Search results for "Conus"
showing 10 items of 40 documents
Genome-wide association meta-analysis of corneal curvature identifies novel loci and shared genetic influences across axial length and refractive err…
2020
Corneal curvature, a highly heritable trait, is a key clinical endophenotype for myopia - a major cause of visual impairment and blindness in the world. Here we present a trans-ethnic meta-analysis of corneal curvature GWAS in 44,042 individuals of Caucasian and Asian with replication in 88,218 UK Biobank data. We identified 47 loci (of which 26 are novel), with population-specific signals as well as shared signals across ethnicities. Some identified variants showed precise scaling in corneal curvature and eye elongation (i.e. axial length) to maintain eyes in emmetropia (i.e. HDAC11/FBLN2 rs2630445, RBP3 rs11204213); others exhibited association with myopia with little pleiotropic effects …
Levels of lactoferrin, lysozyme and albumin in the tear film of keratoconus patients and their correlations with important parameters of the disease
2020
Abstract Background: Despite the fact that keratoconus has been tipically defined as a noninflammatory condition, recent research has promoted the role of inflammatory factors and protein changes of tear film in disease progression. Aims: to determine the level of serum albumin, lactoferrin and lyzozyme in tears of keratoconic patients and their correlations with corneal biomechanical properties. Subjects and methods: 16 eyes of keratoconus patients and 14 eyes of control cases were enrolled in an observational prospective study. We performed a complete ophthalmological examination on all participants. In order to determine the concentration of tear film proteins, a minimum of 20 microlitre…
Evolution of Corneal Graft Survival Over a 30-Year Period and Comparison of Surgical Techniques: A Cohort Study.
2015
Purpose To compare graft survival between 3 10-year periods and according to surgical techniques performed in the last years. Design Cohort study. Methods setting: Regional center (Besancon University Hospital, France). patients: All 1132 patients operated on between 1983 and 2014. Graft and patient baseline characteristics, risk factors for failure, surgical procedures, and postoperative corneal status were collected. main outcome measures: Five-year survival rate in the whole cohort; 1-year and 3-year survival rates, respectively, among 88 patients with endothelial dystrophy (ED) or postoperative bullous keratopathy (PBK) operated on using endothelial lamellar keratoplasty (ELK) or penetr…
Corneoscleral contact lenses for visual rehabilitation after keratoplasty surgery.
2019
Abstract Purpose To report the use of corneoscleral lenses (CSL) in keratoconus patients who were unsatisfied with their visual outcomes after keratoplasty surgery. Methods Eleven consecutive cases with unsatisfactory vision with spectacles, due to irregular astigmatism, preferred to try CSL before SL due to handling or economic issues. An eye examination included refraction and visual acuity assessment, anterior eye biomicroscopy, ocular fundus examination, corneal topographic analysis, endothelial-cell count (ECC) and evaluation of corneal biomechanical parameters (corneal resistance factor, CRF; corneal hysteresis, CH; corneal-compensated intraocular pressure, IOPcc). The fitting process…
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…
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 …
Evaluation of the anterior chamber angle in keratoconus and normal subjects.
2015
To evaluate the anterior chamber angle in keratoconus eyes by use of the Visante™ OCT and Orbscan™ II.Anterior chamber angle was measured with the Visante™ OCT and Orbscan™ II in 52 subjects, 26 KC subjects and 26 age and control subjects.When comparing the nasal and temporal angles obtained with the two techniques no correlation was found (R(2) always below 0.01) in either the control subjects or in the KC subjects. Despite this, there was an overall statistically significant difference in mean anterior chamber angles (p0.001) between Visante™ OCT and Orbscan™ II. There was no statistical difference (p0.05) between nasal and temporal anterior chamber angles when comparing controls and KC s…
Comparison of Macular Thickness in Patients with Keratoconus and Control Subjects Using the Cirrus HD-OCT
2014
Purpose.The aim of the present study was to compare macular thickness in patients with keratoconus (KC) with macular thickness in healthy subjects.Subjects and Methods.Twenty-six patients with KC and 52 control subjects were included. The macular structure was evaluated using a Zeiss Cirrus HD-OCT. The scan pattern used was 512 × 128, which covers an area of approximately 6 × 6 mm of the retina. The cube volume was assessed as well as macular thickness in each of the 9 sectors defined by the software.Results.The mean signal strength was significantly lower in the KC group (mean 8.4, range 6–10) compared with the control group (mean 9.7, range 7–10),P<0.0001(unpairedt-test). There were no…
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 …
Functional and biomechanical changes in keratoconic corneas after implantation of intracorneal ring segments 5 and 6mm in diameter
2012
Purpose To determinate biomechanical and functional changes in human keratoconic corneas after triangular section ring implantation in two designs. Methods Retrospective study of biomechanical properties of 46 patients (60 eyes) with keratoconus undergoing surgery Keraring® intracorneal ring segments divided into two groups according to 5 or 6 mm of diameter. Surgical technique to made the channel was with IntraLase femtosecond laser. UCVA and BSCVA were measured and biomechanical factors provided by the device ORA before surgery and postoperatively one month, 3 months and 6 months. Results After surgery, we obtained a significant increase (p 0.05). At baseline- 6 months, the improvement in…