Epithelium-on Cross-linking Versus Observation of Fellow Eyes of Patients With Unilateral Clinically Evident Keratoconus

NCT ID: NCT06267495

Last Updated: 2024-02-20

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 40 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2017-01-01
• Study Completion Date: 2024-01-31

Brief Summary

Keratoconus (KC) is a bilateral asymmetric progressive corneal degenerative disease. The management of young patients, diagnosed with clinically evident KC in one eye and with no clinical signs of KC in the other eye, represents a real challenge for many ophthalmologists.

The aim of the current study is to investigate the effectiveness and safety of epithelium-on accelerated CXL to stabilize the eye with no clinical signs of KC, in young patients with unilateral clinically evident KC, compared with standard care and follow-up only.

Detailed Description

Keratoconus (KC) is a bilateral asymmetric progressive corneal degenerative disease associated with corneal thinning and protrusion with resultant irregular astigmatism and visual loss.

Although several studies showed that epithelium-off corneal cross-linking (epi-off CXL) is more effective in preventing KC progression compared with epithelium-on corneal cross-linking (epi-on CXL), the removal of corneal epithelium in epi-off CXL might be associated with a number of serious complications such as persistent epithelial defects and sight-threatening infectious keratitis. Additionally, recent systematic reviews and meta-analysis concluded that epi-on CXL is as effective as epi-off CXL in terms of visual and topographic stability of keratoconus, but has the advantage of being much safer avoiding the complications of epithelial removal.

The management of the better eye, of young patients with unilateral clinically evident KC, is controversial. Some ophthalmologists prefer to cross-link the better eye, while others prefer to conservatively follow it up, in order to avoid complications of epithelial removal in epi-off CXL.

Conditions

Keratoconus

Study Design

• Observational Model Type: OTHER
• Study Time Perspective: RETROSPECTIVE

Study Groups

Epithelium-on corneal cross-linking group

Patients in this group underwent epithelium-on accelerated corneal cross-linking (epi-on CXL) for the eye with no clinical signs of keratoconus.

Epithelium-on corneal cross-linking (epi-on CXL)

Intervention Type: PROCEDURE

In epithelium-on corneal cross-linking (epi-on CXL), the cornea is soaked with riboflavin for 10 minutes (Paracel® for 4 minutes and VibeX-xtra® for 6 minutes) . Thereafter, the cornea is subjected to ultraviolet A at a wavelength of 370 nm to give a total dose of 5.4 J/cm² through 10 milliwatt mW/cm² for 9 minutes.

Follow-up group

Patients in this group were planned to have regular follow-up visits, without intervention, for the eye with no clinical signs of keratoconus.

No interventions assigned to this group

Interventions

Epithelium-on corneal cross-linking (epi-on CXL)

In epithelium-on corneal cross-linking (epi-on CXL), the cornea is soaked with riboflavin for 10 minutes (Paracel® for 4 minutes and VibeX-xtra® for 6 minutes) . Thereafter, the cornea is subjected to ultraviolet A at a wavelength of 370 nm to give a total dose of 5.4 J/cm² through 10 milliwatt mW/cm² for 9 minutes.

Intervention Type: PROCEDURE

Eligibility Criteria

Inclusion Criteria

Patients aged 12 to 30 years presented with forme fruste (FFKC) or subclinical KC, based on the following criteria:

1. Normal slit lamp examination

2. Normal topography in FFKC and suspicious topography in subclinical KC with asymmetric bow-tie or inferior steeping (inferior-superior value less than 1.40 D in the anterior sagittal curvature map in pentacam)

3. Clinical and topographic features of KC in the other eye.

Exclusion Criteria

1. Corrected distance visual acuity (CDVA) worse than 0.1 logMAR

2. Corneal thickness at the thinnest location less than 400 μm

3. Severe ocular allergy (active catarrhal keratoconjunctivitis)

4. Other corneal or ocular diseases

5. Systemic diseases such as diabetes mellitus and autoimmune diseases

• Minimum Eligible Age: 12 Years
• Maximum Eligible Age: 30 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Assiut University

OTHER

Sponsor Role: lead

Responsible Party

Mahmoud Abdel-Radi

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Mahmoud Abdel-Radi, MD

Role: PRINCIPAL_INVESTIGATOR

Assiut University

Locations

Tiba Eye Center

Asyut, , Egypt

Countries

Egypt

References

Koh S, Inoue R, Maeda N, Kabata D, Shintani A, Jhanji V, Klyce SD, Maruyama K, Nishida K. Long-term Chronological Changes in Very Asymmetric Keratoconus. Cornea. 2019 May;38(5):605-611. doi: 10.1097/ICO.0000000000001890.

Reference Type: BACKGROUND

PMID: 30702472 (View on PubMed)

Henriquez MA, Hadid M, Izquierdo L Jr. A Systematic Review of Subclinical Keratoconus and Forme Fruste Keratoconus. J Refract Surg. 2020 Apr 1;36(4):270-279. doi: 10.3928/1081597X-20200212-03.

Reference Type: BACKGROUND

PMID: 32267959 (View on PubMed)

Other Identifiers

EOCXLFE

Identifier Type: -

Identifier Source: org_study_id