Clinical Evaluation of Intraocular Caliper-assisted Capsulotomy for Age-related Cataract

Not Applicable

• Conditions: Cataract Extraction
• Interventions: Procedure: Verion navigation system-assisted capsulotomy; Procedure: Intraocular caliper-assisted capsulotomy

• Registration Number: NCT04977115
• Lead Sponsor: Zhongshan Ophthalmic Center, Sun Yat-sen University

Brief Summary

The purpose of this study is to compare the accuracy of capsulotomy assisted by intraocular caliper and Verion navigation system in phacoemulsification surgery and postoperative visual quality of patients.

Detailed Description

Continuous curvilinear capsulorhexis (CCC) is an important and technically challenging procedure in cataract surgery. However, most surgeons perform CCC by experience or referring to the pupil size, which is highly subjective and the accuracy of capsulorhexis is unsatisfactory. The investigators developed a new modified intraocular caliper with standard calibration on the rinse needle, which can measure and locate the position of capsulorhexis. The surgeon can gently use the blunt needle in the front of the intraocular caliper to further make corresponding markers on the lens anterior capsule, and then carry out capsulotomy according to the marks. We found intraocular caliper-assisted capsulotomy can obviously improve the accuracy of capsulorhexis. The purpose of this study is to compare the accuracy and postoperative visual quality of intraocular caliper-assisted capsulotomy with those of digital image projection device VERION navigation system.

Study Timeline

• Status Verified: 2021-07
• Study First Submitted: 2021-07-15
• Study First Submitted QC: 2021-07-20
• Last Update Submitted: 2021-07-20
• Study Start: 2021-07-26
• Study First Posted: 2021-07-26
• Last Update Posted: 2021-07-26
• Primary Completion: 2022-02-28
• Study Completion: 2022-04-30

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 156

Inclusion Criteria

• Adults aged 55 to 80 years with age-related cataract;
• Pupil diameter ≥ 6.5mm after pupil dilation;
• Lens nuclear opacity grading score (LOCS III) lower than 4.0.

Exclusion Criteria

• Patients had previous intraocular surgery;
• Patients with a diagnosed eye disease that may affect the functions of lens suspensory ligament such as previous ocular trauma, lens subluxation, pseudoexfoliation syndrome, retinal pigment degeneration;
• Patients had other ocular diseases that impair visual function include optic neuropathy, uveitis, and tumor.
• Refused to participate the study.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Verion navigation system-assisted capsulotomy group	Verion navigation system-assisted capsulotomy	In the Verion-assisted capsulotomy group, Verion navigation system was applied to project a 5.3 mm capsulorhexis centered on the corneal vertex. According to the projected capsulorhexis, capsulotomy was performed.
Intraocular caliper-assisted capsulotomy group	Intraocular caliper-assisted capsulotomy	In intraocular caliper-assisted capsulotomy group, a modified intraocular caliper with standard calibration on the rinse needle was used to measure and locate the position of capsulorhexis with 5.3 mm diameter and the principle of pupillary margin in concentric circles. The surgeon could gently use the blunt needle in the front of the intraocular caliper to further make corresponding markers on the lens anterior capsule, and then carry out capsulotomy according to the marks.

Primary Outcome Measures

Name	Time	Method
Deviation of horizontal and vertical diameter of capsulorhexis from the target diameter (5.3 mm)	During the surgery	Images of the edges of IOL and capsulorhexis are taken at the end of the operation. Image J image analysis software is used to measure the horizontal diameter and vertical diameter of capsulorhexis with the diameter of IOL optical surface (6 mm) as the reference by two independently professional graders at the meantime, and further calculate the deviation of horizontal and vertical diameter of capsulorhexis from the target diameter (5.3 mm) .

Secondary Outcome Measures

Name	Time	Method
Grades of capsulorhexis-IOL overlap	During the surgery	The capsulorhexis-IOL overlap of each patient is graded as 360-degree continuous overlap, 270\~360-degree overlap, 180\~270-degree overlap, 90\~180-degree overlap, and \< 90-degree overlap.
Intraocular lens tilt	One month after surgery	Measured by anterior segment OCT (CASIA2).
Intraocular aberrations	One month after surgery	Measured by OPD-SCAN III.
Deviation of horizontal and vertical diameter of capsulorhexis from the target diameter (5.3 mm)	One month after surgery
Intraocular lens decentration	One month after surgery	Measured by anterior segment OCT (CASIA2).
Uncorrected and corrected visual acuity	One month after surgery	Visual acuity is evaluated with ETDRS visual acuity chart.
Distance between pupil center and capsulorhexis center	During the surgery	Measured by Image J image analysis software.
Ideal ratio of capsulorhexis	During the surgery	Ideal capsulorhexis is defined as a centered and round capsulorhexis, which can cover the edge of IOL optical surface continuously for 360 degrees with a diameter between 5.0 to 5.5 mm.
Horizontal and vertical diameter of capsulorhexis	During the surgery	Measured by Image J image analysis software.

Trial Locations

Locations (1)

Zhongshan Ophthalmic Center，Sun Yat-Sen University; 🇨🇳 Guangzhou, China