Comparison of Wound Integrity for Clear Corneal Cataract Incisions

Study Overview
=================
Brief Summary
-----------------
This is a randomized controlled trial to evaluate the safety and efficacy of two different closing methods for clear corneal cataract incisions

Detailed Description
-----------------
Compared with other incision types , clear corneal incision has the advantages of simple operation, small incision and good healing. It has been widely used in recent decades and has become the most commonly used incision type in phacoemulsification cataract surgery.However, there is no unified standard for the closed method of the clear corneal incision, and some studies have shown that the wound Integrity of clear corneal incision is not well.In the poorly closed incision, the risk of infection increased due to the leakage .Especially in 2.2mm incision, the frequent entry and exit of the instrument reduces the corneal rebound ability at the incision so that the incision is hard to closed. Ensuring wound Integrity for clear corneal cataract incision is the key to the success of cataract surgery. Clinically closed methods include stromal hydration and suture.The effectiveness of stromal hydration as one of the most commonly used methods has been validated, but also adds additional negative effects. Additionally, the suture extends the operation time and improves the operation cost, and is also accompanied by some complications, which has been less used. Exploring a safe and effective closed method will benefit for most cataract patients. This study intends to evaluate the safety and efficacy of a closed method that incision is pressed by a cotton swab.The investigators planned to select 130 cataract patients who met the inclusion criteria. The investigators will press the clear corneal incision with a cotton swab in experimental group, while the control group used stromal hydration to close the corneal incision. Wound Integrity, wound leakage, corneal thickness at the incision, keratometric value at the incision, anterior chamber depth and incidence of incision-related descemet membrane detachment were compared between the two groups.

Official Title
-----------------
Comparison of Wound Integrity for Clear Corneal Cataract Incisions: Pressure Versus Stromal Hydration

Conditions
-----------------
Cataract

Intervention / Treatment
-----------------
* Procedure: pressure by a cotton swab
* Procedure: stromal hydration with the balanced salt solution（BSS）


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: > 18 years old; Nuclear grade is III or IV; Visually significant cataract; The patient is willing and able to complete all necessary follow-ups and examinations. Exclusion Criteria: Intraoperative or postoperative complications: such as intraoperative posterior capsule rupture, the rupture of zonule, secondary glaucoma, endophthalmitis, etc.; Combined with other eye diseases: such as keratopathy, glaucoma, uveitis, retinopathy, lens dislocation and ocular trauma, etc.; History of intraocular surgery; Severe systemic diseases: such as severe hypertension, diabetes, heart disease, Alzheimer's, Parkinson, etc.; Any condition that the study physician considers to be an impediment to the clinical trial.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 85 Years

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

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

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

Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: cotton swab<br> | Procedure: pressure by a cotton swab<br>* All patients undergo uneventful phacoemulsification by a 2.2 mm temporal transparent corneal incision using Centurion Vision System (Alcon Laboratories, Fort Worth, TX, USA). After the nucleus and cortex are removed, IOL is implanted in the capsular bag. Finally, the clear corneal incision is closed with pressure by a cotton swab.<br>|
| Active Comparator: balanced salt solution (BSS)<br> | Procedure: stromal hydration with the balanced salt solution（BSS）<br>* All patients undergo uneventful phacoemulsification by a 2.2 mm temporal transparent corneal incision using Centurion Vision System (Alcon Laboratories, Fort Worth, TX, USA). After the nucleus and cortex are removed, IOL is implanted in the capsular bag. Finally, the clear corneal incision is closed with stromal hydration.<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Degree of incision closure | Degree of incision closure is evaluated by intraoperative optical coherence tomography. | During surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Rate of wound leakage | Rate of wound leakage is evaluated by fluorescein sodium. | During surgery | 
| Corneal thickness | Corneal thickness is measured by Casia 2. | 1 hour after surgery and 1 day after surgery | 
| Corneal curvature | Corneal curvature is measured by Casia 2. | 1 hour after surgery and 1 day after surgery | 
| Anterior chamber depth | Anterior chamber depth is measured by Casia 2. | 1 hour after surgery and 1 day after surgery | 
| Rate of incision-related descemet membrane detachment during surgery | Rate of incision-related descemet membrane detachment is evaluated by intraoperative optical coherence tomography. | During surgery | 
| Rate of incision-related descemet membrane detachment after surgery | Rate of incision-related descemet membrane detachment after surgery is evaluated by Casia 2. | 1 hour after surgery and 1 day after surgery |