Simultaneous TransPRK and Corneal Collagen Cross-Linking

NCT02208089 | Completed Results DMC

• 1 other identifier: ALLB1018
• Study Type: interventional
• Target: 55
• Locations: 1 country
• Sites: 1

Brief Summary

Young patients with keratoconus face two problems: disease progression and corneal shape irregularity leading to poor vision even in spectacles. Corneal collagen cross-linking (CXL) is a new treatment designed to halt disease progression in keratoconus. The aim is to stiffen the cornea thereby preventing further shape deterioration. Topography or wavefront guided transepithelial photorefractive keratectomy (transPRK) uses the excimer laser (the laser used to correct sight in 'laser eye surgery') to reduce corneal shape irregularity in early stage keratoconus, reducing dependence on contact lenses. In transPRK, the corneal skin layer is removed in a well controlled, no touch procedure, preparing the cornea for CXL. Performing both treatments simultaneously (combining both procedures in one operation) may offer several advantages over performing CXL first then waiting for corneal shape to stabilise before performing transPRK. In particular, visual rehabilitation may be faster. This study aims to evaluate visual recovery after simultaneous CXL and transPRK in progressive early stage keratoconus. Visual recovery in these patients will be compared with results for a similar group of patients with early stage keratoconus who have already been treated with CXL alone.

Conditions

Keratoconus

Keywords

Keratoconus; Corneal collagen cross-linking; Photorefractive keratectomy

Outcome Measures

Primary Outcomes (1)

• Change in LogMAR Corrected Distance Visual Acuity (CDVA)

  Change in spectacle corrected logarithm minimum angle of resolution (LogMAR) distance visual acuity recorded in a 4m testing lane in photopic lighting conditions between baseline measurement and final review at 24 months (note that negative change = better vision; 0.1 logMAR units = 1 line on the test chart)

  Preoperative vs 24 months

Secondary Outcomes (4)

• Clinically Significant Visual Gain

  Preoperative vs 24 months postoperative

• Clinically Significant Visual Loss

  preoperative vs 24 months postoperative

• Change in Kmax - Maximum Local Anterior Corneal Surface Curvature on Tomography Map

  Preoperative vs 24 months postoperative

• Progression Rate

  6 months postoperative - 24 months postoperative

Study Arms (2)

TransPRKCXL

EXPERIMENTAL

Simultaneous combined transepithelial photorefractive keratectomy (TransPRK) and corneal collagen cross-linking (CXL)

Procedure: Transepithelial Photorefractive Keratectomy (TransPRK); Procedure: Corneal Collagen Cross-Linking (CXL)

CXL only

ACTIVE COMPARATOR

Corneal collagen cross-linking (CXL) using the same protocol without transepithelial photorefractive keratectomy

Procedure: Corneal Collagen Cross-Linking (CXL)

Interventions

Transepithelial Photorefractive Keratectomy (TransPRK) PROCEDURE

Aberrometry or topography guided transepithelial photorefractive keratectomy (TransPRK) using the Schwind Amaris 750s excimer laser (www.eye-tech-solutions.com), an 8mm treatment diameter, and a tissue saving algorithm targeting selected higher order aberrations only. TransPRK will be followed immediately by corneal collagen cross-linking (CXL).

Also known as: Corneal surface excimer laser treatment

TransPRKCXL

Corneal Collagen Cross-Linking (CXL) PROCEDURE

Riboflavin soak: 10 minutes total soak time; application of 0.1% riboflavin preparation (VibeX Rapid - www.avedro.com) each 2 minutes with gentle balanced salt solution irrigation to remove excess riboflavin prior to UV light exposure. UV light exposure: Total treatment time 8 minutes (370nm wavelength; 30mW/cm2 irradiance; 4 minutes total UV exposure time, pulsed 1.5 seconds on 1.5 seconds off; Avedro KXL I light source)

Also known as: Rapid corneal collagen cross-linking

CXL only; TransPRKCXL

Eligibility Criteria

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

You may qualify if:

• Patients with progressive stage II or III keratoconus
• CDVA \< 0.00 logMAR or subjective problems with spectacle corrected visual quality (ghost images or light scatter symptoms)

You may not qualify if:

• Active ocular surface disease
• Minimum corneal thickness \<390µm (leaving 325µm residual stromal thickness after transPTK - in line with minimum thickness recommendations for the study CXL protocol)
• Vulnerable groups (patients whose capacity for giving informed consent to participate in the trial may be impaired)

Sponsors & Collaborators

• Bruce Allan: lead
• Moorfields Eye Hospital NHS Foundation Trust: collaborator

Study Sites (1)

Moorfields Eye Hospital NHS Foundation Trust, 162 City Road

London, EC1V 2PD, United Kingdom

Location

Related Publications (2)

• 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.

  PMID: 23258309 BACKGROUND

• Kanellopoulos AJ, Asimellis G. Keratoconus management: long-term stability of topography-guided normalization combined with high-fluence CXL stabilization (the Athens Protocol). J Refract Surg. 2014 Feb;30(2):88-93. doi: 10.3928/1081597X-20140120-03.

  PMID: 24763473 BACKGROUND

MeSH Terms

Conditions

Keratoconus

Interventions

Corneal Cross-Linking

Condition Hierarchy (Ancestors)

Corneal Diseases; Eye Diseases

Intervention Hierarchy (Ancestors)

Photochemotherapy; Combined Modality Therapy; Therapeutics; Drug Therapy; Phototherapy

Results Point of Contact

• Title: Mr Bruce Allan
• Organization: Moorfields Eye Hospital NHS Foundation Trust

bruce.allan@ucl.ac.uk

02075662320

Study Officials

• Bruce D Allan, MD FRCOphth

  Moorfields Eye Hospital NHS Foundation Trust

  PRINCIPAL INVESTIGATOR

• Dan M Gore, FRCOphth

  Moorfields Eye Hospital NHS Foundation Trust

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Consultant Ophthalmic Surgeon

Model Details: Interventional case series with matched historical controls

Study Record Dates

• First Submitted: July 25, 2014
• First Posted: August 4, 2014
• Study Start: August 1, 2014
• Primary Completion: July 1, 2016
• Study Completion: July 1, 2017
• Last Updated: February 8, 2019
• Results First Posted: February 8, 2019

Record last verified: 2018-09

Locations

GB (1)