MyopiaNCT04589091
Corneal Topography Asymmetry Indices Changes After Corneal Refractive Surgery
An observational study of Myopia, run by Tanta University at 1 site in Egypt.
Trial summary
To evaluate the changes that occur in the corneal indices after corneal refractive surgery either PRK or LASIK. Read more about this study
- Who is it for?
- Ages 19 to 35 years
- Conditions the study is for
- Myopia
- What is being tested?
- Refractive surgery
- How many people
- 30 participants
- Where
- 1 siteEgypt
- Study dates
- 13 Apr 2021to 30 Jan 2022
- Phase
- Observational
- 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 19 to 35 years
- All sexes
- No healthy volunteers
- Adult
Study population: We will retrospectively review the medical records of all patients who underwent refractive surgery referred from the out-patient clinic of Tanta University hospital between September 2015 and September 2020
Who may be able to join
- Patients who underwent refractive surgery either PRK, LASIK with age between 19 and 35 years old
Who cannot join
- Kertoconus.
- Corneal scarring.
- Previous corneal infections.
- Minimum corneal thickness at the thinnest location less than 400 µm.
- History of uveitis or ocular allergy.
- Pre-existing glaucoma.
- Data not available
Trial locations and contacts
1 site in 1 country.
About this study
To evaluate the changes that occur in the corneal indices after corneal refractive surgery either PRK or LASIK.
Read the detailed description
Retrospectively review the medical records of all patients who underwent refractive surgery referred from the out-patient clinic of Tanta University hospital between September 2015 and September 2020 .
Data collection will include:
Preoperative and postoperative Evaluation: Age, sex, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest and cycloplegic refraction, Slit lamp biomicroscopy, fundus examination.
Data of Corneal Tomography keratometric using Scheimpflug camera (Pentacam Oculus- Germany) :that includes the following indices
- Average keratometric value (K mean) in diopters
- Maximum simulated keratometry (Kmax) in diopters
- Index of Surface Variance (ISV) in microns
- Index of Vertical Asymmetey (IVA) in microns
- Radii Minimum (R min) in microns
- Index of height asymmetry (IHA) in microns
- Index of height decantation (IHD) in microns
- Aberration coefficient (ABR)
The data of the pentacam will be collected pre-operative and analyzed at 1 month, 3 months and 6 months with recording of the complications.
- Conditions
- Myopia
- Being tested
- Refractive surgery
- Medical subject headings
- Myopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Refractive surgeryOther
Refractive surgery for correction of error of refraction
| Study group | Role | What they receive |
|---|---|---|
| Group(1): Patient who underwent PRK | Not described Receives: Other: Refractive surgery | |
| Group(2): Patient underwent LASIK | Not described Receives: Other: Refractive surgery |
What is being measured
The primary outcome is the main question the study is designed to answer.
To evaluate the changes that occur in the corneal indices after corneal refractive surgery either PRK or LASIK.
Using the results of measurements of Scheimpflug camera (Pentacam Oculus- Germany) :that includes the following indices
- Average keratometric value (K mean) in diopters
- Maximum simulated keratometry (Kmax) in diopters
- Index of Surface Variance (ISV) in microns
- Index of Vertical Asymmetey (IVA) in microns
- Radii Minimum (R min) in microns
- Index of height asymmetry (IHA) in microns
- Index of height decantation (IHD) in microns
- Aberration coefficient (ABR)
The numbers from preoperative records will be compared with postoperative records after the refractive surgery is done . All the values will be expressed as mean ± standard deviation and the data will be analyzed as 1 months, 3 months and 6 months after surgery
Measured: 6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Oct 2020
- Study start13 Apr 2021
- Primary completion30 Oct 2021
- Study completion30 Jan 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for MyopiaStudies of the same condition, open and under way.
- More trials run by Tanta 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
- Other
- Time perspective
- Retrospective
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Tanta University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Dina Tadros, Tanta University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04589091
- Sponsor's protocol ID
- 34081/9/20
- Status last verified
- Feb 2022
- First submitted
- 13 Oct 2020
- Last updated
- 8 Feb 2022
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes
Publications
Bailey MD, Zadnik K. Outcomes of LASIK for myopia with FDA-approved lasers. Cornea. 2007 Apr;26(3):246-54. doi: 10.1097/ICO.0b013e318033dbf0.
PubMed 17413947Sridhar MS, Rao SK, Vajpayee RB, Aasuri MK, Hannush S, Sinha R. Complications of laser-in-situ-keratomileusis. Indian J Ophthalmol. 2002 Dec;50(4):265-82.
PubMed 12532491Mohammadi SF, Nabovati P, Mirzajani A, Ashrafi E, Vakilian B. Risk factors of regression and undercorrection in photorefractive keratectomy: a case-control study. Int J Ophthalmol. 2015 Oct 18;8(5):933-7. doi: 10.3980/j.issn.2222-3959.2015.05.14. eCollection 2015.
PubMed 26558204Belin MW, Ambrosio R Jr. Corneal ectasia risk score: statistical validity and clinical relevance. J Refract Surg. 2010 Apr;26(4):238-40. doi: 10.3928/1081597X-20100318-01. No abstract available.
PubMed 20415320
Study at a glance
From the registry record, last updated by the sponsor on 8 Feb 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Corneal Topography Asymmetry Indices Changes After Corneal Refractive Surgery
- ClinicalTrials.gov ID
- NCT04589091
- Acronym / sponsor ID
- 34081/9/20
- Conditions
- Myopia
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Tanta UniversityUniversity, hospital or other
- Study start
- 13 Apr 2021 (actual)
- Primary completion
- 30 Oct 2021 (actual)
- Study completion
- 30 Jan 2022 (actual)
- First posted
- 19 Oct 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.
To evaluate the changes that occur in the corneal indices after corneal refractive surgery either PRK or LASIK.
Detailed description
Retrospectively review the medical records of all patients who underwent refractive surgery referred from the out-patient clinic of Tanta University hospital between September 2015 and September 2020 .
Data collection will include:
Preoperative and postoperative Evaluation: Age, sex, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest and cycloplegic refraction, Slit lamp biomicroscopy, fundus examination.
Data of Corneal Tomography keratometric using Scheimpflug camera (Pentacam Oculus- Germany) :that includes the following indices
- Average keratometric value (K mean) in diopters
- Maximum simulated keratometry (Kmax) in diopters
- Index of Surface Variance (ISV) in microns
- Index of Vertical Asymmetey (IVA) in microns
- Radii Minimum (R min) in microns
- Index of height asymmetry (IHA) in microns
- Index of height decantation (IHD) in microns
- Aberration coefficient (ABR)
The data of the pentacam will be collected pre-operative and analyzed at 1 month, 3 months and 6 months with recording of the complications.
Study design
- Observational model
- Other
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Group(1): Patient who underwent PRK | – | Other: Refractive surgery |
| Group(2): Patient underwent LASIK | – | Other: Refractive surgery |
Who may qualify
- Ages
- 19 to 35 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- We will retrospectively review the medical records of all patients who underwent refractive surgery referred from the out-patient clinic of Tanta University hospital between September 2015 and September 2020
Key inclusion criteria (1 listed)
- Patients who underwent refractive surgery either PRK, LASIK with age between 19 and 35 years old
Key exclusion criteria (7 listed)
- Kertoconus.
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 |
|---|---|---|
| Refractive surgeryRefractive surgery for correction of error of refraction | Other | Group(1): Patient who underwent PRK, Group(2): Patient underwent LASIK |
Primary outcome
To evaluate the changes that occur in the corneal indices after corneal refractive surgery either PRK or LASIK.
Time frame: 6 months
Using the results of measurements of Scheimpflug camera (Pentacam Oculus- Germany) :that includes the following indices 1. Average keratometric value (K mean) in diopters 2. Maximum simulated keratometry (Kmax) in diopters 3. Index of Surface Variance (ISV) in microns 4. Index of Vertical Asymmetey (IVA) in microns 5. Radii Minimum (R min) in microns 6. Index of height asymmetry (IHA) in microns 7. Index of height decantation (IHD) in microns 8. Aberration coefficient (ABR) The numbers from preoperative records will be compared with postoperative records after the refractive surgery is done . All the values will be expressed as mean ± standard deviation and the data will be analyzed as 1 months, 3 months and 6 months after surgery
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 8 Feb 2022.
- Results publication: PubMed 17413947Bailey MD, Zadnik K. Outcomes of LASIK for myopia with FDA-approved lasers. Cornea. 2007 Apr;26(3):246-54. doi: 10.1097/ICO.0b013e318033dbf0.
- Results publication: PubMed 12532491Sridhar MS, Rao SK, Vajpayee RB, Aasuri MK, Hannush S, Sinha R. Complications of laser-in-situ-keratomileusis. Indian J Ophthalmol. 2002 Dec;50(4):265-82.
- Results publication: PubMed 26558204Mohammadi SF, Nabovati P, Mirzajani A, Ashrafi E, Vakilian B. Risk factors of regression and undercorrection in photorefractive keratectomy: a case-control study. Int J Ophthalmol. 2015 Oct 18;8(5):933-7. doi: 10.3980/j.issn.2222-3959.2015.05.14. eCollection 2015.
- Results publication: PubMed 20415320Belin MW, Ambrosio R Jr. Corneal ectasia risk score: statistical validity and clinical relevance. J Refract Surg. 2010 Apr;26(4):238-40. doi: 10.3928/1081597X-20100318-01. No abstract available.
- Individual participant dataSharing planned: Yes
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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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Myopia, run by Tanta University at 1 site in Egypt.
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 1 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: finished, as of the sponsor's last update on 8 Feb 2022. 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 Egypt. 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?
To evaluate the changes that occur in the corneal indices after corneal refractive surgery either PRK or LASIK. (time frame: 6 months). 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 NCT04589091, which also lists 4 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 8 Feb 2022.