Choroidal arterial watershed zone topography and its relationship with maculopathy in highly myopic eyes.

OBJECTIVES

To evaluate choroidal arterial watershed zones (CWZ) in highly myopic patients. The relationships between CWZ location and myopic maculopathy location and classification were also examined.

METHODS

This retrospective study included 102 consecutive patients who had been diagnosed with myopic maculopathy. Indocyanine green videoangiography was used to evaluate CWZ presence, location, and configuration. Maculopathy signs were used to examine the relationship between CWZ and myopic maculopathy.

RESULTS

Various CWZ types were identified in 102 of 158 eyes. The CWZ patterns were classified as vertical optic nerve head (vertical-ONH) in 30 eyes, stellate in 29 eyes, vertical-ONH extending to the macula in 28 eyes, horizontal fovea in eight eyes, and vertical parafovea in seven eyes. Choroidal neovascularization occurred within CWZs in 35 of 42 eyes, and macular atrophy was located within foveal CWZs in 20 of 23 eyes. The CWZ type was significantly correlated with mCNV presence (OR = 5.652, P = 0.014).

CONCLUSIONS

Variations in CWZ topography are associated with myopic maculopathy, particularly in eyes with myopic choroidal neovascularization (mCNV) and macular atrophy, and CWZ is a risk factor for mCNV. This suggests that eyes with macular CWZs are vulnerable to developing myopic maculopathy and are predisposed to mCNV because of ischaemic hypoxia.