Search results for "Corneal ring"

showing 8 items of 8 documents

Impact of Corneoscleral Contact Lens Usage on Corneal Biomechanical Parameters in Keratoconic Eyes

2019

Objective To analyze the changes in corneal biomechanical parameters of keratoconic eyes with and without intracorneal ring segment (ICRS) implants after 1 year of corneoscleral contact lens (CScL) wear. Methods Seventy-four eyes of 74 patients were divided into three groups: healthy subjects (29 eyes, control group), and 2 groups of subjects with keratoconic eyes (one group of 20 eyes with ICRS implants and one of 25 eyes without them), which were fitted with CScL. Corneal hysteresis (CH), corneal resistance factor (CRF), and corneal-compensated intraocular pressure (IOPcc) were evaluated before fitting CScL and after 1 year of CScL wear. In addition, endothelial cell count (ECC) and centr…

AdultMaleKeratoconusIntraocular pressuremedicine.medical_specialtygenetic structuresContact LensesCorneal StromaKeratoconusEndothelial cell countCorneaProsthesis ImplantationCorneoscleral contact lensCorneal hysteresisTonometry OcularYoung Adult03 medical and health sciences0302 clinical medicineProsthesis FittingCorneaOphthalmologyHumansMedicineProspective StudiesIntracorneal ring segmentIntraocular Pressurebusiness.industryHealthy subjectsProstheses and Implantsmedicine.diseaseElasticityeye diseasesBiomechanical PhenomenaOphthalmologyCross-Sectional Studiesmedicine.anatomical_structure030221 ophthalmology & optometryFemalesense organsbusiness030217 neurology & neurosurgeryEye & Contact Lens: Science & Clinical Practice
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A new approach based on Machine Learning for predicting corneal curvature (K1) and astigmatism in patients with keratoconus after intracorneal ring i…

2014

Keratoconus (KC) is the most common type of corneal ectasia. A corneal transplantation was the treatment of choice until the last decade. However, intra-corneal ring implantation has become more and more common, and it is commonly used to treat KC thus avoiding a corneal transplantation. This work proposes a new approach based on Machine Learning to predict the vision gain of KC patients after ring implantation. That vision gain is assessed by means of the corneal curvature and the astigmatism. Different models were proposed; the best results were achieved by an artificial neural network based on the Multilayer Perceptron. The error provided by the best model was 0.97D of corneal curvature …

AdultMaleKeratoconusgenetic structuresComputer sciencemedicine.medical_treatmentHealth InformaticsAstigmatismMachine learningcomputer.software_genreKeratoconusCorneal TransplantationMachine LearningYoung AdultCorneal ectasiaIntracorneal ringsArtificial IntelligenceProsthesis FittingmedicineHumansIn patientCorneal transplantationAgedRing (mathematics)Corneal curvaturebusiness.industryCorneal TopographyAstigmatismProstheses and ImplantsMiddle AgedDecision Support Systems ClinicalPrognosismedicine.diseaseeye diseasesComputer Science ApplicationsPatient Outcome AssessmentTreatment OutcomeFemalesense organsArtificial intelligencebusinesscomputerLENGUAJES Y SISTEMAS INFORMATICOSSoftware
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Intrastromal corneal ring segment implantation in paracentral keratoconus with coincident topographic and coma axis.

2012

To evaluate the efficacy, predictability, and safety of implantation of Ferrara-type intrastromal corneal ring segments (ICRS) for refractive correction of paracentral keratoconus.Fernández-Vega Ophthalmological Institute, Oviedo, Spain.Cohort study.Snellen uncorrected (UDVA) and corrected (CDVA) distance visual acuities and residual refractive errors were recorded before and 6 months after ICRS implantation for keratoconus. The tunnels for ICRS implantation were created with a femtosecond laser. The power vector and the Alpins method were used to analyze postoperative refractive outcomes.The study evaluated 56 eyes of 49 patients. The mean UDVA was 0.17 ± 0.14 (SD) preoperatively and 0.41 …

AdultMaleKeratoconusmedicine.medical_specialtygenetic structuresmedicine.medical_treatmentCorneal StromaVision DisordersVisual AcuityComa (optics)Power vectorKeratoconusRefraction OcularCohort StudiesProsthesis ImplantationYoung AdultOphthalmologymedicineHumansPolymethyl MethacrylateProspective StudiesAlpins methodAgedIntrastromal corneal ring segmentbusiness.industryCorneal TopographyProstheses and ImplantsMiddle Agedmedicine.diseaseeye diseasesSensory SystemsSurgeryOphthalmologySurgeryFemalesense organsLaser TherapyCorneal ringbusinessJournal of cataract and refractive surgery
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Characterization of the effect of intracorneal ring segment in corneal ectasia after laser refractive surgery

2018

Purpose: To evaluate the visual, refractive, topographic, pachymetric, and biomechanical outcomes after intracorneal ring segment implantation in corneas with post-LASIK ectasia. Methods: Retrospective longitudinal study enrolling 26 eyes of 22 patients with post-LASIK ectasia and undergoing intracorneal ring segment implantation (KeraRing®, Mediphacos) using a 60-kHz femtosecond laser (IntraLase®, IntraLase Corp.) for corneal tunnelization. Visual, refractive, anterior, and posterior corneal topographic (Pentacam HR, Oculus), pachymetric, and corneal biomechanical changes (Ocular response Analyzer, Reichert) were evaluated during a 12-month follow-up. Vector analysis of astigmatic changes …

AdultMaleReoperationmedicine.medical_specialtyCorneal ectasiagenetic structuresCorneal Surgery Lasermedicine.medical_treatmentVisual AcuityAstigmatismProsthesis DesignRefraction OcularCorneal Diseaseslaw.inventionCorneaCorneal ectasiaPostoperative ComplicationsLens Implantation IntraocularlawIntracorneal ring segmentEctasiaOphthalmologyRefractive surgerymedicineHumansPost-LASIK ectasiaPentacam hrIntracorneal ring segmentRetrospective StudiesÓpticaPost-LASIK ectasiabusiness.industryCorneal TopographyGeneral MedicineMiddle Agedmedicine.diseaseLasereye diseasesOphthalmologyFemalesense organsbusinessDilatation PathologicFollow-Up StudiesEuropean Journal of Ophthalmology
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Femtosecond laser–assisted intrastromal corneal ring segment implantation for high astigmatism correction after penetrating keratoplasty

2013

PURPOSE: To assess the visual and refractive outcomes of femtosecond laser-assisted implanta- tion of Ferrara-type intrastromal corneal ring segments (ICRS) in post-penetrating keratoplasty (PKP) eyes. SETTING: Instituto OftalmolFernOviedo, Spain. DESIGN: Cohort study. METHODS: Patients with previous PKP had ICRS implantation after femtosecond laser tunnel creation. The uncorrected (UDVA) and corrected (CDVA) distance visual acuities and residual refractive errors were recorded before and 6 months after ICRS implantation. The power vector method was used to analyze refractive errors preoperatively and postoperatively. RESULTS: This study enrolled 32 eyes of 30 patients. The mean UDVA (Snell…

AdultMalemedicine.medical_specialtygenetic structuresCorneal Stromamedicine.medical_treatmentVisual AcuitySpherical equivalentAstigmatismRefraction OcularPower vectorCorneal DiseasesCohort StudiesProsthesis ImplantationYoung AdultHigh astigmatismOphthalmologymedicineHumansPolymethyl MethacrylateProspective StudiesIntrastromal corneal ring segmentbusiness.industryAstigmatismProstheses and ImplantsMiddle Agedmedicine.diseaseLaser assistedeye diseasesSensory SystemsSurgeryOphthalmologyTreatment OutcomeFemtosecondFemaleSurgeryLaser Therapysense organsCorneal ringbusinessKeratoplasty PenetratingJournal of Cataract and Refractive Surgery
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Are Ocular Response Analyzer useful to measure corneal hysteresis in patients with intracorneal rings?

2008

Purpose Corneal hysteresis is a viscoelastic property characterized by the difference in behavior under loading and unloading. The aim of the study was to determine corneal hysteresis in different eyes: healthy eyes, keratoconic eyes and keratoconic eyes after intracorneal ring implants. Methods This study comprised 95 eyes of 59 patients. The study population was divided into 3 groups. We analyze 30 healthy human eyes, 35 keratoconic eyes (Amsler grade II-III) and 30 keratoconic eyes after intracorneal rings implantation. Corneal biomechanical properties of these eyes were measured with the Ocular Response Analyser (ORA-Reichert) according to two parameters: corneal hysteresis (CH) and cor…

Keratoconusmedicine.medical_specialtygenetic structuresbusiness.industryGeneral Medicinemedicine.diseaseeye diseasesCorneal hysteresisOphthalmologyOphthalmologymedicineOptometryStatistical analysisIn patientsense organsCorneal ringbusinessActa Ophthalmologica
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Visual quality with corneo-scleral contact lenses after intracorneal ring segment (ICRS) implantation for keratoconus management

2019

Purpose: To evaluate the visual quality results when fitting a corneo-scleral contact lens (CScL) after intracorneal ring segment (ICRS) implantation for keratoconus management. Methods: Twenty-seven eyes of 27 patients with keratoconus underwent ICRS implantation and had CScL fitted as their visual quality was unsatisfactory with their spectacles or contact lenses. Patients received a complete eye examination, refraction and visual acuity assessment, anterior eye biomicroscopy, ocular fundus examination, corneal topographic analysis, endothelial-cell count, and visual quality assessment using contrast sensitivity and aberrometry tests. A diagnostic trial set was used in the fitting process…

MaleCorneal Wavefront AberrationVisual acuitygenetic structuresVisual Acuity0302 clinical medicineIntracorneal ring segmentProsthesis FittingContrast (vision)media_commonmedicine.diagnostic_testQuality assessmentCorneoscleral contact lensProstheses and ImplantsGeneral MedicineMiddle AgedRefractive ErrorsEye examinationFemalemedicine.symptomScleraAdultmedicine.medical_specialtyKeratoconusCorneal ectasiaContact LensesCorneal Stromamedia_common.quotation_subjectKeratoconusContrast SensitivityProsthesis ImplantationYoung Adult03 medical and health sciencesOphthalmologyAberrometrymedicineHumansIntracorneal ring segmentbusiness.industryAberrometryCorneal Topographymedicine.diseaseeye diseasesContact lensOphthalmology030221 ophthalmology & optometrysense organsbusiness030217 neurology & neurosurgeryOptometryContact Lens and Anterior Eye
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Evaluation of a new nomogram for Ferrara ring segment implantation in keratoconus

2021

AIM: To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years of research and retrospective analysis of clinical data. METHODS: This prospective longitudinal non-comparative clinical trial evaluated 88 eyes of 88 patients (age 18-62y) with keratoconus diagnosis from two Spanish centers. Ferrara ring segment (AJL Ophthalmic) implantation was performed in all cases, using the mechanical procedure in 25 eyes (28.4%) and a femtosecond laser-assisted procedure in 63 eyes (71.6%). The ring segments implanted in each case were selected using a new optimized nomogram that considered variables such as anterior corneal asph…

ferrara ring segmentKeratoconusmedicine.medical_specialtyDistance visual acuitygenetic structureskeratoconusFemtosecondComa (optics)AstigmatismKeratoconusPupilClinical Researchcoma aberrationIntracorneal ring segmentOphthalmologymedicineRetrospective analysisComa aberrationfemtosecondÓpticaFerrara ring segmentbusiness.industryCorneal asphericityRE1-994Nomogrammedicine.diseaseeye diseasesOphthalmologysense organsbusinessintracorneal ring segmentInternational Journal of Ophthalmology
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