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OpenTrials
Completed

NCT Number: NCT02806921

Changes in the Tear Film With Scleral Contact Lens Wear for Keratoconic Eyes

The purpose of this study is to investigate changes in the level of inflammatory mediators in the tear film of scleral contact lens wearers in a keratoconic population.

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Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

About this study

Scleral contact lenses are rigid gas permeable lenses designed to rest on the sclera while vaulting over the cornea with a fluid reservoir. The use of scleral contact lenses has become the current standard of practice as a nonsurgical management of corneal ectasia and ocular surface diseases. Cases have been recently presented of scleral lens wearers exhibiting adverse corneal findings and conjunctival injection from lens wear. These findings are likely associated with the mechanical and hypoxic effects due to poor fitting characteristics at the limbal area. Tear film analysis detecting changes in the levels of proteinases and cytokines have helped researchers gain a better understanding of the pathophysiology of complications in soft contact lenses wearers, dry eye, and keratoconus. Ultimately, this study will provide insights in relating scleral lens fitting characteristics and corneal and limbal physiological responses.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Had been diagnosed with keratoconus in at least one eye.
  • Is at least 18 years of age and has full legal capacity to volunteer.
  • Has read and understood the information consent letter.
  • Is willing and able to follow instructions and maintain the appointment schedule.

Exclusion criteria

  • Is using any topical medications that will affect ocular health.
  • Has any ocular pathology or severe insufficiency of lacrimal secretion (severe dry eyes) that would affect the wearing of contact lenses.
  • Has persistent, clinically significant corneal or conjunctival staining using sodium fluorescein dye.
  • Has any clinically significant lid or conjunctival abnormalities and active neovascularization.
  • Is aphakic.
  • Has undergone any corneal surgery.
  • Is participating in any other type of eye related clinical or research study.
  • Has any known allergies or sensitivity to the diagnostic pharmaceuticals or products, such as fluorescein, used in this study.

Treatment and study plan

ZenLens

Device

The ZenLens™ semi-scleral lenses are manufactured by Alden Optic Laboratories Inc., Lancaster, NY. They will be made in Boston XO material.

Primary outcomes

  1. Tear Protein

    Time frame: 2 weeks of lens wear with daily schedule of 6-8 hours.

    To measure the level proteases and cytokines in each of the samples using Meso Scale Discovery system (MSD-ECL).

Secondary outcomes

  1. Comfort

    Time frame: 2 weeks of lens wear with daily schedule of 6-8 hours.

    Participants will be asked to rate their ocular comfort, dryness, burning and vision with the contact lenses.

  2. Bulbar and limbal hyperemia

    Time frame: 2 weeks of lens wear with daily schedule of 6-8 hours.

    The eyes of the participants will be imaged using the Keratograph® 5.

  3. Corneal thickness

    Time frame: 2 weeks of lens wear with daily schedule of 6-8 hours.

    Their corneal thickness will be measured with the Visante OCT.

Sponsors and collaborators

Lead sponsor

University of Waterloo

Other

Collaborators

  • Bausch & Lomb Incorporated

Registry information

Official study title

Protease and Cytokine Composition in Post Lens Tear Reservoir of Scleral Lenses for Keratoconic Eyes

Important dates

Study start
2016
Primary completion
2018
Study completion
2018
First posted
Jun 21, 2016
Registry last updated
Jun 27, 2019

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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