Simultaneous pHototherapeutic Keratectomy and corneAl Collagen cRosslinking in Eyes With Keratoconus: a Randomized Trial (SHARK)

The goal of this clinical trial is to compare CXL with combined treatment with CXL and t-PTK.

The main questions it aims to answer are whether combined treatment can give better visual acuity and if the treatments are equally safe.

Study Overview

• Status: Recruiting
• Conditions: Keratoconus
• Intervention / Treatment: Procedure: Corneal collagen cross linking (CXL); Procedure: Transepithelial phototherapeutic keratectomy (t-PTK)

• Study Type: Interventional
• Enrollment (Estimated): 81
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Olav Kristianslund, MD, PhD; Phone Number: +4722118545; Email: olakri@ous-hf.no

Study Locations

• Norway
  • Oslo, Norway
    • Recruiting
    • Department of Ophhtalmology, University of Oslo
    • Contact: Olav Kristianslund, MD, PhD; Email: olakri@ous-hf.no
    • Contact: Bjarne L Thorbjørnsen, MD; Email: uxtbja@ous-hf.no

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients must be 18 years or older at the time of signing the informed consent form. There is no upper age limit.
• Progressive keratoconus with indication for CXL
• Corneal thickness ≥ 420 μm

Exclusion Criteria:

• Other eye disease causing visual impairment

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: CXL; Treatment with CXL alone	Procedure: Corneal collagen cross linking (CXL); Use of Avedro Inc. KXL 1 system to stop progression of keratoconus
Experimental: CXL and t-PTK; Treatment with t-PTK combined with CXL	Procedure: Corneal collagen cross linking (CXL); Use of Avedro Inc. KXL 1 system to stop progression of keratoconus; Procedure: Transepithelial phototherapeutic keratectomy (t-PTK); Use Alcon Wavelight 500, excimer laser to remove the epithelium and some of the stroma over apex

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual acuity	Uncorrected and corrected distance visual acuity in logMAR	1 month after surgery
Risk of progression	Change in keratometric values	1 year after surgery

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual acuity	Uncorrected and corrected distance visual acuity in logMAR	3 month after surgery
Visual acuity	Uncorrected and corrected distance visual acuity in logMAR	6 month after surgery
Visual acuity	Uncorrected and corrected distance visual acuity in logMAR	1 year after surgery
Visual acuity	Uncorrected and corrected distance visual acuity in logMAR	2 years after surgery
Visual acuity	Uncorrected and corrected distance visual acuity in logMAR	5 years after surgery
Risk of progression	Change in keratometric values	1 month after surgery
Risk of progression	Change in keratometric values	3 months after surgery
Risk of progression	Change in keratometric values	6 months after surgery
Risk of progression	Change in keratometric values	2 years after surgery
Risk of progression	Change in keratometric values	5 years after surgery
Depth of demarcation line (OCT)	Measured with corneal optical coherence tomography (OCT)	1 month after surgery
Depth of demarcation line (confocal microscopy)	Measured with confocal microscopy	1 month after surgery
Patient reported outcome measure (PROMs)	National eye institute Visual Function Questionnaire 25	1 month after surgery
Patient reported outcome measure (PROMs)	National eye institute Visual Function Questionnaire 25	6 months after surgery
Patient reported outcome measure (PROMs)	National eye institute Visual Function Questionnaire 25	2 years after surgery
Patient reported pain after surgery	Pain the first 48 hours after the surgery graded on visual analogue scale (VAS); 0 to 10 cm.	48 hours after surgery

Collaborators and Investigators

• Sponsor: Oslo University Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): February 12, 2024
• Primary Completion (Estimated): May 1, 2025
• Study Completion (Estimated): February 1, 2034

Study Registration Dates

• First Submitted: January 29, 2024
• First Submitted That Met QC Criteria: February 9, 2024
• First Posted (Actual): February 16, 2024

Study Record Updates

• Last Update Posted (Actual): February 16, 2024
• Last Update Submitted That Met QC Criteria: February 9, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Corneal Diseases; Keratoconus
• Other Study ID Numbers: 519516

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No