Impact of Positive & Negative Lens-Induced Defocus on Contrast-Sensitivity in Myopic & Non-Myopic Adults

December 22, 2024 updated by: Muhammad Naveed Babur, Superior University
examines the influence of lens-induced defocus on contrast sensitivity-a crucial aspect of visual performance.Each participant experiences both positive and negative defocus through different lenses, with measurements taken for contrast sensitivity using the Pelli-Robson chart. Outcomes are evaluated at baseline, 2 weeks, and 4 weeks to understand the effect of defocus over time.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

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

Additional data on symptoms like visual fatigue and computer vision syndrome are gathered using the Visual Fatigue Questionnaire (VFQ) and the Computer Vision Syndrome Questionnaire (CVS-Q), respectively. This study's findings could be instrumental in refining optical treatments, offering insights into how defocus impacts visual function across refractive conditions. Results may ultimately benefit optometric practices by guiding lens prescriptions for improved contrast sensitivity and quality of life for myopic and non-myopic individuals alike.

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 (Actual)

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.
36

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 Locations

  • Pakistan
    • Punjab
      • Taunsa, Punjab, Pakistan
        • Tehsil Headquarters (THQ)

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

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Adults aged 18 to 50 years.
  • Participants with a confirmed diagnosis of myopia or non-myopia.
  • Best corrected visual acuity of 20/30 or better.
  • No history of ocular surgery or significant ocular disease.
  • Informed consent was obtained.

Exclusion Criteria:

  • Individuals with a history of systemic diseases affecting vision (e.g., diabetes, hypertension).
  • Presence of binocular vision anomalies or strabismus.
  • Pregnant or nursing women.
  • Any current use of medications affecting visual function (e.g., medications causing visual side effects).

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: Diagnostic
  • 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: interventional group
Diagnostic test: Positive Lens-Induced Defocus Using Spectacle Lenses (+2.00 D) for Myopic Participants
Intervention Description: This group will be exposed to positive defocus induced by +2.00 D spectacle lenses. The lenses are designed to create optical blur to evaluate the effects on contrast sensitivity and visual fatigue. Measurements will be conducted at baseline, 2 weeks, and 4 weeks after exposure to assess changes in visual function."
Experimental: Interventional group II
Diagnostic test: Negative Lens-Induced Defocus Using Spectacle Lenses (-2.00 D) for Myopic Participants
Intervention Description: This group will be exposed to negative defocus induced by -2.00 D spectacle lenses. The induced defocus will allow for the evaluation of its impact on contrast sensitivity and visual fatigue. Assessments will be carried out at baseline, 2 weeks, and 4 weeks."
Active Comparator: Interventional group III
Combination product: Positive Lens-Induced Defocus Using Spectacle Lenses (+2.00 D) for Non-Myopic Participants
ntervention Description: This group will undergo positive defocus using +2.00 D spectacle lenses. The intervention aims to examine the effect of induced defocus on contrast sensitivity and visual fatigue in non-myopic participants. Data will be collected at baseline, 2 weeks, and 4 weeks."
Active Comparator: Interventional group IV
Combination product: Negative Lens-Induced Defocus Using Spectacle Lenses (-2.00 D) for Non-Myopic Participants
Intervention Description: This group will experience negative defocus induced by -2.00 D spectacle lenses. The purpose is to evaluate how negative lens-induced defocus affects contrast sensitivity and visual fatigue in non-myopic participants. Measurements will be taken at baseline, 2 weeks, and 4 weeks.

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
Contrast Sensitivity
Time Frame: 12 Months
Measured with the Pelli-Robson Contrast Sensitivity Chart, capturing changes in participants' ability to detect low-contrast visual stimuli under defocus conditions.
12 Months
Visual Fatigue
Time Frame: 12 months
Evaluated with the Visual Fatigue Questionnaire (VFQ) and Computer Vision Syndrome assessing symptoms like eye strain, discomfort, and fatigue following lens-induced defocus.
12 months

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.
Superior University

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.
February 28, 2024

Primary Completion (Actual)

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.
July 31, 2024

Study Completion (Estimated)

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.
March 1, 2025

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).
December 13, 2024

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.
December 22, 2024

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.
March 25, 2025

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.
March 25, 2025

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.
December 22, 2024

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.
December 1, 2024

More Information

Terms related to this study

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.
  • MSRSW/Batch-Fall22/750

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

No

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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