Refractive ErrorsNCT04684888
Femto-flap Versus SBK Flap,Predictability and Variability
A study testing Visumax Femto-flap and Sub Bowman's keratomileusis (SBK)-flap in people with Refractive Errors and Refractive Surgery, run by Suzan A Rattan at 1 site in Iraq.
Trial summary
Laser Insitu keratomileusis (LASIK) has become the most popular procedure for refractive error correction. Lasik flap creation is the first and critical step during LASIK surgery because of its consensual effect on a residual stromal bed, corneal biomechanics, and hence the future risk of ectasia⁴.In the current… Read more about this study
- Who is it for?
- Ages 20 to 38 yearsHealthy volunteers can take part
- Conditions the study is for
- Refractive Errors, Refractive Surgery
- What is being tested?
- Visumax Femto-flap and Sub Bowman's keratomileusis (SBK)-flap
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- 1 siteIraq
- Study dates
- 1 Jan 2019to 30 May 2021
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 20 to 38 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Having refractive errors range from -2 to- 6 DS and from -1 to -3.00DC.
- They have stable refraction for at least one year prior to surgery.
- Normal topography by Placido-Scheimpflug (Sirius, Costruzione Strumenti Oftalmici, Florence, Italia) and normal corneal epithelial map by Anterior segment-OCT system (Optovue Inc, Fremont, California, USA)
Who cannot join
- Patient with suspicious topography and or corneal epithelial map.
- Patient with corneal pachymetry below 500µm.
- Patients who have a history of previous ocular surgery or trauma.
- Patient with a current or previous history of herpes simplex or herpes zoster.
- Patient with severe dry eye, diabetes, thyrotoxicosis, and connective tissue diseases.
- Patient with Combined ocular diseases like retinal dystrophy or glaucoma.
Show all 9Show fewer
- Patient with a history of contact lenses use was meant to stop the use of soft contact lenses for at least 2 weeks or hard type for at least 4 weeks before topography and other investigations were done.
- Patient who refrains from the required follow-up visits; have been excluded from the study.
- -
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Comparison of Corneal Flap Thickness Using Visumax Femto-Lasik With SubBowman Keratomileusis (SBK) Microkeratome
Laser Insitu keratomileusis (LASIK) has become the most popular procedure for refractive error correction. Lasik flap creation is the first and critical step during LASIK surgery because of its consensual effect on a residual stromal bed, corneal biomechanics, and hence the future risk of ectasia⁴.In the current study, we compared the Visumax FSL flap thickness predictability, accuracy, and variability with the flap created by single-use Moria SBK microkeratome.
Read the detailed description
Flap creation techniques have evolved from the old manual procedure of mechanical microkeratome to the automated one with the use of microkeratome and more recently to Femto-laser procedure using a variety of machines.
Authors have reported that the primary vision nearly the same despite the different methods of flap creation in the first 6 months post LASER vision correction. Others have reported that a thinner flap is associated with better primary vision and refractive outcomes. SBK (Sub Bowman Keratomileusis), is a procedure in which the Lasik flap is thinner, and has the advantage of leaving a sufficient stromal bed for safer excimer Laser ablation.
There are five types of femtosecond Laser that were already approved currently for Lasik flap creation.
The Zeiss (Visumax FSL ) which has been used in the current study uses 1043 nm, a repetition rate of 500 kHz, and 220-580 femtoseconds pulse duration. Each laser pulse produces micro-photo disruption in the tissue, contiguous few microns sized photo disruptions will create a continuous cut in the corneal tissue at precise preset position and depth.
In the current study, the Visumax flap thickness predictability, accuracy, and variability were compared with the flap created by a single-use Moria SBK microkeratome.
- Conditions
- Refractive Errors, Refractive Surgery
- Being tested
- Visumax Femto-flap, Sub Bowman's keratomileusis (SBK)-flap
- Keywords
- Visumax, femtolasik, Sub Bowman keratomileusis(SBK), LASIK
- Medical subject headings
- Refractive Errors
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Visumax Femto-flapProcedure or surgery
Under topical anesthesia [Tetracaine eye drop 0.5%]. A-90 µm thick flap was done by using Visumax femtosecond laser. The flap hinge was set to be nasally placed. A nasal-hinge flap with 90 µm thickness, 8.8 mm flap diameter, and 90º side cut angles were created with 500 kHz Visumax FSL, 160 nJ energy [Carl Zeiss, Meditec, Germany]. The sphero- cylindrical refractive corrections with optical zone 6.5 mm and ablation zone 8.0 mm were done by excimer laser operating system [Carl Zeiss, Meditec, MEL 90, Germany]. Automatic iris registration and pupil-tracking system were activated before photoablation. The patient's eyes were examined postoperatively on a slit-lamp biomicroscope and all treatments that were given for home use have been explained in terms of frequency of instillation, possible side effects, and benefits before discharging them on the same day.
Follow up visits were scheduled clearly on printed patients' discharging cards.
Sub Bowman's keratomileusis (SBK)-flapProcedure or surgery
Under topical anesthesia [Tetracaine eye drop 0.5%] .A-90µm flaps done using Maria one use plus SBK mechanical microkeratome with a nasal located hinge. The sphero- cylindrical refractive corrections with optical zone 6.5 mm and ablation zone 8.0 mm were done by excimer laser operating system [Carl Zeiss, Meditec, MEL 90, Germany]. Automatic iris registration and pupil-tracking system were activated before photoablation. The patient's eyes were examined postoperatively on a slit-lamp biomicroscope and all treatments that were given for home use have been explained in terms of the frequency of instillation, possible side effects, and benefits before discharging them on the same day.
Follow up visits were scheduled clearly on printed patients' discharging cards
.
| Study group | Role | What they receive |
|---|---|---|
| Visumax Femto-flap | Active comparator | Fifty eyes of fifty patients with age range 20-38 years, with myopic astigmatism refractive errors, ranged from -2 to- 6 DS and from -1 to -3.00DC, with stable refraction for at least one year before the surgery, normal corneal topography, anterior and posterior segments examinations. Refractive surgery was planned for both eyes and they chose the Visumax Femto-LASIK after a complete explanation of all the possible complications, costs, and differences. The right eye of each patient was taken for analysis, LASIK flap thickness was measured six months after the procedures using the anterior segment OCT, at seven points (one central and 3 points at each side of the horizontal meridian). The three nasal points were located (1mm, 2mm, 3mm respectively) from the center, and the remaining three temporal points located again ( 1mm, 2mm, 3mm) from the center. Receives: Procedure: Visumax Femto-flap |
| Sub Bowman's keratomileusis (SBK )-Flap group | Active comparator | Fifty eyes of fifty patients with age range 20-38 years, with myopic astigmatism refractive errors, ranged from -2 to- 6 DS and from -1 to -3.00DC, with stable refraction for at least one year before the surgery, normal corneal topography, anterior and posterior segments examinations. They chose LASIK with mechanical SBK microkeratome surgical approach to be their refractive surgery for both eyes after all the possible complications, costs and differences had been explained clearly. The right eye of each patient was taken for analysis, LASIK flap thickness was measured six months after the procedures using the anterior segment OCT, at seven points (one central and 3 points at each side of the horizontal meridian). The three nasal points were located (1mm, 2mm, 3mm respectively) from the center, and the remaining three temporal points located again ( 1mm, 2mm, 3mm) from the center. Receives: Procedure: Sub Bowman's keratomileusis (SBK)-flap |
What is being measured
The primary outcome is the main question the study is designed to answer.
Right eye corneal flap thickness was measured by optical coherence tomography(OCT).
The lasik flap thickness in the right eye in both groups were measured six months after the procedures using non touch method by anterior segment OCT without instillation of topical anaesthesia, at seven points in each eye (one central and 3 points at each sides of horizontal meridian).The three nasal points were located (1mm, 2mm, 3mm respectively) from the center and remaining three temporal points located again ( 1mm, 2mm, 3mm) from the center. Data from both groups were comparing to evaluate predictability and variability of the flap thickness.
Measured: 6-months postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Dec 2020
- Study start1 Jan 2019
- Primary completion30 Sep 2020
- Study completion30 May 2021
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Refractive ErrorsStudies of the same condition, open and under way.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 50 participants (actual)
Sponsor and investigators
- Lead sponsor
- Suzan A Rattan
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Suzan A Rattan, Al-Kindy College of Medicine
- Investigators
- Suzan Rattan, lecturer, Study director, Al-Kindy College of Medicine
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04684888
- Sponsor's protocol ID
- 10 Al-KindyCM
- Status last verified
- Jul 2021
- First submitted
- 22 Dec 2020
- Last updated
- 20 Jul 2021
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Rattan SA, Rashid RF, Mutashar MK, Nasser YAR, Anwar DS. Comparison of corneal flap thickness predictability and architecture between femtosecond laser and sub-Bowman keratomileusis microkeratome in laser in situ keratomileusis. Int Ophthalmol. 2023 May;43(5):1553-1558. doi: 10.1007/s10792-022-02551-8. Epub 2022 Oct 29.
PubMed 36307607
Study at a glance
From the registry record, last updated by the sponsor on 20 Jul 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Corneal Flap Thickness Using Visumax Femto-Lasik With SubBowman Keratomileusis (SBK) Microkeratome
- ClinicalTrials.gov ID
- NCT04684888
- Acronym / sponsor ID
- 10 Al-KindyCM
- Conditions
- Refractive Errors, Refractive Surgery
- Keywords
- Visumax, femtolasik, Sub Bowman keratomileusis(SBK), LASIK
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 50 participants (actual)
- Lead sponsor
- Suzan A RattanUniversity, hospital or other
- Study start
- 1 Jan 2019 (actual)
- Primary completion
- 30 Sep 2020 (actual)
- Study completion
- 30 May 2021 (actual)
- First posted
- 28 Dec 2020 (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.
Laser Insitu keratomileusis (LASIK) has become the most popular procedure for refractive error correction. Lasik flap creation is the first and critical step during LASIK surgery because of its consensual effect on a residual stromal bed, corneal biomechanics, and hence the future risk of ectasia⁴.In the current study, we compared the Visumax FSL flap thickness predictability, accuracy, and variability with the flap created by single-use Moria SBK microkeratome.
Detailed description
Flap creation techniques have evolved from the old manual procedure of mechanical microkeratome to the automated one with the use of microkeratome and more recently to Femto-laser procedure using a variety of machines.
Authors have reported that the primary vision nearly the same despite the different methods of flap creation in the first 6 months post LASER vision correction. Others have reported that a thinner flap is associated with better primary vision and refractive outcomes. SBK (Sub Bowman Keratomileusis), is a procedure in which the Lasik flap is thinner, and has the advantage of leaving a sufficient stromal bed for safer excimer Laser ablation.
There are five types of femtosecond Laser that were already approved currently for Lasik flap creation.
The Zeiss (Visumax FSL ) which has been used in the current study uses 1043 nm, a repetition rate of 500 kHz, and 220-580 femtoseconds pulse duration. Each laser pulse produces micro-photo disruption in the tissue, contiguous few microns sized photo disruptions will create a continuous cut in the corneal tissue at precise preset position and depth.
In the current study, the Visumax flap thickness predictability, accuracy, and variability were compared with the flap created by a single-use Moria SBK microkeratome.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Visumax Femto-flap | Active comparator | Procedure: Visumax Femto-flapFifty eyes of fifty patients with age range 20-38 years, with myopic astigmatism refractive errors, ranged from -2 to- 6 DS and from -1 to -3.00DC, with stable refraction for at least one year before the surgery, normal corneal topography, anterior and posterior segments examinations. Refractive surgery was planned for both eyes and they chose the Visumax Femto-LASIK after a complete explanation of all the possible complications, costs, and differences. The right eye of each patient was taken for analysis, LASIK flap thickness was measured six months after the procedures using the anterior segment OCT, at seven points (one central and 3 points at each side of the horizontal meridian). The three nasal points were located (1mm, 2mm, 3mm respectively) from the center, and the remaining three temporal points located again ( 1mm, 2mm, 3mm) from the center. |
| Sub Bowman's keratomileusis (SBK )-Flap group | Active comparator | Procedure: Sub Bowman's keratomileusis (SBK)-flapFifty eyes of fifty patients with age range 20-38 years, with myopic astigmatism refractive errors, ranged from -2 to- 6 DS and from -1 to -3.00DC, with stable refraction for at least one year before the surgery, normal corneal topography, anterior and posterior segments examinations. They chose LASIK with mechanical SBK microkeratome surgical approach to be their refractive surgery for both eyes after all the possible complications, costs and differences had been explained clearly. The right eye of each patient was taken for analysis, LASIK flap thickness was measured six months after the procedures using the anterior segment OCT, at seven points (one central and 3 points at each side of the horizontal meridian). The three nasal points were located (1mm, 2mm, 3mm respectively) from the center, and the remaining three temporal points located again ( 1mm, 2mm, 3mm) from the center. |
Who may qualify
- Ages
- 20 to 38 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Having refractive errors range from -2 to- 6 DS and from -1 to -3.00DC.
- They have stable refraction for at least one year prior to surgery.
- Normal topography by Placido-Scheimpflug (Sirius, Costruzione Strumenti Oftalmici, Florence, Italia) and normal corneal epithelial map by Anterior segment-OCT system (Optovue Inc, Fremont, California, USA)
Key exclusion criteria (9 listed)
- Patient with suspicious topography and or corneal epithelial map.
- Patient with corneal pachymetry below 500µm.
- Patients who have a history of previous ocular surgery or trauma.
- Patient with a current or previous history of herpes simplex or herpes zoster.
- Patient with severe dry eye, diabetes, thyrotoxicosis, and connective tissue diseases.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Visumax Femto-flapUnder topical anesthesia [Tetracaine eye drop 0.5%]. A-90 µm thick flap was done by using Visumax femtosecond laser. The flap hinge was set to be nasally placed. A nasal-hinge flap with 90 µm thickness, 8.8 mm flap diameter, and 90º side cut angles were created with 500 kHz Visumax FSL, 160 nJ energy [Carl Zeiss, Meditec, Germany]. The sphero- cylindrical refractive corrections with optical zone 6.5 mm and ablation zone 8.0 mm were done by excimer laser operating system [Carl Zeiss, Meditec, MEL 90, Germany]. Automatic iris registration and pupil-tracking system were activated before photoablation. The patient's eyes were examined postoperatively on a slit-lamp biomicroscope and all treatments that were given for home use have been explained in terms of frequency of instillation, possible side effects, and benefits before discharging them on the same day. Follow up visits were scheduled clearly on printed patients' discharging cards. | Procedure or surgery | Visumax Femto-flap |
| Sub Bowman's keratomileusis (SBK)-flapUnder topical anesthesia [Tetracaine eye drop 0.5%] .A-90µm flaps done using Maria one use plus SBK mechanical microkeratome with a nasal located hinge. The sphero- cylindrical refractive corrections with optical zone 6.5 mm and ablation zone 8.0 mm were done by excimer laser operating system [Carl Zeiss, Meditec, MEL 90, Germany]. Automatic iris registration and pupil-tracking system were activated before photoablation. The patient's eyes were examined postoperatively on a slit-lamp biomicroscope and all treatments that were given for home use have been explained in terms of the frequency of instillation, possible side effects, and benefits before discharging them on the same day. Follow up visits were scheduled clearly on printed patients' discharging cards . | Procedure or surgery | Sub Bowman's keratomileusis (SBK )-Flap group |
Primary outcome
Right eye corneal flap thickness was measured by optical coherence tomography(OCT).
Time frame: 6-months postoperatively
The lasik flap thickness in the right eye in both groups were measured six months after the procedures using non touch method by anterior segment OCT without instillation of topical anaesthesia, at seven points in each eye (one central and 3 points at each sides of horizontal meridian).The three nasal points were located (1mm, 2mm, 3mm respectively) from the center and remaining three temporal points located again ( 1mm, 2mm, 3mm) from the center. Data from both groups were comparing to evaluate predictability and variability of the flap thickness.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Jul 2021.
- Derived from this study: PubMed 36307607Rattan SA, Rashid RF, Mutashar MK, Nasser YAR, Anwar DS. Comparison of corneal flap thickness predictability and architecture between femtosecond laser and sub-Bowman keratomileusis microkeratome in laser in situ keratomileusis. Int Ophthalmol. 2023 May;43(5):1553-1558. doi: 10.1007/s10792-022-02551-8. Epub 2022 Oct 29.
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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. This study is not recruiting at the moment.
Suzan Rattan, lecturer study director
Al-Kindy College of Medicine
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Visumax Femto-flap and Sub Bowman's keratomileusis (SBK)-flap in people with Refractive Errors and Refractive Surgery, run by Suzan A Rattan at 1 site in Iraq.
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 3 inclusion and 9 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: finished, as of the sponsor's last update on 20 Jul 2021. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Iraq. Whether a site is taking part right now should be confirmed with that site. See every site.
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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Right eye corneal flap thickness was measured by optical coherence tomography(OCT). (time frame: 6-months postoperatively). 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 NCT04684888, which also lists 1 linked publication.
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 20 Jul 2021.