Biomechanical Properties of Keratoconic Eyes

NCT02476149 | Unknown

• 1 other identifier: 15/SW/0107
• Study Type: observational
• Target: 35
• Locations: 1 country
• Sites: 1

Brief Summary

In keratoconus (KC) corneal thinning and protrusion can cause myopia and irregular astigmatism, affecting vision. The biomechanical properties of the cornea is maintained by an intricate collagen network, which is responsible for its shape and function. In KC this collagen network is disrupted resulting in the cornea losing its shape and function. Keratoconic changes are focal and localised to certain regions of the cornea and the early detection of these changes is challenging. Screening methods include corneal topography (evaluation of anterior corneal surface curvature), tomography (assessing the morphological features of the anterior segment) and aberrometry (measuring the optical aberrations of the eye). More recent research suggests that the biomechanical destabilization of the cornea may precede topographic and tomographic evidence of KC. Management of KC depends on disease severity with severe cases being treated with keratoplasty and less severe cases with cornealcollagencrosslinking (CXL). CXL is an emerging technique, which aims to increase the biomechanical strength of the keratoconic cornea. Despite strong evidence of changes in the biomechanical properties in human corneas following CXL, there is a significant need for accurate measures of biomechanical changes in vivo pre and post CXL. Until recently technical limitations have restricted the ability to assess the biomechanical properties of the whole cornea in vivo. With the introduction of the CorvisST (Oculus) it is now possible to assess regional biomechanical behaviour of the cornea. The output from the device provides a variety of parameters to indicate the cornea's biomechanical strength. To date, the association between the deflection behaviours in various regions of the cornea in keratoconic eyes preand post CXL has not been studied. In order to effectively assess the clinical benefits of CXL such information is vital. The primary goal of this investigation is to investigate regional biomechanical properties of the keratoconic eye before and after CXL.

Conditions

Keratoconus

Outcome Measures

Primary Outcomes (1)

• Change of the corneal hysteresis following corneal crosslinking (mmHg)

  Corneal hysteresis as measured using the CorvisST

  Up to 3 months prior to corneal collagen crosslinking treatment and at 3-6 months after treatment

Secondary Outcomes (6)

• Change of refractive error following corneal crosslinking (LogMAR)

  Up to 3 months prior to corneal collagen crosslinking treatment and at 3-6 months after treatment

• Axial Length prior to corneal crosslinking (mm)

  Up to 3 months prior to corneal collagen crosslinking treatment

• Axial Length axial length following corneal crosslinking (mm)

  At 3-6 months after treatment

• Change in corneal curvature following corneal crosslinking (mm)

  Up to 3 months prior to corneal collagen crosslinking treatment and at 3-6 months after treatment

• Tear break up time prior to corneal crosslinking (s)

  Up to 3 months prior to corneal collagen crosslinking treatment

Interventions

Corneal Cross-linking PROCEDURE

All participants recruited for the study will be scheduled for corneal crosslinking treatment

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Potential participants will be identified as those patients who are due to undergo corneal collagen crosslinking treatment

You may qualify if:

• Adult subjects over the age of 18 with keratoconus who are enrolled for collagen crosslinking treatment

You may not qualify if:

• Any patient who has had surgical complications will also be excluded from participation in the study.
• Determination during enrolment:
• Pregnancy or breastfeeding during the study
• Any kind of systemic disease which affect collagen and the body water regulation system (Marfan syndrome, osteogenesis imperfect, pseudozanthoma elasticum, EhlersDanlos, diabetes, rosacea, acne, cardiovascular disease, thyroid disease)

Sponsors & Collaborators

• University of Plymouth: lead

Study Sites (1)

Plymouth University

Plymouth, Devon, PL6 8BH, United Kingdom

RECRUITING

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

Central Study Contacts

Phillip Buckhurst, PhD

CONTACT

01752 588884; phillip.buckhurst@plymouth.ac.uk

Daniela Oehring, MSc

CONTACT

+44 (0) 7584 428 035; daniela.oehring@plymouth.ac.uk

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Study Record Dates

• First Submitted: June 14, 2015
• First Posted: June 19, 2015
• Study Start: June 1, 2015
• Primary Completion: December 1, 2019
• Study Completion: January 1, 2020
• Last Updated: January 23, 2019

Record last verified: 2019-01

Locations

GB (1)