Person: Piedrahita Alonso, María Elena
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First Name
María Elena
Last Name
Piedrahita Alonso
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Óptica y Optometría
Department
Optometría y Visión
Area
Optica
Identifiers
8 results
Search Results
Now showing 1 - 8 of 8
Item Lower tear meniscus height measured by optical coherence tomography in children(Ophthalmic and Physiological Optics, 2023) Martín García, Beatriz; Palomo Álvarez, Catalina; Piedrahita Alonso, María Elena; Gómez de Liaño, Rosario; Fuentes Ferrer, Manuel; Arriola Villalobos, PedroIntroduction: While optical coherence tomography (OCT) measurements of the lower tear meniscus height (LTMH) have been reported in adults, here we obtained LTMH measurements through Fourier Domain OCT in healthy children and compared these with values obtained in healthy adults. Methods: Participants were children 7–17 years of age and a control group of adults 20–40 years of age. Inclusion criteria were no abnormal eye conditions or the use of contact lenses. Candidates who fulfilled the TFOS DEWS II criteria for dry eye disease (DED) were excluded. All subjects underwent LTMH measurement (OCT Spectralis) and tests for non-invasive tear break-up time and ocular surface staining. Participants also completed the ocular surface disease index questionnaire. Results: A total of 86 children and 27 adults were included. Mean LTMH values in the children and adult groups were 217.40 ± 71.40 μm and 225.0 ± 54.86 μm, respectively; p = 0.53. However, 59.3% of the children had an LTMH ≤210 μm suggestive of DED, compared with only 33.3% of adults (p = 0.02). For the children, no significant differences in LTMH were observed with sex or for those more or less than 12 years of age. Conclusions: Optical coherence tomography-derived LTMH measurements were obtained in healthy children. While values were similar in children and adults, a greater proportion of children had an LTMH compatible with a diagnosis of DED. More studies in different paediatric populations are required to establish a complete set of normative LTMH measurements.Item Caracterización de la cicloposición ocular mediante el ángulo fóvea-disco óptico. Evaluación de nuevos métodos de medida(2020) Piedrahita Alonso, María Elena; Gómez de Liaño Sánchez, María Rosario; Valverde Megías, AliciaEn el polo posterior de un ojo sano el disco óptico se halla en posición nasal y ligeramente superior a fóvea. El ángulo que forman estas dos estructuras define la cicloposición ocular y presenta una gran variabilidad interindividual. Una cicloposición fuera del rango normal se denomina torsión ocular y supone una rotación anómala del globo ocular. Puede tener su origen en un estrabismo ciclovertical primario, una alteración de los músculos extraoculares, una afectación orbitaria o una cirugía ocular. En estos casos la cicloposición aporta información esencial acerca del componente torsional de la desviación. En ojos sanos supone, además, una referencia anatómica estable, utilizada en cirugía refractiva y en análisis de patología retiniana. El método gold standard en la evaluación de la cicloposición es la medida del ángulo fóveadisco óptico (AFD) en retinografía. Se determina mediante el ángulo que forma una línea que une la fóvea con el centro del disco óptico respecto a la horizontal. Su valor ronda los 7º en dirección inferior y es una medida repetible y reproducible. Los estudios discrepan en cuanto a las diferencias interoculares y entre sexos, y acerca de la relación entre cicloposición y edad. Además, no se ha descrito el valor del cambio mínimo detectable (CMD) asociado a la medida del AFD, que determina la diferencia entre exploraciones repetidas que debe considerarse un cambio real, no debido al error de medida. Los inconvenientes de la técnica incluyen la necesidad de dilatación pupilar y de exportar la imagen a un software externo para su medida. Además, precisa la determinación manual exacta de la posición foveal, dificultada en ojos con patología que afecta al área macular. La cicloposición puede también valorarse cualitativamente mediante la inclinación de las arcadas vasculares temporales, que viajan a ambos lados del eje fóvea-disco óptico y rotan con el ojo cuando existe torsión ocular. Los autores Parsa y Kumar han descrito un método para cuantificar esta inclinación que no ha sido comprobado junto al AFD, y puede ser de utilidad cuando la fóvea no se localice adecuadamente. Por último, el tomógrafo Spectralis cuenta con el software FoDi, que mide el AFD de manera semiautomática. Detecta la fóvea basándose en la fijación del paciente (importante si existe mala definición macular), y no precisa dilatación pupilar ni exportar la imagen para su medida. Ningún estudio ha comparado el AFD en imagen con el proporcionado por el tomógrafo Spectralis...Item Educational resources for physics 101 instruction with health science degrees(2024) González Fernández, Verónica; González Cano, Agustín; Alda Serrano, Javier; Piedrahita Alonso, María Elena; Fernández Núñez, Sara; Díaz Herrera, Natalia; Navarrete Fernández, María Cruz; Ares, Laura; Orenes Plankova, AlexandraIn the present article, we present a comprehensive suite of educational resources and interactive exercises designed for initial Physics instruction targeted at students pursuing a Degree in Optics and Optometry. These materials have the potential to be adaptable and beneficial across various disciplines within the realm of Health Sciences. We begin by performing a preliminary analysis of the perceptions of older and new students, to develop an optimized teaching program. This consists of several workpackages aiming to increase the personal interest and involvement of the students, as well as the practical aspects regarding the subject. We include several experimental demonstrations and experiences done in the classroom. To reinforce the assimilation of most difficult concepts some educational videos are also recorded for the students.- Project number: 322
Item Aprendizaje de procedimientos clínicos optométricos mediante vídeos demostrativos(2021) Piedrahita Alonso, María Elena; Martín García, Beatriz; Palomo Álvarez, Catalina; Nieto Bona, Amelia; Estrella Lumeras, Miguel Ángel; Barrio De Santos, Ana Rosa; Valcayo Peñalva, Isabel; Baños Morales, CarmeloEl objetivo principal del proyecto ha sido crear en el campus virtual de la asignatura Optometría IV del Grado de Óptica y Optometría una plataforma de material docente virtual basado en presentaciones, vídeos de exploración y cuestionarios autoevaluativos. En ellos el alumno ha podido visualizar la ejecución por parte del profesor de los procedimientos que se estudian en la asignatura en pacientes pediátricos o con alteraciones de la visión binocular, de manera que el aprendizaje ha sido significativo. - Project number: 357
Item Aprendizaje guiado para la aplicación de ejercicios de Terapia Visual con un kit básico de tratamiento(2020) Barrio De Santos, Ana Rosa; Antona Peñalba, Beatriz; Sánchez Pérez, María Isabel; Piedrahita Alonso, María Elena; González Pérez, Mariano Item Comparing methods of determining addition in presbyopes(Clinical and Experimental Optometry, 2008) Antona Peñalba, Beatriz; Barra Lázaro, Francisco; Barrio De Santos, Ana Rosa; Gutiérrez Hernández, Ángel Luis; Piedrahita Alonso, María Elena; Martín Pérez, YolandaBackground: The use of plus lenses to compensate for the reduction in the range of accommodation associated with presbyopia, brings the near point of accommodation to a comfortable distance for near visual tasks. Our aim was to compare the tentative near addition determined using the most common procedures with the final addition prescribed in presbyopic patients. Methods: Sixty-nine healthy subjects with a mean age of 51.0 years (range 40 to 60 years) were studied. Tentative near additions were determined using seven different techniques: dynamic retinoscopy, amplitude of accommodation (AA), age-expected addition, binocular fused cross-cylinder with and without myopisation, near duochrome, and balance of negative and positive relative accommodation. The power of the addition was then refined to arrive at the final addition. Results: The mean tentative near additions were higher than the final addition for every procedure except for the fused cross-cylinder without initial myopisation and ageexpected addition methods. These biases were small in clinical terms (less than 0.25 D) with the exception of the AA procedure (0.34 D). The intervals between the 95% limits of agreement differed substantially and were always higher than ±0.50 D. Conclusions: All the techniques used displayed similar behaviour and provided a tentative addition close to the final addition. Due to the wide agreement intervals observed, the likelihood of error is high and supports the idea that any tentative addition has to be adjusted according to the particular needs of each patient. Among the methods examined here, we would recommend the age-expected procedure, as this technique produced results that correlated best with the final addition.- Project number: 384
Item Complemento audiovisual para el aprendizaje de procedimientos clínicos optométricos de visión binocular no estrábica(2022) Piedrahita Alonso, María Elena; Antona Peñalba, Beatriz; Barrio De Santos, Ana Rosa; Martín García, BeatrizEl resultado de este proyecto consta de 35 vídeotutoriales de exploración a pacientes, que complementan el aprendizaje de procedimientos clínicos relacionados con la visión binocular no estrábica. Sirven como guía previa a la realización de las prácticas y de complemento para el estudio de los procedimientos. Item Rotation of retinal vascular arcades and comparison with disc-fovea angle in the assessment of cycloposition(British Journal of Ophthalmology, 2014) Piedrahita Alonso, María Elena; Valverde Megías, Alicia; Gómez De Liaño Sánchez, María RosarioBackground/aims: To assess the agreement between disc-fovea angle (DFA) and the retinal vascular arcades rotation to measure cycloposition. Device repeatability and reproducibility between observers were also evaluated. Methods: Cycloplegic retinography was taken in 321 eyes of 165 normal patients and repeated in 18 eyes at least 24 h later. Two independent observers used software to determine DFA, vein-related angle (VRA) and artery-related angle (ARA) in every retinography. Mean value of related angle (MRA) (mean value of VRA and ARA) was calculated. Results: Camera repeatability was good (Intra-class Correlation Coefficient, ICC 0.89). In Bland-Altman analysis, mean VRA, ARA and MRA were 4° to 5° different from DFA (p<0.01). There was poor correlation between DFA and other methods (ICC): DFA versus VRA 0.3, versus ARA 0.4, versus MRA 0.5. Reliability between observers was good in all methods. The multivariate analysis showed no interaction between each method and eye side, sex or observer (p>0.05). Conclusions: The rotation of retinal vascular arcades using a first-order approximation technique is no substitute to DFA when assessing torsion in fundus photographs. Of the methods tested, MRA correlated most closely, but DFA remains the gold standard for cycloposition. The rotation of vascular arcades provides a qualitative assessment, particularly in uncertain macular location.