Choroidal filling delay in choroidal neovascularisation due to pathological myopia.

AIM To assess the choroidal thickness and choroidal circulatory changes in eyes with myopic choroidal neovascularisation (mCNV). METHODS Retrospective, consecutive, observational case series. Forty-two consecutive eyes (17 eyes with newly diagnosed mCNV and 25 eyes without CNV) were included. Choroidal circulation was evaluated by indocyanine green angiography (ICGA), and choroidal thickness was measured by spectral-domain optical coherence tomography (SD-OCT). The factors associated with mCNV were evaluated. RESULTS Sixteen (94%) of 17 eyes with mCNV and six (24%) of 25 eyes without mCNV had well-defined hypofluorescence at the macular region on arterial phase ICGA, that is, a choroidal filling delay. Older age (p<0.001), the presence of a choroidal filling delay (p<0.001) and reduced choroidal thickness (p=0.003) were significantly associated with mCNV on univariate analysis. The most important of these three factors associated with mCNV, in order of importance, were the choroidal filling delay (OR=41.5, p<0.001) and choroidal thickness (per 1 microm, OR=0.97, p=0.01). Older age was significantly associated with both choroidal filling delay (per 1 year, OR=1.16, p<0.001) and choroidal thinning (regression coefficient=-1.22, p<0.001). CONCLUSIONS Significant choroidal changes were observed in eyes with mCNV. Ischaemia-induced growth factor expression caused by decreased choroidal perfusion may be related to the development of mCNV.