NCT03990506

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

Comparison of Epi-off and Epi-on Photorefractive Intrastromal Crosslinking (PiXL) for Progressive Keratoconus

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 32 (actual)
• Sponsor: Umeå University · Academic / Other
• Sex: All
• Age: 18 Years – 35 Years
• Healthy volunteers: Not accepted

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.

Detailed description

The study is designed as a prospective, single-masked intraindividually comparing randomized clinical trial involving participants of both genders aged 18-35 years with Keratoconus planned for routine corneal crosslinking at the Department of Ophthalmology, Umeå University Hospital, Umeå, Sweden. The study includes 32 participants with bilateral Keratoconus, receiving Epi-off PiXL (n=32) in one eye and Epi-on PiXL in high oxygen environment (n=32) in the fellow eye. The participants are randomized to epi-on PiXL utilizing block randomization with a sample size of 16 in each block; 16 right eyes and 16 left eyes. All participants are informed about the procedures before consenting to participate in the study. At baseline, before treatment, each eye is examined with slit-lamp microscopy, subjective refraction, determination of uncorrected (UCVA), low contrast visual acuity at 2.5 percentage contrast and 10 percentage contrast and best corrected (BSCVA) visual acuities using the LogMAR fast protocol and intraocular pressure (IOP) using Goldmann applanation tonometry. Under standardized, mesopic light conditions each eye is evaluated by keratometry readings and central corneal thickness using Schemipflug camera measurements, Pentacam HR® (Oculus, Inc. Lynnwood, WA). Endothelial cellcount is assessed (SP-2000P, Topcon, Inc) and total ocular wavefront is measured with iTrace (Tracey Technologies, Inc.). Ocular discomfort is subjectively evaluated in each eye by a specific visual analogous rating scale at 4h, 8h 24h and thereafter daily up to 1 week postoperatively. All the above mentioned examinations are repeated at 1, 3, 6, 12 and 24 months after treatment. At 1 day and 1 week after treatment, solely UCVA, Auto-refractor measurements and slit-lamp examination are evaluated.

Conditions

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

Interventions

Type	Name	Description
PROCEDURE	Epi-on PiXL	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.
PROCEDURE	Epi-Off PiXL	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.

Timeline

• Start date: 2019-04-02
• Primary completion: 2023-01-24
• Completion: 2023-01-24
• First posted: 2019-06-19
• Last updated: 2023-09-01

Locations

1 site across 1 country: Sweden