Search results for "contact lenses"
showing 10 items of 96 documents
“In situ” corneal and contact lens thickness changes with high resolution OCT
2012
Purpose: To show the utility of high resolution spectral domain optical coherence tomography (HR SOCT) for the in situ evaluation of epithelial, stromal and contact lens (CL) thickness changes under closed-eye conditions without lens removal. Settings: Clinical and Experimental Optometry Research Lab, University of Minho, Portugal. Methods: Eight young healthy patients wore a thick soft CL during 90 minutes under closed-eye conditions and measures of epithelial and stromal corneal thickness were obtained at regular intervals using a HR SOCT (Copernicus HR, Optopol Tech. SA, Poland). Results: Minimal changes in epithelial thickness were detected with a transient statistically significant inc…
Efficacy and safety study of an eyelid gel after repeated nocturnal application in healthy contact lens users and non-users
2020
Purpose: To evaluate skin biocompatibility of a nighttime hydrating eyelid gel and possible ocular surface effects in contact lens users (CLU) and non-contact lens users (NCLU). The formulation is registered as a medical device as Tridocosahexaenoine-AOX® (TDHA-AOX) (a concentrated DHA triglyceride), containing also hyaluronic acid (HA). Methods: A prospective, randomized, masked clinical trial was performed with 62 participants of both sexes, aged 20–70 years, split into: (1) CLU (n = 30) and (2) NCLU (n = 32). All participants were instructed to apply a single dose of the moisturizing gel (containing TDHA-AOX and HA) nightly to the upper and inner eyelids of their right eye (RE) only, and…
Oxygen Transmissibility of Piggyback Systems With Conventional Soft and Silicone Hydrogel Contact Lenses
2006
To investigate the apparent oxygen transmissibility of various piggyback systems using conventional and silicone hydrogel soft contact lenses of different water content and permeability, rigid poly(methyl methacrylate), and rigid gas-permeable lenses of medium, high, and ultrahigh oxygen permeability. The aim of the study was to establish which material (rigid or hydrogel) is more representative of the resulting oxygen performance of piggyback systems. METHODS: The apparent oxygen transmissibility of 66 piggyback systems was measured with an electrochemical method. Eighteen of these combinations involved the use of silicone hydrogel contact lenses currently available. One hyperpermeable rig…
Recommendations for eye care during the alarm state by the coronavirus disease pandemic COVID-19.
2020
Abstract Objective Minimize exposure to the SARS-CoV-2, reduce the chances of cross-transmission between patients and healthcare personnel, and prevent the development of postoperative complications from the management of patients with eye diseases during the 2019 coronavirus disease pandemic (COVID-19). Methods COVID-19 literature review and consensus establishment between different Spanish ophthalmology societies in order to provide guidelines and recommendations of maximum resources primarily conditioned by the state of alert, confinement and social distancing that occurs in Spain since March 16, 2020. Results The recommendations will promote the adoption of action and protection measure…
Individuālu mīksto kontaktlēcu pielietojums acs aberāciju kompensācijai
2017
Darbs uzrakstīts angļu valodā uz 63 lapām. Tas satur 46 attēlus, 1 tabulu un 53 atsauces uz literatūras avotiem. Mērķis. Novērtēt agstāko kārtu aberāciju (HOA) ietekmi uz redzes funkcijām un acs optisko kvalitāti FOOT kontaktlēcu (KL) nēsātājiem. Metodes. Tika izmērīts redzes asums gadījumos (RA), kad acī ievietotas FOOT KL un parastās gāzu caurlaidīgās KL. Tika izmērītas visas aberācijas (TA) un HOA gadījumā, kad ievietotas abu veidu lēcas. Rezultāti. FOOT KL gadījumā RA bija tāds pats kā parasto KL gadījumā, vai augstāks (p<.01). FOOT KL gadījumā TA un HOA līmenis bija tāds pats kā parasto KL gadījumā, vai mazāks (p-value < .01). Secinājumi. FOOT KL sniedz augstāku RA nekā parastās KL un …
Impact of contact lens material and design on the ocular surface.
2018
BACKGROUND: To evaluate the impact on the ocular surface of a daily disposable hydrogel contact lens with high water content compared with two silicone hydrogel daily disposable lenses of lower water content. METHODS: The hydrogel lens assessed was made from nesofilcon A and the silicone hydrogel lenses were made of delefilcon A and stenfilcon A. Contact lens thickness was measured to assess material stability during daily wear, and ocular surface parameters such as tear film osmolarity, tear meniscus area and central corneal thickness were also assessed. Optical quality was analysed for all cases by means of wavefront aberrometry. RESULTS: The nesofilcon A was shown to be the thinnest lens…
Light transmission and ultraviolet protection of contact lenses under artificial illumination
2016
Purpose: To determine the spectral transmission of contact lenses (CLs), with and without an ultraviolet (UV) filter to evaluate their capacity for protection under UV radiation from artificial illumination (incandescent, fluorescent, xenon (Xe) lamps, or white LEDs (light-emitting diode)). Methods: The transmission curves of nine soft CLs were obtained by using a PerkinElmer Lambda 35 UV-vis spectrophotometer. A CIE standard was used for the emission spectra of incandescent and fluorescent lamps, and Xe lamps and white LEDs were measured by using an International Light Technologies ILT-950 spectroradiometer. Results: Five of the nine soft CLs analysed state that they incorporate UV filters…
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…
Corneo-scleral contact lens in a piggyback system for keratoconus: A case report.
2017
Purpose: We describe a case of fitting a corneo-scleral contact lens with a multi-aspheric geometry design (MAGD CScL) on top of a daily silicone hydrogel lens (piggyback system) for keratoconus management. Methods: A 48-year-old man using soft toric contact lenses required an improvement in the unsatisfactory quality of his vision. He presented with bilateral asymmetric keratoconus with high myopia in the right eye (RE) and severe myopia in the left eye (LE). In addition, he had low vision in his LE because of a maculopathy. He was fitted with MAGD CScL to correct his irregular astigmatism. A diagnostic trial set was used in the fitting process and the patient was assessed according to a s…
Fitting Scleral Lenses Less Than 15 mm in Diameter: A Review of the Literature.
2020
OBJECTIVE To perform a comprehensive review of the current and historical scientific literature on fitting small scleral lenses (diameter <15 mm) and clarifying their advantages and disadvantages, in addition to their clinical applications. METHODS The literature search was performed through PubMed from MEDLINE. RESULTS Eleven studies of case series (258 eyes) were found. Indications were similar to those of larger scleral lenses, 74% for corneal irregularities (mainly keratoconus), whereas 26% for ocular surface diseases. In the studies on cases of irregular corneas, visual acuity improved significantly regarding the values before and after fitting the lenses (mean, 0.4-0.03 logMar, respec…