Non-pathological high myopia patients and controls undergoing a comprehensive ophthalmologic examination are included. The Optical Coherence Tomography Angiography (OCTA) software automatically segments these full-thickness retinal scans into the superficial and deep inner retinal vascular plexuses, outer retina, and choriocapillaris (CC). The vascular density in the superficial and deep retinal vascular zones is calculated automatically by the software, and the foveal avascular zone (FAZ) and foveal density (FD) are also automatically determined. Choroidal thickness is calculated manually by two retinal specialists, and the average value was used.

Non-pathological high myopia patients and controls undergoing a comprehensive ophthalmologic examination, including measurements of best-corrected visual acuity, refractive error; intraocular pressure, axial length, slit lamp examination of the anterior segment, dilated fundus examination and OCTA imaging are included. The best-corrected visual acuity is convert into the logarithm of minimal angle resolution. The OCTA images are independently graded and assessed by two retinal specialists. The software automatically segmented these full-thickness retinal scans into the superficial and deep inner retinal vascular plexuses, outer retina, and choriocapillaris (CC). The vascular density in the superficial and deep retinal vascular zones is calculated automatically by the software, and the foveal avascular zone (FAZ) and foveal density (FD) are also automatically determined. Choroidal thickness is calculated manually by two retinal specialists, and the average value was used.

Right eye of each participant is included in the study. If the right eye shows any exclusion criteria, then the left eye is selected for enrollment. Eyes with an AL longer than 26 mm are included in the HM group. The classification of myopic maculopathy is applied in identification of fundus alterations. Patients with category 0 (no myopic retinopathy lesions) and category 1 (tessellated fundus) are included in the study.

Inclusion Criteria:

• Patients with category 0 (no myopic retinopathy lesions)
• Patients with category 1 (tessellated fundus)

Exclusion Criteria:

• poor image quality (signal strength index (SSI) <60) due to unstable fixation
• IOP >21 mm Hg; logMAR > 0.1
• pre-existing ophthalmic pathologies
• prior ocular surgery
• systemic chronic disease which can cause retinopathy
• such as diabetes mellitus, hypertension etc.

Study population includes a convenience sampling from the patients admitted to outpatient clinic between November 2020 and December 2020.