Active — Not RecruitingNot Applicable

Effect of Defocus in Soft Contact Lenses on Internal Retinal Vascularization

Canada25 participantsStarted 2024-06-25

Plain-language summary

The purpose of this study is to gain a better understanding of the retinal vascular changes that occur in response to the optical effect of a myopic defocus daily disposable soft contact lens (MDSL) in a group of healthy young myopic adults (18-35 years; myopia -1.00D to -4.00D; all genders). It will also learn about the acceptance of this visual correction modality compared to regular contact lenses. The main questions to be answered are: * To evaluate changes in retinal blood flow by visualizing retinal vascular density in the superficial and deep plexus after one week of MDSL wear. * To evaluate changes in choroidal thickness at the macular level after one week of MDSL wear. * To evaluate the visual comfort provided by this MDSL design using a questionnaire. Researchers will compare the MDSL to a daily disposable single vision soft lens (SVSL) used to correct myopia to determine if the addition of a defocus area makes a difference in the retinal response to the visual signal. Participants will be required to * Wear both MDSL and SVSL for one week each, in a random order. * Read letters to measure visual acuity * Have a deep scan of their retina with an optical coherence tomography (OCT) device * Rate the comfort and vision provided by both devices using a questionnaire.

Who can participate

Age range

18 Years – 35 Years

Sex

ALL

See this in plain English?

AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.

Inclusion Criteria: * · Astigmatism ≤ 1.00 D * Myopia between -0.50 and -4.00D * Aged between 18 and 35 * Binocular acuity of 6/6 or better Exclusion Criteria: * · Recent intake (\< 3 months) of medication affecting blood pressure (e.g. hypotensive, anovulant, CNS stimulant, etc.). * Corneal dystrophy or irregularity * Use of topical ocular medications * Smoking (tobacco or marijuana) * Have contraindications to wearing soft contact lenses * Being currently under myopia control treatment or had been under control in the last 3 months * Being pregnant or breast-feeding * History of refractive surgery * Addiction to drugs or alcohol

Questions worth asking your doctor

Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.

1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?

Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.

Questions for the trial coordinator

The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.

1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?

A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.

What they're measuring

Measurement of Retinal blood vessel density measured by Triton OCT-A

Timeframe: Measurement done at baseline and after 1 week of contact lens wear

Trial details

NCT IDNCT06527274

SponsorUniversité de Montréal

Sponsor typeOTHER

Study typeINTERVENTIONAL

Primary completion2025-01-31

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