Abstract Background: Scorpions can use their pincers and/or stingers to subdue and immobilize their prey. A scorpion can thus choose between strategies involving force or venom, or both, depending on what is required to subdue its prey. Scorpions vary greatly in the size and strength of their pincers, and in the efficacy of their venom. Whether this variability is driven by their defensive or prey incapacitation functionis unknown. In this study, we test if scorpion species with different pincer morphologies and venom efficacies use these weapons differently during prey subjugation. To that end, we observed Opisthacanthus elatus and Chactas sp. with large pincers and Centruroides edwardsii and Tityus sp. with slender pincers. Methods: The scorpion pinch force was measured, and behavioral experiments were performed with hard and soft prey (Blaptica dubia and Acheta domesticus). Stinger use, sting frequency and immobilization time were measured. Results: We found that scorpions with large pincers such as O. elatus produce more force and use the stinger less, mostly subjugating prey by crushing them with the pincers. In C. edwardsii and Tityus sp. we found they use their slender and relatively weak pincers for holding the prey, but seem to predominantly use the stinger to subjugate them. On the other hand, Chactas sp. uses both strategies although it has a high pinch force. Conclusions: Our results show that scorpionspecies with massive pincers and high pinch force as O. elatus use the stinger less for prey subjugation than scorpionspecies with slenderpincers.

ABSTRACT The importance of early diagnosis of compressive lesions of the optic nerve is on the increase. Timely decompression of the optic nerve or the optic chiasm may bring about significant visual function improvement, whereas erroneous diagnosis may result in irreversible visual loss, neurological dysfunction or death. The causes of compression of the anterior visual pathway are incredibly varied. Meningiomas, pituitary tumors and aneurysms are the lesions most commonly identified as causes of compressive optic neuropathy without disc edema. A case is presented of a female 50-year-old patient undergoing congenital cataract surgery of her left eye without visual function improvement, alongside unspecific visual quality worsening. Visual psychophysical testing, automated campimetry and optical coherence tomography contributed findings suggestive of intracranial visual pathway compression. Magnetic resonance imaging of the brain and orbits was indicated to confirm the diagnostic suspicion. Cerebral angiography revealed the presence of an internal carotid artery aneurysm which was treated by endovascular procedure with satisfactory results.

RESUMEN El diagnóstico temprano de las lesiones compresivas del nervio óptico adquiere cada vez mayor importancia. La descompresión precoz de este o del quiasma puede resultar una mejora significativa de la función visual, mientras que el diagnóstico erróneo puede ocasionar pérdida visual irreversible, disfunción neurológica o la muerte. Las causas de la compresión de la vía visual anterior son increíblemente variadas. Los meningiomas, los tumores hipofisarios y los aneurismas son las lesiones comúnmente más identificadas como causa de neuropatía óptica compresiva sin edema del disco. Presentamos una paciente femenina de 50 años de edad, quien se sometió a la cirugía de catarata congénita del ojo izquierdo, sin mejoría de la función visual, a lo que se sumó el empeoramiento inespecífico de la calidad visual. La psicofísica visual, la campimetría automatizada y la tomografía de coherencia óptica aportaron hallazgos sugestivos de compresión de la vía visual intracraneal. Se indicó imagen por resonancia magnética de cráneo y órbitas para confirmar la sospecha diagnóstica. La angiografía cerebral demostró la presencia de un aneurisma de la arteria carótida interna, que se trató por vía endovascular con resultados satisfactorios.

Abstract Background: In the present study, we have tested whether specimens of the medically relevant scorpion Tityus pachyurus, collected from two climatically and ecologically different regions, differ in the biological activities of the venom. Methods: Scorpions were collected in Tolima and Huila, Colombia. Chemical profiles of the crude venom were obtained from 80 scorpions for each region, using SDS-PAGE and RP-HPLC. Assays for phospholipase A2, direct and indirect hemolytic, proteolytic, neuromuscular, antibacterial, and insecticidal activities were carried out. Results: The electrophoretic profiles of venom from the two regions showed similar bands of 6-14 kDa, 36-45 kDa, 65 kDa and 97 kDa. However, bands between 36 kDa and 65 kDa were observed with more intensity in venoms from Tolima, and a 95 kDa band occurred only in venoms from Huila. The chromatographic profile of the venoms showed differences in the intensity of some peaks, which could be associated with changes in the abundance of some components between both populations. Phospholipase A2 and hemolytic activities were not observable, whereas both venoms showed proteolytic activity towards casein. Insecticidal activity of the venoms from both regions showed significant variation in potency, the bactericidal activity was variable and low for both venoms. Moreover, no differences were observed in the neuromuscular activity assay. Conclusion: Our results reveal some variation in the activity of the venom between both populations, which could be explained by the ecological adaptations like differences in feeding, altitude and/or diverse predator exposure. However more in-depth studies are necessary to determine the drivers behind the differences in venom composition and activities.

ABSTRACT Optic nerve drusens were first described by Liebreich in the year 1868. Other terms to designate this condition are optic disc hyaline bodies and colloid bodies. They have a prevalence of 1 per 500 and 60% of the cases occur deep in the optic nerve head. The primary pathogenesis of drusens may be an inherited dysplasia of the optic canal of the disc and its vasculature, which leads to their formation. The natural evolution of drusens is a lifelong dynamic process. Associated complications include visual field defects, central vision loss (rare but well documented), ischemic optic neuropathy, retinal vascular occlusion, transient sight loss, peripapillary subretinal neovascularization, central serous peripapillary chorioretinopathy, and pre- and peripapillary bleeding. A case is reported of a 64-year-old female patient with a history of surgery for retinal detachment of the left eye. In the right eye the patient presented deep peripapillary subretinal bleeding associated to drusen.

RESUMEN Los drusen de nervio óptico fueron descritos por primera vez por Liebreich en el año 1868. Otros términos para designar esta entidad incluyen cuerpos hialinos y cuerpos coloides del disco óptico. Tienen una prevalencia de 1 por 500 y el 60 % de los casos se encuentran profundos en la cabeza del nervio óptico. La patogenia primaria de los drusen puede ser una displasia hereditaria del canal óptico del disco óptico y su vasculatura, lo que predispone a la formación de estos. La evolución natural de los drusen es un proceso dinámico que transcurre durante toda la vida. Entre las complicaciones asociadas se presentan defectos de campo visual, pérdida de visión central (rara pero bien documentada), neuropatía óptica isquémica, oclusiones vasculares retinales, pérdidas transitorias de la visión, neovascularización subretinal peripapilar, corioretinopatia serosa central peripapilar y hemorragias pre y peripapilares. Se presenta una paciente de 64 años de edad con antecedente de haber sido operada de desprendimiento de retina del ojo izquierdo, y en el ojo derecho presentaba una hemorragia peripapilar subretinal profunda asociada a drusen.

Gyrate atrophy of the choroid and the retina was first described by Fuchs as a clinically defined condition in 1896. Human hereditary deficiency of ornithine aminotransferase activity is transmitted as an autosomal recessive trait and results in increased level of plasma ornithine and is associated with gyrate atrophy of the choroid and the retina. A 6-year-old girl was taken to the ophthalmologist’s because of her far poor vision detected by her teacher at the school. In the initial eye fundus examination the ophthalmologist observed some changes indicating retinal dystrophy. The indirect binocular funduscopy revealed extensive areas of choroidal atrophy outside the vascular archades respected the posterior pole whereas the macula impressed as normal. Cystoid macular edema was evident in both eyes according to the results of the optic coherence tomography performed with Spectralis tomograph. The aminoacid analysis revealed high serum ornithine level (975 µmol/mL). The clinical diagnosis of the patient was consistent with hyper-ornithinemia and gyrate atrophy of the choroid and the retina. She was treated with vitamin B6 and dietary supplementation but no significant reduction on her serum ornithine level was observed.

La atrofia gyrata de coroides y retina fue descrita por vez primera por Fuchs en el año 1896 como una entidad clínicamente definida. La deficiencia de la enzima ornitina delta aminotransferasa se hereda de forma autosómica recesiva; resulta en incremento plasmático de las concentraciones de ornitina y se asocia con atrofia gyrata de coroides y retina. Se presenta una paciente de 6 años de edad que es llevada a consulta, ya que en la escuela la maestra notaba mala visión de lejos. En un examen inicial del fondo de ojo el oftalmólogo observó cambios sugestivos de distrofia retiniana. En la oftalmoscopia binocular indirecta se encontraron extensas zonas confluentes de atrofia coroidea por fuera de las arcadas vasculares que respetaban el polo posterior; la mácula impresionaba normal. Se realizó un estudio de tomografía de coherencia óptica en dominio espectral en tomógrafo Spectralis que demostró la presencia de edema macular cistoide en ambos ojos. La determinación de niveles de ornitina en sangre arrojaron niveles muy elevados de este aminoácido (975 µmol/mL). Con todos estos hallazgos se llegó al diagnóstico de hiperornitinemia y atrofia gyrata de coroides y retina. Se indicó tratamiento dietético y vitamina B6 oral a pesar de que no se ha obtenido hasta el momento reducción significativa de los niveles de ornitina en plasma.

Since the first reported case of choroidal folds in 1884, the understanding of their mechanisms, aetiologies, and management has expanded signally. With ophthalmoscopy, choroidal folds can be appreciated by the light and dark bands observed deep to the retina. While choroidal folds are visible on ophthalmoscopic examination, they are more easily identified using fluorescein angiography. A-scan ultrasound may reveal a shortened axial length. Common B-scan ultrasonographic findings include thickening of the choroid or flattening of the posterior aspect of the globe. Causes of choroidal folds are many, among them are idiophatic, increased intracranial pressure, diffusely infiltrative conditions (lymphomas and benign lymphoid hiperplasia), hypotony, drug induced (an unusual complication of certain medications such as Topiramate), contraction of fibrovascular tissue, choroidal neoplasms and orbital mass lesions (intraconal and extraconal tumours). We report a 57 years old woman who came to ophthalmogy consultation first in 2008 complaning of slowly progressive loss of vision. Fundoscopy showed well defined optic disc with radial choroidal folds of the posterior pole in both eyes. Manifest refraction showed hyperopia that increased in the following visits until the present. Fundoscopy showed not changes. Definitive diagnosis was syndrome of acquired hyperopia with choroidal folds.

Desde el primer reporte de pliegues coroideos, en el año 1884, el conocimiento sobre su etiología, el mecanismo de producción y su manejo se ha incrementado notablemente. Las causas de los pliegues coroideos abarcan un extenso número de condiciones muy variadas; entre ellas se encuentran los idiopáticos, la hipertensión intracraneana, algunas drogas como el topiramato, las infiltraciones difusas de la coroides por linfomas e hiperplasia linfoide, la hipotonía por contracción de tejido fibrovascular, los tumores coroideos y orbitarios (intraconales y extraconales), entre otras. Se presenta una paciente femenina de 57 años de edad quien acudió por vez primera a la Consulta de Oftalmología en el año 2008 por disminución lenta y progresiva de la agudeza visual de ambos ojos. El examen de fondo de ojo mostró discos ópticos con bordes definidos, buena coloración y presencia de pliegues coroideos radiales al disco en polo posterior de ambos ojos. La refracción arrojó una hipermetropía que fue en aumento en las consultas de seguimiento hasta el presente sin variar el aspecto del fondo de ojo. Se concluye que el caso presenta síndrome de hipermetropía adquirida con pliegues coroideos.

Neurophthalmology is considerate "frontier speciality" because of their relationships with many other medical and surgical specialities. Pituitary tumors are so important from neuro-ophthalmological point of view that they appear as special chapter in text books. Our objective in the present review is to refer the neurophthalmological finfings in two main entities: pituitary adenomas and multiple endocrine neoplasia syndromes and to establish the important role of neuro-ophthalmologist in those neuroendocrine conditions. It was proved the diversity of neurophthalmological findings in neuroendocrine entities, the important role of ophthalmologist in diagnosis and pursuance of patients with pituitary adenomas and its peremptory role in screening finding associated to 2 B type multiple endocrine neoplasia syndrome.

La neuroftalmología es considerada una "especialidad frontera" por su vínculo con otras múltiples especialidades médicas, clínicas y quirúrgicas. Los tumores de hipófisis son de tal importancia desde el punto de vista neuroftalmológico que son tratados separadamente en casi todos los textos de la especialidad. El objetivo de la presente revisión es aproximarnos, sobre la base de los conocimientos actuales, a los hallazgos neuroftalmológicos de algunas enfermedades neuroendocrinas, haciendo hincapié en dos temas fundamentales: los adenomas hipofisarios y el síndrome de neoplasias endocrinas múltiples, y demostrar además el importante papel del neuroftalmólogo en estas dos entidades. Quedan aquí evidenciadas las variadas manifestaciones neuroftalmológicas de estas entidades neuroendocrinas, el importante cometido del oftalmólogo en el diagnóstico y el ulterior seguimiento de los pacientes con adenomas hipofisarios, así como lo decisiva que puede resultar su actuación en la identificación de los hallazgos asociados al síndrome de neoplasias endocrinas múltiples tipo 2 B.

Patients with physical signs and symptoms for which no adequate organic cause can be found may receive a wide range of diagnoses, and represent a diagnostic challenge with medical and legal implications. Twenty five to fifty percent of patients with apparent nonorganic visual loss have concomitant organic pathology that explains at least some visual deficit. Additional difficulty is the best selected medical term to call it, and this is our objective in this review. In the light of the current knowledge and after evaluating several alternatives, we consider that the best term for them is nonorganic losses of vision. Nonorganic visual loss is never a excluding diagnosis; positive findings are required to make the diagnosis. The clinical method (visual psychophysics) and certain diagnostic tools in addition to some clinical ones are sufficient to set a diagnosis of nonorganic ocular disease in the majority of cases.

Los pacientes con síntomas y signos para los que no puede encontrarse una causa orgánica adecuada reciben una variada gama de diagnósticos, los cuales representan un reto con implicaciones médicas legales. Entre el 25 y el 50 % de los casos con aparente pérdida no orgánica concomita una enfermedad orgánica que explica algo del déficit visual. Una dificultad adicional es la selección del mejor término médico para designarlos y ese es nuestro objetivo en esta revisión. A la luz de los conocimientos actuales, y después de evaluar varias alternativas, consideramos que lo más acertado es denominarlos pérdidas no orgánicas de la visión. El diagnóstico de estas no es nunca de exclusión; se requieren hallazgos positivos para llegar a él. El método clínico (psicofísica visual) y ciertas herramientas diagnósticas, también clínicas, son suficientes en la mayoría de los casos.