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

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

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.

Study Overview

• Status: Completed
• Conditions: Myopia
• Intervention / Treatment: Procedure: PRK

• Study Type: Interventional
• Enrollment (Actual): 104
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Giza, Egypt
    • Dar Al Oyun hospital
  • Cairo
    • Maadi, Cairo, Egypt
      • Eyecare centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: SINGLE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: topography guided PRK in one eye; Topography-guided (placido disk- based) using T-CAT Contoura treatment.	Procedure: PRK; PRK using Alcon-Wavelight Excimer Laser EX 500
ACTIVE_COMPARATOR: Q-value adjusted ( custom Q) PRK in the other eye; The target Q will be estimated according to a nomogram considering the patient's age	Procedure: PRK; PRK using Alcon-Wavelight Excimer Laser EX 500

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 corneal wavefront aberrations	assessed by topolyzer	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	by CSO Sirius scheimpflug	1,3 and 6months
change in total RMS	by CSO Sirius scheimpflug	1,3 and 6months
change in strehl ratio	by CSO scheimpflug	1,3 and 6 months
change in Q value	assessed by topolyzer	1,3 and 6 months

Secondary Outcome Measures

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

Collaborators and Investigators

• Sponsor: Kasr El Aini Hospital

Study record dates

Study Major Dates

• Study Start (ACTUAL): October 25, 2017
• Primary Completion (ACTUAL): June 25, 2019
• Study Completion (ACTUAL): June 25, 2019

Study Registration Dates

• First Submitted: August 8, 2017
• First Submitted That Met QC Criteria: September 21, 2017
• First Posted (ACTUAL): September 25, 2017

Study Record Updates

• Last Update Posted (ACTUAL): July 7, 2020
• Last Update Submitted That Met QC Criteria: July 1, 2020
• Last Verified: July 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Refractive Errors; Astigmatism; Myopia
• Other Study ID Numbers: 900800700600500400300200100900

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No