¿De qué colores es el vestido? Revisión de una ilusión óptica atípica / Which are the colors of the dress? Review of an atypical optic illusion

OBJETIVO: En 2015 la fotografía de un vestido se hizo viral. Un porcentaje amplio de la población veía el vestido blanco y dorado (ByD) en tanto que otra parte importante de la población lo veía azul y negro (AyN). El objetivo de este trabajo es revisar la bibliografía publicada en relación con este tema. MATERIAL Y MÉTODOS: Se realizó una búsqueda bibliográfica en Pubmed y Google. El algoritmo utilizado fue: (color OR colour) AND (dress OR #thedress). La búsqueda se limitó a los años 2015-2017. No se limitó la búsqueda a una lengua concreta. La bibliografía de los artículos localizados se utilizó de forma secundaria para ampliar la búsqueda. RESULTADOS: El algoritmo utilizado localizó un total de 23 artículos relacionados con el tema. La mayor parte de los trabajos han sido publicados en revistas del ámbito de la percepción y analizan la cuestión desde el punto de vista de la constancia cromática. Los factores genéticos parecen tener un bajo peso en el modo en el que la imagen es percibida. La potencial influencia de factores oculares ha sido poco estudiada. CONCLUSIÓN: Esta ilusión ha recibido poca atención por parte de las revistas del ámbito de la oftalmología. Aunque sin duda la constancia cromática está implicada, de momento no se ha elaborado una teoría capaz de explicar el carácter dicotómico de esta ilusión óptica

OBJECTIVE: In 2015 the picture of a dress went viral on social media. A significant proportion of the population saw it as golden and white (G&W), while another significant proportion saw it as blue and black (B&B). The aim of this article is to review the related literature. MATERIAL AND METHODS: Bibliographic search conducted in Pubmed and Google. The algorithm used was: (color OR colour) AND (dress OR #thedress). The search was limited to the years 2015-2017. No language restrictions were used. The references of the located articles were used to widen the search. RESULTS: The search algorithm retrieved 23 articles related to the topic. Most of the works have been published in journals in the field of perception. Most works address the topic from the point of view of chromatic constancy. Genetic factors seem to have a low weight in the way the dress is perceived. There are few studies on the potential influence of ocular factors. CONCLUSION: This illusion has gained little attention in ophthalmology journals. Although colour constancy is certainly involved, there is still no theory available to explain the dichotomous character of this optical illusion

Which are the colors of the dress? Review of an atypical optic illusion. / ¿De qué colores es el vestido? Revisión de una ilusión óptica atípica.

OBJECTIVE: In 2015 the picture of a dress went viral on social media. A significant proportion of the population saw it as golden and white (G&W), while another significant proportion saw it as blue and black (B&B). The aim of this article is to review the related literature. MATERIAL AND METHODS: Bibliographic search conducted in Pubmed and Google. The algorithm used was: (color OR colour) AND (dress OR #thedress). The search was limited to the years 2015-2017. No language restrictions were used. The references of the located articles were used to widen the search. RESULTS: The search algorithm retrieved 23 articles related to the topic. Most of the works have been published in journals in the field of perception. Most works address the topic from the point of view of chromatic constancy. Genetic factors seem to have a low weight in the way the dress is perceived. There are few studies on the potential influence of ocular factors. CONCLUSION: This illusion has gained little attention in ophthalmology journals. Although colour constancy is certainly involved, there is still no theory available to explain the dichotomous character of this optical illusion.

Maculopatía por puntero láser. ¿Un nuevo problema de salud pública? / Laser pointer maculopathy. A new public health problem?

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Nonsurgical Procedures for Keratoconus Management.

OBJECTIVES: To describe the past 20 years' correction modalities for keratoconus and their visual outcomes and possible complications. METHODS: A review of the published literature related to the visual outcomes and possible complications in the context of keratoconus management using nonsurgical procedures for the last 20 years (glasses and contact lenses) was performed. Original articles that reported the outcome of any correction modalities of keratoconus management were reviewed. RESULTS: The most nonsurgical procedure used on keratoconus management is the contact lens fitting. Soft contact lenses and soft toric contact lenses, rigid gas-permeable contact lenses, piggyback contact lens system, hybrid contact lenses, and scleral and corneoscleral contact lenses form the contemporary range of available lens types for keratoconus management with contact lenses. All of them try to restore the vision, improve the quality of life, and delay surgical procedures in patients with this disease. Complications are derived from the intolerance of using contact lens, and the use of each depends on keratoconus severity. CONCLUSIONS: In the context of nonsurgical procedures, the use of contact lenses for the management of keratoconic patients represents a good alternative to restore vision and improve the quality of live in this population.

Evolución histórica de nuestro conocimiento del sistema visual de las luciérnagas. Potenciales funciones ópticas del protórax / Historical evolution of our knowledge of firefly eyes. Potential optical functions of the prothorax

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Engañando a las células on-off: evolución histórica de nuestra compresión del modo en que los animales se camuflan / Deceiving the on-off cells: Historic evolution of our comprehension of the way animals camouflage themselves

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Opacificación de la cápsula posterior, síndrome de distensión capsular y síndrome de fimosis de la cápsula anterior: estudio de cohortes retrospectivo / Posterior capsule opacification, capsular bag distension syndrome, and anterior capsular phimosis: A retrospective cohort study

OBJETIVO: Determinar la incidencia y los factores de riesgo implicados en el desarrollo de las tres principales complicaciones capsulares postoperatorias: opacificación de cápsula posterior (OCP), síndrome de distensión capsular (SDC) y fimosis de la cápsula anterior (FCA). Sujetos, material y métodos: Estudio de cohortes retrospectivo. Se incluyó a 801 pacientes operados mediante cirugía de catarata en el Servicio de Oftalmología del Hospital del Henares (Madrid), entre el 2 de marzo de 2009 y el 28 de febrero de 2010. La historia clínica electrónica fue revisada durante el mes de julio de 2012. La OCP se estudió utilizando el método de Kaplan-Meier (log rank test). RESULTADOS: Un total de 167 pacientes desarrollaron OCP. No se pudo demostrar asociación entre la OCP y edad, sexo, diabetes mellitus, técnica de facoemulsificación, modelo de lente intraocular (LIO), consumo de tamsulosina, grado de síndrome de iris flácido intraoperatorio, glaucoma ni la degeneración macular asociada a la edad. Tres pacientes desarrollaron SDC, todos ellos habían recibido una LIO Akreos Adapt AO® (Bausch & Lomb). Dos de ellos eran varones jóvenes, con diagnóstico de catarata subcapular posterior. Tres pacientes desarrollaron FCA, dos de ellos habían recibido una LIO MicroSlim® (PhysIOL). CONCLUSIONES: No pudo demostrarse asociación de la OCP con ninguna de las variables estudiadas. El sexo masculino, la edad joven, la catarata subcapsular posterior y las LIO grandes no anguladas como la Akreos Adapt AO®podrían asociarse al desarrollo de SDC. Las LIO de microincisión, como la MicroSlim®, podrían asociarse al desarrollo de FCA

OBJECTIVE: To determine the incidence and the risk factors involved in the development of the three main postoperative capsular complications: posterior capsule opacification (PCO), capsular bag distension syndrome (CBDS), and anterior capsular phimosis syndrome (ACP). Subjects, material and methods: A retrospective cohort study was conducted on 801 patients submitted to cataract surgery in the ophthalmology unit of Hospital del Henares (Madrid) from March 2, 2009 to February 28, 2010. Computerized clinical charts were reviewed during July 2012. PCO was studied using the Kaplan-Meier method (log rank test). RESULTS: A total of 167 patients developed PCO. No association could be demonstrated between PCO and age, sex, diabetes mellitus, phaco technique, IOL model, tamsulosin intake, glaucoma, and age-related macular degeneration. Three patients developed CBDS, all of them have received and Akreos Adapt AO® (Bausch & Lomb). Two of them were young men who had received surgery for posterior subcapsular cataracts. Three patients developed ACP, 2 of whom had received a MicroSlim® IOL (PhysIOL). CONCLUSIONS: No association was found between PCO and any of the studied variables. Male gender, young age, subcapsular cataract and large non-angulated lens such as Akreos Adapt AO® could be associated with CBDS. ACP could be more frequent when microincision IOLs (like MicroSlim®) are implanted

[Posterior capsule opacification, capsular bag distension syndrome, and anterior capsular phimosis: A retrospective cohort study]. / Opacificación de la cápsula posterior, síndrome de distensión capsular y síndrome de fimosis de la cápsula anterior: estudio de cohortes retrospectivo.

OBJECTIVE: To determine the incidence and the risk factors involved in the development of the three main postoperative capsular complications: posterior capsule opacification (PCO), capsular bag distension syndrome (CBDS), and anterior capsular phimosis syndrome (ACP). SUBJECTS, MATERIAL AND METHODS: A retrospective cohort study was conducted on 801 patients submitted to cataract surgery in the ophthalmology unit of Hospital del Henares (Madrid) from March 2, 2009 to February 28, 2010. Computerized clinical charts were reviewed during July 2012. PCO was studied using the Kaplan-Meier method (log rank test). RESULTS: A total of 167 patients developed PCO. No association could be demonstrated between PCO and age, sex, diabetes mellitus, phaco technique, IOL model, tamsulosin intake, glaucoma, and age-related macular degeneration. Three patients developed CBDS, all of them have received and Akreos Adapt AO(®) (Bausch & Lomb). Two of them were young men who had received surgery for posterior subcapsular cataracts. Three patients developed ACP, 2 of whom had received a MicroSlim(®) IOL (PhysIOL). CONCLUSIONS: No association was found between PCO and any of the studied variables. Male gender, young age, subcapsular cataract and large non-angulated lens such as Akreos Adapt AO(®) could be associated with CBDS. ACP could be more frequent when microincision IOLs (like MicroSlim(®)) are implanted.

La forma de la pupila en el reino animal: de la pseudopupila a la pupila vertical / Pupil shape in the animal kingdom: From the pseudopupil to the vertical pupil

OBJETIVO: Estudiar las distintas formas que la pupila adquiere en las diferentes especies animales. MATERIAL Y MÉTODOS: Revisión de la literatura, utilizando PubMed. La estrategia inicial de búsqueda fue pupil shape (limitada a animals). También se revisaron 2 textos relacionados: System of Ophthalmology (Duke-Elder) y Evolution's witness (I. Schwab). RESULTADOS: En los ojos compuestos de los insectos es habitual observar una ilusión óptica que recibe el nombre de pseudopupila. La pupila tiene en la mayor parte de los vertebrados forma circular. Sin embargo en los gatos y en algunas especies de serpiente adopta forma vertical. La apertura vertical podría tener una función fotoprotectora al conseguir una reducción más efectiva de la entrada de luz en el ojo. Se ha especulado con que ayudaría a corregir la aberración cromática, y probablemente ayuda a camuflar al animal. En los rumiantes es habitual la pupila en hendidura horizontal. Esta forma podría potenciar la capacidad del sistema visual para detectar siluetas verticales. En el medio marino es frecuente que la pupila adopte forma de creciente, debido a la presencia de un opérculo superior que protegería la retina del exceso de luz procedente de la superficie. CONCLUSIÓN: La forma de la pupila ofrece una sorprendente variabilidad gracias a la cual la naturaleza ha adaptado el ojo a diversas circunstancias. Las teorías propuestas para justificar esta gran variabilidad se discuten de forma detallada en el artículo

OBJECTIVE: To study the different pupil shapes adopted by the different animal species. MATERIAL AND METHODS: Review of the related literature, using PubMed database. The initial search strategy was pupil shape (limited to animals). The first volume of System of Ophthalmology (Duke-Elder) and Evolution's witness (I. Schwab) were also reviewed. RESULTS: An optic illusion called pseudopupil is usually observed in the compound eyes of insects. The pupil is circular in most vertebrates, however slit vertical pupils are present in cats and in some snake species. Vertical pupils could have a photoprotective function, as it makes a more complete closure possible in photopic conditions, and helps to camouflage the predator. It has also been hypothesized that it could help to correct chromatic aberration. Ruminants are usually endowed with horizontal pupils. This shape could improve the capacity of the eye to detect vertical silhouettes. Some marine animals have crescent-shaped pupils. In these animals, a superior operculum helps to protect the inferior retina from the great amount of light coming from above. CONCLUSION: There is a surprising variability in pupil shape. Through this variability, nature has fitted the eye to different circumstances. The theories proposed to explain this high variability are discussed in detail in the article

Pupil shape in the animal kingdom: from the pseudopupil to the vertical pupil.

OBJECTIVE: To study the different pupil shapes adopted by the different animal species. MATERIAL AND METHODS: Review of the related literature, using PubMed database. The initial search strategy was pupil shape (limited to animals). The first volume of System of Ophthalmology (Duke-Elder) and Evolution's witness (I. Schwab) were also reviewed. RESULTS: An optic illusion called pseudopupil is usually observed in the compound eyes of insects. The pupil is circular in most vertebrates, however slit vertical pupils are present in cats and in some snake species. Vertical pupils could have a photoprotective function, as it makes a more complete closure possible in photopic conditions, and helps to camouflage the predator. It has also been hypothesized that it could help to correct chromatic aberration. Ruminants are usually endowed with horizontal pupils. This shape could improve the capacity of the eye to detect vertical silhouettes. Some marine animals have crescent-shaped pupils. In these animals, a superior operculum helps to protect the inferior retina from the great amount of light coming from above. CONCLUSION: There is a surprising variability in pupil shape. Through this variability, nature has fitted the eye to different circumstances. The theories proposed to explain this high variability are discussed in detail in the article.

Anisocoria cotidiana: epidemiología de la anisocoria en un centro de nivel secundario / Everyday anisocoria: anisocoria epidemiology in a secondary care setting

Objetivo: Determinar la importancia relativa de las distintas formas de anisocoria en un centro sanitario de nivel secundario. Métodos: Estudio prospectivo longitudinal, incluyendo todos los pacientes remitidos por este motivo a la consulta de Neuroftalmología del Hospital Universitario del Henares, Madrid, España, desde noviembre de 2008 hasta octubre de 2011. Se estudiaron las diferencias en el diámetro pupilar en condiciones de alta y baja luminosidad. Los pacientes fueron sometidos a una exploración oftalmológica completa, y a las pruebas de apraclonidina, cocaína, pilocarpina 0,125% y pilocarpina 2% en caso de considerarse necesario. Resultados: Treinta y dos casos de anisocoria fueron referidos durante estos 3 años. No se encontró asociación con la edad ni el sexo. Los diagnósticos fueron: pupila de Adie, 4 casos; síndrome de Horner, 5 casos; midriasis unilateral episódica benigna, 3 casos; causas locales, 4 casos; anisocoria fisiológica, 5 casos. A pesar de una completa historia clínica y exploración, la causa de la anisocoria no se pudo determinar en 11 casos. En 4 de estos casos el paciente padecía migrañas y en otros 4 consumía psicofármacos. En 3 casos ambos factores de riesgo estaban presentes. En un caso la anisocoria fue la pista inicial que llevó al diagnóstico de un paraganglioma cervical. Conclusiones: La anisocoria es un signo clínico que no traduce habitualmente enfermedad grave. Con nuestros protocolos, un número alto de los casos de anisocoria queda sin filiar. La migraña y los psicofármacos podrían estar asociados a estas formas de anisocoria(AU)

Objetive: To determine the relative importance of the different forms of anisocoria in a General Hospital. Methods: A prospective, longitudinal study was conducted including all patients referred for this reason to the Neuro-Ophthalmology Unit of the Henares University Hospital, Madrid (Spain), from November 2008 to October 2011. The differences in pupil diameter were studied under high and low luminosity. The patients were given a full ophthalmological examination, as well as performing the apraclonidine, cocaine, pilocarpine 0.125% and pilocarpine 2% tests, if they were considered necessary. Results: Thirty-two cases of anisocoria were referred during the three years of the study. No relationship was found with age or gender. The diagnostic results were: Adie's pupil, 4 cases; Horner syndrome, 5 cases; benign episodic unilateral mydriasis, 3 cases; local causes, 4 cases; physiological anisocoria, 5 cases. Despite a full clinical history and examination, the cause of the anisocoria could not be determined in 11 cases. In 4 of these cases, the patient suffered from migraines and in another 4 psychotropic drugs were taken. Both risk factors were present in 3 cases. In one case the anisocoria was the initial clue that led to the diagnosis of a cervical paraganglioma. Conclusions: Anisocoria is a clinical sign that does not usually signify a serious disease. With our protocols, a high number of anisocoria cases are still of unknown origin. Migraines and psychotropic drugs could be linked to these forms of anisocoria(AU)

[Everyday anisocoria: anisocoria epidemiology in a secondary care setting]. / Anisocoria cotidiana: epidemiología de la anisocoria en un centro de nivel secundario.

OBJECTIVE: [corrected] To determine the relative importance of the different forms of anisocoria in a General Hospital. METHODS: A prospective, longitudinal study was conducted including all patients referred for this reason to the Neuro-Ophthalmology Unit of the Henares University Hospital, Madrid (Spain), from November 2008 to October 2011. The differences in pupil diameter were studied under high and low luminosity. The patients were given a full ophthalmological examination, as well as performing the apraclonidine, cocaine, pilocarpine 0.125% and pilocarpine 2% tests, if they were considered necessary. RESULTS: Thirty-two cases of anisocoria were referred during the three years of the study. No relationship was found with age or gender. The diagnostic results were: Adie's pupil, 4 cases; Horner syndrome, 5 cases; benign episodic unilateral mydriasis, 3 cases; local causes, 4 cases; physiological anisocoria, 5 cases. Despite a full clinical history and examination, the cause of the anisocoria could not be determined in 11 cases. In 4 of these cases, the patient suffered from migraines and in another 4 psychotropic drugs were taken. Both risk factors were present in 3 cases. In one case the anisocoria was the initial clue that led to the diagnosis of a cervical paraganglioma. CONCLUSIONS: Anisocoria is a clinical sign that does not usually signify a serious disease. With our protocols, a high number of anisocoria cases are still of unknown origin. Migraines and psychotropic drugs could be linked to these forms of anisocoria.