Corneal Biomechanical Analysis Using Brillouin Microscopy

NCT04598932 | Enrolling By Invitation FDA Device

• 1 other identifier: 20-355
• Study Type: observational
• Target: 220
• Locations: 1 country
• Sites: 1

Brief Summary

The objective of this study is to measure the Brillouin biomechanical properties in keratoconic corneas and characterize biomechanical alterations that occur after corneal procedures that inherently strengthen or weaken the cornea by evaluating the change in Brillouin metrics before and after treatments.

Conditions

Keratoconus; Keratoconus, Unstable; Keratoconus, Stable

Keywords

Brillouin; Keratoconus; Keratoconus, Unstable; Corneal Cross Linking; CXL; LASIK; PRK; SMILE

Outcome Measures

Primary Outcomes (1)

• Change in Brillouin Metrics

  Brillouin metrics to be evaluated include localized Mean Brillouin modulus measure across the cornea and at each depth of the corneal stroma

  Difference between baseline and 3 months after intervention

Study Arms (6)

1: Normal Controls

Patients with normal corneas without any prior surgery to serve as the control group

Device: Brillouin microscopy

2 Keratoconus

Patients with various stages of keratoconus

Device: Brillouin microscopy

3: LASIK

Patients with normal corneas who are undergoing laser in situ keratomileusis (LASIK)

Device: Brillouin microscopy

Group 4: PRK

Patients with normal corneas who are undergoing photorefractive keratectomy (PRK)

Device: Brillouin microscopy

5: SMILE

Patients with normal corneas who are undergoing small incision lenticular extraction (SMILE)

Device: Brillouin microscopy

6: CXL

Patients with keratoconus who are undergoing corneal cross-linking (CXL)

Device: Brillouin microscopy

Interventions

Brillouin microscopy DEVICE

The Brillouin clinical instrument is comprised of three parts: a human interface, a laser-scanning confocal microscope, and an etalon-based spectrometer. The human interface is a modified ophthalmic slit-lamp instrument with chin support and headrest. The light source is a single longitudinal mode CW laser at 780 nm. A polarizing beam splitter and quarter-wave plate assembly sends the laser beam to the human interface. To focus light into the eye, a long-working distance microscope objective is used. Brillouin scattered light from the eye is collected with a single-mode optical fiber. For spectral analysis, a two-stage VIPA-etalon spectrometer configured with the cross-axis cascade principle and the spectrum is measured on a EM-CCD camera.

1: Normal Controls; 2 Keratoconus; 3: LASIK; 5: SMILE; 6: CXL; Group 4: PRK

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Group 1: Patients with normal corneas Group 2: Patients with keratoconus Group 3: Patients with normal corneas undergoing LASIK Group 4: Patients with normal corneas undergoing PRK Group 5: Patients with normal corneas undergoing SMILE Group 6: Patients with keratoconus undergoing CXL

You may qualify if:

• patients aged 18-60 with keratoconus
• patients aged 18-60 with normal corneas,
• patients aged 18-60 undergoing refractive surgery (LASIK, PRK, SMILE)
• patients aged 18-60 with keratoconus undergoing CXL

You may not qualify if:

• outside age range
• history of previous ocular surgeries
• unable to cooperate for the Brillouin microscopic examination
• unable to provide informed consent

Sponsors & Collaborators

• The Cleveland Clinic: lead
• University of Maryland: collaborator

Study Sites (1)

Cleveland Clinic Cole Eye Institute

Cleveland, Ohio, 44195, United States

Location

Related Publications (7)

• Zhang H, Roozbahani M, Piccinini AL, Golan O, Hafezi F, Scarcelli G, Randleman JB. Depth-Dependent Reduction of Biomechanical Efficacy of Contact Lens-Assisted Corneal Cross-linking Analyzed by Brillouin Microscopy. J Refract Surg. 2019 Nov 1;35(11):721-728. doi: 10.3928/1081597X-20191004-01.

  PMID: 31710374 BACKGROUND

• Webb JN, Langille E, Hafezi F, Randleman JB, Scarcelli G. Biomechanical Impact of Localized Corneal Cross-linking Beyond the Irradiated Treatment Area. J Refract Surg. 2019 Apr 1;35(4):253-260. doi: 10.3928/1081597X-20190304-01.

  PMID: 30984983 BACKGROUND

• Randleman JB, Su JP, Scarcelli G. Biomechanical Changes After LASIK Flap Creation Combined With Rapid Cross-Linking Measured With Brillouin Microscopy. J Refract Surg. 2017 Jun 1;33(6):408-414. doi: 10.3928/1081597X-20170421-01.

  PMID: 28586502 BACKGROUND

• Scarcelli G, Pineda R, Yun SH. Brillouin optical microscopy for corneal biomechanics. Invest Ophthalmol Vis Sci. 2012 Jan 20;53(1):185-90. doi: 10.1167/iovs.11-8281.

  PMID: 22159012 RESULT

• Scarcelli G, Kling S, Quijano E, Pineda R, Marcos S, Yun SH. Brillouin microscopy of collagen crosslinking: noncontact depth-dependent analysis of corneal elastic modulus. Invest Ophthalmol Vis Sci. 2013 Feb 19;54(2):1418-25. doi: 10.1167/iovs.12-11387.

  PMID: 23361513 RESULT

• Scarcelli G, Besner S, Pineda R, Yun SH. Biomechanical characterization of keratoconus corneas ex vivo with Brillouin microscopy. Invest Ophthalmol Vis Sci. 2014 Jun 17;55(7):4490-5. doi: 10.1167/iovs.14-14450.

  PMID: 24938517 RESULT

• Scarcelli G, Besner S, Pineda R, Kalout P, Yun SH. In vivo biomechanical mapping of normal and keratoconus corneas. JAMA Ophthalmol. 2015 Apr;133(4):480-2. doi: 10.1001/jamaophthalmol.2014.5641. No abstract available.

  PMID: 25611213 RESULT

MeSH Terms

Conditions

Keratoconus

Condition Hierarchy (Ancestors)

Corneal Diseases; Eye Diseases

Study Design

• Study Type: observational
• Observational Model: CASE CONTROL
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Staff Physician

Study Record Dates

• First Submitted: May 19, 2020
• First Posted: October 22, 2020
• Study Start: June 1, 2021
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: February 17, 2026

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)