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

University of Waterloo13 enrolled

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Enrollment

Conditions

Keratoconus

Interventions

ZenLensDEVICE

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

Eligibility

Sex: ALLMin age: 18 YearsHealthy volunteers:

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

Tear Protein

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

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

Secondary Outcomes

Comfort

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

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

Bulbar and limbal hyperemia

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

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

Corneal thickness

Their corneal thickness will be measured with the Visante OCT.

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

Data from ClinicalTrials.gov

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