High myopes may be at increased risk for choroidal neovascularization if they’re older or have decreased choroidal vascular density. Photo: Xuehui Lu/Journal of Ophthalmology. Click image to enlarge.

Researchers have previously observed that the retinal and choroidal thinning myopic eyes are subjected to is accompanied by decreased retinal vessel density and choroidal blood flow. “Alterations in the retina and choroid of high myopia could [induce] several pathological structural changes, including lacquer crack formation, chorioretinal atrophy, myopic maculopathy, retinal detachment and choroidal neovascularization (CNV),” researchers noted in their paper recently published in the Journal of Ophthalmology.

To learn more, they used OCT angiography (OCT-A) to analyze choroidal vascular density alterations in eyes with high myopia with and without CNV. A total of 60 eyes were included in the cross-sectional, observational study, 30 with CNV and 30 without CNV or other fundus pathology. Here are some of the findings:

• Mean age of high myopes was greater in the CNV vs. normal group (48 vs. 28 years)
• Mean choroidal thickness of high myopes was less in the CNV vs. normal group (68.8µm vs. 137µm)
• Mean choroidal vascular density was less in the CNV vs. normal group (67.54 vs. 82.43)
• Spherical equivalent was not significantly different between the CNV and normal groups (-10.56D vs. -11.93D)

The researchers concluded that highly myopic eyes with CNV had decreased choroidal thicknesses compared with normal eyes with high myopia. They also noted that lower choroidal vascular density and older age were independently associated with CNV in high myopes based on multivariate analysis.

“Consequently, new treatments should be developed to increase the choroidal blood flow in high myopic eyes and prevent the development of CNV,” they wrote in their paper. “Also, OCT-A may help us identify the highly myopic patients who need [intervention].”