Surgical Procedure, UnspecifiedNCT02943967
Corneal Cross-linking and Refractive Surface Ablation in Patients With Asymmetric Corneas
A study testing CXL + PRK group and PRK group in people with Surgical Procedure, Unspecified, run by Federal University of São Paulo at 1 site in Brazil.
Trial summary
The purpose of this study is to evaluate safety and efficacy of corneal cross-linking and photorefractive keratectomy for refractive correction in patients with bilateral asymmetric topography. Read more about this study
- Who is it for?
- Ages 23 to 51 yearsHealthy volunteers can take part
- Conditions the study is for
- Surgical Procedure, Unspecified
- What is being tested?
- CXL + PRK group and PRK group
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 44 participants
- Where
- 1 siteBrazil
- Study dates
- Jan 2010to Jan 2014
- 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 23 to 51 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- bilateral asymmetric topography with inferior steepening
- corneal thickness of 440 micra at the thinnest point
- inferior-to-superior index (I-S) between 1.0D and 1.4D
- maximum keratometric steepness < 47.00D
- stable refraction more than 1 year.
Who cannot join
- forme fruste keratoconus and keratoconus
- previous eye surgery
- previous eye trauma
- confirmed pregnancy
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Two Years Follow up of Corneal Cor Cross-linking and Refractive Surface Ablation in Patients With Asymmetric Corneal Topography
The purpose of this study is to evaluate safety and efficacy of corneal cross-linking and photorefractive keratectomy for refractive correction in patients with bilateral asymmetric topography.
Read the detailed description
Corneal cross-linking (CXL) by the photosensitizer, riboflavin (vitamin B2), and ultraviolet A (UVA) light increases corneal rigidity and has been described as an effective method for stabilizing the cornea in patients with progressive keratoconus. The photochemical reaction in this procedure causes the collagen to form additional covalent connections between its fibers, which stabilizes the stromal collagen fibers, improving the collagen's structure and the cornea rigidity. It is a relatively safe procedure with low rates of complications Photorefractive keratectomy (PRK) it is a traditional technique for refractive surgery. In cases of irregular corneas or re-operation normally the favorite ablation profile chosen is the guided surgery, topography guided or wavefront guided, showing better results. This technique is also relatively safe procedure with low rates of complications. One of the most unwanted complications of this surgery and also rare is corneal ectasia.
Combining PRK and CXL is already done in patients with keratoconus and suspected keratoconus.
This combined procedure uses the principle that CXL stiffen the cornea making it possible to reduce corneal thickness with PRK without weakening corneal strength. Literature show better results, in keratoconus, with simultaneous procedures. Guedj et al performed PRK in keratoconus suspects and within 5 years he did not found any corneal ectasia.
- Conditions
- Surgical Procedure, Unspecified
- Being tested
- CXL + PRK group, PRK group
- Keywords
- Refractive Surgical Procedures, Photorefractive Keratectomy, Aberrometry
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CXL + PRK groupProcedure or surgery
Corneal cross-linking with subsequent photorefractive keratotomy after 6 months was performed in one eye
PRK groupProcedure or surgery
Photorefractive keratotomy alone was performed in contra lateral eyes
| Study group | Role | What they receive |
|---|---|---|
| CXL + PRK group | Active comparator | Corneal cross-linking surgery is perfomed in one eye : deepithelization of the cornea and instillation of 0,1% riboflavin (ophthalmos - Brazil) for 30 minutes and UVA for irradiated for 30 minutes with ultraviolet-A of 365nm light with an irradiance of 3 mW/cm2 using Xlink (Opto - São Carlos) Photorefractive keratotomy will be perfomed in the same eye using excimer laser Ladarvision (Alcon - USA) with 0,02 % mitomicin for 30 seconds (Ophthalmos - Brasil) simultaneously with the other eye.
Both procedures will have the same post operative treatment :
gatifloxacin 0,3% 6/6h for 10 days prednisolone acetate 0,12% 6/6h por 14 days Receives: Procedure: CXL + PRK group |
| PRK group | Active comparator | Photorefractive keratotomy will be perfomed in the fellow eye using excimer laser Ladarvision (Alcon - USA) with 0,02 % mitomicin for 30 seconds (Ophthalmos - Brasil) simultaneously with the other eye.
Both procedures will have the same post operative treatment :
gatifloxacin 0,3% 6/6h for 10 days prednisolone acetate 0,12% 6/6h por 14 days Receives: Procedure: PRK group |
What is being measured
The primary outcome is the main question the study is designed to answer.
Refractive results - spherical equivalent in diopters
Measured: 30 months
Secondary outcomes (5)
Biomicroscopy findings with the slit lamp
Measured: 30 months
Visual acuity in logMar
Measured: 30 months
Aberrometric Results in root mean square
Only coma and spherical aberration
Measured: 18 months
Topographic results in diopters
we will measure the increase in diopters with time
Measured: 30 months
Pachymetric results in micra
Measured: 30 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Oct 2016 (estimated)
- Study startJan 2010
- Primary completionJan 2014
- Study completionJan 2014
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (13)Papers the sponsor has linked to this study.
- Other trials for Surgical Procedure, UnspecifiedStudies 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
- None (open label)
- Enrolment
- 44 participants (actual)
Sponsor and investigators
- Lead sponsor
- Federal University of São Paulo
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mauro Campos, Federal University of São Paulo
- Investigators
- Mauro Campos, MD, Principal investigator, Federal University of São Paulo
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02943967
- Sponsor's protocol ID
- 2088/88
- Status last verified
- Oct 2016
- First submitted
- 21 Oct 2016
- Last updated
- 26 Oct 2016
- Results posted
- No
- Data monitoring committee
- No
- Individual data sharing
- Yes
Publications
Cheema AS, Mozayan A, Channa P. Corneal collagen crosslinking in refractive surgery. Curr Opin Ophthalmol. 2012 Jul;23(4):251-6. doi: 10.1097/ICU.0b013e3283543cbd.
PubMed 22569468Raiskup F, Theuring A, Pillunat LE, Spoerl E. Corneal collagen crosslinking with riboflavin and ultraviolet-A light in progressive keratoconus: ten-year results. J Cataract Refract Surg. 2015 Jan;41(1):41-6. doi: 10.1016/j.jcrs.2014.09.033.
PubMed 25532633Carones F, Vigo L, Scandola E, Vacchini L. Evaluation of the prophylactic use of mitomycin-C to inhibit haze formation after photorefractive keratectomy. J Cataract Refract Surg. 2002 Dec;28(12):2088-95. doi: 10.1016/s0886-3350(02)01701-7.
PubMed 12498842Randleman JB, Woodward M, Lynn MJ, Stulting RD. Risk assessment for ectasia after corneal refractive surgery. Ophthalmology. 2008 Jan;115(1):37-50. doi: 10.1016/j.ophtha.2007.03.073. Epub 2007 Jul 12.
PubMed 17624434Navas A, Ariza E, Haber A, Fermon S, Velazquez R, Suarez R. Bilateral keratectasia after photorefractive keratectomy. J Refract Surg. 2007 Nov;23(9):941-3. doi: 10.3928/1081-597X-20071101-14.
PubMed 18041251Guedj M, Saad A, Audureau E, Gatinel D. Photorefractive keratectomy in patients with suspected keratoconus: five-year follow-up. J Cataract Refract Surg. 2013 Jan;39(1):66-73. doi: 10.1016/j.jcrs.2012.08.058. Epub 2012 Oct 24.
PubMed 23102727Koller T, Mrochen M, Seiler T. Complication and failure rates after corneal crosslinking. J Cataract Refract Surg. 2009 Aug;35(8):1358-62. doi: 10.1016/j.jcrs.2009.03.035.
PubMed 19631120Abib FC, Holzchuh R, Schaefer A, Schaefer T, Godois R. The endothelial sample size analysis in corneal specular microscopy clinical examinations. Cornea. 2012 May;31(5):546-50. doi: 10.1097/ICO.0b013e3181cc7961.
PubMed 22333658Kontadakis GA, Kankariya VP, Tsoulnaras K, Pallikaris AI, Plaka A, Kymionis GD. Long-Term Comparison of Simultaneous Topography-Guided Photorefractive Keratectomy Followed by Corneal Cross-linking versus Corneal Cross-linking Alone. Ophthalmology. 2016 May;123(5):974-83. doi: 10.1016/j.ophtha.2016.01.010. Epub 2016 Feb 17.
PubMed 26896122Camellin M, Guidotti JM, Arba Mosquera S. Corneal-Wavefront guided transepithelial photorefractive keratectomy after corneal collagen cross linking in keratoconus. J Optom. 2017 Jan-Mar;10(1):52-62. doi: 10.1016/j.optom.2016.02.001. Epub 2016 Mar 21.
PubMed 27012841Shaheen MS, Shalaby Bardan A, Pinero DP, Ezzeldin H, El-Kateb M, Helaly H, Khalifa MA. Wave Front-Guided Photorefractive Keratectomy Using a High-Resolution Aberrometer After Corneal Collagen Cross-Linking in Keratoconus. Cornea. 2016 Jul;35(7):946-53. doi: 10.1097/ICO.0000000000000888.
PubMed 27191671Tomita M, Yoshida Y, Yamamoto Y, Mita M, Waring G 4th. In vivo confocal laser microscopy of morphologic changes after simultaneous LASIK and accelerated collagen crosslinking for myopia: one-year results. J Cataract Refract Surg. 2014 Jun;40(6):981-90. doi: 10.1016/j.jcrs.2013.10.044.
PubMed 24857441Guell JL, Verdaguer P, Elies D, Gris O, Manero F. Persistent stromal scar after PRK and CXL: different preoperative findings, similar complication. J Refract Surg. 2015 Mar;31(3):211-2. No abstract available.
PubMed 25870865
Study at a glance
From the registry record, last updated by the sponsor on 26 Oct 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Two Years Follow up of Corneal Cor Cross-linking and Refractive Surface Ablation in Patients With Asymmetric Corneal Topography
- ClinicalTrials.gov ID
- NCT02943967
- Acronym / sponsor ID
- 2088/88
- Conditions
- Surgical Procedure, Unspecified
- Keywords
- Refractive Surgical Procedures, Photorefractive Keratectomy, Aberrometry
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 44 participants (actual)
- Lead sponsor
- Federal University of São PauloUniversity, hospital or other
- Study start
- Jan 2010
- Primary completion
- Jan 2014 (actual)
- Study completion
- Jan 2014 (actual)
- First posted
- 25 Oct 2016 (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.
The purpose of this study is to evaluate safety and efficacy of corneal cross-linking and photorefractive keratectomy for refractive correction in patients with bilateral asymmetric topography.
Detailed description
Corneal cross-linking (CXL) by the photosensitizer, riboflavin (vitamin B2), and ultraviolet A (UVA) light increases corneal rigidity and has been described as an effective method for stabilizing the cornea in patients with progressive keratoconus. The photochemical reaction in this procedure causes the collagen to form additional covalent connections between its fibers, which stabilizes the stromal collagen fibers, improving the collagen's structure and the cornea rigidity. It is a relatively safe procedure with low rates of complications Photorefractive keratectomy (PRK) it is a traditional technique for refractive surgery. In cases of irregular corneas or re-operation normally the favorite ablation profile chosen is the guided surgery, topography guided or wavefront guided, showing better results. This technique is also relatively safe procedure with low rates of complications. One of the most unwanted complications of this surgery and also rare is corneal ectasia.
Combining PRK and CXL is already done in patients with keratoconus and suspected keratoconus.
This combined procedure uses the principle that CXL stiffen the cornea making it possible to reduce corneal thickness with PRK without weakening corneal strength. Literature show better results, in keratoconus, with simultaneous procedures. Guedj et al performed PRK in keratoconus suspects and within 5 years he did not found any corneal ectasia.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| CXL + PRK group | Active comparator | Procedure: CXL + PRK groupCorneal cross-linking surgery is perfomed in one eye : deepithelization of the cornea and instillation of 0,1% riboflavin (ophthalmos - Brazil) for 30 minutes and UVA for irradiated for 30 minutes with ultraviolet-A of 365nm light with an irradiance of 3 mW/cm2 using Xlink (Opto - São Carlos) Photorefractive keratotomy will be perfomed in the same eye using excimer laser Ladarvision (Alcon - USA) with 0,02 % mitomicin for 30 seconds (Ophthalmos - Brasil) simultaneously with the other eye. Both procedures will have the same post operative treatment : gatifloxacin 0,3% 6/6h for 10 days prednisolone acetate 0,12% 6/6h por 14 days |
| PRK group | Active comparator | Procedure: PRK groupPhotorefractive keratotomy will be perfomed in the fellow eye using excimer laser Ladarvision (Alcon - USA) with 0,02 % mitomicin for 30 seconds (Ophthalmos - Brasil) simultaneously with the other eye. Both procedures will have the same post operative treatment : gatifloxacin 0,3% 6/6h for 10 days prednisolone acetate 0,12% 6/6h por 14 days |
Who may qualify
- Ages
- 23 to 51 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- bilateral asymmetric topography with inferior steepening
- corneal thickness of 440 micra at the thinnest point
- inferior-to-superior index (I-S) between 1.0D and 1.4D
- maximum keratometric steepness < 47.00D
- stable refraction more than 1 year.
Key exclusion criteria (4 listed)
- forme fruste keratoconus and keratoconus
- previous eye surgery
- previous eye trauma
- confirmed pregnancy
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 |
|---|---|---|
| CXL + PRK groupCorneal cross-linking with subsequent photorefractive keratotomy after 6 months was performed in one eye | Procedure or surgery | CXL + PRK group |
| PRK groupPhotorefractive keratotomy alone was performed in contra lateral eyes | Procedure or surgery | PRK group |
Primary outcome
Refractive results - spherical equivalent in diopters
Time frame: 30 months
5 secondary outcomes
Biomicroscopy findings with the slit lamp
Time frame: 30 months
Visual acuity in logMar
Time frame: 30 months
Aberrometric Results in root mean square
Time frame: 18 months
Topographic results in diopters
Time frame: 30 months
Pachymetric results in micra
Time frame: 30 months
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 26 Oct 2016.
- Background: PubMed 22569468Cheema AS, Mozayan A, Channa P. Corneal collagen crosslinking in refractive surgery. Curr Opin Ophthalmol. 2012 Jul;23(4):251-6. doi: 10.1097/ICU.0b013e3283543cbd.
- Background: PubMed 25532633Raiskup F, Theuring A, Pillunat LE, Spoerl E. Corneal collagen crosslinking with riboflavin and ultraviolet-A light in progressive keratoconus: ten-year results. J Cataract Refract Surg. 2015 Jan;41(1):41-6. doi: 10.1016/j.jcrs.2014.09.033.
- Background: PubMed 12498842Carones F, Vigo L, Scandola E, Vacchini L. Evaluation of the prophylactic use of mitomycin-C to inhibit haze formation after photorefractive keratectomy. J Cataract Refract Surg. 2002 Dec;28(12):2088-95. doi: 10.1016/s0886-3350(02)01701-7.
- Background: PubMed 17624434Randleman JB, Woodward M, Lynn MJ, Stulting RD. Risk assessment for ectasia after corneal refractive surgery. Ophthalmology. 2008 Jan;115(1):37-50. doi: 10.1016/j.ophtha.2007.03.073. Epub 2007 Jul 12.
- Background: PubMed 18041251Navas A, Ariza E, Haber A, Fermon S, Velazquez R, Suarez R. Bilateral keratectasia after photorefractive keratectomy. J Refract Surg. 2007 Nov;23(9):941-3. doi: 10.3928/1081-597X-20071101-14.
- Background: PubMed 23102727Guedj M, Saad A, Audureau E, Gatinel D. Photorefractive keratectomy in patients with suspected keratoconus: five-year follow-up. J Cataract Refract Surg. 2013 Jan;39(1):66-73. doi: 10.1016/j.jcrs.2012.08.058. Epub 2012 Oct 24.
- Background: PubMed 19631120Koller T, Mrochen M, Seiler T. Complication and failure rates after corneal crosslinking. J Cataract Refract Surg. 2009 Aug;35(8):1358-62. doi: 10.1016/j.jcrs.2009.03.035.
- Background: PubMed 22333658Abib FC, Holzchuh R, Schaefer A, Schaefer T, Godois R. The endothelial sample size analysis in corneal specular microscopy clinical examinations. Cornea. 2012 May;31(5):546-50. doi: 10.1097/ICO.0b013e3181cc7961.
- Background: PubMed 26896122Kontadakis GA, Kankariya VP, Tsoulnaras K, Pallikaris AI, Plaka A, Kymionis GD. Long-Term Comparison of Simultaneous Topography-Guided Photorefractive Keratectomy Followed by Corneal Cross-linking versus Corneal Cross-linking Alone. Ophthalmology. 2016 May;123(5):974-83. doi: 10.1016/j.ophtha.2016.01.010. Epub 2016 Feb 17.
- Background: PubMed 27012841Camellin M, Guidotti JM, Arba Mosquera S. Corneal-Wavefront guided transepithelial photorefractive keratectomy after corneal collagen cross linking in keratoconus. J Optom. 2017 Jan-Mar;10(1):52-62. doi: 10.1016/j.optom.2016.02.001. Epub 2016 Mar 21.
- Background: PubMed 27191671Shaheen MS, Shalaby Bardan A, Pinero DP, Ezzeldin H, El-Kateb M, Helaly H, Khalifa MA. Wave Front-Guided Photorefractive Keratectomy Using a High-Resolution Aberrometer After Corneal Collagen Cross-Linking in Keratoconus. Cornea. 2016 Jul;35(7):946-53. doi: 10.1097/ICO.0000000000000888.
- Background: PubMed 24857441Tomita M, Yoshida Y, Yamamoto Y, Mita M, Waring G 4th. In vivo confocal laser microscopy of morphologic changes after simultaneous LASIK and accelerated collagen crosslinking for myopia: one-year results. J Cataract Refract Surg. 2014 Jun;40(6):981-90. doi: 10.1016/j.jcrs.2013.10.044.
- Individual participant dataSharing planned: Yes
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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.
Mauro Campos, MD principal investigator
Federal University of São Paulo
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing CXL + PRK group and PRK group in people with Surgical Procedure, Unspecified, run by Federal University of São Paulo at 1 site in Brazil.
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 5 inclusion and 4 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 26 Oct 2016. 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 Brazil. 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?
Refractive results - spherical equivalent in diopters (time frame: 30 months). 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 NCT02943967, which also lists 13 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 26 Oct 2016.