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Moderate KeratoconusNCT03355430

Simultaneous Corneal Wavefront-Guided Trans-PRK and Corneal Collagen Crosslinking After ICRS Implantation for Moderate Keratoconus

An observational study of Moderate Keratoconus, run by Yonsei University at 1 site in South Korea.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The investigators aim to investigate the effects of combined corneal wavefront-guided transepithelial photorefractive keratectomy (tPRK) and accelerated corneal collagen cross-linking (CXL) after intracorneal ring segment (ICRS) implantation in patients with moderate keratoconus. Read more about this study

Who is it for?
Ages 20 to 45 years
Conditions the study is for
Moderate Keratoconus
What is being tested?
combined corneal wavefront-guided transepithelial photorefractive keratectomy (tPRK) and accelerated corneal collagen cross-linking (CXL)
Type of treatment
Surgery or procedure
How many people
23 participants
Where
1 siteSouth Korea
Study dates
7 Jul 2016to 2 Jan 2017
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 20 to 45 years
  • All sexes
  • No healthy volunteers
  • Adult

Study population: Patient was intolerant to contact lenses, had moderate keratoconus without apical scarring, and if progression had been noted over the previous 6 months. All included patients underwent combined corneal wavefront-guided tPRK and CXL at least 1 month (average 2.7 ± 1.1 months; range 1 to 4 months) after ICRS implantation. We excluded patients with central or para-central corneal scarring, central pachymetry < 400 microns, corneal endothelial cell density of less than 2000 cells/mm2, systemic autoimmune disease, a history of herpetic corneal disease, pregnancy, lactation, or severe dry eye syndrome.

Who may be able to join

  • intolerant to contact lenses
  • moderate keratoconus without apical scarring
  • if progression had been noted over the previous 6 months
  • All included patients underwent combined corneal wavefront-guided tPRK and CXL at least 1 month (average 2.7 ± 1.1 months; range 1 to 4 months) after ICRS implantation.

Who cannot join

  • central or para-central corneal scarring
  • central pachymetry < 400 microns
  • corneal endothelial cell density of less than 2000 cells/mm2
  • systemic autoimmune disease
  • a history of herpetic corneal disease
  • pregnancy
  • lactation
  • severe dry eye syndrome

Trial locations and contacts

1 site in 1 country.

South Korea1 site
  • Department of Ophthalmology, Yonsei University College of Medicine

    Seoul, 03722

Other trials in South Korea

About this study

The investigators aim to investigate the effects of combined corneal wavefront-guided transepithelial photorefractive keratectomy (tPRK) and accelerated corneal collagen cross-linking (CXL) after intracorneal ring segment (ICRS) implantation in patients with moderate keratoconus. Medical records of 23 eyes of 23 patients undergoing combined tPRK and CXL after ICRS implantation were retrospectively analyzed. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), corneal indices based on Scheimpflug tomography, higher-order aberrations (HOAs), and corneal biomechanical properties were evaluated before and after ICRS implantation, and at 1, 3, and 6 months after combined tPRK and CXL. Corneal biomechanical properties were measured using the dynamic Scheimpflug analyzer at approximately the same time of day.

Read the detailed description

The investigators aim to investigate the effects of combined corneal wavefront-guided transepithelial photorefractive keratectomy (tPRK) and accelerated corneal collagen cross-linking (CXL) after intracorneal ring segment (ICRS) implantation in patients with moderate keratoconus. Medical records of 23 eyes of 23 patients undergoing combined tPRK and CXL after ICRS implantation were retrospectively analyzed. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction spherical equivalent (MRSE), corneal indices based on Scheimpflug tomography, higher-order aberrations (HOAs), and corneal biomechanical properties were evaluated before and after ICRS implantation, and at 1, 3, and 6 months after combined tPRK and CXL. Corneal biomechanical properties were measured using the dynamic Scheimpflug analyzer at approximately the same time of day. The dynamic Scheimpflug analyzer automatically calculated corneal deformation amplitude, radius values, and maximal concave power when the cornea is deformed to its greatest curvature by the air puff. The deformation amplitude is defined as the maximum amplitude when the cornea is deformed to its greatest concave curvature and is influenced by corneal stiffness. The radius values represent the central concave curvature at the highest concavity (depressed to the highest concavity), while maximal concave power is the inverse radius of the curvature at the highest concavity.

Being tested
combined corneal wavefront-guided transepithelial photorefractive keratectomy (tPRK), accelerated corneal collagen cross-linking (CXL)

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • combined corneal wavefront-guided transepithelial photorefractive keratectomy (tPRK)Procedure or surgery

    After at least 1 month (average 2.7 ± 1.1 months; range 1 to 4 months), all patients were scheduled for combined corneal wavefront-guided tPRK and accelerated CXL treatment. tPRK between the corneal ring segments was performed using an excimer laser (Amaris 1050 Excimer Laser platform; Schwind eye-tech-solutions GmbH and Co KG, Kleinostheim, Germany).

  • accelerated corneal collagen cross-linking (CXL)Procedure or surgery

    After at least 1 month (average 2.7 ± 1.1 months; range 1 to 4 months), all patients were scheduled for combined corneal wavefront-guided tPRK and accelerated CXL treatment. tPRK between the corneal ring segments was performed using an excimer laser (Amaris 1050 Excimer Laser platform; Schwind eye-tech-solutions GmbH and Co KG, Kleinostheim, Germany).

Study groups in NCT03355430
Study groupRoleWhat they receive
moderate keratoconus groupmoderate keratoconus group underwent combined corneal wavefront-guided transepithelial photorefractive keratectomy (tPRK) and accelerated corneal collagen cross-linking (CXL) after intracorneal ring segment (ICRS) implantation
Receives: Procedure: combined corneal wavefront-guided transepithelial photorefractive keratectomy (tPRK); Procedure: accelerated corneal collagen cross-linking (CXL)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. visual acuity

    visual acuity in eyes undergoing combined corneal wavefront-guided transepithelial photorefractive keratectomy and accelerated corneal collagen cross-linking after intracorneal ring segment implantation in patients with moderate keratoconus

    Measured: Pre-operation (baseline)

  2. visual acuity

    visual acuity in eyes undergoing combined corneal wavefront-guided transepithelial photorefractive keratectomy and accelerated corneal collagen cross-linking after intracorneal ring segment implantation in patients with moderate keratoconus

    Measured: 1 minute before tPRK-CXL(transepithelial photorefractive keratectomy-accelerated corneal collagen cross-linking)

  3. visual acuity

    visual acuity in eyes undergoing combined corneal wavefront-guided transepithelial photorefractive keratectomy and accelerated corneal collagen cross-linking after intracorneal ring segment implantation in patients with moderate keratoconus

    Measured: 1 month after tPRK-CXL

  4. visual acuity

    visual acuity in eyes undergoing combined corneal wavefront-guided transepithelial photorefractive keratectomy and accelerated corneal collagen cross-linking after intracorneal ring segment implantation in patients with moderate keratoconus

    Measured: 3-month after tPRK-CXL

  5. visual acuity

    visual acuity in eyes undergoing combined corneal wavefront-guided transepithelial photorefractive keratectomy and accelerated corneal collagen cross-linking after intracorneal ring segment implantation in patients with moderate keratoconus

    Measured: 6-month after tPRK-CXL

Secondary outcomes (5)
  1. Corneal indices

    Multiple corneal indices were measured at the 8-mm zone using the Scheimpflug tomography system (Pentacam HR; OCULUS).

    Measured: Pre-operation (baseline)

  2. Corneal indices

    Multiple corneal indices were measured at the 8-mm zone using the Scheimpflug tomography system (Pentacam HR; OCULUS).

    Measured: 1 minute before tPRK-CXL

  3. Corneal indices

    Multiple corneal indices were measured at the 8-mm zone using the Scheimpflug tomography system (Pentacam HR; OCULUS).

    Measured: 1 month after tPRK-CXL

  4. Corneal indices

    Multiple corneal indices were measured at the 8-mm zone using the Scheimpflug tomography system (Pentacam HR; OCULUS).

    Measured: 3-month after tPRK-CXL

  5. Corneal indices

    Multiple corneal indices were measured at the 8-mm zone using the Scheimpflug tomography system (Pentacam HR; OCULUS).

    Measured: 6-month after tPRK-CXL

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted28 Nov 2017
  2. Study start7 Jul 2016
  3. Primary completion2 Jan 2017
  4. Study completion2 Jan 2017

Resources

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 only
Time perspective
Retrospective
Enrolment
23 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03355430
Sponsor's protocol ID
4-2016-0403
Status last verified
Nov 2017
First submitted
20 Nov 2017
Last updated
28 Nov 2017
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Lee H, Kang DSY, Ha BJ, Choi JY, Kim EK, Seo KY, Kim TI. Visual rehabilitation in moderate keratoconus: combined corneal wavefront-guided transepithelial photorefractive keratectomy and high-fluence accelerated corneal collagen cross-linking after intracorneal ring segment implantation. BMC Ophthalmol. 2017 Dec 29;17(1):270. doi: 10.1186/s12886-017-0666-1.

    PubMed 29284455

Questions about this trial

What is this clinical trial studying?

An observational study of Moderate Keratoconus, run by Yonsei University at 1 site in South Korea.

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 8 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 28 Nov 2017. 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 South Korea. 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?

visual acuity (time frame: Pre-operation (baseline)). The study lists 5 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 NCT03355430, 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 28 Nov 2017.

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