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

NCT03291873 | Completed

• 1 other identifier: 900800700600500400300200100900
• Study Type: interventional
• Target: 104
• Locations: 1 country
• Sites: 2

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.

Conditions

Myopia

Outcome Measures

Primary Outcomes (7)

• 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 Outcomes (5)

• efficacy:ratio of postoperative decimal UDVA to preoperative decimal CDVA

  6 months

• contrast sensitivity

  6 months

• predictability

  6 months

• safety:ratio of mean preoperative decimal CDVA to mean postoperative decimal CDVA

  6 months

• stability

  6 months

Study Arms (2)

topography guided PRK in one eye

ACTIVE COMPARATOR

Topography-guided (placido disk- based) using T-CAT Contoura treatment.

Procedure: PRK

Q-value adjusted ( custom Q) PRK in the other eye

ACTIVE COMPARATOR

The target Q will be estimated according to a nomogram considering the patient's age

Procedure: PRK

Interventions

PRK PROCEDURE

PRK using Alcon-Wavelight Excimer Laser EX 500

Q-value adjusted ( custom Q) PRK in the other eye; topography guided PRK in one eye

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

• 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

Sponsors & Collaborators

• Kasr El Aini Hospital: lead

Study Sites (2)

Eyecare centre

Maadi, Cairo Governorate, Egypt

Location

Dar Al Oyun hospital

Giza, Egypt

Location

MeSH Terms

Conditions

Myopia

Condition Hierarchy (Ancestors)

Refractive Errors; Eye Diseases

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assisstant lecturer Faculty of Medicine Helwan University

Study Record Dates

• First Submitted: August 8, 2017
• First Posted: September 25, 2017
• Study Start: October 25, 2017
• Primary Completion: June 25, 2019
• Study Completion: June 25, 2019
• Last Updated: July 7, 2020

Record last verified: 2020-07

Locations

EG (2)