In patients with high myopia — defined as a spherical equivalent refractive error more negative than -6.00 D — researchers have found elevated levels of proinflammatory cytokines and angiogenic growth factors in the vitreous humor, a study shows. This suggests that an elevated inflammatory status and higher levels of angiogenic factors are present in eyes with high myopia, the investigators say.
Researchers studied vitreous humor samples collected following vitrectomy surgeries from 78 patients, 36 with high myopia and another 42 eyes without high myopia as the control group. They used a multiplex bead immunoassay to measure the levels of 29 factors, including proinflammatory cytokines and angiogenesis-related growth factors, in the vitreous humor.
The investigation found that vascular endothelial growth factor (VEGF) was significantly higher in the samples from high myopia patients than in those from the controls. In addition, the high myopia group had significantly higher levels of 5 different inflammation-related factors; interferon γ (IFN-γ), interleukin 6 (IL6), IFN-γ-induced protein 10 (IP-10), eotaxin, and macrophage inflammatory protein 1α (MIP-1α). The high myopia patients also exhibited significantly elevated vitreous concentrations of well-known angiogenic growth factors monocyte chemoattractant protein 1 (MCP1) and IL5.
While the precise factors that lead to myopia remain unknown, researchers do speculate that the prevalence of high myopia is expected to grow to nearly a billion people by 2050. Researchers point out that prior investigations show approximately 39% of 75-year-olds with high myopia suffer from uncorrectable visual impairment and associations with conditions such as rhegmatogenous retinal detachment, myopic retinoschisis, glaucoma, cataract, choroidal neovascularization, and myopic macular degeneration.
Researchers pointed to the relatively small number of enrolled patients and the lack of a detailed grading system for myopic retinopathy as potential limitations.
The results of this research provide evidence that the vitreous bodies of highly myopic eyes may be characterized by a proinflammatory and proangiogenic state.
Wei Q , Zhuang X , Fan J, et al. Proinflammatory and angiogenesis-related cytokines in vitreous samples of highly myopic patients. Cytokine. 2021;137(1):155308. doi: 10.1016/j.cyto.2020.155308.