Outcomes of a New Trans-epithelial Photorefractive Keratectomy (Streamlight PRK) Compared to Conventional PRK Procedures

July 19, 2021 updated by: Mahmoud Abdel-Radi, Assiut University
Photorefractive keratectomy (PRK) involves mechanical or alcohol assisted debridement of the epithelium that leads to potential basement membrane (BM) injury ,with resultant more significant haze and pain compared to laser assisted epithelial removal known as 2 step trans-epithelial PRK (PTK-PRK). Our study is focusing on comparing the outcomes of the conventional 2 step trans-epithelial PTK-PRK to the new single step trans-epithelial PRK (StreamLight PRK, Alcon lab, TX, USA).

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Photorefractive keratectomy (PRK) is nowadays one of the commonest refractive procedures in laser vision correction (LVC). PRK differs from laser in situ keratomileusis (LASIK) in that it's a flapless procedure involving the removal of corneal epithelium with different techniques including manual removal , alcohol assisted removal or excimer laser assisted removal with phototherapeutic keratectomy (PTK). Mechanical or alcohol assisted debridement of the epithelium may lead to potential basement membrane (BM) injury ,with resultant more significant haze and pain compared to laser assisted epithelial removal known as 2 step trans-epithelial PRK (PTK-PRK).

Single step trans-epithelial PRK allows removing the epithelium and stroma in a single step with a single ablation profile.

Previous studies paid particular attention for comparing the 2 step PTK-PRK procedure or the new single step PRK procedure to the conventional PRK procedures involving epithelial removal whether manual or alcohol assisted.

The aim of this study is to focus on comparing the different outcomes of the new single step Trans-epithelial PRK (StreamLight Technology) versus the routine 2 step PTK-PRK in terms of postoperative vision, epithelial healing, pain scoring and haze evaluation.

Study Type

Interventional

Enrollment (Actual)

50

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Egypt
      • Assiut, Egypt
        • TIBA Eye Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

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: Candidates for Laser vision correction (LVC) with

    1. Myopia up to -6 diopters
    2. Myopic astigmatism up to -4 diopters
    3. Corneal thinnest location ≥ 500 um and a residual stromal bed ≥ 300um.

  • Exclusion criteria

    1. Patients not candidates for LVC.
    2. Hyperopic patients.
    3. Systemic disease that contraindicates LVC.
    4. Intra- or post-operative complications.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Patients planned to undergo conventional 2 step trans-epithelial PTK-PRK

Patients planned to undergo:

  1. Epithelial removal using Phototherapeutic Keratectomy PTK as a separate step.
  2. Laser Vision Correction using Excimer laser wavefront optimized technology.
Procedure: Photorefractive keratectomy (PRK)
Photorefractive keratectomy (PRK) is a surgical procedure used by ophthalmic surgeons to treat patients presented with refractive errors and involves corneal epithelial removal followed by application of excimer laser to correct different refractive errors including Myopia, Hyperopia and Astigmatism.
Active Comparator: Patients planned to undergo the new single step trans-epithelial (StreamLight) PRK.

Patients planned to undergo:

Epithelial removal and Excimer wavefront optimized Laser Vision Correction in a single step using the new StreamLight Technology.
Procedure: Photorefractive keratectomy (PRK)
Photorefractive keratectomy (PRK) is a surgical procedure used by ophthalmic surgeons to treat patients presented with refractive errors and involves corneal epithelial removal followed by application of excimer laser to correct different refractive errors including Myopia, Hyperopia and Astigmatism.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Uncorrected distant visual acuity (UDVA)
Time Frame: 6 months
Visual acuity measurement using Snellen's Acuity Chart and will be expressed as decimal notation
6 months
Postoperative Refraction (Spherical equivalent)
Time Frame: 6 months
Measured by Topcon Auto-Keratorefractometer
6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Epithelial healing duration
Time Frame: 2 weeks
Time for the epithelium to heal reported in days after PRK procudre
2 weeks
Postoperative pain
Time Frame: 1 week
Verbal Rating Scale(a series of words commonly used to describe pain (0: no pain, 1: mild pain, 2: moderate pain, 3: severe pain, 4: disabling pain)
1 week
Postoperative Haze
Time Frame: 3 months

Corneal Haze scoring using slit lamp bio-microscopy according to Fantes scoring system:

0: No haze, completely clear cornea

0.5: Trace haze seen with careful oblique illumination

  1. Haze not interfering with visibility of fine iris details
  2. Mild obscuration of iris details
  3. Moderate obscuration of the iris and lens
  4. Complete opacification of the stroma in the area of the scar, anterior chamber is totally obscured
3 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Assiut University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2020

Primary Completion (Actual)

June 30, 2021

Study Completion (Actual)

June 30, 2021

Study Registration Dates

First Submitted

January 8, 2021

First Submitted That Met QC Criteria

January 12, 2021

First Posted (Actual)

January 14, 2021

Study Record Updates

Last Update Posted (Actual)

July 20, 2021

Last Update Submitted That Met QC Criteria

July 19, 2021

Last Verified

July 1, 2021

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TEPRK

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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