Topography Guided LASIK by Different Protocols for Treatment of Astigmatism

NCT ID: NCT03597906

Last Updated: 2020-01-28

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

COMPLETED

Clinical Phase

NA

Total Enrollment

30 participants

Study Classification

INTERVENTIONAL

Study Start Date

2018-08-15

Study Completion Date

2020-01-20

Brief Summary

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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.

Detailed Description

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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

Conditions

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Refractive Surgery

Study Design

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Allocation Method

RANDOMIZED

Intervention Model

PARALLEL

A prospective, randomized and comparative interventional study
Primary Study Purpose

TREATMENT

Blinding Strategy

DOUBLE

Participants Investigators

Study Groups

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Group A: Manifest

20 eyes will be treated using Contoura, topography guided ablation vision with the standard manifest refraction.

Group Type EXPERIMENTAL

topography guided ablation

Intervention Type PROCEDURE

using the data obtained from the topolyzer for correction of refractive errors specially astigmatism we use 3 different treatment protocols

manifest refraction

Intervention Type PROCEDURE

using for ablation the exact manifest refraction

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).

Group Type EXPERIMENTAL

topography guided ablation

Intervention Type PROCEDURE

using the data obtained from the topolyzer for correction of refractive errors specially astigmatism we use 3 different treatment protocols

partial topography modified refraction

Intervention Type PROCEDURE

partial topography modified refraction means changing only cylinder power and axis in the ablation profile

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).

Group Type EXPERIMENTAL

topography guided ablation

Intervention Type PROCEDURE

using the data obtained from the topolyzer for correction of refractive errors specially astigmatism we use 3 different treatment protocols

full topography modified refraction

Intervention Type PROCEDURE

full topography modified refraction means changing both sphere and cylinder power in the ablation profile

Interventions

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topography guided ablation

using the data obtained from the topolyzer for correction of refractive errors specially astigmatism we use 3 different treatment protocols

Intervention Type PROCEDURE

manifest refraction

using for ablation the exact manifest refraction

Intervention Type PROCEDURE

full topography modified refraction

full topography modified refraction means changing both sphere and cylinder power in the ablation profile

Intervention Type PROCEDURE

partial topography modified refraction

partial topography modified refraction means changing only cylinder power and axis in the ablation profile

Intervention Type PROCEDURE

Eligibility Criteria

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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

1. Estimated postoperative residual stromal bed thickness of less than 300µm.
2. Glaucomatous patients.
3. Patients with keratoconus.
4. Patients with pervious refractive surgery.
5. History of previous ocular trauma or surgery.
6. History of recent herpetic ulcer or viral keratitis.
7. Basement membrane disease, history of recurrent corneal erosions.
8. Sicca syndrome, dry eye.
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Cairo University

OTHER

Sponsor Role lead

Responsible Party

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Fayrouz Aboalazayem

the principal investigator

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Mohmed Hosny, MD

Role: STUDY_DIRECTOR

Cairo University

Locations

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Kasr Alainy

Cairo, , Egypt

Site Status

Countries

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Egypt

Other Identifiers

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N-18-2018

Identifier Type: -

Identifier Source: org_study_id

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