To observe the retinal microvascular alteration during 3 months follow-up after Implantable Collamer Lens (ICL) operation in moderate and high myopia patients using quantitative optical coherence tomography angiography (OCTA) analysis.

The study object is moderate and high myopia patients, underwent ICL implantation. OCTA was used to image the superficial and deep retinal vascular plexuses before ICL implantation surgery and at 3 months follow-up. OCTA images were corrected for magnification, skeletonized, separated the large vessels and partitioned. Retinal microvascular density was measured by using fractal dimension analysis. The aim of this study was to uncover potential retinal vascular network alterations induced by ICL implantation surgery.

Inclusion Criteria:

• 18 to 45 years old;
• Binocular myopia, with a refraction of greater than -3 diopters (D);
• anterior chamber depth (ACD, measured from the endothelium to the crystalline lens) > 2.8 mm;
• corneal endothelial cell count (cECC) ≥ 2000 cells/mm2;
• stable refraction at least 1 year before surgery;
• unsatisfactory vision with contact lenses or spectacles.

Exclusion Criteria:

• history of intraocular surgery
• other ocular pathology (uveitis, glaucoma, cataract, keratoconus, severe dry eye, etc.)
• other serious systemic disease (diabetes, uncontrolled hypertension, severe hyperthyroidism, etc.).

Moderate and high myopia patients, underwent ICL implantation surgery at the Department of Ophthalmology, Peking University Third Hospital