Postoperative Total Wavefront Pattern Between Two Types of Intraocular Lenses Implanted in Cataract Surgery

January 11, 2021 updated by: Aya Ghonaim, Cairo University

Difference in Postoperative Total Wavefront Pattern Between Aspheric and Negative Spherical Aberration Intraocular Lenses Implanted in Cataract Surgery

With the advancement of cataract eye surgery and wavefront sensors, the previously unquantifiable refractive measurements have been identified and the high order aberrations have shown their effect on high resolution imaging.

In the human phakic eye, the shape of the normal cornea induces average positive spherical aberration and remains unchanged over time, whereas the crystalline lens has a negative spherical aberration. As a result, overall spherical aberration in the young eye is low.

However, the compensation slowly decreases with the aging lens and is fully lost after cataract extraction and implantation of a standard intraocular lens.

Optical studies showed that conventional biconvex spherical intraocular lenses add their intrinsic positive spherical aberration to the positive spherical aberration of the cornea resulting in image imperfection and blur. As a useful side effect, this also increases the depth of focus -often referred to as pseudo-accommodation.

New Aspheric intraocular lenses designs currently in use impart negative spherical aberration, about 0.17 to 0.20 microns of negative spherical aberration. This added negative spherical aberration partially corrects the average amount of corneal positive spherical aberration & compensate for its effect. Our study will include (FocusForce foldable aspheric intraocular lens, Bausch & Lomb, New Jersey, USA) as an example of this type of negative spherical aberration intraocular lenses.

In order to improve retinal image quality without compromising depth of field, or introducing other aberrations, aberration-free aspheric intraocular lenses were developed with no inherent spherical aberration.

The other intraocular lens targeted in our study (Akreos AO Microincision lens, Bausch & Lomb, New Jersey, USA) is an example of this type of IOLs.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Unknown

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

A customized correction for the individual eye seems to be the most promising solution for tailored correction of spherical aberration.

On the other hand, Wave front analysis of the ocular optical system has increased our knowledge of the aberrations in the eye. The importance of measuring optical aberrations lies not only in the presence of natural aberrations in the human eye, but also in its usefulness for evaluating individual surgical outcomes. By using Zernike polynomials, the aberrations of the ocular system can be characterized. Zernike coefficients of the higher-order aberrations can be derived from corneal topographic data. And for those generated by the whole optical system of the eye can be derived from aberrometry.

With current small-incision cataract surgery, it has been reported that the average postoperative corneal topography does not differ significantly from average preoperative corneal topography, so in our study we will focus on the ocular & internal wave front changes.

With the high resolution pyramid wavefront sensor incorporated in (SCHWIND PERAMIS®, topography and Aberrometry, Kleinostheim, Germany) we will evaluate and compare the total ocular wave front and the corneal wave front in our study to identify and estimate the internal aberrations . This new sensor uses an extended source instead of a point-like source avoiding in this manner the oscillation of the pyramid.

SCHWIND PERAMIS evaluates the ocular wave front aberrations with 45,000 measuring points - without any overlap and with clear assignment of each point & records 33 images per second and automatically selects the image with the best measurement. Together with real-time measurement, this ensures a new level of detail resolution and precision. SCHWIND PERAMIS can also be used to compare a patient's corneal and ocular wave front data. The direct comparison provides information about whether a visual defect is located on the surface of the cornea or within the eye itself, thus allowing us to identify and evaluate internal aberrations.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Anticipated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • Egypt
      • Cairo, Egypt, 12563
        • Recruiting
        • facultyof medicine, Cairo university

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

21 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

1-All patients with written informed consent, between the age of 21 -75 years who will undergo phacoemulsification procedure with intraocular lens implantation of one of the targeted lenses in the study

Exclusion Criteria:

  1. Previous corneal intervention or refractive surgery.
  2. Persistent Corneal edema (epithelial or stromal).
  3. Co-existing corneal pathology.
  4. Ocular surface disease & Dry eye syndrome.
  5. Posterior capsular opacity .
  6. Anterior capsular contraction (phimosis).
  7. Ocular inflammation.
  8. Co-existing Vitreoretinal diseases.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: aberration-free IOL
20 human eyes with aberration-free intraocular lens Implantation after phacoemulsification cataract surgery
Procedure: phacoemulsification with intraocular lens implantation
treatment of cataract by phacoemulsification procedure and implantation of different types of IOLs.
Device: ocular aberrometer assesment
evaluate total ocular wavefront, corneal wavefront & internal wavefront (High order aberrations ) post operative by corneal tomography and aberrometer
Active Comparator: negative spherical aberration IOL
20 human eyes with negative spherical aberration intraocular lens Implantation after phacoemulsification cataract surgery
Procedure: phacoemulsification with intraocular lens implantation
treatment of cataract by phacoemulsification procedure and implantation of different types of IOLs.
Device: ocular aberrometer assesment
evaluate total ocular wavefront, corneal wavefront & internal wavefront (High order aberrations ) post operative by corneal tomography and aberrometer

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Corneal, Ocular, and Internal spherical aberrations
Time Frame: 1 month postoperative
assessment of ocular, corneal & internal wavefront by aberrometer & corneal tomography
1 month postoperative

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
corneal wavefront changes
Time Frame: 1 month postoperative
• Compare pre-operative and post-operative corneal spherical aberrations of every patient and evaluate any significant changes.
1 month postoperative
near vision addition
Time Frame: 1 month postoperative
the plus lenses needed to be add to correct near vision which reflect the depth of focus of the IOL implanted
1 month postoperative

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Cairo University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Aya G Ibrahim, MBBCh, Dar El Oyoun ophthalmology hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 9, 2020

Primary Completion (Anticipated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2021

Study Completion (Anticipated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 30, 2021

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 6, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 6, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 8, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 13, 2021

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 11, 2021

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 336-2020

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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