The influence of the choroid on the onset and development of myopia: from perspectives of choroidal thickness and blood flow

Abstract

Myopia is the most common type of refractive errors characterized by excessive elongation of the ocular globe. With the increasing prevalence of myopia, improved knowledge of factors involved in myopia development is of particular importance. There are growing evidence suggesting that the choroid plays an important role in the regulation of eye growth and the development of myopia. Studies have demonstrated that thinning choroid is a structural feature of myopia, with a negative correlation between choroidal thickness and axial length, suggesting that the change in choroidal thickness may be a predictive biomarker for long‐term changes in ocular elongation. Given the fact that the choroid is primarily a vascular structure capable of rapidly changing blood flow, variations of choroidal thickness might be primarily caused by changes in choroidal blood flow. Considering that hypoxia is associated with myopia and choroidal blood flow is the main source of oxygen and nourishment supply, apart from the effect on myopia possibly by changing choroidal thickness, decreasing choroidal blood flow may contribute to scleral ischaemia and hypoxia, resulting in alterations in the scleral structure and thus leading to myopia. This review aims to provide an overview of recent work exploring the influence of the choroid on myopia from perspectives of choroidal thickness and blood flow, which may present new predictive indicators for the onset of myopia and new targets for the development of novel therapeutic approaches for myopia.

Differences in Retinal and Choroidal Vasculature and Perfusion Related to Axial Length in Pediatric Anisomyopes

“…Alternatively, a detailed, comprehensive assessment of the choroidal vasculature and choriocapillaris perfusion might be more informative. 46,47 Studies with animal models in which myopia is induced by unilateral manipulation of visual inputs have established that alteration in ChT is an early sign of vision-driven changes in ocular growth and myopia development. [13][14][15] The ChT responds to visual stimuli in a bidirectional, rapid, and regionally selective manner.…”

Investigation of Macular Choroidal Thickness and Blood Flow Change by Optical Coherence Tomography Angiography After Posterior Scleral Reinforcement

“…The nutrient supply of the choroid mainly comes from the short-posterior ciliary artery. As one of the most highly vascularized tissues of the body, the choroid accounts for 65% of the blood supply within the eye; hence, it is reasonable to assume that the progression of pathological myopia is linked to the structural and functional alterations of the choroid (5,(24)(25)(26).…”

“…The nutrient supply of the choroid mainly comes from the short-posterior ciliary artery. As one of the most highly vascularized tissues of the body, the choroid accounts for 65% of the blood supply within the eye; hence, it is reasonable to assume that the progression of pathological myopia is linked to the structural and functional alterations of the choroid ( 5 , 24 – 26 ). Studies have shown that CT alterations occurred earlier than the fundus changes and that visual function abnormalities occurred in the early stage of pathologic myopia ( 27 , 28 ).…”

Lowering Intraocular Pressure: A Potential Approach for Controlling High Myopia Progression

“… 66 Hence, choroidal thinning was supposed to serve as a new target or predictor biomarker for myopic development and progression. 67 , 68 …”