A Study to Test the Potential of Brillouin Microscopy for Biomechanical Properties Measurements in Human Cornea

Not Applicable

Completed

• Conditions: Keratectasia; Keratoconus; Pellucid Marginal Corneal Degeneration
• Interventions: Device: Brillouin Ocular Scanner

• Registration Number: NCT03220529
• Lead Sponsor: Massachusetts General Hospital

Brief Summary

The purpose of this research study is to find out if the new Brillouin Ocular Scanner can measure the variation (difference) of the corneal elastic changes involved in the onset of corneal ectasia, induced by LASIK surgery and cornea collagen crosslinking (CXL) treatment. Ectasia refers to the thinning and bulging of the cornea and results in severe vision degradation (loss), which may occur because of a progressive disease (keratoconus) or because of LASIK surgery. It is believed that the structural weakening of the cornea plays a major role in developing ectasia. CXL is a treatment that is able to halt the progression of ectasia.

The Brillouin Ocular Scanner is a technique based on the principles used in the laser speed measuring of a car (radar gun). When laser light illuminates a moving sample, a portion of the light slightly changes color. In our body, e.g in eye and corneal tissue, very weak sound waves are naturally present and they can induce a similar color shift. Measuring this color shift with a sensitive light color meter (spectrometer), we will measure the sound speed in the tissue.

Detailed Description

Not available

Study Timeline

• Study Start: 2016-11
• Study First Submitted: 2017-06-09
• Study First Submitted QC: 2017-07-16
• Study First Posted: 2017-07-18
• Primary Completion: 2019-09
• Study Completion: 2020-09
• Status Verified: 2022-07
• Last Update Submitted: 2022-07-29
• Last Update Posted: 2022-08-02

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 85

Inclusion Criteria

• Subjects with healthy cornea
• Patients with mild, moderate, or advanced keratoconus
• Subjects diagnosed with PMD
• Patients before and after LASK surgery
• Patients with keratoconus before and after collagen crosslinking treatment

Exclusion Criteria

• Normal volunteer group: presbyopia and/or cataract
• Keratoconus subjects group: corneas with scars developed, received any ocular surgery, such as laser vision correction surgeries or CXL treatment
• Subjects diagnosed with PMD: excludes corneas received any ocular surgery, such as laser vision correction or CXL treatment
• Patients before and after LASK surgery Corneas received priori ocular surgeries, taking any ocular medications except season allergy medicine such as artificial tears

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Normal healthy subjects	Brillouin Ocular Scanner	Healthy subjects with normal appearing corneas respecting all the general inclusion/exclusion criteria. Multiple axial measurements with the Brillouin Ocular Scanner on the cornea will be carried out.
Subjects diagnosed with PMD	Brillouin Ocular Scanner	Subjects with Pellucid marginal corneal degeneration (PMD). Multiple axial measurements with the Brillouin Ocular Scanner on the cornea will be carried out.
Patients before and after LASK surgery	Brillouin Ocular Scanner	Healthy subjects who are scheduled to undergo LASIK surgery. Multiple axial measurements with the Brillouin Ocular Scanner on the cornea will be carried out.
Keratoconus subjects	Brillouin Ocular Scanner	Subjects classified as patients with mild, moderate, or advanced keratoconus. Multiple axial measurements with the Brillouin Ocular Scanner on the cornea will be carried out.
Patients with keratoconus before and after CXL	Brillouin Ocular Scanner	Subjects who are scheduled to undergo collagen crosslinking treatment. Multiple axial measurements with the Brillouin Ocular Scanner on the cornea will be carried out.

Primary Outcome Measures

Name	Time	Method
Brillouin frequency shift of corneal stroma	at time of measurement	Brillouin frequency shift of corneal stroma in normal corneas and corneas diagnosed with keratoconus and pellucid marginal degeneration
Change of Brillouin frequency shift from base line in corneas received crosslinking treatment	3 days, 1 month, 3 months, 6 months	Brillouin frequency shift in corneas before and after receiving crosslinking surgery
Change of Brillouin frequency shift from base line in corneas received LASIK surgery	1 day and 4-8 weeks	Brillouin frequency shift in corneas before and after receiving LASIK surgery

Trial Locations

Locations (2)

Institute for Refractive and Ophthalmic Surgery; 🇨🇭 Zurich, Switzerland

Massachusetts Eye and Ear Infirmary; 🇺🇸 Boston, Massachusetts, United States