Pupil Centroid Shift Compensation in Photorefractive Keratectomy Candidates
Role of Pupil Centroid Shift Compensation on Lower and Higher Order Aberrations During Photorefractive Keratectomy: An Eye-to-Eye Study
1 other identifier
interventional
104
1 country
1
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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P50-P75 for phase_2
Started Feb 2019
Shorter than P25 for phase_2
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
February 2, 2019
CompletedStudy Start
First participant enrolled
February 10, 2019
CompletedFirst Posted
Study publicly available on registry
February 18, 2019
CompletedPrimary Completion
Last participant's last visit for primary outcome
June 1, 2019
CompletedStudy Completion
Last participant's last visit for all outcomes
July 1, 2019
CompletedFebruary 18, 2019
February 1, 2019
4 months
February 2, 2019
February 13, 2019
Conditions
Outcome Measures
Primary Outcomes (1)
Postoperative refractive error
Snellen chart and subjective refraction
2 months
Secondary Outcomes (1)
Root Mean Square (RMS) of higher order aberration
6 months
Study Arms (2)
The right eyes with compensation for Pupil centroid shift
ACTIVE COMPARATORThe left eyes without compensation for Pupil centroid shift
ACTIVE COMPARATORInterventions
The option for compensation of Pupil centroid shift was ON
The option for compensation of Pupil centroid shift was OFF
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. Excimer laser ablation will be performed by Wavelight Allegretto EX500 (Alcon, Fort Worth, TX, USA)
Eligibility Criteria
You may qualify if:
- myopia
- myopic astigmatism
You may not qualify if:
- 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
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (1)
Ophthalmic Research Center
Tehran, Iran
MeSH Terms
Interventions
Intervention Hierarchy (Ancestors)
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- phase 2
- Allocation
- RANDOMIZED
- Masking
- SINGLE
- Who Masked
- PARTICIPANT
- Purpose
- TREATMENT
- Intervention Model
- SINGLE GROUP
- Sponsor Type
- OTHER
- Responsible Party
- PRINCIPAL INVESTIGATOR
- PI Title
- Head of ophthalmic research center
Study Record Dates
First Submitted
February 2, 2019
First Posted
February 18, 2019
Study Start
February 10, 2019
Primary Completion
June 1, 2019
Study Completion
July 1, 2019
Last Updated
February 18, 2019
Record last verified: 2019-02