Prospective Clinical Study of Retinal Microvascular Alteration After ICL Implantation

Study Overview
=================
Brief Summary
-----------------
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.

Detailed Description
-----------------
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.

Official Title
-----------------
Prospective Clinical Study of Retinal Microvascular Alteration After ICL Implantation

Conditions
-----------------
Adolescent, Adult, Human, Male, Female, Follow-up Studies, Prospective Studies, Lens Implantation, Intraocular, Myopia, Phakic Intraocular Lenses, Retinal Vessels, Postoperative Period, Preoperative Period, Tomography, Optical Coherence

Intervention / Treatment
-----------------
* Device: Optical Coherence Tomography Angiography


Participation Criteria
=================
Eligibility Criteria
-----------------
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.).

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: Optical Coherence Tomography Angiography|AngioVue (Optovue, Fremont, CA, USA) was used to capture the OCTA images before ICL surgery and at 3 months follow-up.|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Retinal microvessels density | Retinal microvessels density was measured with fractal dimension analysis by using Matalb (The Mathworks, Inc., Natick, MA, USA) | 3 months postoperatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Best corrected visual acuity | BCVA was evaluated by decimal Snellen and converted to the logarithm of the minimum angle of resolution (logMAR) for statistical analysis. | 3 months postoperatively | 
| Mean refractive spherical equivalent | MRSE = Spherical power + 0.5 * Cylindrical power | 3 months postoperatively | 
| Intraocular pressure | The IOP was measured using a non-contact tonometer (CT-80; Topcon, Tokyo, Japan). | 3 months postoperatively | 
| Vault | The central vault of the ICL (distance from posterior surface of ICL to the crystalline lens) was measured using Optical Coherence Tomography (Visante; Carl Zeiss Meditec, Jena, Germany) | 3 months postoperatively |