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Bueno-Gimeno I.,University of Valencia | Gene-Sampedro A.,University of Valencia | Pinero-Llorens D.P.,Foundation for the Visual Quality | Pinero-Llorens D.P.,University of Alicante | And 2 more authors.
Optometry and Vision Science | Year: 2014

Purpose. To evaluate the possible associations between corneal biomechanical parameters, optic disc morphology, and retinal nerve fiber layer (RNFL) thickness in healthy white Spanish children. Methods. This cross-sectional study included 100 myopic children and 99 emmetropic children as a control group, ranging in age from 6 to 17 years. The Ocular Response Analyzer was used to measure corneal hysteresis (CH) and corneal resistance factor. The optic disc morphology and RNFL thickness were assessed using posterior segment optical coherence tomography (Cirrus HD-OCT). The axial length was measured using an IOLMaster, whereas the central corneal thickness was measured by anterior segment optical coherence tomography (Visante OCT). Results. The mean (+SD) age and spherical equivalent were 12.11 (+2.76) years and -3.32 (+2.32) diopters for the myopic group and 11.88 (+2.97) years and +0.34 (+0.41) diopters for the emmetropic group. In a multivariable mixed-model analysis in myopic children, the average RNFL thickness and rim area correlated positively with CH (p = 0.007 and p = 0.001, respectively), whereas the average cup-to-disc area ratio correlated negatively with CH (p = 0.01). We did not observe correlation between RNFL thickness and axial length (p = 0.05). Corneal resistance factor was only positively correlated with the rim area (p = 0.001). The central corneal thickness did not correlate with the optic nerve parameters or with RNFL thickness. These associations were not found in the emmetropic group (p < 0.05 for all). Conclusions. The corneal biomechanics characterized with the Ocular Response Analyzer system are correlated with the optic disc profile and RNFL thickness in myopic children. Low CH values may indicate a reduction in the viscous dampening properties of the cornea and the sclera, especially in myopic children. Copyright © American Academy of Optometry. Source

Artigas J.M.,University of Valencia | Navea A.,Fisabio Oftalmologia Medica FOM | Garcia-Domene M.,Fisabio Oftalmologia Medica FOM | Gene A.,University of Valencia | Artigas C.,CEU Cardenal Herrera University
Contact Lens and Anterior Eye | Year: 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, but the other four do not specify anything in this regard. The spectral transmission of all the CLs studied is excellent in the visible region. The CLs with UV filters filter out this radiation more or less effectively. Xe lamps emit a part in the UV region. Incandescent, fluorescent and white LEDs do not emit at all in the UV. Conclusions: Incorporating UV filters is important when the illumination is from a Xe lamp since this light source emits in the UV region. This, however, does not occur with incandescent and fluorescent lamps or white LEDs. The CLs that do incorporate UV filters meet all the standard requirements that the U.S. FDA (Food and Drug Administration) has for UV-blocking CLs Class II (OcularScience, CooperVision and Neolens), and AcuvueMoist and HydronActifresh400 even comply with the stricter Class I. The CLs without UV filters let UVA, UVB and even some UVC through. © 2015 . Source

Artigas C.,CEU Cardenal Herrera University | Navea A.,Fisabio Oftalmologia Medica FOM | Lopez-Murcia M.-M.,CEU Cardenal Herrera University | Felipe A.,Fisabio Oftalmologia Medica FOM | And 4 more authors.
Journal Francais d'Ophtalmologie | Year: 2014

Objective. - To determine the spectral transmission curve of the crystalline lens of the pig. To analyse how this curve changes when the crystalline lens is irradiated with ultraviolet A + B radiation similar to that of the sun. To compare these results with literature data from the human crystalline lens. Procedures. - We used crystalline lenses of the common pig from a slaughterhouse, i.e. genetically similar pigs, fed with the same diet, and slaughtered at six months old. Spectral transmission was measured with a Perkin-Elmer Lambda 35 UV/VIS spectrometer. The lenses were irradiated using an Asahi Spectra Lax-C100 ultraviolet source, which made it possible to select the spectral emission band as well as the intensity and exposure time. Results. - The pig lens transmits all the visible spectrum (95%) and lets part of the ultraviolet A through (15%). Exposure to acute UV (A + B) irradiation causes a decrease in its transmission as the intensity or exposure time increases: this decrease is considerable in the UV region. Conclusions. - We were able to determine the mean spectral transmission curve of the pig lens.It appears to be similar to that of the human lens in the visible spectrum, but different in theultraviolet. Pig lens transmission is reduced by UV (A + B) irradiation and its transmission in theUV region can even disappear as the intensity or exposure time increases. An adequate exposureintensity and time of UV (A + B) radiation always causes an anterior subcapsular cataract (ASC). 2014 Published by Elsevier Masson SAS. Source

Artigas J.M.,Fisabio Oftalmologia Medica FOM | Artigas J.M.,University of Valencia | Navea A.,Fisabio Oftalmologia Medica FOM | Garcia-Domene M.C.,Fisabio Oftalmologia Medica FOM | And 3 more authors.
Journal Francais d'Ophtalmologie | Year: 2016

Objective. - To analyze the photoprotection and phototransmission that various intraocular lenses (IOLs) provide under the illumination of a xenon (Xe) lamp and white LEDs (light emitting diode). Methods. - The spectral transmission curves of six representative IOLs were measured using a Perkin-Elmer Lambda 35 UV/VIS spectrometer. Various filtering simulations were performed using a Xe lamp and white LEDs. The spectral emissions of these lamps were measured with an ILT-950 spectroradiometer. Results. - The IOLs analyzed primarily show transmission of nearly 100% in the visible spectrum. In the ultraviolet (UV) region, the filters incorporated in the various IOLs did not filter equally, and some of them let an appreciable amount of UV through. The Xe lamp presented a strong emission of ultraviolet A (UVA), and its emission under 300 nm was not negligible. The white LED did not present an appreciable emission under 380 nm. © 2016 Elsevier Masson SAS. Source

Artigas J.M.,University of Valencia | Felipe A.,University of Valencia | Navea A.,Fisabio Oftalmologia Medica FOM | Garcia-Domene M.C.,University of Valencia | And 2 more authors.
Journal of Biomedical Optics | Year: 2014

This study presents a method for measuring scattering in explanted intraocular lenses (IOLs). Currently, determining scattering in IOLs is usually performed by Scheimpflug cameras and the results are expressed in the units used by this apparatus. The method we propose uses a spectrophotometer and this makes it possible to measure the total transmission of the IOL by using an integrating sphere; the direct transmission is determined by the double-beam mode. The difference between these two transmissions gives a value of the scattering in percentage values of light lost. In addition, by obtaining the spectral transmission curve, information about the most scattered wavelengths is also obtained. The IOL power introduces errors when directly measured, particularly with high powers. This problem can be overcome if a tailor-made cuvette is used that shortens the distance between the IOL and the condensing lens of the spectrophotometer when the IOL powers are below 24 diopters. We checked the effectiveness of this method by measuring the scattering of three explanted IOLs from cornea donors. This method, however, does not make it possible to ascertain whether the scattering measured is caused by surface light scattering or internal light scattering. © The Authors. Source

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