- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT03597906
Topography Guided LASIK by Different Protocols for Treatment of Astigmatism
Comparison of the Outcome of Topography Modified Refraction Correction to Standard Clinical Refraction Correction in Myopic Astigmatic Topography-guided LASIK
Background and Rationale:
LASIK has been among the highest satisfaction rates of surgical procedures, ranging from 82%-98%. Different ablation profiles have been developed over the years. The purpose of this study is to validate this novel measurement by comparing the visual outcomes when the TMR is used in myopic astigmatic LASIK to using the standard manifest refraction or the Topolyzer measurements alone.
Objectives :
To evaluate the safety, efficacy and predictability of topography-guided myopic LASIK with three different refraction treatment strategies.
Study Overview
Status
Conditions
Detailed Description
Candidates for refractive surgery above 18 years with myopic astigmatism and no previous ocular surgery.
Sample size 60 eyes. surgery:
- 60 eyes of myopic topography-guided LASIK procedures with the same refractive platform (FS200 femtosecond to create a flap between90: 110 μm with diameter 8:9 mm and EX500 excimer lasers) will be randomized for treatment as follows:
- Group A: 20 eyes will be treated using Contoura vision with the standard manifest refraction.
- Group B: 20 eyes will be treated with Contoura vision using the topographic astigmatic power and axis and without change in the spherical power (using the same spherical power as the manifest refraction).
- Group C [TMR]: 20 eyes will be treated with Contoura vision using the topographic astigmatic power and axis and modifying the spherical power to obtain the same spherical equivalent as the manifest refraction. This is done by subtracting half of the difference between topographic astigmatic power and the manifest astigmatic power from the spherical power (topography-modified treatment refraction).
- The standard postoperative treatment is combined steroids and antibiotics eye drops 5 times daily for one week ,then three times daily for three days and lubricant eye drops 5 times daily for six months.
Postoperatively, the patients will be examined at 1 week, 1 month and 3 months. All postoperative follow-up visits included measurement of UDVA, CDVA (if indicated) and refraction, besides full ophthalmological examination and performing pentacam and topolyzer after 3 months
Study Type
Enrollment (Actual)
Phase
- Not Applicable
Contacts and Locations
Study Locations
-
-
-
Cairo, Egypt, 11562
- Kasr Alainy
-
-
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- Stable refractive error: Myopic astigmatism ≥ -1.5 D
- Valid Topolyzer maps (at least four out of eight right maps with green analyzed area and the registration box is green).
Exclusion Criteria:
- Estimated postoperative residual stromal bed thickness of less than 300µm.
- Glaucomatous patients.
- Patients with keratoconus.
- Patients with pervious refractive surgery.
- History of previous ocular trauma or surgery.
- History of recent herpetic ulcer or viral keratitis.
- Basement membrane disease, history of recurrent corneal erosions.
- Sicca syndrome, dry eye.
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Treatment
- Allocation: Randomized
- Interventional Model: Parallel Assignment
- Masking: Double
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
---|---|
Experimental: Group A: Manifest
20 eyes will be treated using Contoura, topography guided ablation vision with the standard manifest refraction.
|
using the data obtained from the topolyzer for correction of refractive errors specially astigmatism we use 3 different treatment protocols
using for ablation the exact manifest refraction
|
Experimental: Group B: partial TMR
20 eyes will be treated with Contoura vision, topography guided ablation using the topographic astigmatic power and axis and without change in the spherical power (using the same spherical power as the manifest refraction).
|
using the data obtained from the topolyzer for correction of refractive errors specially astigmatism we use 3 different treatment protocols
partial topography modified refraction means changing only cylinder power and axis in the ablation profile
|
Experimental: Group C: Full TMR
20 eyes will be treated with Contoura vision, topography guided ablation using the topographic astigmatic power and axis and modifying the spherical power to obtain the same spherical equivalent as the manifest refraction.
This is done by subtracting half of the difference between topographic astigmatic power and the manifest astigmatic power from the spherical power (topography-modified treatment refraction).
|
using the data obtained from the topolyzer for correction of refractive errors specially astigmatism we use 3 different treatment protocols
full topography modified refraction means changing both sphere and cylinder power in the ablation profile
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
post operative residual astigmatism
Time Frame: 3 months
|
measuring the post operative residual astigmatism and comparison between the 3 group to reach to the most accurate protocol.
|
3 months
|
Secondary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
---|---|---|
measurement of the postoperative unaided visual acuity
Time Frame: 3 months
|
measurement of the postoperative unaided visual acuity and comparison between the 3 group to reach to the most accurate protocol.
|
3 months
|
Collaborators and Investigators
Sponsor
Investigators
- Study Director: Mohmed Hosny, MD, Cairo University
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- N-18-2018
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
product manufactured in and exported from the U.S.
This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.
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