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Pupil Centroid Shift Compensation in Photorefractive Keratectomy Candidates

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ClinicalTrials.gov Identifier: NCT03844178
Recruitment Status : Recruiting
First Posted : February 18, 2019
Last Update Posted : February 18, 2019
Sponsor:
Information provided by (Responsible Party):
Zahra Rabbani Khah, Shahid Beheshti University of Medical Sciences

Brief Summary:

patients who are candidates of PRK will be recruited in this intrasubject randomized clinical trial. Inclusion criteria are myopia or myopic astigmatism with refractive cylinder. Exclusion criteria were unstable refractive error, age less than 21 years old, corneal opacity, keratoconus, keratoconus suspects, residual corneal stromal thickness less than 350 µm, moderate or severe dry eye disease and any other ocular pathology other than refractive error. Complete eye exam will be performed preoperatively including: uncorrected distance visual acuity (UDVA), best spectacle corrected distance visual acuity (CDVA), cyclorefraction, slit lamp biomicroscopy, Goldmann applannation tonometry, dual scheimpflug tomography (Ziemmer), topography in mesopic condition accompanied by pupilometry and iris registration (Topolyzer Vario, Alcon Laboratories, Inc., Fort Worth, TX), and funduscopy with dilated pupil.

Surgical Technique The same surgeon (A.F.) will perform all surgeries. After installation of Tetracaine 1%, periorbital skin will be prepared with povidone iodine 5%. Iris registration will be performed in all eyes before epithelial removal. Ethylalcohol 20.0% into a 9.0 mm well for 20 seconds will be applied on the central cornea, and then the epithelium of the central 9.0 mm area will be removed by hockey knife. In the right eye of each patient PCS compensation will be turned on (PCS-On group) and in the left eye it will be turned off (PCS-Off group). Excimer laser ablation will be performed by Wavelight Allegretto EX500 (Alcon, Fort Worth, TX, USA). Selection of which eye to be first ablated will be done randomly. Randomization will be performed based on a computer software by a Biostatistician which produced the first eye to be operated. Static cyclotorsion compensation will be active in all eyes. The ablation profile will be wavefront-optimized in all cases.

Postoperative Course Postoperatively, chloramphenicol 0.5% eye drops and betamethasone 0.1% eye drops will be prescribed every 6 hours for 10 days. Thereafter, Fluorometholone 0.1% eye drops every 6 hours for 1 month and every 8 hours for the next month will be given. Follow-up examinations were scheduled at 1, 2, 3, 4, 7 and 15 days and 1, 2, 3, and 6 months postoperatively. After contact lens removal each follow-up examination includes the UDVA, manifest refraction, and IOP measurements as well as a slit lamp biomicroscopy. Corneal imaging with Galilei tomography, CDVA and cyclorefraction will be performed at the final follow-up examination 6 months postoperatively.


Condition or disease Intervention/treatment Phase
Pupil Centroid Shift Procedure: The option for compensation of Pupil centroid shift was ON Procedure: The option for compensation of Pupil centroid shift was OFF Drug: installation of Tetracaine 1% Procedure: Photorefractive keratectomy (PRK) Phase 2

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 104 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Single (Participant)
Primary Purpose: Treatment
Official Title: Role of Pupil Centroid Shift Compensation on Lower and Higher Order Aberrations During Photorefractive Keratectomy: An Eye-to-Eye Study
Estimated Study Start Date : February 10, 2019
Estimated Primary Completion Date : June 1, 2019
Estimated Study Completion Date : July 1, 2019

Arm Intervention/treatment
Active Comparator: The right eyes with compensation for Pupil centroid shift Procedure: The option for compensation of Pupil centroid shift was ON
The option for compensation of Pupil centroid shift was ON

Drug: installation of Tetracaine 1%
installation of Tetracaine 1%

Procedure: Photorefractive keratectomy (PRK)
periorbital skin will be prepared with povidone iodine 5%. Iris registration will be performed in all eyes before epithelial removal. Ethylalcohol 20.0% into a 9.0 mm well for 20 seconds will be applied on the central cornea, and then the epithelium of the central 9.0 mm area will be removed by hockey knife. Excimer laser ablation will be performed by Wavelight Allegretto EX500 (Alcon, Fort Worth, TX, USA)

Active Comparator: The left eyes without compensation for Pupil centroid shift Procedure: The option for compensation of Pupil centroid shift was OFF
The option for compensation of Pupil centroid shift was OFF

Drug: installation of Tetracaine 1%
installation of Tetracaine 1%

Procedure: Photorefractive keratectomy (PRK)
periorbital skin will be prepared with povidone iodine 5%. Iris registration will be performed in all eyes before epithelial removal. Ethylalcohol 20.0% into a 9.0 mm well for 20 seconds will be applied on the central cornea, and then the epithelium of the central 9.0 mm area will be removed by hockey knife. Excimer laser ablation will be performed by Wavelight Allegretto EX500 (Alcon, Fort Worth, TX, USA)




Primary Outcome Measures :
  1. Postoperative refractive error [ Time Frame: 2 months ]
    Snellen chart and subjective refraction


Secondary Outcome Measures :
  1. Root Mean Square (RMS) of higher order aberration [ Time Frame: 6 months ]
    wavefront analysis by galilei scan



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Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • myopia
  • myopic astigmatism

Exclusion Criteria:

  • unstable refractive error, age less than 21 years old
  • corneal opacity
  • keratoconus, keratoconus suspects
  • residual corneal stromal thickness less than 350 µm
  • moderate or severe dry eye disease
  • any other ocular pathology other than refractive error

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03844178


Contacts
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Contact: Amir Faramarzi, MD 009822591616 labbafi@hotmail.com

Locations
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Iran, Islamic Republic of
Ophthalmic Research Center Recruiting
Tehran, Iran, Islamic Republic of
Contact: Amir Faramarzi, MD    009822591616    labbafi@hotmail.com   
Sponsors and Collaborators
Shahid Beheshti University of Medical Sciences

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Responsible Party: Zahra Rabbani Khah, Head of ophthalmic research center, Shahid Beheshti University of Medical Sciences
ClinicalTrials.gov Identifier: NCT03844178     History of Changes
Other Study ID Numbers: 97362
First Posted: February 18, 2019    Key Record Dates
Last Update Posted: February 18, 2019
Last Verified: February 2019

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Additional relevant MeSH terms:
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Tetracaine
Anesthetics, Local
Anesthetics
Central Nervous System Depressants
Physiological Effects of Drugs
Sensory System Agents
Peripheral Nervous System Agents