Topography-Guided Customized PRK Versus Q-value Adjusted PRK in Correction of Myopia With or Without Astigmatism

Not Applicable

Completed

• Conditions: Myopia
• Interventions: Procedure: PRK

• Registration Number: NCT03291873
• Lead Sponsor: Kasr El Aini Hospital

Brief Summary

This study will include patients who will undergo PRK in both eyes, for each patient each eye will be randomly allocated to one of 2 procedures:

topography-guided ablation in one eye (group I) and Q-factor customized ablation in the other eye (group II).

Alcon/Wavelight Light Laser Technolo¬gie (GmbH, Erlangen, Germany) will be used for photoablation.

The wavelight Topolyzer (Wavelight AG, Erlan¬gen, Germany)and CSO Sirius scheimpflug camera combined with Placido corneal topography (CSO, Florence,Italy) will be used before and 1, 3 and 6 months after PRK. Refrac¬tive visual outcomes and corneal aberration changes will be compared between the two treatment modalities.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2017-08-08
• Study First Submitted QC: 2017-09-21
• Study First Posted: 2017-09-25
• Study Start: 2017-10-25
• Primary Completion: 2019-06-25
• Study Completion: 2019-06-25
• Status Verified: 2020-07
• Last Update Submitted: 2020-07-01
• Last Update Posted: 2020-07-07

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 104

Inclusion Criteria

• Age more than 18 years
• Myopia with up to -6.5 D with or without astigmatism up to -4.75 D

Exclusion Criteria

• anterior segment abnormalities (ie, cataracts, corneal scarring)
• basement membrane disease
• history of recurrent corneal erosions
• Schirmer's test less than 5 mm
• established or forme fruste keratoconus
• macular or retinal disease
• current use of immunosuppressive therapy
• autoimmune disease
• pregnancy, and lactation

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Q-value adjusted ( custom Q) PRK in the other eye	PRK	The target Q will be estimated according to a nomogram considering the patient's age
topography guided PRK in one eye	PRK	Topography-guided (placido disk- based) using T-CAT Contoura treatment.

Primary Outcome Measures

Name	Time	Method
change in strehl ratio	1,3 and 6 months	by CSO scheimpflug
change in Q value	1,3 and 6 months	assessed by topolyzer
change in corneal wavefront aberrations	1 , 3 and 6 months postoperative	assessed by topolyzer
change in Postoperative spherical equivalent depending on manifest refraction after autorefractometer	1 , 3 and 6 months postoperative
change in visual acuity using snellen chart	1 , 3 and 6 months postoperative
change in Q value anterior at 6mm RMS, RMS of astigmatism, RMS of coma and RMS of spherical aberrations. Strehl ratio : Qvalue,RMS,strehl ratio by CSO Sirius scheimpflug	1,3 and 6months	by CSO Sirius scheimpflug
change in total RMS	1,3 and 6months	by CSO Sirius scheimpflug

Secondary Outcome Measures

Name	Time	Method
stability	6 months	change of more than 0.5D over
predictability	6 months	eyes within 1.0 D of emmetropia
efficacy:ratio of postoperative decimal UDVA to preoperative decimal CDVA	6 months	ratio of postoperative decimal UDVA to preoperative decimal CDVA
contrast sensitivity	6 months	cambridge low contrast sensitivity
safety:ratio of mean preoperative decimal CDVA to mean postoperative decimal CDVA	6 months	ratio of mean preoperative decimal CDVA to mean postoperative decimal CDVA

Trial Locations

Locations (2)

Eyecare centre; 🇪🇬 Maadi, Cairo, Egypt

Dar Al Oyun hospital; 🇪🇬 Giza, Egypt