I read with great interest the article by Kuroda et al.
1 on the association of focal choroidal excavation (FCE) with age-related macular degeneration (AMD). Focal choroidal excavation is a recently reported clinical entity, first described by Jampol et al.,
2 and has been suggested to form the basis of choroidal neovascularizations (CNVs).
The authors hypothesized that FCE may be involved in the development of CNV associated with exudative AMD. Using swept-source optical coherence tomography (OCT) they examined the macular area in 243 consecutive eyes (217 patients) with exudative AMD to study the possible association with FCE. Overall, 15 FCEs were found in 12 eyes.
I noted that the authors did not report the inclusion criteria (they only reported the exclusion criteria), neither specified which characteristics established the diagnosis of AMD. I also noted, that the cases provided to illustrate the FCEs miss the typical signs of AMD, including the visualization of drusen on fundus color pictures and fluorescein angiography frames, and the typical retinal pigment epithelium elevations on OCT (B-scans and three-dimensional image reconstructions). In addition, the OCT scans show a dilation of choroidal vessels and overall choroidal thickening, which is unusual for AMD.
3–4 Dilation of choroidal vessels characterizes polypoidal choroidal vasculopathy (PCV) and central serous chorioretinopathy (CSC), both considered part of a pachychoroid-driven disease spectrum.
5 The PCV is particularly frequent in Asians, and in the current series (all patients were Japanese) accounts for 8 of the 12 eyes. While PCV may represent a manifestation of long-standing CNVs in AMD, at least in Caucasian it is not considered in the spectrum of typical AMD. The PCV also may represent a manifestation of long-standing CSC. Moreover, CSC was shown to be associated with Type 1 neovascularization, which could lead to the misdiagnosis of exudative AMD.
6 The association between PCV and FCEs has been reported previously.
7,8 Similarly, the association between CSC and FCEs has been reported previously.
9
The authors highlight how the clinical characteristics of the CNVs reported in their series are different from those of typical exudative AMD, and that are rather similar to those of secondary CNV; indeed, this could be simply due to the fact that the series reported probably is not AMD.
Before definitively stating that, at least in Asians, FCE is quite commonly associated with AMD (4.9% in the current series), the authors should provide clarifications regarding the criteria adopted to establish the diagnosis of AMD.