I read with great interest a recent article by Koizumi and associates entitled “Short-term changes in choroidal thickness after aflibercept therapy for neovascular age-related macular degeneration.” The study demonstrated a marked decrease in choroidal thickness in eyes treated with intravitreal aflibercept. Moreover, the amount of decrease after aflibercept therapy seems to be greater than the values reported after ranibizumab treatment. The authors of this study postulated that reduction in choroidal vascular permeability from fenestrated vascular walls and the narrowing of choroidal vessels may partially influence the observed change in choroidal thickness.
Although their study provides useful information, one important piece of data is missing: changes in choroidal thickness in eyes with retinal angiomatous proliferation (RAP). It is well known that the choroid is prominently thinned in eyes with RAP. Some investigators have postulated that compromised choroidal perfusion owing to choroidal thinning may influence the development of this peculiar type of neovascularization. In addition, thinner choroids in RAP were found to be associated with increased risk of geographic atrophy after anti–vascular endothelial growth factor treatment.
If marked choroidal thinning is also noted after intravitreal aflibercept therapy in RAP eyes, I suspect a possible negative influence of aflibercept on choroidal perfusion in RAP, which may already show thinned choroids. To date, little knowledge is available regarding intravitreal aflibercept treatment outcome in RAP. In addition, no previous study has reported changes in choroidal thickness following intravitreal aflibercept therapy in RAP. Fortunately, in the study by Koizumi and associates, indocyanine green angiography was routinely performed. Re-analysis of the indocyanine green angiography results in the typical neovascular AMD group may reveal some RAP cases. Although a relatively small number of RAP cases may not provide firm evidence regarding changes in choroidal thickness, I believe that presenting choroidal thickness data in this cohort may provide useful information for clinicians as well as investigators who are interested in RAP.