Refractive Corneal Cross-linking for Progressive Keratoconus

NCT ID: NCT03531047

Last Updated: 2023-12-08

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

Get a concise snapshot of the trial, including recruitment status, study phase, enrollment targets, and key timeline milestones.

Recruitment Status

COMPLETED

Clinical Phase

NA

Total Enrollment

53 participants

Study Classification

INTERVENTIONAL

Study Start Date

2018-11-01

Study Completion Date

2019-11-27

Brief Summary

Review the sponsor-provided synopsis that highlights what the study is about and why it is being conducted.

Young patients with keratoconus face two problems: disease progression and corneal shape irregularity. Both underlie the 20% rate of corneal transplantation in keratoconics required to maintain useful vision.

Corneal collagen cross-linking (CXL) is a now the gold-standard treatment to halt disease progression. The aim is to strengthen the cornea to prevent further shape deterioration. For patients whose quality of vision has already suffered, standard CXL can generally only prevent further deterioration, rather than improving vision. Refractive CXL, a new iteration of CXL in which a bespoke treatment pattern is applied to the cornea, aims to smooth out surface irregularities thereby improving vision.

This primary objective of this study is to compare the visual outcome in patients with progressive keratoconus treated with refractive CXL, as compared with historical controls treated with standard CXL.

Detailed Description

Dive into the extended narrative that explains the scientific background, objectives, and procedures in greater depth.

Irregular astigmatism (irregular corneal shape leading to irregular focus) is a common cause of failure to achieve an adequate spectacle correction for many patients with corneal disease. For patients affected, rigid gas permeable contact lenses are the only means of visual rehabilitation. Not all patients tolerate rigid contact lens wear, and those that do are often uncomfortable and have a restricted wearing time.

Keratoconus, in which the corneal shape becomes progressively steeper and more irregular in the 2nd to 4th decades of life, is a common cause of irregular astigmatism. Disease progression in keratoconus can be stabilised with corneal collagen cross-linking (CXL), effective in 90% of cases. Pre-existing irregular astigmatism often remains after CXL, with many patients requiring rigid gas permeable contact lenses to regain good vision.

The investigators have recently demonstrated improvements in vision following simultaneous combined cross-linking with laser refractive surgery (TransPRK/CXL). The excimer laser is used to create a smoother, more regular focusing shape on the cornea to improve the quality of vision achieved in spectacles. Although effective, the downsides of using this approach are both the cost and limited availability of excimer laser equipment in the National Health Service (NHS) in the United Kingdom. Also, excimer laser smoothing works by removing corneal tissue. It is not yet known whether this tissue removal will have any detrimental effect on corneal shape stability post CXL.

As a cheaper and potentially more widely accessible alternative, refractive CXL aims to regularise the corneal surface by applying a bespoke treatment pattern based on pre-operative corneal surface shape (topography) scans. At least two-thirds of patients undergoing standard CXL already have impaired vision at the time treatment. The investigators are aiming to offer these patients both long-term stability of their keratoconus and an improvement in vision in a single treatment.

Conditions

See the medical conditions and disease areas that this research is targeting or investigating.

Keratoconus

Keywords

Explore important study keywords that can help with search, categorization, and topic discovery.

progressive cross-linking customised refractive

Study Design

Understand how the trial is structured, including allocation methods, masking strategies, primary purpose, and other design elements.

Allocation Method

NA

Intervention Model

SINGLE_GROUP

Primary Study Purpose

TREATMENT

Blinding Strategy

NONE

Study Groups

Review each arm or cohort in the study, along with the interventions and objectives associated with them.

Refractive CXL

Tomography-customised CXL

Group Type EXPERIMENTAL

Customised CXL

Intervention Type PROCEDURE

As for standard CXL, following mechanical removal of the corneal surface layer (epithelium), 0.1% riboflavin drops will be applied every 2 minutes for 10 minutes prior to ultraviolet A (UVA) irradiation - UVA power, distribution and timing as determined by analysis of Pentacam tomography scans. A bandage contact lens will be applied to encourage regrowth of the corneal surface and reduce post-operative pain.

Interventions

Learn about the drugs, procedures, or behavioral strategies being tested and how they are applied within this trial.

Customised CXL

As for standard CXL, following mechanical removal of the corneal surface layer (epithelium), 0.1% riboflavin drops will be applied every 2 minutes for 10 minutes prior to ultraviolet A (UVA) irradiation - UVA power, distribution and timing as determined by analysis of Pentacam tomography scans. A bandage contact lens will be applied to encourage regrowth of the corneal surface and reduce post-operative pain.

Intervention Type PROCEDURE

Other Intervention Names

Discover alternative or legacy names that may be used to describe the listed interventions across different sources.

Riboflavin drops (drug): Vibex Rapid (Avedro Inc.)

Eligibility Criteria

Check the participation requirements, including inclusion and exclusion rules, age limits, and whether healthy volunteers are accepted.

Inclusion Criteria

* Patients with progressive stage I - III keratoconus
* Corrected distance visual acuity (CDVA) \< 0.00 logMAR

Exclusion Criteria

* Patients under the age of 18 years
* Active ocular surface disease
* Minimum corneal thickness \< 375 µm
* Vulnerable groups
* Pregnancy
Minimum Eligible Age

18 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

No

Sponsors

Meet the organizations funding or collaborating on the study and learn about their roles.

Moorfields Eye Hospital NHS Foundation Trust

OTHER

Sponsor Role lead

Responsible Party

Identify the individual or organization who holds primary responsibility for the study information submitted to regulators.

Responsibility Role SPONSOR

Principal Investigators

Learn about the lead researchers overseeing the trial and their institutional affiliations.

Daniel M Gore

Role: PRINCIPAL_INVESTIGATOR

Moorfields Eye Hospital NHS Foundation Trust

Locations

Explore where the study is taking place and check the recruitment status at each participating site.

Moorfields Eye Hospital NHS Foundation Trust

London, , United Kingdom

Site Status

Countries

Review the countries where the study has at least one active or historical site.

United Kingdom

References

Explore related publications, articles, or registry entries linked to this study.

Gore DM, Shortt AJ, Allan BD. New clinical pathways for keratoconus. Eye (Lond). 2013 Mar;27(3):329-39. doi: 10.1038/eye.2012.257. Epub 2012 Dec 21.

Reference Type RESULT
PMID: 23258309 (View on PubMed)

O'Brart DP, Chan E, Samaras K, Patel P, Shah SP. A randomised, prospective study to investigate the efficacy of riboflavin/ultraviolet A (370 nm) corneal collagen cross-linkage to halt the progression of keratoconus. Br J Ophthalmol. 2011 Nov;95(11):1519-24. doi: 10.1136/bjo.2010.196493. Epub 2011 Feb 24.

Reference Type RESULT
PMID: 21349938 (View on PubMed)

Other Identifiers

Review additional registry numbers or institutional identifiers associated with this trial.

GORD1003

Identifier Type: -

Identifier Source: org_study_id