Corneal Cross-linking and Refractive Surface Ablation in Patients With Asymmetric Corneas

NCT ID: NCT02943967

Last Updated: 2016-10-26

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

44 participants

Study Classification

INTERVENTIONAL

Study Start Date

2010-01-31

Study Completion Date

2014-01-31

Brief Summary

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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

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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

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Surgical Procedure, Unspecified

Keywords

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Refractive Surgical Procedures Photorefractive Keratectomy Aberrometry

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

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CXL + PRK group

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

Group Type ACTIVE_COMPARATOR

CXL + PRK group

Intervention Type PROCEDURE

Corneal cross-linking with subsequent photorefractive keratotomy after 6 months was performed in one eye

PRK group

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

Group Type ACTIVE_COMPARATOR

PRK group

Intervention Type PROCEDURE

Photorefractive keratotomy alone was performed in contra lateral eyes

Interventions

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CXL + PRK group

Corneal cross-linking with subsequent photorefractive keratotomy after 6 months was performed in one eye

Intervention Type PROCEDURE

PRK group

Photorefractive keratotomy alone was performed in contra lateral eyes

Intervention Type PROCEDURE

Eligibility Criteria

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Inclusion Criteria

* 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.

Exclusion Criteria

* forme fruste keratoconus and keratoconus
* previous eye surgery
* previous eye trauma
* confirmed pregnancy
Minimum Eligible Age

23 Years

Maximum Eligible Age

51 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Federal University of São Paulo

OTHER

Sponsor Role lead

Responsible Party

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Mauro Campos

medical doctor

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Mauro Campos, MD

Role: PRINCIPAL_INVESTIGATOR

Federal University of São Paulo

Locations

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Federal University of São Paulo

São Paulo, São Paulo, Brazil

Site Status

Countries

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Brazil

References

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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.

Reference Type BACKGROUND
PMID: 22569468 (View on PubMed)

Raiskup 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.

Reference Type BACKGROUND
PMID: 25532633 (View on PubMed)

Carones 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.

Reference Type BACKGROUND
PMID: 12498842 (View on PubMed)

Randleman 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.

Reference Type BACKGROUND
PMID: 17624434 (View on PubMed)

Navas 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.

Reference Type BACKGROUND
PMID: 18041251 (View on PubMed)

Guedj 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.

Reference Type BACKGROUND
PMID: 23102727 (View on PubMed)

Koller 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.

Reference Type BACKGROUND
PMID: 19631120 (View on PubMed)

Abib 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.

Reference Type BACKGROUND
PMID: 22333658 (View on PubMed)

Kontadakis 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.

Reference Type BACKGROUND
PMID: 26896122 (View on PubMed)

Camellin 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.

Reference Type BACKGROUND
PMID: 27012841 (View on PubMed)

Shaheen 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.

Reference Type BACKGROUND
PMID: 27191671 (View on PubMed)

Tomita 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.

Reference Type BACKGROUND
PMID: 24857441 (View on PubMed)

Guell 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.

Reference Type BACKGROUND
PMID: 25870865 (View on PubMed)

Other Identifiers

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2088/88

Identifier Type: -

Identifier Source: org_study_id