A Meta-Analysis of Alterations in the Retina and Choroid in High Myopia Assessed by Optical Coherence Tomography Angiography.

Background: High myopia (HM) is a risk factor for several pathological structural changes in retinal and choroidal thickness or vessel. To date, changes in retinal and choroidal microvasculature circulations in HM have yielded inconsistent results. Objectives: The objective of this article was to evaluate alterations in retinal and choroidal thickness, and capillary microvasculature using optical coherence tomography angiography (OCTA) in HM. Methods: PubMed, Embase, and the Cochrane Library databases were searched for relevant published studies. Primary outcomes were foveal avascular zone, vessel density, retinal nerve fiber layer (RNFL) thickness, foveal thickness, sub-foveal choroidal thickness, and chorio-capillary density. Alterations in outcomes were evaluated by standardized mean difference with a 95% confidence interval. Results: Eleven eligible articles were included for the meta-analysis. The whole superficial and deep vessel densities of macular and parapapillary superficial vessel density were lower in HM than in control eyes. The thickness of parafoveal RNFL, parapapillary RNFL, and sub-foveal choroid was significantly lower in HM eyes. Also, chorio-capillary density was shown to be lower in HM eyes. Conclusions: The retinal and choroidal vessel network change may be related to the axial elongation in the progression of myopia. Furthermore, OCTA is an effective and noninvasive technology for monitoring the progress of myopia eyes. [ABSTRACT FROM AUTHOR]