Photorefractive KeratectomyNCT06748599
A Comparative Study Between Laser and Manual Removal of Corneal Epithelium for Photorefractive Keratectomy
An observational study of Photorefractive Keratectomy, run by Assiut University.
Trial summary
Photorefractive keratectomy (PRK) is a laser eye surgery used to ablate the corneal stroma to correct visual refractive errors . PRK was developed in 1983 by Dr. Steven Trokel and colleagues and first performed in 1987 by Dr. Theo Seiler in Berlin. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Photorefractive Keratectomy
- How many people
- 64 participants
- Where
- No sites listed yet
- Study dates
- 1 Jan 2025to 1 Mar 2026
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients in the age group between 18 and 45 years will be included in this study. Subjects selected, which will consist of patients with myopia ( less than - 6 D ) will be divided into 2 groups.
Who may be able to join
- • Age : older than 18 years old .
- Gender: Include both males and females.
- Stable refraction for at least 12 months .
- Intraocular pressure less than 21mmHg.
- A period without wearing contact lenses (more than 4 days for soft , more than 2 weeks for rigid contact lenses )
- No history of any Autoimmune disease .
- The refractive error must be one that can be treated by PRK
Who cannot join
- _ patients with any eye disease (significant cataract or unstable glaucoma )
- uncontrolled external disease such as blepharitis, dry eye syndrome, and atopy/allergy.
- patients with Keratoconus and other abnormalities of the cornea such as corneal ectasias , thinning , edema , interstitial or neurotrophic keratitis and extensive vascularisation .
- Patients with active systemic connective tissue disease such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA)
- Ineligibility for Surgery: Exclude patients who are not suitable candidates for surgery .
- Consider excluding pregnant or lactating women .
- Patients unwilling to participate in the study .
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Photorefractive keratectomy (PRK) is a laser eye surgery used to ablate the corneal stroma to correct visual refractive errors . PRK was developed in 1983 by Dr. Steven Trokel and colleagues and first performed in 1987 by Dr. Theo Seiler in Berlin. After receiving approval by the US Food and Drug Administration (FDA) in 1996, PRK was briefly the preferred surgical treatment of ametropia as it provided more predictable and stable results than incisional keratotomy. However, the number of PRK procedures fell in the late 1990s with the growing popularity of laser in situ keratomileusis (LASIK).
The study aims to compare the visual and refractive outcomes along with the pain score and patient satisfaction after photorefractive keratectomy in patients who underwent transepithelial or mechanical removal technique
Read the detailed description
Today, LASIK remains the most commonly performed visual refractive surgery; nonetheless, there remain select situations in which PRK may be preferable, such as post penetrating keratoplasty , in thin corneas , irregular topographies , treatment of some LASIK flap complications or residual refractive errors after LASIK, It is also indicated in patients that have a high risk for traumatic postoperative flap dislocation as athletes .Several modifications of the traditional PRK have been introduced in an attempt to overcome drawbacks of postoperative pain and corneal haze and irregular epithelial healing associated with the procedure .PRK employs an excimer laser ablation of the anterior corneal stroma beneath the epithelium .The first step of PRK is the removal of the superficial epithelial cells, which may be through a variety of techniques such as mechanical removal with spatula , application of a diluted alcohol solution , use a rotatory brush or transepithelial laser . Each of these techniques should be performed quickly to avoid desiccation and skillfully to avoid nicking Bowman's layer.
The first technique, Mechanical debridement, involves using a blunt spatula to scrape off epithelium from the periphery toward the center. The next step is wiping a sponge hydrated with balanced salt solution (BSS) or carboxymethylcellulose 0.5% across the cornea. This technique benefits from not depending on laser optics; however, mechanical debridement tends to be a lengthy process in inexperienced surgeons, which subsequently increases patient anxiety and reduces stromal hydration .
In the late 1990s, Transepithelial PRK was introduced as an alternative laser-assisted method for epithelial removal . The advantages of this method have been cited as minimum surgical time, zero contact of laser machine with corneal surface, shorter time for surface healing and visual correction, and decreased post-operative discomfort and dry eyes,this technique is popular among patients but requires a longer time for mastery.
- Conditions
- Photorefractive Keratectomy
- Keywords
- removal of corneal epithelium
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| group A | patients who are assigned for transepithelial PRK | |
| group B | patients who are mechanical PRK using a spatula |
What is being measured
The primary outcome is the main question the study is designed to answer.
visual acuity
best corrected visual acuity (BCVA) will be observed for at least 6 months postoperatively.
Measured: 6 month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Dec 2024
- Study start1 Jan 2025 (estimated)
- Primary completion1 Jan 2026 (estimated)
- Study completion1 Mar 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (5)Papers the sponsor has linked to this study.
- Other trials for Photorefractive KeratectomyStudies of the same condition, open and under way.
- More trials run by Assiut UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 64 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Assiut University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Sandra Adel Nashed, Assiut University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06748599
- Sponsor's protocol ID
- Laser Vs Manual Keratectomy
- Status last verified
- Dec 2024
- First submitted
- 19 Dec 2024
- Last updated
- 27 Dec 2024
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Edwards JD, Bower KS, Sediq DA, Burka JM, Stutzman RD, Vanroekel CR, Kuzmowych CP, Eaddy JB. Effects of lotrafilcon A and omafilcon A bandage contact lenses on visual outcomes after photorefractive keratectomy. J Cataract Refract Surg. 2008 Aug;34(8):1288-94. doi: 10.1016/j.jcrs.2008.04.024.
PubMed 18655978Gamaly TO, El Danasoury A, El Maghraby A. A prospective, randomized, contralateral eye comparison of epithelial laser in situ keratomileusis and photorefractive keratectomy in eyes prone to haze. J Refract Surg. 2007 Nov;23(9 Suppl):S1015-20. doi: 10.3928/1081-597X-20071102-07.
PubMed 18047000Diakonis VF, Pallikaris A, Kymionis GD, Markomanolakis MM. Alterations in endothelial cell density after photorefractive keratectomy with adjuvant mitomycin. Am J Ophthalmol. 2007 Jul;144(1):99-103. doi: 10.1016/j.ajo.2007.03.039. Epub 2007 May 23.
PubMed 17509511Barreto J Jr, Netto MV, Reis A, Nakano M, Alves MR, Bechara SJ. Topography-guided (NIDEK customized aspheric treatment zone) photorefractive keratectomy with mitomycin C after penetrating keratoplasty for keratoconus: case report. J Refract Surg. 2009 Jan;25(1 Suppl):S131-5. doi: 10.3928/1081597X-20090115-10.
PubMed 19248542Alio JL, Soria FA, Abbouda A, Pena-Garcia P. Fifteen years follow-up of photorefractive keratectomy up to 10 D of myopia: outcomes and analysis of the refractive regression. Br J Ophthalmol. 2016 May;100(5):626-32. doi: 10.1136/bjophthalmol-2014-306459. Epub 2015 Sep 10.
PubMed 26359339
Study at a glance
From the registry record, last updated by the sponsor on 27 Dec 2024. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Comparative Study Between Laser and Manual Removal of Corneal Epithelium for Photorefractive Keratectomy
- ClinicalTrials.gov ID
- NCT06748599
- Acronym / sponsor ID
- Laser Vs Manual Keratectomy
- Conditions
- Photorefractive Keratectomy
- Keywords
- removal of corneal epithelium
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 64 participants (estimated)
- Lead sponsor
- Assiut UniversityUniversity, hospital or other
- Study start
- 1 Jan 2025 (estimated)
- Primary completion
- 1 Jan 2026 (estimated)
- Study completion
- 1 Mar 2026 (estimated)
- First posted
- 27 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Photorefractive keratectomy (PRK) is a laser eye surgery used to ablate the corneal stroma to correct visual refractive errors . PRK was developed in 1983 by Dr. Steven Trokel and colleagues and first performed in 1987 by Dr. Theo Seiler in Berlin. After receiving approval by the US Food and Drug Administration (FDA) in 1996, PRK was briefly the preferred surgical treatment of ametropia as it provided more predictable and stable results than incisional keratotomy. However, the number of PRK procedures fell in the late 1990s with the growing popularity of laser in situ keratomileusis (LASIK).
The study aims to compare the visual and refractive outcomes along with the pain score and patient satisfaction after photorefractive keratectomy in patients who underwent transepithelial or mechanical removal technique
Detailed description
Today, LASIK remains the most commonly performed visual refractive surgery; nonetheless, there remain select situations in which PRK may be preferable, such as post penetrating keratoplasty , in thin corneas , irregular topographies , treatment of some LASIK flap complications or residual refractive errors after LASIK, It is also indicated in patients that have a high risk for traumatic postoperative flap dislocation as athletes .Several modifications of the traditional PRK have been introduced in an attempt to overcome drawbacks of postoperative pain and corneal haze and irregular epithelial healing associated with the procedure .PRK employs an excimer laser ablation of the anterior corneal stroma beneath the epithelium .The first step of PRK is the removal of the superficial epithelial cells, which may be through a variety of techniques such as mechanical removal with spatula , application of a diluted alcohol solution , use a rotatory brush or transepithelial laser . Each of these techniques should be performed quickly to avoid desiccation and skillfully to avoid nicking Bowman's layer.
The first technique, Mechanical debridement, involves using a blunt spatula to scrape off epithelium from the periphery toward the center. The next step is wiping a sponge hydrated with balanced salt solution (BSS) or carboxymethylcellulose 0.5% across the cornea. This technique benefits from not depending on laser optics; however, mechanical debridement tends to be a lengthy process in inexperienced surgeons, which subsequently increases patient anxiety and reduces stromal hydration .
In the late 1990s, Transepithelial PRK was introduced as an alternative laser-assisted method for epithelial removal . The advantages of this method have been cited as minimum surgical time, zero contact of laser machine with corneal surface, shorter time for surface healing and visual correction, and decreased post-operative discomfort and dry eyes,this technique is popular among patients but requires a longer time for mastery.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| group A | – | –patients who are assigned for transepithelial PRK |
| group B | – | –patients who are mechanical PRK using a spatula |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients in the age group between 18 and 45 years will be included in this study. Subjects selected, which will consist of patients with myopia ( less than - 6 D ) will be divided into 2 groups.
Key inclusion criteria (7 listed)
- • Age : older than 18 years old .
Key exclusion criteria (7 listed)
- _ patients with any eye disease (significant cataract or unstable glaucoma )
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
visual acuity
Time frame: 6 month
best corrected visual acuity (BCVA) will be observed for at least 6 months postoperatively.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Dec 2024.
- Results publication: PubMed 18655978Edwards JD, Bower KS, Sediq DA, Burka JM, Stutzman RD, Vanroekel CR, Kuzmowych CP, Eaddy JB. Effects of lotrafilcon A and omafilcon A bandage contact lenses on visual outcomes after photorefractive keratectomy. J Cataract Refract Surg. 2008 Aug;34(8):1288-94. doi: 10.1016/j.jcrs.2008.04.024.
- Results publication: PubMed 18047000Gamaly TO, El Danasoury A, El Maghraby A. A prospective, randomized, contralateral eye comparison of epithelial laser in situ keratomileusis and photorefractive keratectomy in eyes prone to haze. J Refract Surg. 2007 Nov;23(9 Suppl):S1015-20. doi: 10.3928/1081-597X-20071102-07.
- Results publication: PubMed 17509511Diakonis VF, Pallikaris A, Kymionis GD, Markomanolakis MM. Alterations in endothelial cell density after photorefractive keratectomy with adjuvant mitomycin. Am J Ophthalmol. 2007 Jul;144(1):99-103. doi: 10.1016/j.ajo.2007.03.039. Epub 2007 May 23.
- Results publication: PubMed 19248542Barreto J Jr, Netto MV, Reis A, Nakano M, Alves MR, Bechara SJ. Topography-guided (NIDEK customized aspheric treatment zone) photorefractive keratectomy with mitomycin C after penetrating keratoplasty for keratoconus: case report. J Refract Surg. 2009 Jan;25(1 Suppl):S131-5. doi: 10.3928/1081597X-20090115-10.
- Results publication: PubMed 26359339Alio JL, Soria FA, Abbouda A, Pena-Garcia P. Fifteen years follow-up of photorefractive keratectomy up to 10 D of myopia: outcomes and analysis of the refractive regression. Br J Ophthalmol. 2016 May;100(5):626-32. doi: 10.1136/bjophthalmol-2014-306459. Epub 2015 Sep 10.
- Individual participant dataSharing planned: Undecided
Related trials for Photorefractive Keratectomy
Active, not recruitingObservational study
Visual and Refractive Outcomes Following Stream Light Photorefractive Keratectomy (55μm Epithelial Removal) Versus Conventional Photorefractive Keratectomy
Photorefractive Keratectomy
Not yet recruiting
Comparison of Ketorolac Tromethamine 0.5%-Soaked Bandage Contact Lenses Versus Non-Medicated Bandage Contact Lenses on Postoperative Pain Control After Photorefractive Keratectomy
Refraction Error, Photorefractive Keratectomy
Not yet recruiting
Analysis of The Outcomes of Therapeutic Photorefractive Keratectomy Combined With Prophylactic Accelerated Cross-Linking (PRK-Plus), for Treatment of Thin Suspicious Cornea
Thin Suspicious Cornea
Recruiting
CONTOURA vs WFO Ablation PRK & LASIK
Refractive Surgery
Not yet recruiting
Effectiveness and Safety of the TENEO 317 Model 2 Excimer Laser to Treat Myopia With or Without Astigmatism by Transepithelial Photorefractive Keratectomy
Myopia
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Questions about this trial
What is this clinical trial studying?
An observational study of Photorefractive Keratectomy, run by Assiut University.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 27 Dec 2024. Status can change between updates, so confirm with the study contact before making plans.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Sandra Adel Nashed, resident doctor (+201276485120, sandraadelnashed0@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
visual acuity (time frame: 6 month). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06748599, which also lists 5 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 27 Dec 2024.