study reported upregulation of VEGF in the choroid after PDT. Thus, the combination of PDT and anti-VEGF therapy may have a synergetic effect on CNV and polypoidal lesions. We must address the possible thromboembolic complications of intravitreal ranibizumab.
During the 12-month follow-up, the mean number of the combined PDT and IVB treatments was 1.59. We believe that the combined therapy is superior to anti-VEGF monotherapy in reducing the retreatment rates and economic burden.