Keratoconic SubjectsNCT07540208
Keraring Implantation Based on Alfonso Nomogram
A study testing Intrastromal corneal ring segment implantation (ICRS) in people with Keratoconic Subjects, run by Assiut University at 1 site in Egypt.
Trial summary
Keratoconus (KC) is a bilateral asymmetric progressive corneal degenerative disease associated with corneal thinning and protrusion. The management of moderate progressive keratoconus involves halting its progression through corneal cross-linking as well as flattening of the ectatic steep cornea through the… Read more about this study
- Who is it for?
- Ages 18 to 35 years
- Conditions the study is for
- Keratoconic Subjects
- What is being tested?
- Intrastromal corneal ring segment implantation (ICRS)
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 25 participants
- Where
- 1 siteEgypt
- Study dates
- 1 Sep 2025to 1 Sep 2026
- 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 18 to 35 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Patients aged between 18-35 years.
- Patients diagnosed with progressive keratoconus.
- Mean keratometry (Km) between 48-60 D.
- Clear cornea
Who cannot join
- Mild or advanced keratoconus
- Corneal scarring.
- Other corneal or ocular diseases.
- Systemic diseases such as diabetes mellitus and autoimmune diseases.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Outcomes of Keraring Implantation in Patients With Keratoconus Guided by the Alfonso Morphological Surgical Nomogram
Keratoconus (KC) is a bilateral asymmetric progressive corneal degenerative disease associated with corneal thinning and protrusion. The management of moderate progressive keratoconus involves halting its progression through corneal cross-linking as well as flattening of the ectatic steep cornea through the implantation of intrastromal corneal rings (ICR). Different nomograms were used to guide ophthalmic surgeons for the proper choice of ICR implantation to achieve the best results. The aim of the current study is to assess the visual, refractive and tomographic outcomes of Keraring implantation based on the Alfonso nomogram, in patients with keratoconus.
- Conditions
- Keratoconic Subjects
- Being tested
- Intrastromal corneal ring segment implantation (ICRS)
- Keywords
- Keratoconus, Intrastromal corneal rings, Alfonso nomogram
- Medical subject headings
- Keratoconus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intrastromal corneal ring segment implantation (ICRS)Procedure or surgery
Patients with moderate progressive keratoconus underwent femtosecond laser-assisted intrastromal corneal ring (Keraring) implantation based on the Alfonso morphological surgical nomogram.
| Study group | Role | What they receive |
|---|---|---|
| Keraring implantation based on Alfonso nomogram | Active comparator | Patients with moderate progressive keratoconus, underwent Keraring implantation based on Alfonso morphological surgical nomogram. Receives: Procedure: Intrastromal corneal ring segment implantation (ICRS) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Corrected distance visual acuity
Corrected distance visual acuity is measured with Snellen's acuity chart and converted to logarithm of the minimum angle of resolution (logMAR) notation.
Measured: 6 months
Spherical equivalent refraction
Spherical equivalent in diopters is measured with Topcon autorefractometer.
Measured: 6 months
Maximum keratometry
The maximum keratometry in diopters is measured using pentacam.
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 posted20 Apr 2026
- Study start1 Sep 2025
- Primary completion1 Sep 2026
- Study completion1 Sep 2026
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 Keratoconic SubjectsStudies 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 25 participants (actual)
Sponsor and investigators
- Lead sponsor
- Assiut University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mahmoud Abdel-Radi, Assiut University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07540208
- Sponsor's protocol ID
- OKIPKGASN
- Status last verified
- Sep 2026
- First submitted
- 13 Apr 2026
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Sakellaris D, Balidis M, Gorou O, Szentmary N, Alexoudis A, Grieshaber MC, Sagri D, Scholl H, Gatzioufas Z. Intracorneal Ring Segment Implantation in the Management of Keratoconus: An Evidence-Based Approach. Ophthalmol Ther. 2019 Oct;8(Suppl 1):5-14. doi: 10.1007/s40123-019-00211-2. Epub 2019 Oct 11.
PubMed 31605316
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Outcomes of Keraring Implantation in Patients With Keratoconus Guided by the Alfonso Morphological Surgical Nomogram
- ClinicalTrials.gov ID
- NCT07540208
- Acronym / sponsor ID
- OKIPKGASN
- Conditions
- Keratoconic Subjects
- Keywords
- Keratoconus, Intrastromal corneal rings, Alfonso nomogram
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 25 participants (actual)
- Lead sponsor
- Assiut UniversityUniversity, hospital or other
- Study start
- 1 Sep 2025 (actual)
- Primary completion
- 1 Sep 2026 (actual)
- Study completion
- 1 Sep 2026 (actual)
- First posted
- 20 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.
Keratoconus (KC) is a bilateral asymmetric progressive corneal degenerative disease associated with corneal thinning and protrusion. The management of moderate progressive keratoconus involves halting its progression through corneal cross-linking as well as flattening of the ectatic steep cornea through the implantation of intrastromal corneal rings (ICR). Different nomograms were used to guide ophthalmic surgeons for the proper choice of ICR implantation to achieve the best results. The aim of the current study is to assess the visual, refractive and tomographic outcomes of Keraring implantation based on the Alfonso nomogram, in patients with keratoconus.
Study design
- Primary purpose
- Treatment
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Keraring implantation based on Alfonso nomogram | Active comparator | Procedure: Intrastromal corneal ring segment implantation (ICRS)Patients with moderate progressive keratoconus, underwent Keraring implantation based on Alfonso morphological surgical nomogram. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Patients aged between 18-35 years.
- Patients diagnosed with progressive keratoconus.
- Mean keratometry (Km) between 48-60 D.
- Clear cornea
Key exclusion criteria (4 listed)
- Mild or advanced keratoconus
- Corneal scarring.
- Other corneal or ocular diseases.
- Systemic diseases such as diabetes mellitus and autoimmune 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 |
|---|---|---|
| Intrastromal corneal ring segment implantation (ICRS)Patients with moderate progressive keratoconus underwent femtosecond laser-assisted intrastromal corneal ring (Keraring) implantation based on the Alfonso morphological surgical nomogram. | Procedure or surgery | Keraring implantation based on Alfonso nomogram |
Primary outcome
Corrected distance visual acuity
Time frame: 6 months
Corrected distance visual acuity is measured with Snellen's acuity chart and converted to logarithm of the minimum angle of resolution (logMAR) notation.
Spherical equivalent refraction
Time frame: 6 months
Spherical equivalent in diopters is measured with Topcon autorefractometer.
Maximum keratometry
Time frame: 6 months
The maximum keratometry in diopters is measured using pentacam.
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 2 Oct 2026.
- Background: PubMed 31605316Sakellaris D, Balidis M, Gorou O, Szentmary N, Alexoudis A, Grieshaber MC, Sagri D, Scholl H, Gatzioufas Z. Intracorneal Ring Segment Implantation in the Management of Keratoconus: An Evidence-Based Approach. Ophthalmol Ther. 2019 Oct;8(Suppl 1):5-14. doi: 10.1007/s40123-019-00211-2. Epub 2019 Oct 11.
- Individual participant dataSharing planned: No
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?
A study testing Intrastromal corneal ring segment implantation (ICRS) in people with Keratoconic Subjects, run by Assiut 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 4 inclusion and 4 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 2 Oct 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?
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?
Corrected distance visual acuity (time frame: 6 months). The study lists 3 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 NCT07540208, 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 2 Oct 2026.