Predicting the Lens Capsular Bag Size Using Pre-operative Biometry

Aim of this study is to assess whether a high-resolution scan of the crystalline lens before surgery may be helpful in predicting post-operative capsule bag diameter.

Study Overview

• Status: Completed
• Conditions: Cataract Senile
• Intervention / Treatment: Device: Biometry

Detailed Description

Most of the measurement procedures used in this study are non-invasive and all are used in standard routine clinical practice, the benefit/risk ratio appears acceptable.

However, a capsule tension ring will be used. A CTR is not used routinely, usually only in cataract operations in which the lens capsule is not stable enough - in other words, for stabilization. The insertion of the CTR is problem-free in most cases. In extremely rare cases, however, the lens capsule may be injured. And document complications will be collected, report them in a final paper. The CTR used in the study is a standard device and CE-marked device. Studies using CTR showed that it is beneficial in difficult cases.

Gonioscopy after cataract surgery will be performed after 1 week. At this time point the wound is already sealed and there appears to be no increased risk to the patient. In the first study performed in a similar fashion in 1999 gonioscopy was performed one day after surgery.

Aim of this study is to predict the diameter of the capsular bag using pre-operative optical biometry findings.

This is a prospective, observer-blind and monocentric study that includes patients scheduled for cataract surgery. Recruitment will take part on the day of pre-assessment. For each patient only one eye will be included.

In total 50 eyes of 50 patients will be included, of which at least 5 eyes with an axial eye length below 22.5mm and 5 eyes with an axial eye length above 25.0mm.

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Austria
  • Vienna, Austria, 1140
    • Hanusch Hospital, Department of Ophthalmology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 100 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Patient scheduled for cataract surgery
• Well dilated pupil at the pre-assessment visit (dilated pupil size at least 6.0mm)
• Age 21 and older
• Pre-operative visual acuity of at least 0.25 Snellen

Exclusion Criteria:

• Parameters that influence the capsular bag stability (pseudoexfoliation syndrome, St. p. severe eye trauma, Phakodonesis)
• In women of childbearing age, a pregnancy test will be performed before inclusion into the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Other: Capsular bag size; Lens thickness, lens shape, anterior chamber depth, axial eye length and angle-to-angle will be used as explanatory variables (independent variables) and the size of the capsular bag will be used as main outcome parameter (dependent variable). We will perform a multiple linear regression analysis (that allows determination of the overall fit (variance explained) of the model and the relative contribution of each of the predictors to the total variance explaine) between the independent and the dependent variable.

Device: Biometry; Lens thickness, lens shape, anterior chamber depth, axial eye length and angle-to-angle will be used as explanatory variables (independent variables) and the size of the capsular bag will be used as main outcome parameter (dependent variable).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Capsular bag size	• Prediction of the size of the post-operative capsular bag diameter using pre-operative optical biometry (lens thickness, lens shape, anterior chamber depth, axial eye length and angle-to-angle distance)	2 months

Collaborators and Investigators

• Sponsor: Vienna Institute for Research in Ocular Surgery

Study record dates

Study Major Dates

• Study Start (Actual): May 1, 2020
• Primary Completion (Actual): August 30, 2021
• Study Completion (Actual): December 20, 2021

Study Registration Dates

• First Submitted: January 30, 2022
• First Submitted That Met QC Criteria: October 12, 2022
• First Posted (Actual): October 13, 2022

Study Record Updates

• Last Update Posted (Actual): October 13, 2022
• Last Update Submitted That Met QC Criteria: October 12, 2022
• Last Verified: October 1, 2022

More Information

Terms related to this study

• Keywords: capsular bag
• Additional Relevant MeSH Terms: Eye Diseases; Lens Diseases; Cataract
• Other Study ID Numbers: Capsular bag size

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No
• IPD Plan Description: all results will be published

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No