An interventional study of Intraocular caliper-assisted capsulotomy and Verion navigation system-assisted capsulotomy in Cataract Extraction, sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University. Status unknown at 1 site in China. Open to participants aged 55 Years to 80 Years. Per ClinicalTrials.gov, last updated 2021-07-26.
Sponsored by Zhongshan Ophthalmic Center, Sun Yat-sen University · Not applicable, Interventional, and Other
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.
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.
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This study's planned enrollment of 74 is close to the median of 80 across 1,155 interventional studies indexed under Cataract.
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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.
Procedure: Intraocular caliper-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.
Procedure: Verion navigation system-assisted capsulotomy
Intraocular caliper is a modified intraocular caliper with standard calibration on the rinse needle.
Verion Image Guided System (Alcon Laboratories, Inc.) is a digital image guidance system consisting of a diagnostic reference unit and a surgery pilot for intraoperative surgical assistance. The device can be used to align toric intraocular lens during surgery as well as support manual creation of a capsulorhexis with a predefined target diameter.
Distance between pupil center and capsulorhexis center
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.
Time frame: During the surgery
Uncorrected and corrected visual acuity
Evaluated with ETDRS visual acuity chart.
Time frame: One month after surgery
Ideal ratio of capsulorhexis
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.
Time frame: During the surgery
Grades of capsulorhexis-IOL overlap
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.
Time frame: During the surgery
Deviation of horizontal and vertical diameter of capsulorhexis from the target diameter (5.3 mm)
Measured by Image J image analysis software.
Time frame: During the surgery
Horizontal and vertical diameter of capsulorhexis
Measured by Image J image analysis software.
Time frame: During the surgery
Intraocular lens tilt
Measured by anterior segment OCT (CASIA2).
Time frame: One month after surgery
Intraocular lens decentration
Measured by anterior segment OCT (CASIA2).
Time frame: One month after surgery
Intraocular aberrations
Measured by OPD-SCAN III.
Time frame: One month after surgery
Distance between pupil center and capsulorhexis center
Time frame: One month after surgery
This study is status unknown, as verified in Jul 2021. You cannot join it, but the record below documents what was studied.
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Zhongshan Ophthalmic Center, Sun Yat-sen University