Corneal Cross-Linking for Keratoconus

Recruiting at 3 trial locations

Overseen By Marco Armijo

Age: 18 - 65

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Phase 1 & 2

Recruiting

Sponsor: Glaukos Corporation

Disqualifiers: Allergy, Abnormal topography, Ocular condition

No Placebo Group

Trial Summary

What is the purpose of this trial?

This trial is testing a treatment that uses light and vitamins to strengthen the cornea in people with keratoconus, a condition that makes the cornea thin and cone-shaped. The new treatment option aims to improve the cornea's strength and shape.

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment for keratoconus?

Research shows that corneal cross-linking (CXL) is effective in stopping the progression of keratoconus, a condition where the cornea (the clear front part of the eye) becomes thin and cone-shaped. Studies have demonstrated that CXL can stabilize the cornea and improve its strength, making it a reliable treatment option for this eye condition. ^{1 2 3 4 5}

Is corneal cross-linking safe for humans?

Corneal cross-linking (CXL) is generally considered safe for treating keratoconus, although rare severe complications can occur. Studies have shown it to be effective and safe in stopping the progression of keratoconus, but results can vary, especially in certain cases like very advanced keratoconus. ^{3 6 7 8 9}

How is the treatment NXL Energy 1, NXL Energy 2, NXL Energy 3 for keratoconus different from other treatments?

Corneal cross-linking (CXL) is unique because it strengthens the cornea (the clear front part of the eye) by using a special light and vitamin B2 (riboflavin) to create new bonds between collagen fibers, which helps stop the progression of keratoconus and can improve vision. ^{1 3 4 10 11}

Eligibility Criteria

This trial is for individuals with keratoconus, a condition that affects the shape of the cornea. Participants must be able to keep their gaze stable and give written consent. It's not open to those with other diseases affecting eye topography, prior eye conditions that could complicate results, or allergies to components used in the treatments.

Inclusion Criteria

Provide written informed consent

I have been diagnosed with keratoconus.

I can keep my eyes fixed on one point without moving.

Exclusion Criteria

Known allergy or sensitivity to the test articles or components

I have an eye condition that is not keratoconus.

I have an eye condition that could lead to future problems.

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants receive Riboflavin Ophthalmic Solution and UV-A Irradiation or a sham solution as part of the corneal cross-linking procedure

1 day

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment, including changes in visual acuity and corneal topography

12 months

Multiple visits (in-person)

Treatment Details

Interventions

• NXL Energy 1 (Corneal Cross-linking)
• NXL Energy 2 (Corneal Cross-linking)
• NXL Energy 3 (Corneal Cross-linking)
• Sham Treatment (Procedure)

Trial Overview The study tests three different energy levels (NXL Energy 1, NXL Energy 2, NXL Energy 3) of corneal cross-linking against a sham treatment to see which is safest and most effective at stabilizing the cornea in keratoconus patients.

Participant Groups

Group I: Riboflavin Ophthalmic Solution and UV-A Irradiation Group 1 / Cohort 1 Experimental Treatment 1 Intervention

Riboflavin Solution + Exposure to NXL system to achieve total energy level 3

Group II: Riboflavin Ophthalmic Solution and UV-A Irradiation Group 3 / Cohort 2A Active Control 1 Intervention

Riboflavin Solution + Exposure to NXL system to achieve total energy level 1

Group III: Riboflavin Ophthalmic Solution and UV-A Irradiation Group 4 / Cohort 2A Active Control 1 Intervention

Riboflavin Solution + Exposure to NXL system to achieve total energy level 2

Group IV: Riboflavin Ophthalmic Solution and UV-A Irradiation Group 5 / Cohort 2A Active Control 1 Intervention

Riboflavin Solution + Exposure to NXL system to achieve total energy level 3

Group V: Riboflavin Ophthalmic Solution and UV-A Irradiation Group 3 / Cohort 2B Active Control 1 Intervention

Riboflavin Solution + Exposure to NXL system to achieve total energy level 1

Group VI: Riboflavin Ophthalmic Solution and UV-A Irradiation Group 4 / Cohort 2B Active Control 1 Intervention

Riboflavin Solution + Exposure to NXL system to achieve total energy level 2

Group VII: Riboflavin Ophthalmic Solution and UV-A Irradiation Group 5 / Cohort 2B Active Control 1 Intervention

Riboflavin Solution + Exposure to NXL system to achieve total energy level 3

Group VIII: Placebo Group 2 / Cohort 2B Placebo Group 1 Intervention

Sham Solution with no exposure to NXL System

NXL Energy 1 is already approved in Canada for the following indications:

Approved in Canada as Corneal Cross-linking for:

• Keratoconus
• Ectasia

Who Is Running the Clinical Trial?

Glaukos Corporation

Lead Sponsor

Trials

69

Recruited

9,500+

Thomas Burns

Glaukos Corporation

Chief Executive Officer since 2002

B.A. from Yale University

Dr. Tomas Navratil

Glaukos Corporation

Chief Medical Officer since 2022

MD from Harvard Medical School

Findings from Research

Corneal cross-linking (CXL) significantly improved best-corrected visual acuity (BCVA) in patients with progressive keratoconus, with an average BCVA of 0.8 six months post-procedure compared to lower scores before treatment.

CXL also led to a reduction in spherical equivalent refraction, cylinder, and maximum keratometry (max K), indicating enhanced corneal stability and potential refractive benefits.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The results of corneal cross-linking in the treatment of keratoconus. Kasumovic, SS., Pavljasevic, S., Dacic-Lepara, S., et al.[2019]

In a study of 27 eyes from 24 patients with progressive keratoconus, customized corneal crosslinking (CXL) using a transepithelial approach and supplemental oxygen led to significant improvements in corrected distance visual acuity (CDVA) and corneal curvature after 6 months.

The procedure resulted in a flattening of steep keratometry by an average of -1.9 diopters and a reduction in corneal aberrations, all without significant adverse events, indicating its safety and efficacy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Customized corneal crosslinking for treatment of progressive keratoconus: Clinical and OCT outcomes using a transepithelial approach with supplemental oxygen. Mazzotta, C., Sgheri, A., Bagaglia, SA., et al.[2021]

Corneal cross-linking (CXL) has proven to be an effective and safe treatment for halting the progression of keratoconus and other corneal ectasias, with its use now extending to patients at risk of progression, particularly younger individuals.

The outcomes of CXL can vary, and different treatment protocols exist, highlighting the importance of careful patient selection and consideration of specific cases, such as those with thin corneas.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Patient selection for corneal collagen cross-linking: an updated review. Galvis, V., Tello, A., Ortiz, AI., et al.[2020]

Corneal cross-linking (CXL) has been established as a safe and effective treatment for keratoconus and corneal ectasias, supported by numerous laboratory and clinical studies.

Recent research is paving the way for advancements in CXL techniques, including accelerated methods and epithelium-sparing protocols, which may enhance treatment outcomes and broaden the applications of CXL.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Current and future applications of corneal cross-linking. Khandelwal, SS., Randleman, JB.[2018]

In a study of 96 patients with keratoconus, 39.6% experienced disease progression during an average waiting time of 153 days before receiving corneal cross-linking (CXL) treatment.

Specific preoperative tomographic parameters, such as the index of surface variance and keratoconus index, were significantly different between eyes that progressed and those that remained stable, suggesting these factors could help identify patients at higher risk for progression while awaiting treatment.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prospective Clinical Study of Keratoconus Progression in Patients Awaiting Corneal Cross-linking. Goh, YW., Gokul, A., Yadegarfar, ME., et al.[2021]

Standard corneal collagen crosslinking (epithelium-off CXL) is more effective than transepithelial CXL in reducing maximum keratometry in patients with keratoconus, based on a study of 244 eyes over at least 12 months.

Transepithelial CXL resulted in better improvements in corrected distant visual acuity (CDVA) compared to standard CXL, while both methods showed similar safety profiles.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficacy and safety of transepithelial corneal collagen crosslinking surgery versus standard corneal collagen crosslinking surgery for keratoconus: a meta-analysis of randomized controlled trials. Li, W., Wang, B.[2022]

In a case series of four keratoconus patients treated with corneal collagen cross-linking (CXL), severe complications occurred within the first month, including bacterial infections and an autoimmune response, leading to permanent corneal scarring in some cases.

While severe complications after CXL are rare, they often arise from indirect factors during the healing process, such as patient behavior and the use of bandage contact lenses, highlighting the need for improved techniques and careful postoperative management.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Severe Complications after Corneal Collagen Cross-Linking (CXL). Blaser, F., Zweifel, S., Wiest, MRJ., et al.[2023]

Accelerated corneal cross-linking (CXL) showed significant improvements in keratometric values in pediatric patients with keratoconus, indicating its efficacy in stabilizing the condition, although it did not lead to significant changes in visual acuity.

Both accelerated and conventional CXL were effective in managing keratoconus, with the accelerated method offering a shorter treatment time, making it a viable alternative for young patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Efficacy of Conventional Versus Accelerated Corneal Cross-linking in Pediatric Keratoconus: Two-Year Outcomes. Turhan, SA., Yargi, B., Toker, E.[2021]

Collagen cross-linking (CXL) is a safe and effective treatment for halting the progression of advanced keratoconus, with 27 out of 28 eyes showing no further progression after the procedure.

Despite starting with a high maximum keratometry (maxK) of 61.2 D, CXL led to a significant reduction in maxK to 59.5 D, indicating that CXL can be beneficial even in cases previously thought to have a higher risk of treatment failure.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Collagen cross-linking for advanced progressive keratoconus. Ivarsen, A., Hjortdal, J.[2022]

A combined treatment of topography-guided photorefractive keratectomy (PRK) with mitomycin-C and corneal collagen cross-linking (CXL) significantly improved best corrected visual acuity in patients with mild to moderate keratoconus over a 2-year follow-up, with a notable improvement from 0.15 to 0.08 logMAR.

The procedure also effectively reduced keratometry measurements, indicating a flattening of the cornea, which is crucial for managing keratoconus, with significant reductions in both steepest and flattest meridian keratometry values.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Combined photorefractive keratectomy and corneal collagen cross-linking for treatment of keratoconus: a 2-year follow-up study. De Rosa, G., Rossi, S., Santamaria, C., et al.[2022]

In a study of 239 eyes from 171 patients with progressive keratoconus, the CXL-plus-PTK procedure showed superior effectiveness compared to the standard Accelerated CXL, particularly in reducing maximum keratometry (Kmax).

The Iontophoresis CXL procedure also demonstrated better outcomes in terms of minimum corneal thickness (C value) compared to the Accelerated CXL group, indicating that different CXL modalities can have varying impacts on corneal health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Independent-effect comparison of five crosslinking procedures for Progressive Keratoconus based on Keratometry and the ABCD Grading System using Generalized Estimating Equations (GEE). Liu, Y., Shen, D., Wang, HY., et al.[2023]

References

1. Bosnia and Herzegovina pubmed.ncbi.nlm.nih.gov

The results of corneal cross-linking in the treatment of keratoconus. [2019]

2. United States pubmed.ncbi.nlm.nih.gov

Customized corneal crosslinking for treatment of progressive keratoconus: Clinical and OCT outcomes using a transepithelial approach with supplemental oxygen. [2021]

3. New Zealand pubmed.ncbi.nlm.nih.gov

Patient selection for corneal collagen cross-linking: an updated review. [2020]

4. United States pubmed.ncbi.nlm.nih.gov

Current and future applications of corneal cross-linking. [2018]

5. United States pubmed.ncbi.nlm.nih.gov

Prospective Clinical Study of Keratoconus Progression in Patients Awaiting Corneal Cross-linking. [2021]

6. England pubmed.ncbi.nlm.nih.gov

Efficacy and safety of transepithelial corneal collagen crosslinking surgery versus standard corneal collagen crosslinking surgery for keratoconus: a meta-analysis of randomized controlled trials. [2022]

7. Germany pubmed.ncbi.nlm.nih.gov

Severe Complications after Corneal Collagen Cross-Linking (CXL). [2023]

8. United States pubmed.ncbi.nlm.nih.gov

Efficacy of Conventional Versus Accelerated Corneal Cross-linking in Pediatric Keratoconus: Two-Year Outcomes. [2021]

9. United States pubmed.ncbi.nlm.nih.gov

Collagen cross-linking for advanced progressive keratoconus. [2022]

10. United States pubmed.ncbi.nlm.nih.gov

Combined photorefractive keratectomy and corneal collagen cross-linking for treatment of keratoconus: a 2-year follow-up study. [2022]

11. England pubmed.ncbi.nlm.nih.gov

Independent-effect comparison of five crosslinking procedures for Progressive Keratoconus based on Keratometry and the ABCD Grading System using Generalized Estimating Equations (GEE). [2023]