Search results for "Keratoconus"
showing 7 items of 37 documents
Visual Acuity and Contrast Sensitivity Depending from Keratoconus Apex Position
2017
Abstract Various studies have demonstrated that patients with keratoconus have significant loss of contrast sensitivity while its value varies in different studies. None of these studies has analysed reduced contrast sensitivity depending on the position of apex of corneal conus. Visual acuity and contrast sensitivity were evaluated for patients with keratoconus using the FrACT software. Contrast sensitivity was assessed at the following frequencies: 1, 3, 5, 7, 9, 11, 13, and 15 cycles per degree (cpd). Twenty-four eyes with keratoconus were analysed. Contrast sensitivity was significantly lower for patients with the apex at the centre compared with apex on the periphery both with (p = 0.0…
Koriģētais redzes asums, kontrastjutība un aberācijas keratokonusa pacientiem atkarībā no virsotnes atrašanās vietas
2018
Promocijas darbs ir uzrakstīts angļu valodā uz 29 lappusēm. Tajā ir 17 attēli, 2 tabulas un 26 atsauces. Mērķis. Novērtēt keratokonusa virsotnes radītās izmaiņas redzes asumā, kontrastjutībā un aberācijās. Metode. Noteikts redzes asums un kontrastjutība piecās dažādās frekvencēs ar FrACT programmu, lietojot briļļu un kontaktlēcu korekciju. Noteikts zīlītes diametra mērījums un topogrāfiskā karte ar Keratronu un Optikon. Rezultāti. Salīdzinot pacientus ar keratokonusa virsotni centrā un perifērijā, redzes asums ir statistiski nozīmīgi lielāks pacientiem ar keratokonusa virsotni centrā ar alfa=10% līmeni. Kontrastjutība ir statistiski nozīmīgi atšķirīga pacientiem, kuri lieto brilles un cietā…
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…
Kontaktlēcu ietekme uz redzes asumu pacientiem ar neregulāru radzeni
2017
Darbs uzrakstīts angļu valodā uz 39 lapām. Tas satur 11 attēlus, 1 aptaujas lapu, 11 tabulas and 24 atsauces uz literatūras avotiem. Mērķis: darba galvenais mērķis ir salīdzināt parastās gāzu caurlaidīgās kontaktlēcas ar gāzu caurlaidīgajām intralimbālajām lēcām. Metodes: gāzu caurlaidīgās intralimbālās lēcas tika novērtētas, pētījuma dalībniekiem aizpildot anketu. Rezultāti: pētījuma dalībnieki deva priekšroku gāzu caurlaidīgajām intralimbālajām lēcām un novērtēja to sniegto komfortu, tomēr nebija būtiskas atšķirības starp iegūto redzes asumu abu lēcu gadījumā. Secinājumi: izvērtējot katra pacienta individuālo sutāciju, optometrists var apsvērt intralimbālo lēcu izrakstīšanu pecientam, lai…
Genome-wide association analyses identify multiple loci associated with central corneal thickness and keratoconus
2013
The author manuscript of this article is open access and is freely available online at PubMed Central
Implantation of a custom intraocular lens with a 30-diopter torus for the correction of high astigmatism after penetrating keratoplasty.
2003
Abstract We present a 62-year-old woman who had implantation of an intraocular lens (IOL) with a torus of 30.0 diopters (D) in an eye after penetrating keratoplasty. The patient presented with cataract and a best corrected visual acuity of 20/400. Penetrating keratoplasty was performed in 1975 because of decompensated keratoconus. With a clear but inferiorly decentered corneal graft, visual acuity was limited because of keratoplasty-related high corneal astigmatism of 22.5@156 that could not be successfully treated with spectacles or contact lenses. A custom toric IOL with –30.0 D of cylindrical power was implanted in the capsular bag via a sclerocorneal tunnel incision. Additionally, a sph…
Optical quality of hyperopic and myopic phakic intraocular lenses
2013
Aims: To assess and compare the optical quality of the myopic and hyperopic implantable collamer lens (ICL) from its wavefront aberrations for different powers and pupil diameters. Settings and Design: Prospective study. Material and Methods: The wavefront aberrations of two myopic (−3 and −6 diopters (D)) and two hyperopic V4b ICLs (+3 and +6D) were measured in vitro . To assess and compare the optical quality of different powers of ICLs, we analyzed the root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration at 3- and 4.5-mm pupil. In addition, the point spread functions (PSFs) of each ICL evaluated were ca…