- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT03249233
Corneal Thickness Changes With Scleral Contact Lenses
Changes in Corneal Thickness in Keratoconic Eyes With Variation in Scleral Contact Lens Central Clearance
Study Overview
Status
Conditions
Intervention / Treatment
Detailed Description
The purpose of this study is to investigate changes in the corneal thickness of scleral contact lens wearers in a keratoconic (KC) population and compare to age-matched controls. The hypothesis is that scleral contact lens wear is associated with low levels of corneal hypoxia including measurable changes in corneal thickness.
This will be a prospective, dispensing study design. The study will involve up to 20 keratoconic participants and up to 20 age matched controls. Participants will attend 1 screening/fitting visit wearing their habitual contact lenses where the two test lens designs (350 and 450microns) will be fitted. There will then be a delivery visit for each design (randomly selected) and a single follow up visit after 8-10 hours of scleral lens wear, three weeks later. A washout period of a minimum of 48 hours will be applied between the cross-over of each lens design. Lenses to be worn in this study will be made of Boston XO material and are approved by Health Canada. The lenses will have a diameter of 14.8-17.0mm with a high and low sagittal depth in the corneal zone. As to which of the two lenses is being assessed, both the investigator and the participant will be masked as the assistant will provide the lenses in an unlabeled case. Masking the investigator will prevent bias when measuring corneal thickness and analyzing the data. The objectives of this study are to take a sample of keratoconic and control participants, fit them in scleral lenses, and to measure topographic corneal thickness after 8-10 hours of scleral lens wear after three weeks of wear, to compare two instruments in the measurement of corneal thickness, and to compare the effects of varying central corneal clearance of the scleral lens on corneal thickness. Secondary objectives include comparing ocular physiological outcomes between the two test lens designs. Corneal thickness will be altered post scleral lens wear compared to pre-lens wear and the amount of alteration will correlate to the fitting characteristics in the central zone of the scleral lenses.
Study Type
Enrollment (Anticipated)
Phase
- Not Applicable
Contacts and Locations
Study Locations
-
-
Ontario
-
Waterloo, Ontario, Canada, N2L3G1
- Recruiting
- University of Waterloo School of Optometry and Vision Science
-
Contact:
- Kirsten S Carter, BSc OD
- Phone Number: 5193018487
- Email: kirsten.carter@uwaterloo.ca
-
Contact:
- Luigina Sorbara, OD MSc
- Phone Number: 33085 519-888-4567
- Email: gsorbara@uwaterloo.ca
-
-
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria (Test Group):
- 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.
Inclusion Criteria (Control Group)
- Had been NOT 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 (Test Group):
- 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 penetrating keratoplasty.
- 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.
Exclusion Criteria (Control Group):
- 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.
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Treatment
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Double
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
---|---|
Experimental: Keratoconics wearing ZenLens with high central clearance
Scleral contact lenses designed to provide approximately 450 microns of central clearance.
|
The ZenLens™ semi-scleral lenses are manufactured by Alden Optic Laboratories Inc., Lancaster, NY.
They will be made in Boston XO material.
|
Experimental: Keratoconics wearing ZenLens with low central clearance
Scleral contact lenses designed to provide approximately 350 microns of central clearance.
|
The ZenLens™ semi-scleral lenses are manufactured by Alden Optic Laboratories Inc., Lancaster, NY.
They will be made in Boston XO material.
|
Active Comparator: Healthy controls wearing ZenLens with high central clearance
Scleral contact lenses designed to provide approximately 450 microns of central clearance.
|
The Zen™ RC semi-scleral lenses are manufactured by Alden Optic Laboratories Inc., Lancaster, NY.
They will be made in Boston XO material.
|
Active Comparator: Healthy controls wearing ZenLens with low central clearance
Scleral contact lenses designed to provide approximately 350 microns of central clearance.
|
The Zen™ RC semi-scleral lenses are manufactured by Alden Optic Laboratories Inc., Lancaster, NY.
They will be made in Boston XO material.
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
Corneal Thickness
Time Frame: 6 weeks
|
Corneal thickness after 8-10 hours of scleral contact lens wear will be measured with the Spectralis OCT and Oculus Pentacam
|
6 weeks
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
Visual acuity
Time Frame: 6 weeks
|
Both high and low contrast visual acuity will be measured before and after 8-10 hours of scleral contact lens wear
|
6 weeks
|
Conjunctival redness
Time Frame: 6 weeks
|
Conjunctival redness will be measured with the Keratograph before and after 8-10 hours of scleral lens wear
|
6 weeks
|
Corneal and conjunctival staining
Time Frame: 6 weeks
|
Corneal and conjunctival staining will be assessed with the Keratograph and biomicroscope before and after 8-10 hours of scleral lens wear
|
6 weeks
|
Tear biochemistry: proteases and cytokines
Time Frame: 6 weeks
|
The level of proteases (MMP-1, MMP-9) and cytokines (IL-1, IL-6, IL-8, TNFα) in each of the tear samples collected from the lenses will be measured using the Meso Scale Discovery System (MSD-ECL) before and after 8-10 hours of scleral lens wear.
|
6 weeks
|
Tear biochemistry: cell count
Time Frame: 6 weeks
|
Polymorphonuclear leukocyte (PMN) cells in each of the tear samples collected from the lenses will be analyzed and counted using the BD FACS Calibur™ Flow Cytometer and Bright-Line Hemacytometer before and after 8-10 hours of scleral lens wear.
|
6 weeks
|
Collaborators and Investigators
Sponsor
Collaborators
Investigators
- Principal Investigator: Luigina Sorbara, OD MSc, University of Waterloo
Publications and helpful links
General Publications
- van der Worp E, Bornman D, Ferreira DL, Faria-Ribeiro M, Garcia-Porta N, Gonzalez-Meijome JM. Modern scleral contact lenses: A review. Cont Lens Anterior Eye. 2014 Aug;37(4):240-50. doi: 10.1016/j.clae.2014.02.002. Epub 2014 Mar 12.
- Romero-Rangel T, Stavrou P, Cotter J, Rosenthal P, Baltatzis S, Foster CS. Gas-permeable scleral contact lens therapy in ocular surface disease. Am J Ophthalmol. 2000 Jul;130(1):25-32. doi: 10.1016/s0002-9394(00)00378-0.
- Walker MK, Bergmanson JP, Miller WL, Marsack JD, Johnson LA. Complications and fitting challenges associated with scleral contact lenses: A review. Cont Lens Anterior Eye. 2016 Apr;39(2):88-96. doi: 10.1016/j.clae.2015.08.003. Epub 2015 Sep 2.
- Ucakhan OO, Ozkan M, Kanpolat A. Corneal thickness measurements in normal and keratoconic eyes: Pentacam comprehensive eye scanner versus noncontact specular microscopy and ultrasound pachymetry. J Cataract Refract Surg. 2006 Jun;32(6):970-7. doi: 10.1016/j.jcrs.2006.02.037.
- Liesegang TJ. Contact lens-related microbial keratitis: Part I: Epidemiology. Cornea. 1997 Mar;16(2):125-31.
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Anticipated)
Study Completion (Anticipated)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- 22186
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.
Clinical Trials on Keratoconus
-
The Cleveland ClinicUniversity of MarylandEnrolling by invitationKeratoconus | Keratoconus, Unstable | Keratoconus, StableUnited States
-
Eye Hospital Pristina KosovoActive, not recruitingKeratoconus | Keratoconus of Right Eye | Keratoconus, Unstable, Right EyeKosovo
-
Tianjin Eye HospitalRecruitingScansys, Pentacam, Keratoconus, Subclinical KeratoconusChina
-
Tianjin Eye HospitalActive, not recruitingScansys, Pentacam, Corvis ST, Keratoconus, Subclinical KeratoconusChina
-
Heba Allah Nashaat MohamedAssiut UniversityRecruitingKeratoconus, CollagenEgypt
-
Kent Wellish MDNot yet recruitingKeratoconus, Unstable
-
Kasr El Aini HospitalUnknownProgressive KeratoconusEgypt
-
Centre Hospitalier Régional Metz-ThionvilleCompletedProgressive Keratoconus
-
Glaukos CorporationCompletedProgressive KeratoconusUnited States
-
Tianjin Eye HospitalCompletedKeratoconus, StableChina
Clinical Trials on ZenLens™
-
University of WaterlooBausch & Lomb IncorporatedCompleted
-
London South Bank UniversityCompletedKeratoconus | Irregular Astigmatism | Irregular; Contour of Cornea | Pellucid Marginal Corneal Degeneration | Injury of CorneaUnited Kingdom
-
BaroNova, Inc.Completed
-
London Health Sciences CentreUniversity of Western Ontario, Canada; Synaptive MedicalUnknownBrain Damage, Chronic | Cerebellar Cognitive Affective Syndrome | Cerebellar Mutism
-
Asklepios Kliniken Hamburg GmbHUniversity of KielCompletedAirway Management | Laryngeal Mask Airway | Fibreoptic Intubation
-
CereVasc IncAlvaMed, Inc.; Simplified Clinical Data Systems, LLC; Bioscience Consulting,...RecruitingHydrocephalus | Hydrocephalus, CommunicatingArgentina
-
Medtronic CardiovascularActive, not recruitingAortic AneurysmGermany, New Zealand, United States, Netherlands, Switzerland, United Kingdom, Spain, Australia, Italy, Sweden, France, Austria, Slovakia
-
Andrew ParrentUniversity of Western Ontario, Canada; Synaptive MedicalUnknownTemporal Lobe Epilepsy
-
Gülçin Özalp GerçekerCompletedCatheter Complications | Catheter LeakageTurkey
-
GlaxoSmithKlineCompletedTetanus | Diphtheria | Acellular Pertussis | Poliomyelitis | Haemophilus Influenzae Type bKorea, Republic of