Search

Este artículo se encuentra disponible en la siguiente URL: https://www.mdpi.com/2076-3921/9/1/48 Este artículo pertenece al número especial "Natural products in health promotion and disease prevention". En este artículo también participa: Vincent M. Villar. The retina is subjected to oxidative stress due to its high vascularization, long time light exposition and a high density of mitochondria. Oxidative stress can lead to pathological processes, like cell apoptosis, angiogenesis and inflammation ending in retinal pathologies. Curcumin, a major bioactive component obtained from the spice turmeric (Curcuma longa) rhizome has been used for centuries in Asian countries for cooking and for curing all kinds of diseases like dysentery, chest congestion and pain in general, due to its antioxidant e ects. Curcumin prevents the formation of reactive oxygen species and so it is a good protective agent. Curcumin has shown also anti-inflammatory, and antitumor properties. Curcumin is a natural product, which can be a therapeutic option in a variety of retinal diseases due to its pleiotropic properties. Some drawbacks are its poor solubility, bioavailability and lack of stability at physiological conditions; which have been shown in curcumin skeptical publications. In this review, we provide some lights and shadows on curcumin administration on the major retinal pathologies.

The white-eye syndrome as a cause of blindness encompass a group of eye diseases whose outcome is visual loss. The etiology of these diseases is diverse, ranging from diseases associated with an increase in intraocular pressure such as openangle glaucoma, vascular occlusive diseases of the principal retinal vessels or inflammatory diseases of the optic nerve. El Síndrome de ojo blanco como causa de ceguera busca englobar un grupo de patologías oculares cuyo desenlace es la pérdida visual. La etiología de estas enfermedades es diversa, se trata desde enfermedades asociadas a un aumento de la presión intraocular como el glaucoma de ángulo abierto, enfermedades obstructivas vasculares de los vasos retinianos principales o problemas inflamatorios del nervio óptico.

Like other tissues of the central nervous system, the retina is susceptible to damage by oxidative processes that result in several neurodegenerative disease such as age-related macular degeneration, diabetic retinopathy, glaucoma, ischaemic retinal disease, retinal disease produced by light oxidation, and detached retina, among other diseases. The use of antioxidant substances is a solution to some health problems caused by oxidative stress, because they regulate redox homeostasis and reduce oxidative stress. This is important for neurodegeneration linked to oxidation processes. In line with this, Ginkgo biloba is a medicinal plant with excellent antioxidant properties whose effects have been demonstrated in several degenerative processes, including retinal diseases associated with neurodegeneration. This review describes the current literature on the role of ginkgo in retinal diseases associated with neurodegeneration. The information leads to the conclusion that G. biloba extracts might be a good option to improve certain neurodegenerative retinal diseases, but more research is needed to determine the safety and efficacy of G. biloba in these retinal degenerative processes.

Casos clínicos: Se presentan los casos clínicos de dos varones de 38 y 39 años, diagnosticados de síndrome de Alport, que presentaron respectivamente un agujero macular bilateral y un agujero unilateral gigante con adelgazamiento retiniano en el otro ojo. Discusión: El síndrome de Alport es un desorden genético caracterizado por la mutación de genes que codifican el colágeno tipo IV, principal componente de la membrana limitante interna, estructura identificada en el complejo membrana basal del epitelio pigmentario de la retina-membrana de Brüch. Esta alteración puede condicionar la predisposición a la aparición de agujeros maculares. Case report: We present the clinical cases of two male patients of 38 and 39 years, diagnosed with Alport's syndrome, who suffered a bilateral macular hole and a giant unilateral macular hole with retinal thinning in the other eye, respectively. Discussion: Alport's syndrome is a genetic disorder characterised by mutation of genes encoding type IV collagen, the main component of the internal limiting membrane, a structure identified in basal membrane of the retinal pigment epithelium-Brüch's membrane complex. This alteration can influence the predisposition to macular holes.

Diabetic retinopathy early is not usually perceivable in patients with diabetic. Their first signs, like micro-aneurysms, often are unnoticed in preliminary test due to its difficult detection by means specialists. In addition, its presence is necessarily not directly related to diabetic retinopathy, since there are others pathologies that may also cause those. Until the detection of the presence of exudates, a specialist can deduce the presence of diabetic retinopathy. This paper presents a method to assist the identification and differentiation of exudates on color retinal images based on a variety of k-nn filters. The proposed method proved to be a sensitive and specific detection of bright lesions, able to determine with sufficient certainty, a possible injury, with a specificity of 99%. La retinopatía diabética en etapas tempranas suele ser imperceptible para los pacientes diabéticos. Sus primeras manifestaciones, tal como los microaneurismas, suelen pasar desapercibidas en exámenes especializados por su difícil detección; además, su presencia única no implica necesariamente relación directa con la retinopatía diabética, puesto que existen otras patologías que también pueden producirlas. Solo hasta la detección de la presencia de exudados un especialista puede deducir la presencia de la retinopatía diabética. Este artículo presenta un método que permite asistir la identificación y diferenciación de exudados sobre retinografías mediante la utilización de una variedad de clasificadores de tipo k-nn. El método propuesto demostró ser un método sensible y específico en la detección de lesiones brillantes, capaz de determinar con certeza suficiente una posible lesión en una retinografía a color, con una especificidad de 99%.

Objetivo: Determinar la relación entre los parámetros de la capa de fibras nerviosas de la retina (CFNR) obtenidos mediante la polarimetría láser con compensación corneal variable (GDx VCC), y los resultados de la perimetría automatizada convencional (PA) en sujetos normales, hipertensos oculares con glaucomas preperimétricos y glaucomatosos. Material y método: 423 ojos de 423 sujetos consecutivos fueron prospectivamente incluidos en el estudio y clasificados según los resultados de la presión intraocular basal, PA y morfología papilar en 4 grupos: 87 normales, 192 hipertensos oculares, 70 con glaucoma preperimétrico y 74 glaucomatosos. En los diferentes grupos diagnósticos se calcularon los coeficientes de correlación de Pearson entre la desviación media (DM), la desviación sobre modelo (DSM), el número de puntos alterados en cada uno de los cuadrantes y el número de puntos alterados a diferentes niveles de probabilidad del campo visual con los parámetros de la CFNR obtenidos mediante el GDx VCC. En el grupo de glaucomas se calcularon además las correlaciones entre los 52 puntos que evalúa la estrategia 24-2 SITA Standard y los parámetros del GDx. También se trazaron las curvas de regresión para los parámetros que presentaron las correlaciones más fuertes. Resultados: En general las correlaciones estadísticamente significativas fueron escasas y de carácter débil en los sujetos normales, hipertensos oculares y con glaucomas preperimétricos. Sin embargo, el grupo de glaucomas presentó correlaciones de leves a moderadas entre varios parámetros del GDx VCC y las variables del campo visual estudiadas. Las correlaciones más fuertes fueron entre la desviación estándar TSNIT y la DM (0,460) para los índices de la PA y entre el promedio superior y el punto 45 (0,496) para los puntos del campo visual. Conclusiones: Los parámetros de la CFNR medidos con el GDx VCC presentaron correlaciones de débiles a moderadas con los índices del campo visual y el número de puntos alterados por cuadrantes en el grupo de glaucomas. Purpose: To determine the relationship between the structural parameters of the retinal nerve fiber layer (RNFL) obtained by using the scanning laser polarimetry with variable corneal compensation (GDx VCC) and the results of standard automated perimetry (SAP), in normal, ocular hypertensive, preperimetric glaucomas and glaucoma subjects. Methods: A total of 423 eyes of 423 consecutive subjects were prospectively included in the study and classified depending on the basal intraocular pressure, optic nerve head appearance and SAP results into four groups: 87 normal eyes, 192 ocular hypertensive eyes, 70 preperimetric glaucomas and 74 glaucomatous eyes. Pearson´s correlation coefficients, between mean deviation (MD), pattern standard deviation, number of points altered in each quadrant, and number of points altered at different probability levels of SAP and structural parameters of RNFL obtained by using GDx VCC, were calculated in the different diagnostic groups. In the glaucoma group correlations between the 52 points tested by 24- 2 SITA standard and GDx parameters were also calculated. Regression curves were plotted for the strongest correlations. Results: Weak or non-significant correlations were found in the normal, ocular hypertensive and preperimetric glaucoma groups. However, the glaucoma group presented weak to moderate correlations between several GDx VCC parameters and the SAP variables analysed. The strongest correlation was observed between the standard deviation TSNIT and the MD (0.460). Conclusions: RNFL parameters measured with the GDx VCC presented weak to moderate correlations with the visual field indices and the number of altered points in the glaucoma group.

Objetivo: Determinar si existen concentraciones de compuestos lipofílicos de origen orgánico en muestras de aceite de silicona extraídas de ojos humanos y comprobar si existe alguna relación con el tiempo de permanencia intraocular del aceite. Métodos: Por cromatografía líquida de alta resolución (HPLC) se han determinado las concentraciones de ácido retinoico, retinol, retinal, colesterol y alfa -tocoferol en 23 muestras de aceite de silicona de 1.000 cs, extraνdas de pacientes con desprendimientos complejos de retina con tiempos de permanencia intraocular variables (3 a 50 meses). Resultados: Se han encontrado concentraciones de todos los compuestos, sobre todo de colesterol, y en menor medida de alfa -tocoferol. Se ha observado una correlaciσn inversa de la edad y las concentraciones de alfa cido retinoico (p=0,023). Y una correlaciσn directa entre el tiempo de permanencia intraocular del aceite y los niveles de colesterol (p=0,0008) que se mantiene hasta los 20 meses. Conclusiones: Se confirma que el aceite de silicona no es una sustancia tan inerte ya que es capaz de disolver compuestos lipídicos procedentes de tejidos intraoculares. Existe una elevación linear de los niveles de colesterol que podría utilizarse como orientación para decidir cuándo extraer el aceite de silicona, aunque hacen falta estudios con series más grandes. Objective: To verify the existence of organic lipophylic compounds in silicone oil extracted from human eyes following its use for previous retinal detachment, and to determine the intraocular permanence time of these substances in the oil. Methods: Concentrations of retinoic acid, retinol, retinal, cholesterol and alpha -tocopherol were detected by HPLC in 23 samples of silicone oil extracted from patients with complicated retinal detachments. The time interval between the time of injection of the silicone oil and the subsequent assessment varied from 3 to 50 months (the permanence time). Results: All tested compounds were found in the samples, but these were most commonly cholesterol and less frequently alpha -tocopherol. There was an inverse relationship between retinoic acid concentration and age (p=0.023), and a direct relationship between cholesterol concentration and permanence time (p=0.0008) at least up to 20 months. Conclusions: These findings confirm that silicone oil is not an inert substance but is capable of extracting lipophylic compounds from the intraocular tissues. There is a clear linear elevation of cholesterol levels with increased intraocular permanence time. This finding could be used to further establish a safe permanence time for intraocular silicone oil used in ophthalmologic surgery. More studies with larger samples are warranted to evaluate this further.

In this paper we analyze the topographic distribution and cell body size of neurons (ganglion and displaced amacrine) of layer 8 of the retina in the chilean reptile Callopistes palluma; using whole mount retinaswith nissl stain. Callopistes palluma retina has an area centralis without fovea in which the ganglion cell density amounts 20.000 cells / µm2 while the displaced amacrine neurons is about 7.000 cells / µm2. This neural density decreased gradually towards the peripheral retina. A horizontal streak is also present for both types of neurons. In the different areas of the retina the displaced amacrine neurons correspond to 25%-30% of the total number of neurons in layer 8. The analysis of the neuronal size shows that in the area centralis the ganglion cells have a mean body size of 32 µm2 while the displaced amacrine neurons have a mean body size of 8 µm2. In the peripheral retina the cell body size increase to 42 µm2 for the ganglion cells and to 12 µm2 for the displaced amacrine neurons. In the paper is discussed the correlation betweem retinal characteristics and styles of prey hunting