KeratoconusNCT01527721
Blurring Strength & Aberrometric Changes Following Corneal Cross-linking (CxL) and CxL Combined With Photorefractive Keratectomy (PRK) in Keratoconus
A study testing Corneal Collagen Cross-Linking (CxL) and Corneal Collagen Cross-Linking combined with t-PRK in people with Keratoconus, run by Democritus University of Thrace at 1 site in Greece.
Trial summary
Primary objective of this study was to assess the impact of the two prevalent therapeutic options, CxL and CxL combined with topography-guided photorefractive keratectomy (t-PRK), on both anterior and posterior corneal High order aberations (HOAs). Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Keratoconus
- What is being tested?
- Corneal Collagen Cross-Linking (CxL) and Corneal Collagen Cross-Linking combined with t-PRK
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 1 siteGreece
- Study dates
- Sep 2010to Jan 2012
- 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
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- progressive keratoconus
Who cannot join
- glaucoma or suspicion for glaucoma,
- central corneal thickness (CCT) less than 400μm,
- K-readings more than 60D,
- history of herpetic keratitis,
- pregnancy or nursing,
- underlying autoimmune disease
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Blurring Strength & Aberrometric Changes Following Corneal Cross-linking (CxL) and CXL Combined With Photorefractive Keratectomy (PRK) in Keratoconus.
Primary objective of this study was to assess the impact of the two prevalent therapeutic options, CxL and CxL combined with topography-guided photorefractive keratectomy (t-PRK), on both anterior and posterior corneal High order aberations (HOAs).
Read the detailed description
The Pentacam Classic (Oculus Optikgerate GmbH, Heidelberg, Germany, software version 1.14r04) was used for the sake of the study.32 patients with keratoconus were included in the study. Of them, 19 patients underwent CxL treatment (CxL group), while the rest 13 patients underwent CxL combined with t-PRK (tCxL) [tCxL group]. If both eyes were eligible, only one eye was enrolled in the study.Regarding Scheimpflug camera (Pentacam Classic, Oculus Optikgerate GmbH, Heidelberg, Germany, software version 1.14r04 ) measurements, acceptable maps had at least 10.0mm of corneal coverage. Moreover, images with extrapolated data in the central 9.0mm zone were excluded.
For both anterior and posterior corneal surfaces, Pentacam-derived HOAs parameters for both pupil diameters of 4mm and 6mm were calculated, as well as the HOA root mean square (RMS)values. Pentacam-derived HOA measurements were obtained one day prior to treatment and then one year post-op.The impact of the surgical technique (either CXL or tCXL) on spherocylindrical error was evaluated by power vector analysis as described before. Furthermore, manifest refractions comprising of sphere (S), cylinder (C) and axis (φ), were converted into three dioptric powers (M, J0 and J45). Moreover, we calculated the overall blurring strength (B) of the spherocylindrical error by measuring the length of the produced vector.
- Conditions
- Keratoconus
- Being tested
- Corneal Collagen Cross-Linking (CxL), Corneal Collagen Cross-Linking combined with t-PRK
- Keywords
- keratoconus, CxL, CxL combined with t-PRK
- Medical subject headings
- Keratoconus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Corneal Collagen Cross-Linking (CxL)Procedure or surgery
The same surgical procedure was applied to all keratoconus patients that included: Instillation of proparacaine hydrochloride 0.5% drops for topical anaesthesia, application of a sponge saturated with 10% alcohol to the central cornea for 30 seconds and subsequent de-epithelialization by means of a hockey knife. Following de-epithelialization, a mixture of 0.1% riboflavin in 20% Dextran solution was instilled to the cornea for 30 minutes (2 drops every 2 minutes) prior to the irradiation, until the stroma was completely penetrated and aqueous was stained yellow. The UVA radiation source was UV-XTM Zurich, . Instillation of riboflavin drops (1 drop every 2 minutes) was continued during irradiation, as well, in order to sustain the necessary concentration of the riboflavin. Moreover, balanced salt solution (BSS) was applied every 6 minutes to moisten the cornea.
Corneal Collagen Cross-Linking combined with t-PRKProcedure or surgery
For tCxL group, the topo-guided PRK preceded the CXL. The epithelium was mechanically removed with a hockey knife and ablation was performed in a 9.0 mm zone with a maximal intended ablation depth of 50μm. No adjuvant Mitomycin-C was applied in any case. For the photorefractive ablation we used the Allegretto Wave 200 Hz (1.0071-1-0.81/1.208 software/ WaveLight AG, Erlangen, Germany) with the T-CAT ablation profile.
| Study group | Role | What they receive |
|---|---|---|
| CxL group | Experimental | Volunteers of this group received CxL treatment. Receives: Procedure: Corneal Collagen Cross-Linking (CxL) |
| tCxL group | Experimental | Volunteers of this group received CxL combined with t-PRK treatment Receives: Procedure: Corneal Collagen Cross-Linking combined with t-PRK |
What is being measured
The primary outcome is the main question the study is designed to answer.
Higher order corneal aberations
Measured: 1 year postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Feb 2012 (estimated)
- Study startSep 2010
- Primary completionDec 2011
- Study completionJan 2012
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)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
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 32 participants (actual)
Sponsor and investigators
- Lead sponsor
- Democritus University of Thrace
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Georgios Labiris, Democritus University of Thrace
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01527721
- Sponsor's protocol ID
- 3/2/2012 37
- Status last verified
- Jan 2017
- First submitted
- 3 Feb 2012
- Last updated
- 18 Jan 2017
- Results posted
- No
- Data monitoring committee
- No
Publications
Labiris G, Sideroudi H, Angelonias D, Georgantzoglou K, Kozobolis VP. Impact of corneal cross-linking combined with photorefractive keratectomy on blurring strength. Clin Ophthalmol. 2016 Apr 1;10:571-6. doi: 10.2147/OPTH.S100770. eCollection 2016.
PubMed 27099464
Study at a glance
From the registry record, last updated by the sponsor on 18 Jan 2017. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Blurring Strength & Aberrometric Changes Following Corneal Cross-linking (CxL) and CXL Combined With Photorefractive Keratectomy (PRK) in Keratoconus.
- ClinicalTrials.gov ID
- NCT01527721
- Acronym / sponsor ID
- 3/2/2012 37
- Conditions
- Keratoconus
- Keywords
- keratoconus, CxL, CxL combined with t-PRK
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 32 participants (actual)
- Lead sponsor
- Democritus University of ThraceUniversity, hospital or other
- Study start
- Sep 2010
- Primary completion
- Dec 2011 (actual)
- Study completion
- Jan 2012 (actual)
- First posted
- 7 Feb 2012 (estimated)
- 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.
Primary objective of this study was to assess the impact of the two prevalent therapeutic options, CxL and CxL combined with topography-guided photorefractive keratectomy (t-PRK), on both anterior and posterior corneal High order aberations (HOAs).
Detailed description
The Pentacam Classic (Oculus Optikgerate GmbH, Heidelberg, Germany, software version 1.14r04) was used for the sake of the study.32 patients with keratoconus were included in the study. Of them, 19 patients underwent CxL treatment (CxL group), while the rest 13 patients underwent CxL combined with t-PRK (tCxL) [tCxL group]. If both eyes were eligible, only one eye was enrolled in the study.Regarding Scheimpflug camera (Pentacam Classic, Oculus Optikgerate GmbH, Heidelberg, Germany, software version 1.14r04 ) measurements, acceptable maps had at least 10.0mm of corneal coverage. Moreover, images with extrapolated data in the central 9.0mm zone were excluded.
For both anterior and posterior corneal surfaces, Pentacam-derived HOAs parameters for both pupil diameters of 4mm and 6mm were calculated, as well as the HOA root mean square (RMS)values. Pentacam-derived HOA measurements were obtained one day prior to treatment and then one year post-op.The impact of the surgical technique (either CXL or tCXL) on spherocylindrical error was evaluated by power vector analysis as described before. Furthermore, manifest refractions comprising of sphere (S), cylinder (C) and axis (φ), were converted into three dioptric powers (M, J0 and J45). Moreover, we calculated the overall blurring strength (B) of the spherocylindrical error by measuring the length of the produced vector.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| CxL group | Experimental | Procedure: Corneal Collagen Cross-Linking (CxL)Volunteers of this group received CxL treatment. |
| tCxL group | Experimental | Procedure: Corneal Collagen Cross-Linking combined with t-PRKVolunteers of this group received CxL combined with t-PRK treatment |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- progressive keratoconus
Key exclusion criteria (6 listed)
- glaucoma or suspicion for glaucoma,
- central corneal thickness (CCT) less than 400μm,
- K-readings more than 60D,
- history of herpetic keratitis,
- pregnancy or nursing,
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 |
|---|---|---|
| Corneal Collagen Cross-Linking (CxL)The same surgical procedure was applied to all keratoconus patients that included: Instillation of proparacaine hydrochloride 0.5% drops for topical anaesthesia, application of a sponge saturated with 10% alcohol to the central cornea for 30 seconds and subsequent de-epithelialization by means of a hockey knife. Following de-epithelialization, a mixture of 0.1% riboflavin in 20% Dextran solution was instilled to the cornea for 30 minutes (2 drops every 2 minutes) prior to the irradiation, until the stroma was completely penetrated and aqueous was stained yellow. The UVA radiation source was UV-XTM Zurich, . Instillation of riboflavin drops (1 drop every 2 minutes) was continued during irradiation, as well, in order to sustain the necessary concentration of the riboflavin. Moreover, balanced salt solution (BSS) was applied every 6 minutes to moisten the cornea. | Procedure or surgery | CxL group |
| Corneal Collagen Cross-Linking combined with t-PRKFor tCxL group, the topo-guided PRK preceded the CXL. The epithelium was mechanically removed with a hockey knife and ablation was performed in a 9.0 mm zone with a maximal intended ablation depth of 50μm. No adjuvant Mitomycin-C was applied in any case. For the photorefractive ablation we used the Allegretto Wave 200 Hz (1.0071-1-0.81/1.208 software/ WaveLight AG, Erlangen, Germany) with the T-CAT ablation profile. | Procedure or surgery | tCxL group |
Primary outcome
Higher order corneal aberations
Time frame: 1 year postoperatively
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 18 Jan 2017.
- Results publication: PubMed 27099464Labiris G, Sideroudi H, Angelonias D, Georgantzoglou K, Kozobolis VP. Impact of corneal cross-linking combined with photorefractive keratectomy on blurring strength. Clin Ophthalmol. 2016 Apr 1;10:571-6. doi: 10.2147/OPTH.S100770. eCollection 2016.
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Corneal Collagen Cross-Linking (CxL) and Corneal Collagen Cross-Linking combined with t-PRK in people with Keratoconus, run by Democritus University of Thrace at 1 site in Greece.
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 1 inclusion and 6 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: finished, as of the sponsor's last update on 18 Jan 2017. 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 Greece. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Higher order corneal aberations (time frame: 1 year postoperatively). 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 NCT01527721, which also lists 1 linked publication.
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 18 Jan 2017.