Calidad de vida en pacientes de baja visión con degeneración macular asociada a la edad

I Congreso Online Internacional de Salud Visual, 12-15 de Marzo de 2019, http://www.congresodesaludvisual.orgAntecedentes/objetivos: La calidad de vida (CV) de las personas de baja visión (BV) con DMAE afecta gravemente a la capacidad para realizar actividades cotidianas. Los objetivos son analizar y evaluar la bibliografía científica que estudia la CV en pacientes de BV con DMAE. Método: Se realizó una revisión y un estudio bibliométrico a través de las publicaciones existentes, hasta febrero de 2018. Se consultó en MEDLINE, SCOPUS Y WOS. Los descripciones utilizados fueron “baja visión”, “degeneración macular”, “calidad de vida”. Se incluyeron trabajos originales que estudian la CV en pacientes con BV y DMAE, realizados en cualquier país y que disponen de texto completo. Se excluyeron estudios no originales, informes de casos, estudios de animales, estudios con idioma distinto al inglés o español y estudios que validen el instrumento. Resultados: Se han identificado 501 artículos, después de eliminar los duplicados y aplicar los criterios de exclusión, se incluyeron 52 artículos que representan la información más relevante. Con mucha diferencia América es el continente que más investiga (45%), seguido de Europa (27%). Las dos revistas que más publican son: IOVS (12%) y Archives of Ophthalmology (10%). La Univ. que más ha investigado de Melbourne (12%). Dentro de los 11 autores que más publican, se encuentran Keeffe y Lamoureux. Con relación al género de los autores, no existen diferencias en el número de publicaciones aunque si en el orden de autoría, ellos ocupan la 1ª posición, mientras que ellas tienen un porcentaje más alto como corresponding. Los artículos incluidos además de hablar de la CV en paciente de BV con DMAE también abordan otros temas como la depresión, la importancia de la luz en a la hora de realizar actividades cotidianas, la medida de la AV, la efectividad de la rehabilitación y la velocidad de lectura. Las personas con BV y DMAE muestran una serie de problemas relacionados con su funcionalidad; en concreto, la relación con la movilidad, tienen un riesgo importante de caídas y fracturas. En lo que se refiere a la salud mental, como sentimientos de aislamiento social, angustia emocional y depresión. Además, el impedimento visual ha sido asociado con un menor bienestar, expresado por la pérdida de interés y la incapacidad para disfrutar de las actividades. Conclusiones: Se concluye que los pacientes con DMAE experimentan mayores pérdidas en la CV relacionada con la salud que los pacientes de la misma edad con otras enfermedades crónicas. Estas disminuciones en la CV se explican claramente por la pérdida de la AV y las limitaciones que ésta les afecta a la hora de realizar actividades en su día a día

Distributed feedback lasers based on dichromated poly(vinyl alcohol) reusable surface-relief gratings

A simple, low-cost and versatile holographic method to produce reusable surface-relief gratings on dichromated poly(vinyl alcohol) (DCPVA) films, with periods Λ ≥ 270 nm and modulation depths up to 300 nm, is reported. DCPVA presents processing advantages with respect to other photoresists, such as dichromated gelatine, i.e. higher light sensitivity, simpler fabrication process and better batch to batch reproducibility. The successful use of these DCPVA relief gratings as distributed feedback (DFB) laser resonators is demonstrated. Second-order DFB devices emitting in the wavelength range 577-614 nm have been easily prepared by coating a dye-doped polymer film on top of the resonators.We thank the Spanish Government (MINECO) and the European Union (FEDER) for grant no. MAT2011-28167-C02

Perylenediimide-based distributed feedback lasers with holographic relief gratings on dichromated gelatine

One dimensional second-order distributed feedback (DFB) lasers consisting of polystyrene (PS) films doped with a perylenediimide laser dye, deposited over dichromated gelatine (DCG) photoresist layers with solvent resistant relief gratings recorded by holographic lithography, are reported. The advantage of using the grating on DCG in the final device is that the fabrication process is simplified and the grating pattern better preserved, since no etching methods to transfer the grating to another substrate are needed. A very simple model, proposed to explain the experimental waveguide properties, has allowed identifying the waveguide mode at which DFB emission appears, which was the key to optimize the device performance. In the frame of this model, the thickness of the PS and DCG films could be adjusted in order to minimize the laser threshold and to control its wavelength tuneability. The performance of these lasers is comparable to that of recently reported devices based on the same active material, but deposited over high-quality DFB gratings engraved on SiO2 by nanoimprint lithography.We thank support from the Spanish Government (MINECO) and the European Community (FEDER) through Grant Nos. MAT2008-06648-C02 and MAT-2011-28167-C02, as well as to the University of Alicante. M.G.R. was supported by a CSIC fellowship within the program JAE

Sub-400 nm film thickness determination from transmission spectra in organic distributed feedback lasers fabrication

The design and fabrication of thin-film based organic optoelectronic devices require knowledge of the film optical properties. A low-cost and non-destructive method often used for optical characterization of films is the well-established spectrophotometric envelope method. However, this method is typically limited to thickness above 400 nm, a value often higher than that of the films involved in these devices. This paper studies a procedure to obtain the thickness of sub-400 nm active films from their spectrophotometric trace when the refractive index is previously known. The proposed procedure is based on comparing the experimental transmission spectrum in the transparent spectral window with that obtained by simulation. The capabilities of the proposed method are demonstrated here by its application in the fabrication of organic distributed feedback lasers, for which a fine control of film thickness is important to obtain an optimized and reproducible response. Results are verified with other techniques, such as ellipsometry and profilometry. Thus, with the proposed method, film thickness can be easily determined down to 40 nm maintaining an accuracy of about 5 nm even for films with low refractive index (1.5–1.7). Different methods to determine refractive index of these films are also discussed.Spanish Ministry of Economy and Competitivity (MINECO) and European Community (FEDER) through grant no. MAT2015-66586-R

Medida de la Sensibilidad al Contraste en miopes magnos

La medida de la Función de Sensibilidad al Contraste (CSF) constituye un buena manera de caracterizar la función visual, de modo que las variaciones respecto de la norma en la curva de la CSF pueden indicar la existencia de distintos tipos de problemas visuales, ya sea de enfoque, patológicos o neurológicos. Cualquier alteración en los medios oculares, la retina, las vías neurales o el cortex visual puede afectar a la sensibilidad al contraste, sin que necesariamente se manifieste una pérdida de agudeza visual. Este hecho evidencia la importancia diagnóstica que presenta la medida de la CSF frente a la simple medida de agudeza visual

Distributed feedback lasers based on perylenediimide dyes for label-free refractive index sensing

The refractive index sensing capabilitity of distributed feedback (DFB) lasers based on highly photostable (under ambient conditions) perylenediimide-based active films, are reported. The sensor bulk sensitivity is determined from changes in the laser emission wavelength upon exposure to different liquids. The role of the active film thickness (hf) on the sensor sensitivity and on the laser parameters is studied. Sensors based on very thin films (hf = 160 nm) show the highest sensitivities, but their laser thresholds are relatively high and their operational durabilities moderate. The use of thicker films (hf = 850 nm) allows reducing the laser threshold and increasing the durability by two orders of magnitude. In this case, a higher sensitivity is achieved when the sensor operates at the wavelength corresponding to the first-order TE1 mode, instead of at the TE0 one. Finally, it is also shown that the inclusion of a high refractive index TiO2 layer on top of the sensor structure improves the sensitivity by around two times.This work was supported by the Spanish Government (MINECO) and the European Community (FEDER) through grant no. MAT-2011–28167-C02. This work was partially funded by the Basque Government within the framework of the Etortek Program (Grant No. IE13-360). M. Morales-Vidal has been partly supported by a MINECO FPI fellowship (no. BES-2009-020747)

1,7-Bay-Substituted Perylenediimide Derivative with Outstanding Laser Performance

Efficient ASE at wavelengths >620 nm from PS films doped with a bay-substituted perylenediimide (PDI) derivative is reported. The maximum PDI content is around 40 times larger than in prior studies. The ability to introduce large dye amounts into the film without photoluminescence (PL) quenching allows very high PL and ASE efficiencies with low thresholds. A distributed feedback (DFB) laser device using one of the best-performing films is fabricated and characterized.We thank support from the Spanish Government (MINECO), the European Community (FEDER) and the Generalitat Valenciana through MAT-2011–28167-C02, CTQ2011–26455, PROMETEO 2012/010 and ISIC/2012/008, as well as to the University of Alicante and the University Miguel Hernández de Elche

Calibrado del programa CSF-Test utilizado como sistema de medida de la función de sensibilidad al contraste

La Función de Sensibilidad al Contraste (CSF) nos proporciona una buena información sobre la calidad del sistema visual de modo que las diferentes modificaciones en la CSF pueden indicar distintos tipos de problemas visuales, ya sean de tipo óptico, patológico o neurológico. Teniendo en cuenta estas consideraciones es necesario disponer de un buen sistema de medida que permita determinar la CSF con precisión, intentando que los errores sistemáticos sean mínimos y no alteren el valor absoluto de las medidas

Improved performance of perylenediimide-based lasers

The aim of this work was to improve the laser performance, in terms of threshold and operational lifetime, of lasers based on polymer films doped with perylenediimide (PDI) derivatives as active media. For such purpose, we first investigated the amplified spontaneous emission (ASE) properties of perylene orange (PDI-O), when doped into polystyrene (PS) films. Lower ASE thresholds and larger photostabilities than those of similar films containing another PDI derivative (PDI-C6), recently reported in the literature, have been measured. Results have been interpreted in terms of the photoluminescence efficiency of the films, which depends on the type of molecular arrangement, inferred with the help of nuclear magnetic resonance experiments. We also show that PS films have a better ASE performance, i.e. lower thresholds and larger photostabilities, than those based on poly(methyl methacrylate), which was recently highlighted as one of the best matrixes for PDI-O. Finally, a one-dimensional second-order distributed feedback laser using PS doped with PDI-O was fabricated and characterized. This device has shown a threshold significantly lower (by around one order of magnitude) than that of a similar laser based on PDI-C6-doped PS.We thank support from the Spanish Government (MECC) and the European Community (FEDER) through grants MAT2008-06648-C02 and MAT-2011-28167-C02, as well as from the University of Alicante. MGR and MM are supported respectively by a CSIC fellowship within the program JAE and by MEC through a FPI fellowship