KeratoconusNCT03249233
Corneal Thickness Changes With Scleral Contact Lenses
A study testing ZenLens™ and Zen™ RC in people with Keratoconus and Healthy Controls, run by University of Waterloo at 1 site in Canada.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Keratoconus, Healthy Controls
- What is being tested?
- ZenLens™ and Zen™ RC
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteCanada
- Study dates
- 22 Jun 2017to Dec 2020
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- 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.
- 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.
Who cannot join
- 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.
Show all 16Show fewer
- 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.
- 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.
Trial locations and contacts
1 site in 1 country.
Canada1 site, 1 recruiting
- Recruiting
University of Waterloo School of Optometry and Vision Science
Waterloo, Ontario, N2L3G1
Kirsten S Carter, BSc OD, 5193018487, kirsten.carter@uwaterloo.ca
Luigina Sorbara, OD MSc, 519-888-4567 ext. 33085, gsorbara@uwaterloo.ca
About this study
Official title: Changes in Corneal Thickness in Keratoconic Eyes With Variation in Scleral Contact Lens Central Clearance
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. 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. We propose 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.
Read the 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.
- Conditions
- Keratoconus, Healthy Controls
- Being tested
- ZenLens™, Zen™ RC
- Medical subject headings
- Keratoconus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ZenLens™Device
The ZenLens™ semi-scleral lenses are manufactured by Alden Optic Laboratories Inc., Lancaster, NY. They will be made in Boston XO material.
Zen™ RCDevice
The Zen™ RC semi-scleral lenses are manufactured by Alden Optic Laboratories Inc., Lancaster, NY. They will be made in Boston XO material.
| Study group | Role | What they receive |
|---|---|---|
| Keratoconics wearing ZenLens with high central clearance | Experimental | Scleral contact lenses designed to provide approximately 450 microns of central clearance. Receives: Device: ZenLens™ |
| Keratoconics wearing ZenLens with low central clearance | Experimental | Scleral contact lenses designed to provide approximately 350 microns of central clearance. Receives: Device: ZenLens™ |
| Healthy controls wearing ZenLens with high central clearance | Active comparator | Scleral contact lenses designed to provide approximately 450 microns of central clearance. Receives: Device: Zen™ RC |
| Healthy controls wearing ZenLens with low central clearance | Active comparator | Scleral contact lenses designed to provide approximately 350 microns of central clearance. Receives: Device: Zen™ RC |
What is being measured
The primary outcome is the main question the study is designed to answer.
Corneal Thickness
Corneal thickness after 8-10 hours of scleral contact lens wear will be measured with the Spectralis OCT and Oculus Pentacam
Measured: 6 weeks
Secondary outcomes (5)
Visual acuity
Both high and low contrast visual acuity will be measured before and after 8-10 hours of scleral contact lens wear
Measured: 6 weeks
Conjunctival redness
Conjunctival redness will be measured with the Keratograph before and after 8-10 hours of scleral lens wear
Measured: 6 weeks
Corneal and conjunctival staining
Corneal and conjunctival staining will be assessed with the Keratograph and biomicroscope before and after 8-10 hours of scleral lens wear
Measured: 6 weeks
Tear biochemistry: proteases and cytokines
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.
Measured: 6 weeks
Tear biochemistry: cell count
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.
Measured: 6 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Aug 2017
- Study start22 Jun 2017
- Primary completionDec 2020 (estimated)
- Study completionDec 2020 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for KeratoconusStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Waterloo
- Sponsor type
- University, hospital or other
- Collaborators
- Bausch & Lomb Incorporated
- Responsible party
- Principal investigator, Luigina Sorbara, University of Waterloo
- Investigators
- Luigina Sorbara, OD MSc, Principal investigator, University of Waterloo
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03249233
- Sponsor's protocol ID
- 22186
- Status last verified
- Apr 2020
- First submitted
- 15 Jun 2017
- Last updated
- 10 Apr 2020
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
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.
PubMed 24631015Romero-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.
PubMed 11004256Walker 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.
PubMed 26341076Ucakhan 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.
PubMed 16814055Liesegang TJ. Contact lens-related microbial keratitis: Part I: Epidemiology. Cornea. 1997 Mar;16(2):125-31.
PubMed 9071523
Study at a glance
From the registry record, last updated by the sponsor on 10 Apr 2020. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Changes in Corneal Thickness in Keratoconic Eyes With Variation in Scleral Contact Lens Central Clearance
- ClinicalTrials.gov ID
- NCT03249233
- Acronym / sponsor ID
- 22186
- Conditions
- Keratoconus, Healthy Controls
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- University of WaterlooUniversity, hospital or other
- Collaborators
- Bausch & Lomb Incorporated
- Study start
- 22 Jun 2017 (actual)
- Primary completion
- Dec 2020 (estimated)
- Study completion
- Dec 2020 (estimated)
- First posted
- 15 Aug 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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. 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. We propose 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.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Keratoconics wearing ZenLens with high central clearance | Experimental | Device: ZenLens™Scleral contact lenses designed to provide approximately 450 microns of central clearance. |
| Keratoconics wearing ZenLens with low central clearance | Experimental | Device: ZenLens™Scleral contact lenses designed to provide approximately 350 microns of central clearance. |
| Healthy controls wearing ZenLens with high central clearance | Active comparator | Device: Zen™ RCScleral contact lenses designed to provide approximately 450 microns of central clearance. |
| Healthy controls wearing ZenLens with low central clearance | Active comparator | Device: Zen™ RCScleral contact lenses designed to provide approximately 350 microns of central clearance. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- 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.
- Had been NOT diagnosed with keratoconus in at least one eye.
Key exclusion criteria (16 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ZenLens™The ZenLens™ semi-scleral lenses are manufactured by Alden Optic Laboratories Inc., Lancaster, NY. They will be made in Boston XO material. | Device | Keratoconics wearing ZenLens with high central clearance, Keratoconics wearing ZenLens with low central clearance |
| Zen™ RCThe Zen™ RC semi-scleral lenses are manufactured by Alden Optic Laboratories Inc., Lancaster, NY. They will be made in Boston XO material. | Device | Healthy controls wearing ZenLens with high central clearance, Healthy controls wearing ZenLens with low central clearance |
Primary outcome
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
5 secondary outcomes
Visual acuity
Time frame: 6 weeks
Conjunctival redness
Time frame: 6 weeks
Corneal and conjunctival staining
Time frame: 6 weeks
Tear biochemistry: proteases and cytokines
Time frame: 6 weeks
Tear biochemistry: cell count
Time frame: 6 weeks
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Apr 2020.
- Background: PubMed 24631015van 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.
- Background: PubMed 11004256Romero-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.
- Background: PubMed 26341076Walker 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.
- Background: PubMed 16814055Ucakhan 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.
- Background: PubMed 9071523Liesegang TJ. Contact lens-related microbial keratitis: Part I: Epidemiology. Cornea. 1997 Mar;16(2):125-31.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Luigina Sorbara, OD MSc principal investigator
University of Waterloo
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing ZenLens™ and Zen™ RC in people with Keratoconus and Healthy Controls, run by University of Waterloo at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 16 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 10 Apr 2020. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Kirsten S Carter, BSc OD (5193018487, kirsten.carter@uwaterloo.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Corneal Thickness (time frame: 6 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT03249233, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Apr 2020.