A Randomized Study of Intraocular Caliper-assisted Capsulotomy for Age-related Cataract Patients With Corneal Limbus Opacity

Not Applicable

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

• Registration Number: NCT04977102
• 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 for age-related cataract patients with corneal limbus opacity.

Detailed Description

Continuous curvilinear capsulorhexis (CCC) is an important and technically challenging procedure in cataract surgery. Too large or too small capsulorhexis can increase the incidence of intraoperative and postoperative complications.

In recent years, the image projection device Verion navigation system has been reported that it can improve the repeatability and accuracy of capsulorhexis via projecting a pre-set size ring to guide capsulorhexis. However, we found that for the patients with corneal geriatric ring, pterygium or limbal lesions leading to unclear limbal boundary, the projected capsulorhexis will deviate from the center, resulting in capsulorhexis is off center in clinical practice. Our self-developed intraocular caliper, which is modified on the conventional intraocular irrigation needle, can accurately measure the size of capsulorhexis, and mark the position and boundary of capsulorhexis on the lens anterior capsule to guide capsulorhexis, thus significantly improves the accuracy and centricity of capsulorhexis.

The purpose of this study is to compare the centricity and accuracy of intraocular caliper-assisted capsulorhexis in phacoemulsification for age-related cataract patients with corneal limbus opacity with that of Verion projection navigation system.

Study Timeline

• Status Verified: 2021-07
• Study First Submitted: 2021-07-16
• Study First Submitted QC: 2021-07-20
• Last Update Submitted: 2021-07-20
• Study First Posted: 2021-07-26
• Last Update Posted: 2021-07-26
• Study Start: 2021-08-01
• Primary Completion: 2022-07-31
• Study Completion: 2022-10-31

Recruitment & Eligibility

• Status: UNKNOWN
• Sex: All
• Target Recruitment: 74

Inclusion Criteria

• Adults aged 55 to 80 years with age-related cataract with pterygium, Corneal geriatric ring, and corneal limbus opacity;
• 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
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.
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.

Primary Outcome Measures

Name	Time	Method
Distance between pupil center and capsulorhexis center	During the surgery	The primary outcome was the distance between pupil center and capsulorhexis center. Clear images of the edges of IOL and capsulorhexis were taken at the end of the operation, and Image J image analysis software is used to measure the distance between pupil center and capsulorhexis center with the diameter of IOL optical surface (6 mm) as the reference by two independently professional graders at the meantime.

Secondary Outcome Measures

Name	Time	Method
Uncorrected and corrected visual acuity	One month after surgery	Evaluated with ETDRS visual acuity chart.
Intraocular lens tilt	One month after surgery	Measured by anterior segment OCT (CASIA2).
Intraocular aberrations	One month after surgery	Measured by OPD-SCAN III.
Horizontal and vertical diameter of capsulorhexis	During the surgery	Measured by Image J image analysis software.
Intraocular lens decentration	One month after surgery	Measured by anterior segment OCT (CASIA2).
Distance between pupil center and capsulorhexis center	One month after surgery
Grades of capsulorhexis-IOL overlap	During the surgery	The capsulorhexis-IOL overlap of each patient was graded as 360-degree continuous overlap, 270\~360-degree overlap, 180\~270-degree overlap, 90\~180-degree overlap, and \< 90-degree overlap.
Deviation of horizontal and vertical diameter of capsulorhexis from the target diameter (5.3 mm)	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.

Trial Locations

Locations (1)

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