KeratoconusNCT07461129
Electrophysiological Changes in Cases of Different Stages of Keratoconus
An observational study of Keratoconus, run by Minia University at 1 site in Egypt.
Trial summary
Keratoconus is a bilateral and asymmetric disease which results in progressive thinning and steeping of the cornea leading to irregular astigmatism and decreased visual acuity.A typical patient with keratoconus presents in the teens or early twenties with complaints of blurring or distortion in vision and having to… Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Keratoconus
- How many people
- 50 participants
- Where
- 1 siteEgypt
- Study dates
- 20 Aug 2025to 20 Aug 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 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Study participants will be : from 18 to 40 years old: 50 eyes of control patients 50 eyes of patients who had KC
Who may be able to join
- Patients aged from 18 to 40 years with keratoconus of different stages
Who cannot join
- Keratoconus Patients with any prior history of ocular procedures.
- Patients with dense cataract.
- Patients with retinal , vitreous problems or uveiitis .
- Patients with optic nerve pathology
- History of ocular medications e.g antiglaucoma
- History of previous ocular surgery
Trial locations and contacts
1 site in 1 country.
About this study
Keratoconus is a bilateral and asymmetric disease which results in progressive thinning and steeping of the cornea leading to irregular astigmatism and decreased visual acuity.A typical patient with keratoconus presents in the teens or early twenties with complaints of blurring or distortion in vision and having to change glasses frequently due to changes in refractive error.
Corneal thinning frequently precedes ectasia. In moderate and advance cases, a hemosiderin arc or circle line, known as Fleischer's ring, is frequently seen around the cone base. Vogt's striaes, which are fine vertical lines produced by Descemet's membrane compression, is another characteristic sign. Most patients eventually develop corneal scarring. Munson's sign, a V-shape deformation of the lower eyelid in downward position; Rizzuti's sign, a bright reflection from the nasal area of the limbus when light is directed to the limbus temporal area; and breakages in Descemet's membrane causing acute stromal oedema, known as hydrops, are observed in advanced stages.
Read more
Corneal blindness is one of the major causes of reversible blindness, which can be managed with transplantation of a healthy donor cornea. It is the most successful organ transplantation in the human body as cornea is devoid of vasculature, minimizing the risk of graft rejection.
Preoperative clinical evaluation of visual potential after corneal transplantation in the patient with dense corneal opacity remains difficult using only history and biomicroscopic examination. Some studies found that electrophysiologic tests were good predictors of visual prognosis prior to corneal transplantation.
Electrophysiology is an objective functional test of the visual pathway and allows the location of visual dysfunctions to be detected. Full-field electroretinography (ERG) is an established clinical technique used to evoke and record mass responses of the retina to flashes of light. The ISCEV Standard full-field ERGs assess generalized retinal function under dark-adapted (DA) and light-adapted (LA) conditions.The visual evoked potential (VEP) is a cortical response and serves as a functional test of the entire visual pathway from the eye to the visual system of the brain.
Read the detailed description
Aim of the Study To assess the effect of different stages of keratoconus on electrophysiology test results.
All patients will undergo a comprehensive ocular examination including:
- Best corrected visual acuity (BCVA).
- Anterior segment examination using slit lamp bio microscopy.
- Posterior segment examination using a +78 D condensing lens and peripheral retinal examination by means of binocular indirect ophthalmoscopy (keeler ophthalmoscope).
- Penatacam examination to define grade of KC and corneal topography.
- OCT-ONH to assess the function of optic nerve. 6-Electrophysiological tests:
All subjects will be examined using:
- FVEP: via the assessment of the amplitude \&latency of P2 wave
- PVEP:via the assessment of the amplitude \&latency of P100 wave 3- Full field flash ERG: via the assessment of the amplitude \& implicit time of a\&b waves
- Conditions
- Keratoconus
- Keywords
- VEP, ERG, Keratoconus
- Medical subject headings
- Keratoconus
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 |
|---|---|---|
| Keratoconus group | Patients with different stages of keratoconus | |
| Normal | patients whose pentacam doesn't show any keratoconus findings or any other abnormalities |
What is being measured
The primary outcome is the main question the study is designed to answer.
Measuring the amplitude of P100 wave in pattern visual evoked potential
Measuring the amplitude of P100 wave of pattern visual evoked potential in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measured: 6 months
Measuring the Latency of P100 wave of pattern evoked potential
Measuring the latency of P100 wave of pattern visual evoked potential in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measured: 6 months
Measuring the Amplitude of P2 of Flash visual evoked potential
Measuring the amplitude of P2 wave of Flash visual evoked potential in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measured: 6 months
measuring the latency of P2 wave of Flash visual evoked potential
Measuring the latency of P2 wave of Flash visual evoked potential in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measured: 6 months
Measuring the Amplitude of a wave of Full Field Flash Electroretinography
Measuring the amplitude of a wave of full field flash ERG in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measured: 6 months
measuring the implicit time of a wave of Full Field Flash Electroretinography
Measuring the Implicit time of a wave of full field flash ERG in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measured: 6 months
Measuring the amplitude of b wave of Full Field Flash Electroretinography
Measuring the amplitude of b wave of full field flash ERG in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measured: 6 months
Measuring the implicit time of b wave of Full Field Flash Electroretinography
Measuring the implicit time of b wave of full field flash ERG in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
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 posted10 Mar 2026
- Study start20 Aug 2025
- Primary completion20 Jun 2026 (estimated)
- Study completion20 Aug 2026 (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 KeratoconusStudies of the same condition, open and under way.
- More trials run by Minia 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
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Minia University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Alaa Mohamed Riad Qassem, Minia University
- Investigators
- Hossameldin Mohamed Mohamed Moharram, ph.D, Study chair, Minia university eye hospitalMohamed Abdelhamid Mahmoud, Ph.D, Study director, Minia university eye hospitalAmr Ahmed Mohamed, Ph.D, Study director, Minia university eye hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07461129
- Sponsor's protocol ID
- VEP,ERG in keratoconus
- Status last verified
- Mar 2026
- First submitted
- 21 Jan 2026
- Last updated
- 11 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
google scholar
Study at a glance
From the registry record, last updated by the sponsor on 11 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Electrophysiological Changes in Cases of Different Stages of Keratoconus
- ClinicalTrials.gov ID
- NCT07461129
- Acronym / sponsor ID
- VEP,ERG in keratoconus
- Conditions
- Keratoconus
- Keywords
- VEP, ERG, Keratoconus
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Minia UniversityUniversity, hospital or other
- Study start
- 20 Aug 2025 (actual)
- Primary completion
- 20 Jun 2026 (estimated)
- Study completion
- 20 Aug 2026 (estimated)
- First posted
- 10 Mar 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.
Keratoconus is a bilateral and asymmetric disease which results in progressive thinning and steeping of the cornea leading to irregular astigmatism and decreased visual acuity.A typical patient with keratoconus presents in the teens or early twenties with complaints of blurring or distortion in vision and having to change glasses frequently due to changes in refractive error.
Corneal thinning frequently precedes ectasia. In moderate and advance cases, a hemosiderin arc or circle line, known as Fleischer's ring, is frequently seen around the cone base. Vogt's striaes, which are fine vertical lines produced by Descemet's membrane compression, is another characteristic sign. Most patients eventually develop corneal scarring. Munson's sign, a V-shape deformation of the lower eyelid in downward position; Rizzuti's sign, a bright reflection from the nasal area of the limbus when light is directed to the limbus temporal area; and breakages in Descemet's membrane causing acute stromal oedema, known as hydrops, are observed in advanced stages.
Corneal blindness is one of the major causes of reversible blindness, which can be managed with transplantation of a healthy donor cornea. It is the most successful organ transplantation in the human body as cornea is devoid of vasculature, minimizing the risk of graft rejection.
Preoperative clinical evaluation of visual potential after corneal transplantation in the patient with dense corneal opacity remains difficult using only history and biomicroscopic examination. Some studies found that electrophysiologic tests were good predictors of visual prognosis prior to corneal transplantation.
Electrophysiology is an objective functional test of the visual pathway and allows the location of visual dysfunctions to be detected. Full-field electroretinography (ERG) is an established clinical technique used to evoke and record mass responses of the retina to flashes of light. The ISCEV Standard full-field ERGs assess generalized retinal function under dark-adapted (DA) and light-adapted (LA) conditions.The visual evoked potential (VEP) is a cortical response and serves as a functional test of the entire visual pathway from the eye to the visual system of the brain.
Detailed description
Aim of the Study To assess the effect of different stages of keratoconus on electrophysiology test results.
All patients will undergo a comprehensive ocular examination including:
- Best corrected visual acuity (BCVA).
- Anterior segment examination using slit lamp bio microscopy.
- Posterior segment examination using a +78 D condensing lens and peripheral retinal examination by means of binocular indirect ophthalmoscopy (keeler ophthalmoscope).
- Penatacam examination to define grade of KC and corneal topography.
- OCT-ONH to assess the function of optic nerve. 6-Electrophysiological tests:
All subjects will be examined using:
- FVEP: via the assessment of the amplitude \&latency of P2 wave
- PVEP:via the assessment of the amplitude \&latency of P100 wave 3- Full field flash ERG: via the assessment of the amplitude \& implicit time of a\&b waves
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Keratoconus group | – | –Patients with different stages of keratoconus |
| Normal | – | –patients whose pentacam doesn't show any keratoconus findings or any other abnormalities |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Study participants will be : from 18 to 40 years old: 50 eyes of control patients 50 eyes of patients who had KC
Key inclusion criteria (1 listed)
- Patients aged from 18 to 40 years with keratoconus of different stages
Key exclusion criteria (6 listed)
- Keratoconus Patients with any prior history of ocular procedures.
- Patients with dense cataract.
- Patients with retinal , vitreous problems or uveiitis .
- Patients with optic nerve pathology
- History of ocular medications e.g antiglaucoma
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
Measuring the amplitude of P100 wave in pattern visual evoked potential
Time frame: 6 months
Measuring the amplitude of P100 wave of pattern visual evoked potential in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measuring the Latency of P100 wave of pattern evoked potential
Time frame: 6 months
Measuring the latency of P100 wave of pattern visual evoked potential in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measuring the Amplitude of P2 of Flash visual evoked potential
Time frame: 6 months
Measuring the amplitude of P2 wave of Flash visual evoked potential in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
measuring the latency of P2 wave of Flash visual evoked potential
Time frame: 6 months
Measuring the latency of P2 wave of Flash visual evoked potential in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measuring the Amplitude of a wave of Full Field Flash Electroretinography
Time frame: 6 months
Measuring the amplitude of a wave of full field flash ERG in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
measuring the implicit time of a wave of Full Field Flash Electroretinography
Time frame: 6 months
Measuring the Implicit time of a wave of full field flash ERG in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measuring the amplitude of b wave of Full Field Flash Electroretinography
Time frame: 6 months
Measuring the amplitude of b wave of full field flash ERG in mico-voltage in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
Measuring the implicit time of b wave of Full Field Flash Electroretinography
Time frame: 6 months
Measuring the implicit time of b wave of full field flash ERG in mico-second in different stages of keratoconus using the (Roland Consult Supercolor Ganzfeld Q450 SC)
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 11 Mar 2026.
- Backgroundgoogle scholar
- Individual participant dataSharing planned: Undecided
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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.
Hossameldin Mohamed Mohamed Moharram, ph.D study chair
Minia university eye hospital
Mohamed Abdelhamid Mahmoud, Ph.D study director
Minia university eye hospital
Amr Ahmed Mohamed, Ph.D study director
Minia university eye hospital
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 Keratoconus, run by Minia 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 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: under way, not looking for participants, as of the sponsor's last update on 11 Mar 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?
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?
Measuring the amplitude of P100 wave in pattern visual evoked potential (time frame: 6 months). The study lists 8 primary outcomes in all. 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 NCT07461129, 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 11 Mar 2026.