Pupil Centroid Shift Compensation in Photorefractive Keratectomy Candidates

NCT ID: NCT03844178

Last Updated: 2019-02-18

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

UNKNOWN

Clinical Phase

PHASE2

Total Enrollment

104 participants

Study Classification

INTERVENTIONAL

Study Start Date

2019-02-10

Study Completion Date

2019-07-01

Brief Summary

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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.

Detailed Description

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Conditions

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Pupil Centroid Shift

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

SINGLE_GROUP

Primary Study Purpose

TREATMENT

Blinding Strategy

SINGLE

Participants

Study Groups

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The right eyes with compensation for Pupil centroid shift

Group Type ACTIVE_COMPARATOR

The option for compensation of Pupil centroid shift was ON

Intervention Type PROCEDURE

The option for compensation of Pupil centroid shift was ON

installation of Tetracaine 1%

Intervention Type DRUG

installation of Tetracaine 1%

Photorefractive keratectomy (PRK)

Intervention Type PROCEDURE

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)

The left eyes without compensation for Pupil centroid shift

Group Type ACTIVE_COMPARATOR

The option for compensation of Pupil centroid shift was OFF

Intervention Type PROCEDURE

The option for compensation of Pupil centroid shift was OFF

installation of Tetracaine 1%

Intervention Type DRUG

installation of Tetracaine 1%

Photorefractive keratectomy (PRK)

Intervention Type PROCEDURE

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)

Interventions

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The option for compensation of Pupil centroid shift was ON

The option for compensation of Pupil centroid shift was ON

Intervention Type PROCEDURE

The option for compensation of Pupil centroid shift was OFF

The option for compensation of Pupil centroid shift was OFF

Intervention Type PROCEDURE

installation of Tetracaine 1%

installation of Tetracaine 1%

Intervention Type DRUG

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)

Intervention Type PROCEDURE

Eligibility Criteria

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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
Minimum Eligible Age

18 Years

Maximum Eligible Age

40 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

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Shahid Beheshti University of Medical Sciences

OTHER

Sponsor Role lead

Responsible Party

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Zahra Rabbani Khah

Head of ophthalmic research center

Responsibility Role PRINCIPAL_INVESTIGATOR

Locations

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Ophthalmic Research Center

Tehran, , Iran

Site Status RECRUITING

Countries

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Iran

Central Contacts

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Amir Faramarzi, MD

Role: CONTACT

009822591616

Facility Contacts

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Amir Faramarzi, MD

Role: primary

009822591616

Other Identifiers

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97362

Identifier Type: -

Identifier Source: org_study_id

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