Structural changes in the retina and choroid in patients with different degrees of myopia

To observe the structural changes of retina and choroid in patients with different degrees of myopia. We recruited 219 subjects with different degrees of myopia for best corrected visual acuity, computer refraction, intraocular pressure, axial length (AL), optical coherence tomography (OCT) imaging, and other examinations. Central macular retinal thickness (CRT), subfoveal choroidal thickness (SFCT), nasal retinal thickness (NRT), temporal retinal thickness (TRT), nasal choroidal thickness (NCT) and temporal choroidal thickness (TCT) were measured by optical coherence tomography. ImageJ software was used to measure the retinal area and choroidal area (CA), and Niblack was used to binarize all OCT images to measure the choroidal vessel area (CVA) and choroidal matrix area (CMA). We found that CRT, SFCT, NRT, TRT, NCT, TCT, CA, CVA, and CMA were significantly reduced in the pathological myopia (PM) group. AL was negatively correlated with NRT, SFCT, CMA, CVA and choroidal stromal index. There was a significant positive correlation between AL and choroidal vascular index. The choroidal vascular index in the PM group was significantly increased compared with the other groups. We established a univariate receiver operating curve to analyze the diagnostic value of all parameters for PM. Spherical equivalent, AL, SFCT, TCT, NCT, CA, CVA, and CMA had high diagnostic value for PM, among which CMA had the highest accuracy. There are changes in choroidal structure in adults with different degrees of myopia. Choroidal thickness, CVA and CMA decrease significantly with the increase of myopia, and are correlated with AL. The decrease of CMA has higher diagnostic value in myopia.