Intraocular PressureNCT07549815
Measuring the Changes of the Intraocular Pressure After Corneal Laser Refractive Surgery Using Different Techniques
A study testing Corvis machine in people with Intraocular Pressure and Refractive Surgery, run by Tanta University at 1 site in Egypt.
Trial summary
To evaluate the changes that occur in the intraocular pressure after corneal refractive surgery either PRK , LASIK and femtosecond laser by using Corvis CT results and applanation tonometer Read more about this study
- Who is it for?
- Ages 19 to 35 years
- Conditions the study is for
- Intraocular Pressure, Refractive Surgery
- What is being tested?
- Corvis machine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 50 participants
- Where
- 1 siteEgypt
- Study dates
- 20 Apr 2026to 16 Jan 2027
- Phase
- Interventional
- 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 19 to 35 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Age between 19 and 35 years old
- Myopia range from (-2.00 to -6.00 Diopter) .
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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Egypt1 site
Tanta Univeristy Hospital
Tanta, 31515
Tamer Ibrahim, Ass professor, +201001243049, dinasabry71@gmail.com
About this study
To evaluate the changes that occur in the intraocular pressure after corneal refractive surgery either PRK , LASIK and femtosecond laser by using Corvis CT results and applanation tonometer
Read the detailed description
This study will be prospective study. 50 Patients who will undergo refractive surgery referred from the out-patient clinic of Tanta University hospital between December 2025 and December 2026 will be included in the study . The patient will be randomly selected to do either LASIK, PRK or femtosecond laser LASIK
Patients who will undergo refractive surgery either PRK, LASIK or femtosecond laser with age between 19 and 35 years old , Myopia range from (-2.00 to -6.00 Diopter) and to maintain stability of the data we will use only the right eye of each patient will be included on the study
Kertoconus, Corneal scarring, Previous corneal infections, Minimum corneal thickness at the thinnest location less than 400 µm, History of uveitis or ocular allergy and Pre-existing glaucoma will be excluded from the study.
Age, sex, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest and cycloplegic refraction, Slit lamp biomicroscopy, fundus examination , Central corneal thickness (CCT) and average Keratometer (K) data will be collected
Intraocular pressure will be measured by by two methods : Corvis CT and applanation tonometer for each patient and will be recorded, all the data will be collected before the refractive surgery and one month after refractive surgery
- Conditions
- Intraocular Pressure, Refractive Surgery
- Being tested
- Corvis machine
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Corvis machineOther
Measuring intraocular pressure by different methods and compare the results
| Study group | Role | What they receive |
|---|---|---|
| Measuring intraocular pressure by using different techniques | Experimental | Not described Receives: Other: Corvis machine |
What is being measured
The primary outcome is the main question the study is designed to answer.
Measuring intraocular pressure
Intraocular pressure will be measured by in mmHg and by two methods : Corvis CT and applanation tonometer for each patient and will be recorded
Measured: -The data collected will be before that laser surgery and one month after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Apr 2026
- Study start20 Apr 2026 (estimated)
- Primary completion20 Oct 2026 (estimated)
- Study completion16 Jan 2027 (estimated)
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 Intraocular PressureStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 50 participants (estimated)
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
- NCT07549815
- Sponsor's protocol ID
- 36264PR1310100/12/25
- Status last verified
- Mar 2026
- First submitted
- 17 Jan 2026
- Last updated
- 24 Apr 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Results after statistical analysis will be shared in the manuscript
Publications
1. Bailey MD, Zadnik K (2007) Outcomes of LASIK for myopia with FDA-approved lasers. Cornea 26(3):246-254 2. Sridhar MS, Rao SK, Vajpayee RB, Aasuri MK, Hannush S, Sinha R (2002) Complications of laser-in situ-ker- atomileusis. Indian J Ophthalmol 50(4):265-282 3. Mohammadi SF, Nabovati P, Mirzajani A, Ashrafi E, Vakilian B (2015) Risk factors of regression and under- correction in photorefractive keratectomy: a case-control study. Int J Ophthalmol 18;8(5): 933-937 4. Diakonis VF, Kankariya VP, Kymionis GD, Kounis G, Kontadakis G, Gkenos E, Grentzelos MA, Hajithanasis G, Yoo SH, Pallikaris IG (2014) Long term followup of pho- torefractive keratectomy with adjuvant use of mitomycin C. J Ophthalmol 2014:821920 5- dos Santos AM, Torricelli AA, Marino GK, Garcia R, Netto MV, Bechara SJ, Wilson SE. Femtosecond Laser-Assisted LASIK Flap Complications. J Refract Surg. 2016 Jan;32(1):52-9 6- Wang LK, Tian L and Zheng YP. Determining in vivo elasticity and viscosity with dynamic Scheimpflug imaging analysis in keratoconic and healthy eyes. J Biophotonics, 2016; 9: 454-463. 7.ConsejoA,MelcerT,RozemaJJ.Introductiontomachinelearningforophthalmologists.SeminOphthalmol.2019;34(1):19 _41.
Study at a glance
From the registry record, last updated by the sponsor on 24 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Measuring the Changes of the Intraocular Pressure After Corneal Laser Refractive Surgery Using Different Techniques
- ClinicalTrials.gov ID
- NCT07549815
- Acronym / sponsor ID
- 36264PR1310100/12/25
- Conditions
- Intraocular Pressure, Refractive Surgery
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Tanta UniversityUniversity, hospital or other
- Study start
- 20 Apr 2026 (estimated)
- Primary completion
- 20 Oct 2026 (estimated)
- Study completion
- 16 Jan 2027 (estimated)
- First posted
- 24 Apr 2026 (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 intraocular pressure after corneal refractive surgery either PRK , LASIK and femtosecond laser by using Corvis CT results and applanation tonometer
Detailed description
This study will be prospective study. 50 Patients who will undergo refractive surgery referred from the out-patient clinic of Tanta University hospital between December 2025 and December 2026 will be included in the study . The patient will be randomly selected to do either LASIK, PRK or femtosecond laser LASIK
Patients who will undergo refractive surgery either PRK, LASIK or femtosecond laser with age between 19 and 35 years old , Myopia range from (-2.00 to -6.00 Diopter) and to maintain stability of the data we will use only the right eye of each patient will be included on the study
Kertoconus, Corneal scarring, Previous corneal infections, Minimum corneal thickness at the thinnest location less than 400 µm, History of uveitis or ocular allergy and Pre-existing glaucoma will be excluded from the study.
Age, sex, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest and cycloplegic refraction, Slit lamp biomicroscopy, fundus examination , Central corneal thickness (CCT) and average Keratometer (K) data will be collected
Intraocular pressure will be measured by by two methods : Corvis CT and applanation tonometer for each patient and will be recorded, all the data will be collected before the refractive surgery and one month after refractive surgery
Study design
- Primary purpose
- Diagnosis
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Measuring intraocular pressure by using different techniques | Experimental | Other: Corvis machine |
Who may qualify
- Ages
- 19 to 35 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Age between 19 and 35 years old
- Myopia range from (-2.00 to -6.00 Diopter) .
Key exclusion criteria (6 listed)
- Kertoconus.
- Corneal scarring.
- Previous corneal infections.
- Minimum corneal thickness at the thinnest location less than 400 µm.
- History of uveitis or ocular allergy.
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 |
|---|---|---|
| Corvis machineMeasuring intraocular pressure by different methods and compare the results | Other | Measuring intraocular pressure by using different techniques |
Primary outcome
Measuring intraocular pressure
Time frame: -The data collected will be before that laser surgery and one month after surgery
Intraocular pressure will be measured by in mmHg and by two methods : Corvis CT and applanation tonometer for each patient and will be recorded
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 24 Apr 2026.
- Results publication1. Bailey MD, Zadnik K (2007) Outcomes of LASIK for myopia with FDA-approved lasers. Cornea 26(3):246-254 2. Sridhar MS, Rao SK, Vajpayee RB, Aasuri MK, Hannush S, Sinha R (2002) Complications of laser-in situ-ker- atomileusis. Indian J Ophthalmol 50(4):265-282 3. Mohammadi SF, Nabovati P, Mirzajani A, Ashrafi E, Vakilian B (2015) Risk factors of regression and under- correction in photorefractive keratectomy: a case-control study. Int J Ophthalmol 18;8(5): 933-937 4. Diakonis VF, Kankariya VP, Kymionis GD, Kounis G, Kontadakis G, Gkenos E, Grentzelos MA, Hajithanasis G, Yoo SH, Pallikaris IG (2014) Long term followup of pho- torefractive keratectomy with adjuvant use of mitomycin C. J Ophthalmol 2014:821920 5- dos Santos AM, Torricelli AA, Marino GK, Garcia R, Netto MV, Bechara SJ, Wilson SE. Femtosecond Laser-Assisted LASIK Flap Complications. J Refract Surg. 2016 Jan;32(1):52-9 6- Wang LK, Tian L and Zheng YP. Determining in vivo elasticity and viscosity with dynamic Scheimpflug imaging analysis in keratoconic and healthy eyes. J Biophotonics, 2016; 9: 454-463. 7.ConsejoA,MelcerT,RozemaJJ.Introductiontomachinelearningforophthalmologists.SeminOphthalmol.2019;34(1):19 _41.
- Individual participant dataSharing planned: Yes. Results after statistical analysis will be shared in the manuscript
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Corvis machine in people with Intraocular Pressure and Refractive Surgery, 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 2 inclusion and 6 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 24 Apr 2026. 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?
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 Dina Tadros, Ass Professor of Ophthalmology (+201224093354, dina.tadros@med.tanta.edu.eg), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Measuring intraocular pressure (time frame: -The data collected will be before that laser surgery and one month after surgery). 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 NCT07549815, 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 24 Apr 2026.