Influence of Capsular Tension Ring on IOL-capsular Complex After Cataract Surgery in Patients With High Myopia: a Clinical Observation Based on SS-OCT

Study Overview
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Brief Summary
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The IOL-capsular complex is formed after cataract surgery and intraocular lens (IOL) implantation.Early postoperative mechanical wrapping of the anterior and posterior capsules plays a significant role in preventing IOL decentration and tilt, as well as formation of the IOL-capsular complex which reduces the incidence of posterior cataract opacity. Capsular tension rings were first introduced in the early 1990s for loosening and tightening the lens bag and maintaining the equatorial contour of the bag after cataract surgery.Today, capsular tension rings of many different designs are in use.The capsular tension rings can be used in eyes with fragile and split zonular fibers, as well as pseudoexfoliation, high myopia, Marfan syndrome, mature cataract and lens subluxation.The capsular tension ring reduces the incidence of decentration and tilt of the IOL by reducing capsular contraction. In addition, multi-focus IOL implantation combine with capsular tension ring result in smaller high-order aberrations in our eyes compared to cataract surgery with multi-focus IOL implantation alone.For patients with high myopia, they often have a longer axial length and a larger capsule diameter, which reduces the rotational stability of the IOL and may lead to tilt ,decentration and displacement of IOL.Currently, there is no literature guidance to compare the results of cataract surgery combined with or without capsular tension ring implantation in patients with high myopia.Our hospital has Swept-source Optical Coherence Tomography ( SS-OCT,Casia2, TOMEY, Japan), which can accurately photograph the process of IOL capsule bending and the changes of lens position after cataract surgery. SS-OCT can be used to evaluate the influence of capsular tension ring on the dynamic changes of IOL-capsular complex in patients with high myopia after cataract surgery.

Detailed Description
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The IOL-capsular complex is formed after cataract surgery and intraocular lens (IOL) implantation.Early postoperative mechanical wrapping of the anterior and posterior capsules plays a significant role in preventing IOL decentration and tilt, as well as formation of the IOL-capsular complex which reduces the incidence of posterior cataract opacity. Capsular tension rings were first introduced in the early 1990s for loosening and tightening the lens bag and maintaining the equatorial contour of the bag after cataract surgery.Today, capsular tension rings of many different designs are in use.The capsular tension rings can be used in eyes with fragile and split zonular fibers, as well as pseudoexfoliation, high myopia, Marfan syndrome, mature cataract and lens subluxation.The capsular tension ring reduces the incidence of decentration and tilt of the IOL by reducing capsular contraction. In addition, multi-focus IOL implantation combine with capsular tension ring result in smaller high-order aberrations in our eyes compared to cataract surgery with multi-focus IOL implantation alone.For patients with high myopia, they often have a longer axial length and a larger capsule diameter, which reduces the rotational stability of the IOL and may lead to tilt ,decentration and displacement of IOL.Currently, there is no literature guidance to compare the results of cataract surgery combined with or without capsular tension ring implantation in patients with high myopia.Our hospital has Swept-source Optical Coherence Tomography ( SS-OCT,Casia2, TOMEY, Japan), which can accurately photograph the process of IOL capsule bending and the changes of lens position after cataract surgery. SS-OCT can be used to evaluate the influence of capsular tension ring on the dynamic changes of IOL-capsular complex in patients with high myopia after cataract surgery.

Official Title
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Influence of Capsular Tension Ring on IOL-capsular Complex After Cataract Surgery in Patients With High Myopia: a Clinical Observation Based on SS-OCT

Conditions
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High Myopia, Capsular Tension Ring

Intervention / Treatment
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* Procedure: Cataract surgery with IOL implantation and with/without capsular tension ring implatation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: The patients are diagnosed age related cataract with axial length over 26mm The patients' age over 50 years old The patients plan to receive cataract surgery in Eye hospital of Wenzhou Medical University The dialated pupils are over 6mm Patients are willing and able to complete the follow-ups. Exclusion Criteria: Patients with other type of cataract Patients have complications in the surgery and after surgery Patients have other severe diseases of eyes

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High myopia patients who had cataract surgery with IOL and capsular tension ring implantation<br>The patients' axial length is over 26 mm and are diagnosed age related cataract The patients' age are over 50 | Procedure: Cataract surgery with IOL implantation and with/without capsular tension ring implatation<br>* Patients in this study will receive cataract surgery with IOL implantation and capsular tension ring implantation or cataract surgery with IOL implantation<br>|
| Experimental: High myopia patients who had cataract surgery with IOL implantation<br>The patients' axial length is over 26 mm and are diagnosed age related cataract The patients' age are over 50 | Procedure: Cataract surgery with IOL implantation and with/without capsular tension ring implatation<br>* Patients in this study will receive cataract surgery with IOL implantation and capsular tension ring implantation or cataract surgery with IOL implantation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The position of IOL | Evaluation of the position of IOL through tilt,decentration and the process of capsule bending. | The 1st day after surgery | 
| The position of IOL | Evaluation of the position of IOL through tilt,decentration and the process of capsule bending. | The 1st week after surgery | 
| The position of IOL | Evaluation of the position of IOL through tilt,decentration and the process of capsule bending. | The 1st month after surgery | 
| The position of IOL | Evaluation of the position of IOL through tilt,decentration and the process of capsule bending. | The 3rd month after surgery |