[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"trial:NCT04598932":3,"trial-entities:NCT04598932":106,"trial-summary:NCT04598932":110},{"id":4,"nct_id":4,"org_study_id":5,"brief_title":6,"official_title":6,"overall_status":7,"completion_date":8,"status_verified_date":9,"last_update_date":10,"start_date":11,"sponsor_name":12,"lead_sponsor_class":13,"has_dmc":14,"brief_summary":15,"detailed_description":16,"conditions":17,"keywords":21,"study_type":28,"primary_purpose":29,"phases":30,"enrollment_info":31,"interventions":34,"primary_outcomes":46,"secondary_outcomes":51,"sex":52,"minimum_age":53,"maximum_age":54,"healthy_volunteers":14,"eligibility_criteria":55,"std_ages":67,"locations":69,"central_contacts":79,"overall_officials":80,"references":81,"see_also_links":105},"NCT04598932","20-355","Corneal Biomechanical Analysis Using Brillouin Microscopy","ENROLLING_BY_INVITATION","2026-12","2025-09","2026-02-17","2021-06-01","The Cleveland Clinic","OTHER",false,"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.","Surgical correction of myopia and keratoconus identification\u002Fmanagement 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.\n\nKeratoconus is up to 10 times more prevalent than the previously reported 1\u002F2000 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.\n\nIn 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.\n\nIt 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.",[18,19,20],"Keratoconus","Keratoconus, Unstable","Keratoconus, Stable",[22,18,19,23,24,25,26,27],"Brillouin","Corneal Cross Linking","CXL","LASIK","PRK","SMILE","OBSERVATIONAL",null,[],{"count":32,"type":33},220,"ESTIMATED",[35],{"type":36,"name":37,"description":38,"armGroupLabels":39},"DEVICE","Brillouin microscopy","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.",[40,41,42,43,44,45],"1: Normal Controls","2 Keratoconus","3: LASIK","5: SMILE","6: CXL","Group 4: PRK",[47],{"measure":48,"description":49,"timeFrame":50},"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",[],"ALL","18 Years","60 Years",{"inclusion":56,"exclusion":61,"raw_text":66},[57,58,59,60],"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",[62,63,64,65],"outside age range","history of previous ocular surgeries","unable to cooperate for the Brillouin microscopic examination","unable to provide informed consent","Inclusion Criteria:\n\n* patients aged 18-60 with keratoconus\n* patients aged 18-60 with normal corneas,\n* patients aged 18-60 undergoing refractive surgery (LASIK, PRK, SMILE)\n* patients aged 18-60 with keratoconus undergoing CXL\n\nExclusion Criteria:\n\n* outside age range\n* history of previous ocular surgeries\n* unable to cooperate for the Brillouin microscopic examination\n* unable to provide informed consent",[68],"ADULT",[70],{"facility":71,"city":72,"state":73,"zip":74,"country":75,"geoPoint":76},"Cleveland Clinic Cole Eye Institute","Cleveland","Ohio","44195","United States",{"lat":77,"lon":78},41.4995,-81.69541,[],[],[82,86,89,92,96,99,102],{"pmid":83,"type":84,"citation":85},"31710374","BACKGROUND","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\u002F1081597X-20191004-01.",{"pmid":87,"type":84,"citation":88},"30984983","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\u002F1081597X-20190304-01.",{"pmid":90,"type":84,"citation":91},"28586502","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\u002F1081597X-20170421-01.",{"pmid":93,"type":94,"citation":95},"22159012","RESULT","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\u002Fiovs.11-8281.",{"pmid":97,"type":94,"citation":98},"23361513","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\u002Fiovs.12-11387.",{"pmid":100,"type":94,"citation":101},"24938517","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\u002Fiovs.14-14450.",{"pmid":103,"type":94,"citation":104},"25611213","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\u002Fjamaophthalmol.2014.5641. No abstract available.",[],{"nct_id":4,"conditions":107,"biomarkers":109},[18,108],"Normal Corneas",[],{"nct_id":4,"found":111,"summary":112,"prompt_version":121},true,{"design":113,"status":114,"heading":6,"summary":115,"follow_up":116,"word_count":117,"commitments":118,"compensation":119,"drugs_mentioned":120},"This is an observational study, meaning researchers will be watching and recording information without giving you a specific treatment. It plans to include 220 participants.","completed","This observational study is looking at how stiff your cornea (the clear front part of your eye) is, using a special device called Brillouin microscopy. Researchers want to understand how corneal stiffness changes in people with keratoconus (a condition where the cornea thins and bulges) and after certain eye procedures like LASIK or corneal cross-linking (CXL). The study will measure changes in corneal stiffness over three months. You might be able to join if you are between 18 and 60 years old and have keratoconus, normal corneas, or are having refractive surgery (like LASIK) or CXL for keratoconus. The study aims to enroll 220 participants.","Your corneal stiffness will be measured at baseline and again 3 months later.",105,"The study will measure changes in Brillouin metrics between your baseline visit and 3 months later. The specific number of visits or procedures is not detailed.","Not stated in the trial record.",[37],"v2"]