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Korneal biomekanisk analyse ved bruk av Brillouin-mikroskopi

28. september 2026 oppdatert av: James Bradley Randleman, The Cleveland Clinic

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.

Studieoversikt

Status

Påmelding etter invitasjon

Forhold

Intervensjon / Behandling

Detaljert beskrivelse

Surgical correction of myopia and keratoconus identification/management are separate but tightly intertwined issues of major significance. For both, there is an unmet need for direct measurements to evaluate corneal stiffness (i.e. its resistance to deformation). The prevalence of myopia is expected to double, affecting more than 50% of the US population, by 2050. Laser in situ keratomileusis (LASIK) is one of the most popular and successful surgeries in the world and compares favorably to long-term contact lens wear use for myopia correction. However, only ~10% of eligible patients undergo LASIK currently; the others cite safety concerns as a major factor in their decision. The primary risk for poor refractive surgery outcomes is biomechanical failure due to unidentified (subclinical) ectasia (i.e. keratoconus). Patients presenting for LASIK evaluation with atypical, suspicious corneal curvature but with undetermined true risk represent the leading reason for surgery screening failures. This results in good candidates being denied surgery, while up to 10% of truly poor candidates are still missed using current screening algorithms.

Keratoconus is up to 10 times more prevalent than the previously reported 1/2000 figure. Corneal cross-linking (CXL) is now FDA approved in the US for keratoconus treatment and is effective at stiffening the cornea and halting ectasia progression. Early identification of keratoconus is critical, but current tests in the clinic are morphological, not biomechanical, and therefore do not allow a definitive diagnosis at the earliest stages resulting in vision loss before CXL treatment is initiated. Thus, the need for accurate identification of subclinical ectasia has never been greater.

In the past years, newly developed technology, Brillouin microscopy, has emerged as the most promising tool to address this clinical need. This study will systemically address the critical gap in current knowledge by linking Brillouin mapping of corneal biomechanical alterations to abnormal morphological behavior and testing the findings in conditions where corneal biomechanics are abruptly altered, by: 1) weakening with refractive surgery procedures, and 2) strengthening through corneal cross-linking.

It is anticipated that a clinical tool assessing the mechanical state of the cornea will improve early diagnosis and management of keratoconus as well as refractive surgery planning. Ultimately, this will lead to predictive models where Brillouin measurements could be an accurate predictor of postoperative outcomes and thus aid in developing individualized surgical parameters.

Studietype

Observasjonsmessig

Registrering (Antatt)

220

Kontakter og plasseringer

Denne delen inneholder kontaktinformasjon for de som utfører studien, og informasjon om hvor denne studien blir utført.

Studiesteder

    • Ohio
      • Cleveland, Ohio, Forente stater, 44195
        • Cleveland Clinic Cole Eye Institute

Deltakelseskriterier

Forskere ser etter personer som passer til en bestemt beskrivelse, kalt kvalifikasjonskriterier. Noen eksempler på disse kriteriene er en persons generelle helsetilstand eller tidligere behandlinger.

Kvalifikasjonskriterier

Alder som er kvalifisert for studier

18 år til 60 år (Voksen)

Tar imot friske frivillige

Nei

Kjønn som er kvalifisert for studier

Alle

Prøvetakingsmetode

Ikke-sannsynlighetsprøve

Studiepopulasjon

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

Beskrivelse

Inclusion Criteria:

  • 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

Exclusion Criteria:

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

Studieplan

Denne delen gir detaljer om studieplanen, inkludert hvordan studien er utformet og hva studien måler.

Hvordan er studiet utformet?

Designdetaljer

  • Observasjonsmodeller: CASE_CONTROL
  • Tidsperspektiver: CROSS_SECTIONAL

Kohorter og intervensjoner

Gruppe / Kohort
Intervensjon / Behandling
1: Normal Controls

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

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.

2 Keratoconus

Patients with various stages of keratoconus

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.

3: LASIK

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

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.

Group 4: PRK

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

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.

5: SMILE

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

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.

6: CXL

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

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.

Hva måler studien?

Primære resultatmål

Resultatmål
Tiltaksbeskrivelse
Tidsramme
Change in Brillouin Metrics
Tidsramme: Difference between baseline and 3 months after intervention

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

Samarbeidspartnere og etterforskere

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Sponsor

Samarbeidspartnere

Publikasjoner og nyttige lenker

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Generelle publikasjoner

Studierekorddatoer

Disse datoene sporer fremdriften for innsending av studieposter og sammendragsresultater til ClinicalTrials.gov. Studieposter og rapporterte resultater gjennomgås av National Library of Medicine (NLM) for å sikre at de oppfyller spesifikke kvalitetskontrollstandarder før de legges ut på det offentlige nettstedet.

Studer hoveddatoer

Studiestart (Faktiske)

1. juni 2021

Primær fullføring (Antatt)

1. juli 2027

Studiet fullført (Antatt)

1. desember 2027

Datoer for studieregistrering

Først innsendt

19. mai 2020

Først innsendt som oppfylte QC-kriteriene

21. oktober 2020

Først lagt ut (Faktiske)

22. oktober 2020

Oppdateringer av studieposter

Sist oppdatering lagt ut (Faktiske)

1. oktober 2026

Siste oppdatering sendt inn som oppfylte QC-kriteriene

28. september 2026

Sist bekreftet

1. september 2026

Mer informasjon

Begreper knyttet til denne studien

Ytterligere relevante MeSH-vilkår

Andre studie-ID-numre

  • 20-355

Plan for individuelle deltakerdata (IPD)

Planlegger du å dele individuelle deltakerdata (IPD)?

NEI

IPD-planbeskrivelse

there is no plan to share data

Legemiddel- og utstyrsinformasjon, studiedokumenter

Studerer et amerikansk FDA-regulert medikamentprodukt

Nei

Studerer et amerikansk FDA-regulert enhetsprodukt

Ja

produkt produsert i og eksportert fra USA

Nei

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