An Innovative Method Fluid-jet to to Remove Residual Lens Fibers

Study Overview
=================
Brief Summary
-----------------
Residual lens fibers (RLFs) on the posterior lens capsule during cataract surgery can cause after cataract, affecting visual quality and increasing the medical cost for further laser posterior capsulotomy. However, conventional polish is inconvenient and time-consuming. We use an innovative fluid-jet method to remove RLFs, and compare the efficacy of fluid-jet and polish to prevent posterior capsular opacity after phacoemulsification.

Detailed Description
-----------------
Purpose: Residual lens fibers (RLFs) on the posterior lens capsule during cataract surgery can cause after cataract, affecting visual quality and increasing the medical cost for further laser posterior capsulotomy. However, conventional polish is inconvenient and time-consuming. We use an innovative fluid-jet method to remove RLFs, and compare the efficacy of fluid-jet and polish to prevent posterior capsular opacity after phacoemulsification. Design: Single-center, prospective, randomized controlled clinical study Subjects of study: Age-related cataract patients receiving phacoemulsification from Zhongshan Ophthalmic Center, Guangzhou, China. Methods: patients are 1: 1 randomized to two groups. Polish group: After irrigation and aspiration (I/A), the RLFs on the posterior capsule are removed by polishing before intraocular lens (IOL) implantation; Fluid-jet group: Polish is not performed. RLFs on posterior capsule are removed by jetting fluid with an irrigating syringe after IOL implantation. The posterior capsular images of all the patients are obtained immediately before and after IOL implantation, and at the end of surgery, then the amount of RLFs is quantitatively analyzed by using LYZ-PCO, a software we developed. Best corrected visual acuity and parameters of visual quality, such as objective scattering index(OSI), Strehl ratio (SR) and Modulation Transfer Function (Mtf)-cut off are evaluated by objective visual quality analyser (OQAS) at 1 day, 1 week and 1 year after surgery. The patients receives telephone follow-up every month. The severity of posterior capsular opacification (PCO) and incidence of laser posterior capsulotomy is recorded. Main indicators for the study: The incidence of laser posterior capsulotomy a year after surgery.

Official Title
-----------------
Efficacy of Fluid-jet as an Innovative Method to Prevent Posterior Capsular Opacity After Phacoemulsification

Conditions
-----------------
Posterior Capsule Opacification

Intervention / Treatment
-----------------
* Procedure: traditional polish
* Procedure: fluid-jet


Participation Criteria
=================
Eligibility Criteria
-----------------
Iinclusion criteria: 1) cataract patients aged between 50 and 80 years; 2) graded 5 or less for lens opalescence by the Lens Opacities Classification System, version III (LOCS III); 3) listed for phacoemulsification combined with intraocular lens implantation in topical anesthesia; 4) Signed informed consent. Exclusion criteria: 1) a history ophthalmic trauma or surgery; 2) other ophthalmic diseases such as glaucoma, uveitis, high myopia; 3) diabetes requiring medical control; 4) disagree with follow-up monitoring; 5) Other factors inappropriate to participate in this project, including but not limited to severe cataracts, very shallow anterior chambers, etc.

Ages Eligible for Study
-----------------
Minimum Age: 50 Years
Maximum Age: 80 Years

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

Accepts Healthy Volunteers
-----------------
No

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

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: traditional group<br>Perform conventional continuous curvilinear capsulorhexis. After phacoemulsification and I/A, switch to polish mode and use I/A instrument to remove the RLFs visible on the posterior capsule before injection of viscoelastic agent. IOP: 55mmHg; Aspiration: 0-10; Vacuum: 0-20. The standard for stopping polish is that the RLFs can no longer be absorbed by the side holes on the I/A instrument in this mode, or there are no discernible RLFs on the posterior capsule. If RLFs on the posterior capsular are found after IOL implantation, polish to remove them after the removal of viscoelastic agents. All operations are videotaped during the whole operation. The total polish time is recorded as the time of all polish procedures. | Procedure: traditional polish<br>* After phacoemulsification and I/A, switch to polish mode and use I/A instrument to remove the RLFs visible on the posterior capsule before injection of viscoelastic agent. IOP: 55mmHg; Aspiration: 0-10; Vacuum: 0-20. The standard for stopping polish is that the RLFs can no longer be absorbed by the side holes on the I/A instrument in this mode, or there are no discernible RLFs on the posterior capsule. If RLFs on the posterior capsular are found after IOL implantation, polish to remove them after the removal of viscoelastic agents.<br>|
| Experimental: fluid-jet group<br>Perform conventional continuous curvilinear capsulorhexis. After phacoemulsification and I/A, inject viscoelastic agent and implant IOL without polish. Use I/A instrument to remove viscoelastic agent. A 27G irrigating syringe was used, and the RLFs on the posterior capsule were gently aligned to make a fluid-jet basically parallel to the iris. The liquid pressure of 50-120 mmHg is produced. The standard for stopping in this mode is that the RLFs can no longer be washed down from the capsule, or there are no discernible RLFs on the posterior capsule. All operations are videotaped during the whole operation. The total time of all jet procedures recorded in the videotape is the total time of jet. | Procedure: fluid-jet<br>* After phacoemulsification and I/A, inject viscoelastic agent and implant IOL without polish. Use I/A instrument to remove viscoelastic agent. A 27G irrigating syringe was used, and the RLFs on the posterior capsule were gently aligned to make a fluid-jet basically parallel to the iris. The liquid pressure of 50-120 mmHg is produced. The standard for stopping in this mode is that the RLFs can no longer be washed down from the capsule, or there are no discernible RLFs on the posterior capsule.<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in rate of posterior capsulotomy | Incidence rate of laser posterior capsulotomy | 1 year, 2 year, 3 year, 4 year, 5 year after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in visual acuity | Best corrected visual acuity tested with ETDRS chart | 1 day, 1 week, 1 year post-op, and every year thereafter. | 
| change in objective scattering index | objective scattering index of participants | 1 day, 1 week, 1 year post-op, and every year thereafter. | 
| change in Strehl ratio | Strehl ratio of participants | 1 day, 1 week, 1 year post-op, and every year thereafter. | 
| change in modulation transfer function cut off | Modulation transfer function cut off of participants | 1 day, 1 week, 1 year post-op, and every year thereafter. | 
| area of posterior capsular opacification | posterior capsular opacification area percentage | 1 year, 2 year, 3 year, 4 year, 5 year after surgery | 
| residual lens fibers | amount of residual lens fibers at the posterior lens capsule | the amount of residual lens fibers is to be measured for every participant using ocular image taken with surgical microscope at the end of the cataract surgery | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
cataract surgery, polish, residual lens fibers, fluid-jet