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

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: Active, not recruiting
• Conditions: Myopia
• Intervention / Treatment: Diagnostic test: Positive Lens-Induced Defocus Using Spectacle Lenses (+2.00 D) for Myopic Participants; Diagnostic test: Negative Lens-Induced Defocus Using Spectacle Lenses (-2.00 D) for Myopic Participants; Combination product: Positive Lens-Induced Defocus Using Spectacle Lenses (+2.00 D) for Non-Myopic Participants; Combination product: Negative Lens-Induced Defocus Using Spectacle Lenses (-2.00 D) for Non-Myopic Participants

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: Interventional
• Enrollment (Actual): 36
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Contrast Sensitivity	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	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

• Sponsor: Superior University

Study record dates

Study Major Dates

• Study Start (Actual): February 28, 2024
• Primary Completion (Actual): July 31, 2024
• Study Completion (Estimated): March 1, 2025

Study Registration Dates

• First Submitted: December 13, 2024
• First Submitted That Met QC Criteria: December 22, 2024
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: December 22, 2024
• Last Verified: December 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Immune System Diseases; Eye Diseases; Refractive Errors; Hypersensitivity; Myopia
• Other Study ID 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