AzTrials
AzTrials

AstigmatismNCT05829980

Contoura vs Wavefront Optimized Ablation

An observational study of Astigmatism, run by Hebatallah MT Abdelmoniem.

Unknown status

Status not confirmed. The sponsor has not verified this record for over two years, so it may be out of date.

Official record
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Trial summary

To evaluate the efficacy, safety and accuracy of Contoura topography-guided LASIK \& PRK in comparison to Wavefront optimized LASIK \& PRK in virgin eyes with astigmatism. Read more about this study

Who is it for?
Ages 18 to 45 years
Conditions the study is for
Astigmatism
What is being tested?
Laser assisted in-situ keratomileusis and Photorefractive keratectomy
Type of treatment
Surgery or procedure
How many people
128 participants
Where
No sites listed yet
Study dates
Jun 2023to Apr 2025
Phase
Observational
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 to 45 years
  • All sexes
  • Adult

Study population: participants who are candidates and scheduled for excimer laser treatment either LASIK or PRK

Who may be able to join

  • Astigmatism (up to 5.0 diopters) or less.
  • Central corneal thickness (CCT) of 500 microns or more
  • Estimated Residual stromal bed thickness (RSB) of 280 microns or more
  • Subject has provided written informed consent

Who cannot join

  • Keratoconus
  • Abnormal topography
  • previous ocular trauma or eye surgery
  • pre-existing diseases of the vitreous, macula, or optic nerve that can affect visual outcome
  • patients with uveitis and anterior segment pathology
  • patients with corneal pathology or Severe dry eye
  • pregnancy or breast-feeding females
  • uncontrolled vascular or autoimmune disease

Trial locations and contacts

No sites are listed yet.

Mohamed S. Saad Abdallah, Professor contact

01001825024

mohsayedsaad@aun.edu.eg

Hany O. Elsedfy, Ass. Prof. contact

01005263681

helsedfy@aun.edu.eg

About this study

Official title: Contoura Topography-guided Ablation Versus Wavefront-optimized Ablation for Correction of Astigmatism

To evaluate the efficacy, safety and accuracy of Contoura topography-guided LASIK \& PRK in comparison to Wavefront optimized LASIK \& PRK in virgin eyes with astigmatism.

Read the detailed description

In Upper Egypt, The second principal cause of blindness was uncorrected refractive errors accounting for 16% of sample population. It was reported that astigmatism (defined as cylinder power > 0.5 D) was the most common refractive errors in children and adults followed by hyperopia and myopia.

Laser vision correction has been established over the last 2 decades as a safe and effective intervention to treat refractive errors, being one of the main techniques practiced globally.

However, many subjects after LASIK had uncorrected distance visual acuity (UDVA) greater than 1.0, they complain about poor night vision, glare, and double vision. As studies have shown that every 1° deviation of the astigmatic axis could result in loss of correction of 3.3%. Even residual astigmatism less than 0.50D could have an actual impact on visual quality.

Excimer laser ablation used in the correction of refracted errors especially astigmatism may reduce quality of vision, and that is attributed to the induced optical aberrations. The most prevalent of these optical aberrations is the spherical aberration.

Among multiple sophisticated profiles that developed to optimize visual outcomes, wavefront optimized profile which compensate for corneal curvature to reduce spherical aberration.

The topographic guided profiles which consider the shape of the anterior corneal surface. Contoura topography guided ablation corrects astigmatic power and axis to create a more uniform, aberration-free cornea.

Treating astigmatism can be challenging as the conventional patterns of Excimer laser treatment of astigmatism is known to be less predictable than that of spherical refractive errors.

Conditions
Astigmatism
Being tested
Laser assisted in-situ keratomileusis, Photorefractive keratectomy
Keywords
Contoura, Wavefront optimized ablation, LASIK, PRK
Medical subject headings
Astigmatism

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Laser assisted in-situ keratomileusisProcedure or surgery

    Also called LASIK

    Laser-Assisted In Situ Keratomileusis is a procedure that permanently changes the shape of the cornea using an excimer laser and the mechanical microkeratome (a blade device) used to cut a flap in the cornea.

  • Photorefractive keratectomyProcedure or surgery

    Also called PRK

    Photorefractive keratectomy is a laser refractive procedure used to ablate the corneal stroma to correct refractive errors without cutting flap

Study groups in NCT05829980
Study groupRoleWhat they receive
Group AContoura topography-guided LASIK
Receives: Procedure: Laser assisted in-situ keratomileusis
Group BContoura topography-guided PRK
Receives: Procedure: Photorefractive keratectomy
Group CWavefront-optimized LASIK
Receives: Procedure: Laser assisted in-situ keratomileusis
Group DWavefront-optimized PRK
Receives: Procedure: Photorefractive keratectomy

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in Postoperative UDVA compared to preoperative CDVA (in LogMAR)

    UCVA 3 month after surgery compared to baseline preoperative CDVA

    Measured: 3 month

  2. Number of lines of preoperative CDVA compared to postoperative

    Change in lines of CDVA from baseline preoperative to 3 month postoperative (in LogMAR)

    Measured: 3 month

  3. Amount of Residual Astigmatism postoperatively (in Diopters)

    residual astigmatism 3 month postoperatively

    Measured: 3 month

  4. Postoperative mean spherical equivalent MSE compared to Preoperative MSE (in Diopters)

    changes in mean spherical equivalent baseline preoperative to 3 month postoperative

    Measured: 3 month

Secondary outcomes (2)

  1. Change in Contrast sensitivity test

    Measured: 3 month

  2. Amount of High order aberrations

    (Spherical aberration, trefoil, vertical \& horizontal coma)

    Measured: 3 month

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted26 Apr 2023
  2. Study startJun 2023 (estimated)
  3. Primary completionDec 2024 (estimated)
  4. Study completionApr 2025 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Prospective
Enrolment
128 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05829980
Sponsor's protocol ID
CONvsWFO
Status last verified
Apr 2023
First submitted
13 Apr 2023
Last updated
26 Apr 2023
Results posted
No
FDA-regulated drug
No
FDA-regulated device
No

Publications

  • Mousa A, Courtright P, Kazanjian A, Bassett K. Prevalence of visual impairment and blindness in Upper Egypt: a gender-based perspective. Ophthalmic Epidemiol. 2014 Jun;21(3):190-6. doi: 10.3109/09286586.2014.906629. Epub 2014 Apr 18.

    PubMed 24746251

  • Hashemi H, Fotouhi A, Yekta A, Pakzad R, Ostadimoghaddam H, Khabazkhoob M. Global and regional estimates of prevalence of refractive errors: Systematic review and meta-analysis. J Curr Ophthalmol. 2017 Sep 27;30(1):3-22. doi: 10.1016/j.joco.2017.08.009. eCollection 2018 Mar.

    PubMed 29564404

  • Lukenda A, Martinovic ZK, Kalauz M. Excimer laser correction of hyperopia, hyperopic and mixed astigmatism: past, present, and future. Acta Clin Croat. 2012 Jun;51(2):299-304.

    PubMed 23115960

  • Bailey MD, Zadnik K. Outcomes of LASIK for myopia with FDA-approved lasers. Cornea. 2007 Apr;26(3):246-54. doi: 10.1097/ICO.0b013e318033dbf0.

    PubMed 17413947

  • Lin Y, Su HJ, Yuan MZ, Zhang Y. Vector analysis of Contoura Vision for the correction of myopia and myopic astigmatism. Int J Ophthalmol. 2022 Jun 18;15(6):983-989. doi: 10.18240/ijo.2022.06.17. eCollection 2022.

    PubMed 35814884

  • Villegas EA, Alcon E, Artal P. Minimum amount of astigmatism that should be corrected. J Cataract Refract Surg. 2014 Jan;40(1):13-9. doi: 10.1016/j.jcrs.2013.09.010.

    PubMed 24355718

  • Gatinel D, Malet J, Hoang-Xuan T, Azar DT. Analysis of customized corneal ablations: theoretical limitations of increasing negative asphericity. Invest Ophthalmol Vis Sci. 2002 Apr;43(4):941-8.

    PubMed 11923232

  • Kanellopoulos AJ. Topography-modified refraction (TMR): adjustment of treated cylinder amount and axis to the topography versus standard clinical refraction in myopic topography-guided LASIK. Clin Ophthalmol. 2016 Nov 3;10:2213-2221. doi: 10.2147/OPTH.S122345. eCollection 2016.

    PubMed 27843292

  • Motwani M. The use of WaveLight(R) Contoura to create a uniform cornea: the LYRA Protocol. Part 3: the results of 50 treated eyes. Clin Ophthalmol. 2017 May 16;11:915-921. doi: 10.2147/OPTH.S133841. eCollection 2017.

    PubMed 28553071

  • Canones-Zafra R, Katsanos A, Garcia-Gonzalez M, Gros-Otero J, Teus MA. Femtosecond LASIK for the correction of low and high myopic astigmatism. Int Ophthalmol. 2022 Jan;42(1):73-80. doi: 10.1007/s10792-021-02001-x. Epub 2021 Aug 9.

    PubMed 34370173

Questions about this trial

What is this clinical trial studying?

An observational study of Astigmatism, run by Hebatallah MT Abdelmoniem.

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 4 inclusion and 8 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 26 Apr 2023. Status can change between updates, so confirm with the study contact before making plans.

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 Mohamed S. Saad Abdallah, Professor (01001825024, mohsayedsaad@aun.edu.eg), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in Postoperative UDVA compared to preoperative CDVA (in LogMAR) (time frame: 3 month). The study lists 4 primary outcomes in all. 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 NCT05829980, which also lists 10 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 Apr 2023.

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