Corneal Biomechanics Study

NCT ID: NCT03658239

Last Updated: 2020-01-29

Basic Information

• Recruitment Status: WITHDRAWN
• Clinical Phase: NA
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-12-31
• Study Completion Date: 2020-12-31

Brief Summary

The goal of the study is to investigate relationship between the corneal response to a temporary increase in intraocular pressure and corneal mechanical properties.

Detailed Description

The preliminary theoretical study in which the corneal geometry at different intraocular pressure (IOP) levels is investigated using a theoretical biomechanical cornea model found changes in both conventional refractive error (sphere and cylinder) and irregular astigmatism i.e. higher order aberrations (e.g. spherical aberration, trefoil and quadrafoil). This is due to the mechanical characteristics of the cornea determined largely by interaction between collagen fibrils organization and extrafibrillar matrix material properties. Corneal geometry and the material properties are the two main factors that contribute to the changes in corneal aberrations with IOP elevation. These aberration changes due to the variation of IOP and the material properties of the cornea can be measured routinely with corneal topography systems (UR) and Brillouin ocular scanner (MGH), respectively and can guide the investigators to study their impact on optical and biomechanical behaviors of the cornea.

Conditions

Myopia

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: NONE

Study Groups

Experimental

Subjects will undergo 4-5 visits total over the course of 6 months. There will be 3-4 visits that will be done at the Flaum Eye Institute. During these sessions the subject will be measured with a stationary topographer (GALILEI G4), with a rotatable topography measurement (Oculus Topographer) and a Tonometer. The subject's heart rate and blood pressure will also be measured (using a commercially available blood pressure and heart rate meter).

The GALILEI measurement will only be done once. The rest of the measurements will be done up to 4 times. Once at the start of the study session then, after the subject has been inverted using a commercially available inversion table to first 135 degrees, then 150 degrees and finally to 165 degrees.

The blood pressure and heart rate will be monitored to ensure subject safety.

There will also be one visit at the Massachusetts General Hospital. The visit will be 2 hours and will involve a Brillouin Microscopy measurement.

Group Type: EXPERIMENTAL

Inversion

Intervention Type: OTHER

Inversions will be done while the subject is on the inversion table. The subject will be inverted to 135, 150 and 165 degrees. There inversion will not last longer than 3 minutes at a time. The inversion will be terminated if the subject's blood pressure drops below 50 mmHg diastolic or if the subject's blood pressure increases more than 50 mmHg systolic.

Interventions

Inversion

Inversions will be done while the subject is on the inversion table. The subject will be inverted to 135, 150 and 165 degrees. There inversion will not last longer than 3 minutes at a time. The inversion will be terminated if the subject's blood pressure drops below 50 mmHg diastolic or if the subject's blood pressure increases more than 50 mmHg systolic.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

A person is eligible for inclusion in the study if he/she:

• Is an adult between the ages of 18 and 55.
• Is under 250 pounds.

Exclusion Criteria

A person will be excluded from the study if he/she:

• Is under the age of 18 or over the age of 55 yrs.
• Weighs more than 250 pounds.
• Has clinically significant dry eye.
• Has glaucoma.
• Has hypertension.
• Has prior CVA.
• Has cardiovascular disease.
• Has lower extremity joint injury, damage, or replacement.
• Has baseline bradycardia.
• Has any orthopaedic injuries.
• Is pregnant.
• Has hiatal and ventral hernias.
• Has vertigo.
• Has acid reflux (GERD).
• Is undergoing myopia control treatment (e.g. atropinisation, Ortho-K, bifocal contact lenses etc.).
• Has conditions or has undergone procedures resulting in significant corneal irregularity (e.g. keratoconus, corneal transplant, etc.). This does not include astigmatism and basic refractive errors.
• Has any ocular or systemic diseases that, in the opinion of the PI/SI, would interfere with obtaining a measurement.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 55 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

University of Rochester

OTHER

Sponsor Role: lead

Responsible Party

Geunyoung Yoon

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Geunyoung Yoon, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Rochester

Other Identifiers

71844

Identifier Type: -

Identifier Source: org_study_id