Myopia patients are likely to see improved retinal blood flow with ortho-K wear. Photo: John Mountford, Dip. App. Sc. Click image to enlarge.

It’s known that high myopes have relatively thinner choroids, so it stands to reason that efforts to curtail myopia development might impact the choroidal vasculature in a positive way. A recent study documented just this phenomenon. Upon observing potential alterations in fundus microcirculation and retinal thickness in adolescent myopic orthokeratology (ortho-K) wearers, researchers recently found that these lenses improved retinal blood flow while controlling myopia.

A total of 48 patients were enrolled and divided into two groups based on the presence or absence of astigmatism: toric ortho-K and spherical ortho-K. OCT-A was used to measure the superficial and deep retinal vessel densities at the macular region, radial peripapillary capillary (RPC) density, foveal avascular zone (FAZ) area and choriocapillaris (ChC) perfusion area before and after ortho-K for three months.

After three months of toric ortho-K wear, the superficial vessel density in the fovea and parafovea had significantly increased, and the deep vessel density in the whole area and fovea were significantly elevated. In the spherical group, the superficial vessel density was significantly higher in the parafovea, and the deep vessel density in the whole area and parafovea was significantly higher. RPC density in the two groups increased after three months of ortho-K in the whole area and inside the disc area. Three months after toric ortho-K wear was initiated, the FAZ area was significantly reduced by 0.05mm², while the ChC perfusion area was enlarged by 0.06mm². The FAZ area in the spherical group significantly decreased by 0.01mm², whereas the ChC perfusion area increased by 0.06mm². Retinal thickness in the two groups increased after three months of ortho-K in the whole area and parafoveal area.

While ortho-K didn’t improve astigmatism in myopia patients, the researchers concluded that this form of therapy affects retinal blood flow and warrants further study to clarify the association.

Wang XQ, Chen M, Zeng LZ, Liu LQ. Investigation of retinal microvasculature and choriocapillaris in adolescent myopic patients with astigmatism undergoing orthokeratology. BMC Ophthalmol. September 23, 2022. [Epub ahead of print].