Flow pattern and perforating vessels in three different phases of myopic choroidal neovascularization seen by swept-source optical coherence tomography angiography

Purpose To compare the choroidal neovascularization (CNV) flow patterns and the relationship between perforating vessels (PVs) and CNV in the three different stages of networks in myopic CNV (mCNV) using swept-source optical coherence tomography angiography (SS-OCTA). Methods This retrospective study included 28 eyes with mCNV that was divided into three phases (active, scar, and atrophic) and observed by SS-OCTA. SS-OCTA findings, with special focus on the relationship between the PVs and CNV, were compared among the three phases. Results Overall, the CNV signal was detected in 31 of the 34 areas of CNV (91%); in the active, scar, and atrophic phases, respectively, CNV signals were detected in eight of eight areas of CNV (100%), 10 of 11 areas of CNV (91%), and 13 of 15 areas of CNV (86%). Two signal patterns were observed in each phase, i.e., dense and loop; in the atrophic phase, seven eyes were unclassifiable. The ratio between the dense and loop patterns did not differ significantly among the phases. In 30 of 34 areas of CNV for which clear images were obtained, the PVs and CNV were connected directly or indirectly in 19 area of CNV, and in five areas of CNV, trunk-like vessels were connected to the PVs within the CNV. The numbers of foveal or parafoveal CNVs accompanied by PVs were significantly (p=0.0048) greater than those of the extrafoveal CNV. Conclusions OCTA provides detailed observation of mCNV and the relationship between CNV and PVs. Although the CNV signal pattern does not differ depending on the degree of atrophy, there are cases in which only the trunk-like vessels connect to the PVs within the CNV in the atrophic phase without CNV flow signal.