Photorefractive Intrastromal Crosslinking (PiXL) for the Treatment of Progressive Keratoconus

NCT03990506 | Completed

• 1 other identifier: PiXLKC-I
• Study Type: interventional
• Target: 32
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this study is to evaluate the efficacy, safety and postoperative ocular discomfort by comparing individually customized Photorefractive intrastromal crosslinking (PiXL) for progressive Keratoconus. The study compares two different protocols, PiXL with corneal epithelium debridement (Epi-off) and PiXL without epithelium debridement in high oxygen environment (Epi-on), with the hypothesis that Epi-on gives less postoperative ocular discomfort.

Conditions

Keratoconus; Corneal Crosslinking; Corneal Biomechanics; Corneal Densitometry; Scheimpflug Photography; Corneal Disease; Eye Diseases

Outcome Measures

Primary Outcomes (1)

• Maximal keratometry (Kmax)

  Kmax assessed with the Pentacam HR Scheimpflug camera, Diopters.

  1 month, 3 months, 6 months, 12 months and 24 months after treatment

Secondary Outcomes (10)

• Uncorrected distance visual acuity (UDVA)

  1 month, 3 months, 6 months, 12 months and 24 months after treatment

• Best corrected visual acuity (BCVA)

  1 month, 3 months, 6 months, 12 months and 24 months after treatment

• Mean keratometry (Kmean)

  1 month, 3 months, 6 months, 12 months and 24 months after treatment

• Subjective Ocular Discomfort Scores

  4 hours, 8 hours, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days and 7 days after treatment

• Low contrast visual acuity (LCVA)

  1 month, 3 months, 6 months, 12 months and 24 months after treatment

Study Arms (2)

Epi-on PiXL

EXPERIMENTAL

Photorefractive intrastromal corneal crosslinking without epithelium debridement during humidified high oxygen flow.

Procedure: Epi-on PiXL

Epi-off PiXL

ACTIVE COMPARATOR

Photorefractive intrastromal corneal crosslinking with epithelium debridement.

Procedure: Epi-Off PiXL

Interventions

Epi-on PiXL PROCEDURE

Photorefractive intrastromal crosslinking (PiXL) After local anaesthetics, the cornea is soaked in Riboflavin by repeated topical application during 10 minutes. For masking purposes, epithelial debridement is simulated by moving a scraping instrument in front of the cornea. A Riboflavin soaked sponge is used to lightly disrupt the epithelium tight junctions, without epithelium debridement. The cornea is illuminated with PiXL under 16:40 minutes during continuously delivery of humidified high oxygen via specific oxygen goggles. The UV-dosage is individually customized based upon Kmax; \< 45D, 7.2J/cm2; 45-50D, 10J/cm2; \> 50D, 15 J/cm2.

Epi-on PiXL

Epi-Off PiXL PROCEDURE

Photorefractive intrastromal crosslinking (PiXL) After local anaesthetics, the corneal epithelium is debrided and the cornea is soaked in Riboflavin by repeated topical application during 10 minutes. The cornea is then illuminated with individually customized topography-guided PiXL under 16:40 minutes. The UV-dosage is individually customized based upon Kmax; \< 45D, 7.2J/cm2; 45-50D, 10J/cm2; \> 50D, 15 J/cm2.

Epi-off PiXL

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Patients planned for corneal crosslinking.
• Progressive keratoconus documented with a consistent decrease of best corrected visual acuity with no other explanation, an unquestionable historical progression, or a progression documented with the Pentacam Scheimpflug camera with at least 2 of the following: progressive anterior and/or posterior corneal steepening and/or progressive corneal thinning and/or increased rate of corneal thickness change from the periphery to the center.
• A keratoconus diagnosis based on abnormal posterior elevation, abnormal corneal thickness distribution and clinical noninflammatory corneal thinning using the "Belin/Ambrósio enhanced ectasia" measurements of the Pentacam Scheimpflug camera.
• Minimum corneal thickness of 400 µm at the thinnest point before epithelial removal.
• years of age
• No ocular abnormalities except keratoconus
• No previous ocular surgery
• No cognitive insufficiency interfering with the informed consent.

You may not qualify if:

• Age under 18 or over 35
• Any corneal abnormalities except keratoconus
• Pregnancy or lactation
• Previous ocular surgery
• Cognitive insufficiency

Sponsors & Collaborators

• Umeå University: lead
• Glaukos Corporation: collaborator

Study Sites (1)

Department of Clinical Sciences/Ophthalmology, Umeå University

Umeå, 901 85, Sweden

Location

MeSH Terms

Conditions

Keratoconus; Corneal Diseases; Eye Diseases

Study Officials

• Anders Behndig, MD, PhD

  Department of Clinical Sciences/Ophthalmology, Umeå University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: The participants are not aware which eye will receive the Epi-off PiXL treatment and which eye will receive the Epi-on PiXL treatment.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: Prospective, single-masked intraindividually comparing randomized controlled trial. Participants will be randomized to receive Epi-off PiXL in one eye and Epi-on PiXL in the other, which is masked to the participant. The participant can choose to treat in eye at a time or both eyes during the same visit.

Study Record Dates

• First Submitted: June 12, 2019
• First Posted: June 19, 2019
• Study Start: April 2, 2019
• Primary Completion: January 24, 2023
• Study Completion: January 24, 2023
• Last Updated: September 1, 2023

Record last verified: 2023-08

Data Sharing

• IPD Sharing: Will not share

Locations

SE (1)