Choroidal thickness change after 1 hour wearing prototype soft contact lenses

Is this trial a fit for you?

A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.

What this trial studies

Adults aged 18–25 with low to moderate myopia will wear three different prototype soft contact lenses, each for one hour, with measurements taken around the wear period. Eye imaging will be used to measure short-term changes in choroidal thickness under controlled conditions (for example, avoiding caffeine, alcohol, smoking, or cannabis before visits). The study excludes people who have used myopia-control treatments in the prior two years and favors participants with prior soft contact lens experience. Results are intended to identify immediate optical effects on the choroid that could inform future contact lens designs.

Why it matters

Who can join: the full rules

Inclusion Criteria:

* Are 18-25 years of age (inclusive) and have full legal capacity to volunteer; Have read (or be read to) and signed the information and consent form; Habitually wear soft contact lenses or are spectacle wearers with previous experience of soft contact lens wear;
* Are myopic with both eyes having a vertex corrected spherical equivalent non-cycloplegic refraction of at least -0.50 DS and no more than -4.50 DS;
* Achieve at least LogMAR +0.10 with spherical equivalent refraction in each eye;
* Are willing and able to maintain the appointment schedule and follow the measurement visit instructions which include no use of caffeine drinks, alcohol or other stimulants 12 hours before each measurement visit and no smoking or use of recreational cannabis 24 hours before the study visit;
* Have not used a myopia control treatment within 2 years prior to Visit 0 (this includes multifocal spectacle or contact lens wear, orthokeratology, or atropine);
* Typically sleeps at least 7 hours per night.

Exclusion Criteria:

* Participating in any concurrent clinical or research study;
* Have astigmatism of more than 1.00 DC in either eye as per non-cycloplegic refraction;
* Have amblyopia in either eye or known to have any other binocular vision disorder, such as accommodative insufficiency;
* Have any known active\* ocular disease and/or infection;
* Have a systemic condition that in the opinion of the investigator may affect a study outcome variable. Examples include diabetes mellitus, hyperthyroidism, and active allergies;
* Are using any systemic or topical medications that in the opinion of the investigator may affect a study outcome variable. Examples include antihistamine, atropine eye drops;
* Have known sensitivity to the sodium fluorescein diagnostic pharmaceutical to be used in the study;
* Self-reports as pregnant, lactating or planning a pregnancy at the time of enrolment;
* Have undergone strabismus surgery, refractive error surgery or intraocular surgery;
* Are an employee of the Centre for Ocular Research \& Education directly involved in this study (i.e. on the delegation log).

Where it's running

• Centre for Ocular Research and Education at the School of Optometry and Vision Science at Waterloo University
  Waterloo, Ontario, Canada Recruiting

Similar studies

Other studies for the same condition or treatment. Recruiting studies are listed first.

• Evaluating a device for screening vision problems in young children

  This study is testing a new device to see if it can effectively find vision problems in children aged 3 to 8, whether they wear glasses or not.

  Recruiting Essilor International · Nancy, France and 1 other locations · NCT06882408

• Optimizing light exposure to prevent and control myopia in children

  This study tests if changing classroom lighting to mimic sunlight or using a smartphone app to guide light exposure can help prevent and control myopia in primary school children.

  Recruiting at 5 sites National University of Singapore · Singapore and 4 other locations · NCT06631339

• A.M.L. spectacle lenses for children with myopia

  We will try A.M.L. spectacle lenses in 6- to 12-year-old children with myopia to see how quickly they adapt and how comfortable the lenses feel.

  Recruiting Essilor International · Shanghai, Shanghai Municipality · NCT07354945

• Optimizing SMILE surgery for correcting vision problems

  This study is testing if using a new system for SMILE eye surgery can help patients see better after the procedure compared to the traditional method.

  Recruiting Affiliated Hospital of Nantong University · Nantong, Jiangsu and 1 other locations · NCT06982807

• Hyperopic reserve screening for kindergartners in Beijing

  A population-wide screening tests whether senior kindergarten children in Beijing have enough hyperopic reserve to help prevent future myopia.

  Recruiting Beijing Tongren Hospital · Beijing · NCT07851532

• Do dual-focus multifocal contact lenses improve hand-eye coordination and sports vision compared with your usual lenses

  This study tests whether wearing dual-focus multifocal contact lenses improves hand-eye coordination and sports vision in adults who play baseball or softball and normally wear contact lenses.

  Recruiting Ohio State University · Columbus, Ohio · NCT07840209

How to take part

1. Review the eligibility criteria above with your treating physician.
2. Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
3. Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.