Simultaneous TransPRK and Corneal Collagen Cross-Linking

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

Interventions

PROCEDURE

Transepithelial Photorefractive Keratectomy (TransPRK)

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).

PROCEDURE

Corneal Collagen Cross-Linking (CXL)

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)

Sponsors & Collaborators

• Moorfields Eye Hospital NHS Foundation Trust

  collaborator OTHER

• Bruce Allan

  lead OTHER

Principal Investigators

• Bruce D Allan, MD FRCOphth · Moorfields Eye Hospital NHS Foundation Trust

• Dan M Gore, FRCOphth · Moorfields Eye Hospital NHS Foundation Trust

Study Design

Allocation

NON_RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

SEQUENTIAL

Eligibility

Min Age

18 Years

Max Age

35 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2014-08-31

Primary Completion

2016-07-31

Completion

2017-07-31

Countries

• United Kingdom

Study Locations