Topography Guided LASIK by Different Protocols for Treatment of Astigmatism

Not Applicable

Completed

• Conditions: Refractive Surgery
• Interventions: Procedure: topography guided ablation; Procedure: manifest refraction; Procedure: partial topography modified refraction; Procedure: full topography modified refraction

• Registration Number: NCT03597906
• Lead Sponsor: Cairo University

Brief Summary

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

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 Timeline

• Study First Submitted: 2018-06-21
• Study First Submitted QC: 2018-07-22
• Study First Posted: 2018-07-24
• Study Start: 2018-08-15
• Primary Completion: 2019-11-15
• Status Verified: 2020-01
• Study Completion: 2020-01-20
• Last Update Submitted: 2020-01-26
• Last Update Posted: 2020-01-28

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 30

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).

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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.

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group A: Manifest	manifest refraction	20 eyes will be treated using Contoura, topography guided ablation vision with the standard manifest refraction.
Group A: Manifest	topography guided ablation	20 eyes will be treated using Contoura, topography guided ablation vision with the standard manifest refraction.
Group B: partial TMR	topography guided ablation	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 B: partial TMR	partial topography modified refraction	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 C: Full TMR	topography guided ablation	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 C: Full TMR	full topography modified refraction	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).

Primary Outcome Measures

Name	Time	Method
post operative residual astigmatism	3 months	measuring the post operative residual astigmatism and comparison between the 3 group to reach to the most accurate protocol.

Secondary Outcome Measures

Name	Time	Method
measurement of the postoperative unaided visual acuity	3 months	measurement of the postoperative unaided visual acuity and comparison between the 3 group to reach to the most accurate protocol.

Trial Locations

Locations (1)

Kasr Alainy; 🇪🇬 Cairo, Egypt