Cataract Extraction
Conditions
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.
Interventions
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.
Sponsors
Zhongshan Ophthalmic Center, Sun Yat-sen University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
55 Years to 80 Years
Healthy volunteers
No
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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. |
| 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. |
| Distance between pupil center and capsulorhexis center | During the surgery | Measured by Image J image analysis software. |
| Horizontal and vertical diameter of capsulorhexis | During the surgery | Measured by Image J image analysis software. |
| Uncorrected and corrected visual acuity | One month after surgery | Visual acuity is evaluated with ETDRS visual acuity chart. |
| Intraocular lens decentration | 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 tilt | One month after surgery | Measured by anterior segment OCT (CASIA2). |
Countries
China
Contacts
Primary ContactXiaoyun Chen, PhD
Outcome results
None listed