This is a randomized controlled trial to evaluate the safety and efficacy of two different closing methods for clear corneal cataract incisions

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.

Inclusion Criteria:

1. > 18 years old;
2. Nuclear grade is III or IV;
3. Visually significant cataract;
4. The patient is willing and able to complete all necessary follow-ups and examinations.

Exclusion Criteria:

1. Intraoperative or postoperative complications: such as intraoperative posterior capsule rupture, the rupture of zonule, secondary glaucoma, endophthalmitis, etc.;
2. Combined with other eye diseases: such as keratopathy, glaucoma, uveitis, retinopathy, lens dislocation and ocular trauma, etc.;
3. History of intraocular surgery;
4. Severe systemic diseases: such as severe hypertension, diabetes, heart disease, Alzheimer's, Parkinson, etc.;
5. Any condition that the study physician considers to be an impediment to the clinical trial.