Retinopatia deficiente de taurina em uma gata / Taurine deficiency retinopathy in a cat

Background: Taurine is an essential amino acid for cats and its deficiency causes an ocular disorder called taurine deficiency retinopathy. The retinal lesion is definitive and can be classified into five progression stages. In an advanced stage, it leads to blindness that in most cases is irreversible. This disease is considered rare as taurine is currently supplemented in commercial cat food. The objective of this report is to describe the ophthalmic changes in a cat with advanced taurine deficiency retinopathy, a rare but current disease that is important for differential diagnosis of blindness in cats. Case: We report the case of an adult mixed-breed cat (weighing 3.4 kg), that was attended by the Ophthalmology Service of the College of Veterinary Medicine and Animal Science (UNESP - Botucatu), which was treated due to complaints of poor visual acuity for about 1 year. The animal, which was previously a stray animal, had been adopted for 2 years and provided premium cat food ad libitum. Ophthalmic examination showed bilateral mydriasis, with negative menace, direct pupillary, and consensual light reflexes. No change was observed in the ocular appendages, cornea, anterior chamber, lens, and vitreous humor. The eyes were normotensive and fluorescein test negative. Direct and indirect fundoscopy revealed an area of ellipsoidal hyperreflexia with darkened margins laterally to the optic nerve disk in the tapetal region and intense retinal vascular attenuation in both eyes, with a diagnosis of taurine deficiency retinopathy. Complete blood count and biochemical analysis parameters were within the normal range, including the leukocyte count. The guardian was instructed to continue feeding the cat balanced cat food and received information on the proper care and management of a blind animal. Discussion: Although taurine deficient retinopathy is currently underdiagnosed due to the supplementation of this amino acid in commercial cat food, animals that are not properly fed, such as those receiving dog food or homemade food, may be deficient in this amino acid. Taurine deficiency and in this case, the consequent taurine deficiency retinopathy, was diagnosed by visualizing the lesion characteristic of this amino acid deficit since no other retinal change presents this aspect in cats. Therefore, this lesion is considered pathognomonic of this deficiency. Hyperreflective retinal lesions with darkened margins indicate the slow chronic progression in the already stabilized lesions. The animal in this report presented pigmented lesion margins, indicating the chronicity of these retinal changes. Moreover, lesion signs are visible on fundoscopy only after a period of 2-11 months of nutritional amino acid deficiency, and complete retinal atrophy usually occurs after at least nine months of taurine deficiency. Thus, complete blindness associated with advanced retinal changes reinforced the suspicion that the animal had taurine deficiency for a prolonged period of time prior to its adoption. Its guardian was instructed to provide balanced commercial cat food, because although retinal lesions are irreversible, cardiac changes resulting from taurine deficiency are reversed with dietary supplementation. In addition, taurine deficiency affects other organs and systems, such as the central nervous, immune, and reproductive systems. In conclusion, although taurine deficiency retinopathy is currently rare, this condition should be considered one of the possible differential diagnoses for blindness in feline patients.

Vitamin A deficiency as a cause of blindness in feedlot calves / Deficiência de vitamina A como causa de cegueira em bezerros confinados

Vitamin A is an essential micronutrient to reproduction, development, normal growth, and function of the nervous system and vision, especially in growing animals. Hypovitaminosis A can affect any of these functions. The aim of this study was to describe the epidemiology, clinical signs, pathological aspects, and diagnostic approach in an outbreak of blindness in feedlot calves fed only grain. Five of 57 ten-month-old calves became blind after eight months at the feedlot. Clinical signs were mydriasis, absent pupillary and menace reflexes, bilaterally. Hypovitaminosis A was suspected and subsequently confirmed by low serum levels of vitamin A. One calf was euthanized and necropsied, and no gross findings were present. Histopathological lesions were restricted to the retina and characterized by degeneration and atrophy of the photoreceptor layer and some retinal scars. The calves were treated with intramuscular vitamin A injection at a dose of 5,000 international units (IU) per kilogram of body weight (kg BW) every 60 days until slaughter. Affected calves did not recover visual capacity, but no other cases occurred.

Vitamina A é um micronutriente essencial para reprodução, desenvolvimento, crescimento normal, além de participar do funcionamento do sistema nervoso central e visão, especialmente em animais em crescimento. Hipovitaminose A pode afetar qualquer uma dessas funções. O objetivo desse artigo é descrever a epidemiologia, sinais clínicos, aspectos patológicos e abordagem diagnóstica em um surto de cegueira em bezerros confinados alimentados apenas com grãos. De 57 bezerros de dez meses de idade, cinco ficaram cegos após oito meses no confinamento. Os sinais clínicos eram midríase, ausência de reflexo pupilar a luz e de ameaça, bilateralmente. Suspeitou-se de hipovitaminose A, que foi subsequentemente confirmada pelos baixos níveis séricos de vitamina A. Um bezerro foi eutanasiado e necropsiado, e alterações macroscópicas não foram encontradas. Lesões histopatológicas estavam restritas a retina e caracterizavam-se por degeneração e atrofia da camada de fotorreceptores, além de cicatrizes na retina. Os bezerros foram tratados com injeção intramuscular de vitamina A, na dose de 5.000 unidades internacionais (UI) por quilograma de peso vivo (Kg PV) a cada 60 dias, até o dia do abate. Os bezerros afetados não recuperaram a capacidade visual, mas novos casos não ocorreram.

Persistência do vítreo primário hiperplásico e catarata em cão / Persistence of hyperplastic primary vitreous and cataract in a dog

Background: Persistent hyperplastic primary vitreous is a rare ocular condition that is usually unilateral, formed when normal regression of the hyaloid vascular system does not occur. Diagnosis is possible through ultrasonography, by obtaining images that provide information and also serve as a differential diagnosis. Clinically the condition presents with signs of leukocoria, microphthalmia, and cataracts, and it can be further classified into 6 degrees according to the evolution. The objective of this work is to describe the case and treatment of a canine of the Pointer breed that presented opacity in both eyes, with diagnosis confirmed through ocular ultrasonography. Case: A 6-year-old male pointer dog, weighing 27 kg, was referred to the Veterinary Medical Teaching Hospital of the Federal University of Santa Maria (UFRGS), Santa Maria, RS - Brazil with a history of blindness. According to the owner, the animal's right eye has always been "white", since it was a puppy and the left eye began to present the same characteristic a short time ago. On ophthalmological examination, neither eye showed signs of ocular discomfort, the Schirmer's tear test was within the range expected for the species, fluorescein and threat tests were negative, and a positive pupillary reflex was observed in the left eye. The right eye had total corneal opacity associated with a chronic lesion and the presence of pigment cells in the medial portion of the eyeball, the opacity making it impossible to visualize the other internal structures of the eyeball. The left eye presented lens opacity. In the ultrasound of the right eye, there were several alterations, the presence of a triangular-shaped hyperechogenic structure in the vitreous chamber, a decrease in the depth of the anterior chamber, and the presence of abnormality in the development of the lens. The findings are compatible with and confirmed the diagnosis of PHPV. In the left eye, the ultrasound images indicated hyperechogenicity of the posterior and anterior poles of the lens, findings compatible with cataracts. Through the animal's history, complete ophthalmic examination, and use of ocular ultrasonography, it was possible to diagnose and differentiate the causes of the white eye in the patient. The preoperative screening was continued with an electroretinography examination, which showed a satisfactory electrical response for the retina of the left eye and an unsatisfactory electrical response for the retina of the right eye. Phacoemulsification surgery was performed to remove the cataract in the left eye with intraocular lens implantation. The positive threat reflex returned in this eye, with a return of visual acuity. Discussion: Persistent hyperplastic tunica lentis and persistent hyperplastic primary vitreous (PHTVL/PHPV) are congenital anomalies caused by a failure to regress the fetal hyaloid vasculature. These conditions are not common, but occur sporadically in dogs. The PHPV classification can be classified into degrees, based on the morphological aspect of the lesion. Following this classification scheme, the PHPV of the animal in question refers to the 6th degree of evolution. The total opacity of the cornea in the right eye was associated with the presence of a hyperplastic primary vitreous and the leukocoria in the left eye was due to the presence of a mature cataract. The conclusion of the diagnosis was only possible through ocular ultrasonography, which is very useful to differentiate the causes of ocular opacity and leukocoria, in addition to allowing complete evaluation of the intraocular structures and being considered an essential exam to confirm the diagnosis of PHPV.

Propolis anti-inflammatory effects on MAGE-1 and retinoic acid-treated dendritic cells and on Th1 and T regulatory cells

Background: Propolis exhibits huge potential in the pharmaceutical industry. In the present study, its effects were investigated on dendritic cells (DCs) stimulated with a tumor antigen (MAGE-1) and retinoic acid (RA) and on T lymphocytes to observe a possible differential activation of T lymphocytes, driving preferentially to Th1 or Treg cells. Methods: Cell viability, lymphocyte proliferation, gene expression (T-bet and FoxP3), and cytokine production by DCs (TNF-α, IL-10, IL-6 and IL-1ß) and lymphocytes (IFN-γ and TGF-ß) were analyzed. Results: MAGE-1 and RA alone or in combination with propolis inhibited TNF-α production and induced a higher lymphoproliferation compared to control, while MAGE1 + propolis induced IL-6 production. Propolis in combination with RA induced FoxP3 expression. MAGE-1 induced IFN-γ production while propolis inhibited it, returning to basal levels. RA inhibited TGF-ß production, what was counteracted by propolis. Conclusion: Propolis affected immunological parameters inhibiting pro-inflammatory cytokines and favoring the regulatory profile, opening perspectives for the control of inflammatory conditions.(AU)

Coloboma eyelid in cats - treatment with carbon dioxide cryosurgery

Background: Eyelid colobomas are congenital and developmental disorders. Generally, they affect the temporal portion of the upper eyelids of cats, bilaterally. This ocular defect is accompanied by trichiasis associated with pain and ulcerative keratitis. Any breed can be affected and it has been reported in Domestic Shorthair, Persian, Burmese, Mongrel cats and captive felids. The objective of this case report is to describe the technique of dioxide carbon cryosurgery for the treatment of eyelid coloboma in felines. Cases: Seven mongrel cats (14 eyes) with bilateral eyelid coloboma were included in this study, 5 females and 2 males, with a median age of 5 months (range 6-8 months). The patients presented with blepharospasm, bilateral mucopurulent ocular discharge and eyelid coloboma extension of 30-50% in the upper eyelid, resulting in severe trichiasis of both eyes. In 5 cats, 1 or both eyes were diagnosed with keratitis and superficial corneal ulcers. Surgical treatment with general anaesthesia was applied. The pre anaesthesia protocol included acepromazine 0.05 mg/kg with methadone 0.2 mg/kg, followed by intravenous propofol and maintenance with isoflurane and oxygen. An ophthalmological cryocautery unit was utilised with carbon dioxide as the cryogenic agent and a retinal cryoprobe of 3.2 mm diameter tip, reaching -50ºC for the procedure. The method used was a double cycle of freezing and thawing for 60 s in the margins of eyelid agenesis. Epilation of hairs was made after freezing with eyelash tweezers. Immediately after the surgical procedure, an Elizabethan collar was placed to safeguard the area and anti-inflammatory therapy with meloxicam 0.1 mg/kg once daily for 3 days was prescribed. Antibiotic ointment every 6 h (chloramphenicol and associations) was also prescribed for topical application. Two weeks post-operatively, hyperaemia, oedema and skin wounds at the margins were observed. After 30 days these clinical signs were minimal. No signs of pain were observed post-operatively. The follow-up was 90 days and the trichiasis was resolved in all cats. Discussion: Usually, young cats are affected with eyelid colobomas. The age of the patients in this study was between 6-8 months. Eyelid colobomas are repaired with a variety of blepharoplastic procedures and the choice depends on the size and position of the defect. Generally, larger defects require more extensive reconstructive procedures. All techniques can have post-operative complications. Suture dehiscence, skin flap necrosis and facial deformation can occur with traditional surgical techniques. Furthermore, posterior hair growth in the margins can lead to new trichiasis. Cryosurgery was chosen and performed as the temperature of -20°C is sufficient to destroy hair follicles, without surgical incisions, avoiding scar formation. Hence, sutures are not necessary in cryosurgery procedures. Carbon dioxide is a good cryogenic agent for the purpose of this procedure. In the cases described, no recurrence of hair growth was observed in the follow-up period of 90 days. Nevertheless, a good aesthetic appearance was maintained. Therefore, the use of carbon dioxide cryosurgery is an effective and safe alternative for treatment of eyelid coloboma in cats. To our knowledge, no paper has described the use of carbon dioxide cryosurgery for the correction of palpebral agenesis in felines and other species as a single treatment. This technique is easy to perform, has good aesthetic and functional results and can be considered a treatment option for this congenital condition.

Linfoma intraocular em cães - achados da ultrassonografia contrastada e elastografia ARFI / Intraocular lymphoma in dogs - findings of contrast enhanced ultrasound and ARFI elastography

Background: Ocular lymphoma can affect the iris, conjunctiva, choroid, and retina and is mostly associated with multicentric disease. Elastography is an ultrasound technique that provides noninvasive, pain-free assessment of tissue stiffness. It has the ability to assess subtle changes throughout the organ as well as focal lesions. Microbubble contrast ultrasound enables the detection of incipient vascular flows, which are difficult to detect using traditional ultrasound methods. This study aimed to describe acoustic radiation force impulse (ARFI) elastography and microbubble contrast ultrasound findings in the eyes of two dogs diagnosed with intraocular T-cell lymphoma. Cases: Case 1. Physical examination revealed an exophytic mass in the left eye. Schirmer test revealed a secretion of 22 mm/min. Negative threat reflex, glare, direct pupillary light reflex, and consensual response were also noted. Biomicroscopy revealed hyperplasia of the third eyelid, overlapping with the affected eye. When the membrane was removed, moderate conjunctival hyperemia, mucoid secretion, and buphthalmia were observed. In addition, significant corneal edema was present, making it impossible to visualize the anterior chamber and perform fundus examination. The intraocular pressure, as measured with a rebound tonometer, was 39 mmHg. B-mode ultrasonography identified amorphous, hyperechoic, and heterogeneous structures throughout the anterior chamber, iris, and ciliary body. The elastogram showed that the mass had greenish tones and intermediate stiffness, and the mean SWV of the ciliary body and iris was 2 m/s. Contrast-enhanced ultrasound (CEUS) revealed vascularization of the neoformation region, with wash-in, peak, and wash-out values of 9.89 s, 24.56 s, and 107.87 s, respectively. Case 2. On physical examination, a change in the shape of the right pupil was observed. Schirmer test revealed a secretion of 20 mm/min, with negative threat, glare, and pupillary reflexes to direct and consensual light. Biomicroscopy revealed neoformation from 7 am to 11 am in the sclera, retina, and choroid complex, concomitant with dyscoria and conjunctival hyperemia. The intraocular pressure, as measured by rebound tonometry, was 33 mmHg. Fundoscopy revealed a mass in the temporal region and focal retinal detachment. No changes were observed in the contralateral eye. B-mode ultrasound revealed an increase in volume in the temporal region of the iris, ciliary body, and choroid with diffuse heterogeneity and partial retinal detachment. Elastographic examination revealed shades of green and yellow compatible with increased tissue stiffness. On quantitative examination, the mean SWVs of the ciliary body and iris were 3.14 m/s. On CEUS, the neoformation region presented wash-in, peak, and wash-out values of 8.67 s, 22.33 s, and 80.20 s. Discussion: B-mode ultrasonography established the tumor extent and evaluated echogenicity, verifying the involved ocular structures. The examination played an important role in the diagnosis as well as clinical management. ARFI elastography can detect small tissue changes, helping to define nodules and masses more reliably, in addition to allowing the verification of tissue stiffness. In both dogs, it was possible to verify that the masses presented greater rigidity than the adjacent tissues both qualitatively and quantitatively. In previous studies, it was found that cutaneous and breast lymphomas in humans were more rigid than adjacent tissues on elastography. This increase in rigidity and heterogeneity observed on elastograms can be explained by the extramedullary interactions of the matrix in T-cell lymphomas. Tumor growth is dependent on the blood supply, which was evaluated using CEUS in these cases. Furthermore, the ciliary body contrast filling times were longer than those described in normal dogs.

Uso de imagens para diagnóstico de afecções oculares - revisão de literatura / Use of images for the diagnosis of ocular pathologies - literature review / Uso de imágenes para el diagnóstico de patologías de los ojos - revisión de la literatura

La oftalmología veterinaria cubre el diagnóstico de alteraciones oculares primarias, perioculares y retrobulbares, así como sus manifestaciones sistémicas y secundarias, lo que es posible gracias a la evaluación completa del bulbo ocular, la órbita y las inserciones mediante un examen oftálmico completo y exámenes complementarios. Entre las pruebas de imagen que ayudan en el diagnóstico de patologías oculares, la ecografía se encuentra entre las pruebas de imagen más utilizadas en la rutina veterinaria, ayudando en la observación de anomalías retrobulbares y en la evaluación de estructuras bulbosas en presencia de medios transparentes opacos, por ejemplo. Además de la ecografía, existen otros tipos de exámenes, que incluyen tomografía computarizada, resonancia magnética, angiografía, microscopía especular, angiografía, tomografía de coherencia óptica (OCT) y angiografía por tomografía de coherencia óptica (OCT-A). Debido a los avances tecnológicos en la obtención de imágenes, la evaluación del globo ocular y de las estructuras orbitarias se puede realizar con mayor precisión, lo que favorece el diagnóstico y la elección terapéutica adecuada. El objetivo de esta revisión es enumerar las pruebas disponibles, sus principales indicaciones, así como su aplicabilidad y estudios en animales domésticos.

Veterinary ophthalmology covers the diagnosis of primary ocular, periocular and retrobulbar alterations, and also their systemic and secondary manifestations. That is possible through the complete clinic avaliation of ocular bulb, orbit and attachments and the use of complementary exams. Among the imaging exams that help in the diagnostics of ocular pathologies, ultrasound is one of the most used exams in the veterinary routine, assisting in the observation of retrobulbar abnormalities and bulbar structures when the transparency of the tissues is committed, for example. There are other modalities of imaging exams like computer tomography, magnetic resonance, angiography, optical coherence tomography (OCT) and angiography optical coherence tomography (OCT-A). Due to technology advances in images, the avaliation of ocular globe and orbital structures is more accurate, allowing accurate diagnosis and adequate treatment. The aim of this literature review is list the available exams and their indications, as well as their applicability and studies in domestic animals.

A oftalmologia veterinária abrange o diagnóstico das alterações oculares, perioculares e retrobulbares primárias, e também suas manifestações sistêmicas e secundárias, o que se torna possível a partir da avaliação completa do bulbo ocular, órbita e anexos por meio do exame oftálmico completo e de exames complementares. Dentre os exames de imagens que auxiliam no diagnóstico das afecções oculares, a ultrassonografia está entre os exames de imagem mais utilizados na rotina veterinária, auxiliando na observação de anormalidades retrobulbares e na avaliação das estruturas bulbares na presença de opacificação de meios transparentes, por exemplo. Além da ultrassonografia, existem outras modalidades de exames, dentre eles a tomografia computadorizada, ressonância magnética, angiografia, microscopia especular, tomografia de coerência óptica (OCT) e angiografia por tomografia de coerência óptica (OCT-A).  Em virtude dos avanços tecnológicos na obtenção de imagens, a avaliação globo ocular e das estruturas orbitárias pode ser realizada com maior precisão, o que favorece o diagnóstico e a escolha terapêutica adequada. Objetiva-se com esta revisão enumerar os exames disponíveis, suas principais indicações, bem como sua aplicabilidade e estudos em animais domésticos.

Uso de imagens para diagnóstico de afecções oculares - revisão de literatura / Use of images for the diagnosis of ocular pathologies - literature review / Uso de imágenes para el diagnóstico de patologías de los ojos - revisión de la literatura

La oftalmología veterinaria cubre el diagnóstico de alteraciones oculares primarias, perioculares y retrobulbares, así como sus manifestaciones sistémicas y secundarias, lo que es posible gracias a la evaluación completa del bulbo ocular, la órbita y las inserciones mediante un examen oftálmico completo y exámenes complementarios. Entre las pruebas de imagen que ayudan en el diagnóstico de patologías oculares, la ecografía se encuentra entre las pruebas de imagen más utilizadas en la rutina veterinaria, ayudando en la observación de anomalías retrobulbares y en la evaluación de estructuras bulbosas en presencia de medios transparentes opacos, por ejemplo. Además de la ecografía, existen otros tipos de exámenes, que incluyen tomografía computarizada, resonancia magnética, angiografía, microscopía especular, angiografía, tomografía de coherencia óptica (OCT) y angiografía por tomografía de coherencia óptica (OCT-A). Debido a los avances tecnológicos en la obtención de imágenes, la evaluación del globo ocular y de las estructuras orbitarias se puede realizar con mayor precisión, lo que favorece el diagnóstico y la elección terapéutica adecuada. El objetivo de esta revisión es enumerar las pruebas disponibles, sus principales indicaciones, así como su aplicabilidad y estudios en animales domésticos.(AU)

Veterinary ophthalmology covers the diagnosis of primary ocular, periocular and retrobulbar alterations, and also their systemic and secondary manifestations. That is possible through the complete clinic avaliation of ocular bulb, orbit and attachments and the use of complementary exams. Among the imaging exams that help in the diagnostics of ocular pathologies, ultrasound is one of the most used exams in the veterinary routine, assisting in the observation of retrobulbar abnormalities and bulbar structures when the transparency of the tissues is committed, for example. There are other modalities of imaging exams like computer tomography, magnetic resonance, angiography, optical coherence tomography (OCT) and angiography optical coherence tomography (OCT-A). Due to technology advances in images, the avaliation of ocular globe and orbital structures is more accurate, allowing accurate diagnosis and adequate treatment. The aim of this literature review is list the available exams and their indications, as well as their applicability and studies in domestic animals.(AU)

A oftalmologia veterinária abrange o diagnóstico das alterações oculares, perioculares e retrobulbares primárias, e também suas manifestações sistêmicas e secundárias, o que se torna possível a partir da avaliação completa do bulbo ocular, órbita e anexos por meio do exame oftálmico completo e de exames complementares. Dentre os exames de imagens que auxiliam no diagnóstico das afecções oculares, a ultrassonografia está entre os exames de imagem mais utilizados na rotina veterinária, auxiliando na observação de anormalidades retrobulbares e na avaliação das estruturas bulbares na presença de opacificação de meios transparentes, por exemplo. Além da ultrassonografia, existem outras modalidades de exames, dentre eles a tomografia computadorizada, ressonância magnética, angiografia, microscopia especular, tomografia de coerência óptica (OCT) e angiografia por tomografia de coerência óptica (OCT-A).  Em virtude dos avanços tecnológicos na obtenção de imagens, a avaliação globo ocular e das estruturas orbitárias pode ser realizada com maior precisão, o que favorece o diagnóstico e a escolha terapêutica adequada. Objetiva-se com esta revisão enumerar os exames disponíveis, suas principais indicações, bem como sua aplicabilidade e estudos em animais domésticos.(AU)

Cirurgia corretiva para coloboma palpebral em um felino através da técnica de transposição da comissura labial / Corrective surgery for palpebral coloboma in a feline using the technique of transposition of the lip commissure

Background: Eyelid coloboma is considered a disease caused by failure in eye development during the first semester of pregnancy. In felines, its prevalence occurs in the upper eyelids, temporal region, and bilaterally. Coloboma, whether to a large or small extent, can lead to keratoconjunctivitis sicca and trichiasis, situations that can give rise to secondary ulcerative keratitis. The only corrective method is blepharoplasty. The current work aims to report the case of corrective surgery for eyelid coloboma in a feline with a successful postoperative period, in order to corroborate the effectiveness of the technique. We also report a finding of persistent pupillary membrane. Case: A 7-month-old male feline, no defined breed, was analyzed with a purulent mucus secretion and signs of discomfort in the right eye. After the ophthalmic screening, the presence of a coloboma was identified, which occupied approximately 50% of the size of the upper eyelid, in the temporal-dorsal region of the right eye. The cat had already undergone an enucleation of the left eye due to a perforation arising from ulcerative keratitis. Together with coloboma, the presence of blepharospasm, trichiasis, keratoconjunctivitis sicca, and secondary ulcerative keratitis were diagnosed. The presence of persistent pupillary membrane was also observed, a rare condition in the feline species. To confirm the ulcer, the fluorescein test was applied and treatment with antibiotic eye drops and lacrimomimetics (tear film replacements) drops was administered until the day of surgery, one week later. Concomitant with the institution of treatment prior to surgery, blood was collected for complementary pre-surgical tests such as blood count and biochemistry, which demonstrated satisfactory results. Corrective surgery was then instituted by the technique of transposing the labial commissure...

Accuracy of ARFI elastography in the differentiation of cataract stages in dogs

ABSTRACT: Objective was to evaluate the accuracy of elastography in the differentiation between normal and cataract lenses One hundred forty-five eyes of 98 dogs were divided into groups according to cataract stage. Forty-twoeyes were submitted to phacoemulsification. Biometric parameters, echogenicity and echotexture patterns of the anterior, posterior and vitreous chambers, lens and retina-choroid-sclera complexes were evaluated by ocular ultrasound in modes A and B. Deformability, and color (blue color = indicated less rigid structures, color red = more rigid structures) of the lenses were evaluated by the elastogram. The shear wave velocity (SWV; m/s) was calculated in three regions of the lens, both in the cortex and in the nucleus. The SWV of nucleus was statistically different between the normal lenses and with cataracts, and between the stages of cataract (P 0.001). Healthy lenses and incipient cataracts had a more rigid nucleus. Mature cataracts presented lowest nuclear rigidity (P 0.001). On cortical region the SWV was significantly higher (P 0.01) in intumescent and incipient cataracts. SWV less than 2.67m/s indicates cataract with a sensitivity of 72% and specificity of 94%. Values lower than 2.23m/s suggest mature cataract, with sensitivity of 71% and specificity of 76%. SWV greater than 2.66 m/s are associated with normal lenses or incipient cataract, presenting sensitivity of 94% and specificity of 84%. Qualitative method allowed differentiation between healthy and affected lenses and the classification of evolutionary stages. There was a correlation between the degree of stiffness of lens in cortical and nuclear regions (p=00165, r=0.37) and between the balanced saline solution quantitative and surgical time (P 0.01, r=0.73). Degree of stiffness of lens did not correlate with parameters of phacoemulsification. Elastographic proved feasible for evaluating the lens of dogs, characterizing the types of cataracts, and demonstrating increased stiffness of the diseased lenses.

RESUMO: O objetivo foi avaliar a precisão da elastografia na diferenciação entre lentes normais e de catarata. Cento e quarenta e cinco olhos de 98 cães foram divididos em grupos de acordo com o estágio de maturação da catarata. Quarenta e dois olhos foram submetidos à facoemulsificação. Parâmetros biométricos, ecogenicidade e padrões de ecotextura das câmaras anterior, posterior e vítrea, lente e complexos retina-coróide-esclera foram avaliados por ultrassonografia ocular nos modos A e B. A deformabilidade e a coloração (cor azul = indicou estruturas menos rígidas, cor vermelha = estruturas mais rígidas) das lentes foram avaliadas pelo elastograma. A velocidade da onda de cisalhamento (SWV; m/s) foi calculada em três regiões da lente, tanto no córtex quanto no núcleo. A SWV do núcleo foi estatisticamente diferente entre as lentes normais e com catarata e entre os estágios da catarata (P 0,001). Lentes saudáveis e cataratas incipientes tinham um núcleo mais rígido. Cataratas maduras apresentaram menor rigidez nuclear (P 0,001). Na região cortical, a SWV foi significativamente maior (P 0,01) nas cataratas intumescentes e incipientes. Uma SWV menor que 2,67m/s indica catarata com sensibilidade de 72% e especificidade de 94%. Valores inferiores a 2,23m/s sugerem catarata madura, com sensibilidade de 71% e especificidade de 76%. Uma SWV superior a 2,66m/s está associada à catarata normal ou incipiente, apresentando sensibilidade de 94% e especificidade de 84%. O método qualitativo permitiu a diferenciação entre lentes normais de olhos saudáveis e afetadas e a classificação dos estágios evolutivos. A elastografia se mostrara uma ferramenta viável para avaliar as lentes de cães, caracterizando os tipos de catarata e demonstrando maior rigidez das lentes doentes.

Accuracy of ARFI elastography in the differentiation of cataract stages in dogs / Acurácia da elastografia ARFI na diferenciação dos estágios da catarata em cães

Objective was to evaluate the accuracy of elastography in the differentiation between normal and cataract lenses One hundred forty-five eyes of 98 dogs were divided into groups according to cataract stage. Forty-twoeyes were submitted to phacoemulsification. Biometric parameters, echogenicity and echotexture patterns of the anterior, posterior and vitreous chambers, lens and retina-choroid-sclera complexes were evaluated by ocular ultrasound in modes A and B. Deformability, and color (blue color = indicated less rigid structures, color red = more rigid structures) of the lenses were evaluated by the elastogram. The shear wave velocity (SWV; m/s) was calculated in three regions of the lens, both in the cortex and in the nucleus. The SWV of nucleus was statistically different between the normal lenses and with cataracts, and between the stages of cataract (P<0.001). Healthy lenses and incipient cataracts had a more rigid nucleus. Mature cataracts presented lowest nuclear rigidity (P<0.001). On cortical region the SWV was significantly higher (P<0.01) in intumescent and incipient cataracts. SWV less than 2.67m/s indicates cataract with a sensitivity of 72% and specificity of 94%. Values lower than 2.23m/s suggest mature cataract, with sensitivity of 71% and specificity of 76%. SWV greater than 2.66 m/s are associated with normal lenses or incipient cataract, presenting sensitivity of 94% and specificity of 84%. Qualitative method allowed differentiation between healthy and affected lenses and the classification of evolutionary stages. There was a correlation between the degree of stiffness of lens in cortical and nuclear regions (p=00165, r=0.37) and between the balanced saline solution quantitative and surgical time (P<0.01, r=0.73). Degree of stiffness of lens did not correlate with parameters of phacoemulsification. Elastographic proved feasible for evaluating the lens of dogs, characterizing the types of cataracts, and demonstrating increased stiffness of the diseased lenses.(AU)

O objetivo foi avaliar a precisão da elastografia na diferenciação entre lentes normais e de catarata. Cento e quarenta e cinco olhos de 98 cães foram divididos em grupos de acordo com o estágio de maturação da catarata. Quarenta e dois olhos foram submetidos à facoemulsificação. Parâmetros biométricos, ecogenicidade e padrões de ecotextura das câmaras anterior, posterior e vítrea, lente e complexos retina-coróide-esclera foram avaliados por ultrassonografia ocular nos modos A e B. A deformabilidade e a coloração (cor azul = indicou estruturas menos rígidas, cor vermelha = estruturas mais rígidas) das lentes foram avaliadas pelo elastograma. A velocidade da onda de cisalhamento (SWV; m/s) foi calculada em três regiões da lente, tanto no córtex quanto no núcleo. A SWV do núcleo foi estatisticamente diferente entre as lentes normais e com catarata e entre os estágios da catarata (P<0,001). Lentes saudáveis e cataratas incipientes tinham um núcleo mais rígido. Cataratas maduras apresentaram menor rigidez nuclear (P<0,001). Na região cortical, a SWV foi significativamente maior (P<0,01) nas cataratas intumescentes e incipientes. Uma SWV menor que 2,67m/s indica catarata com sensibilidade de 72% e especificidade de 94%. Valores inferiores a 2,23m/s sugerem catarata madura, com sensibilidade de 71% e especificidade de 76%. Uma SWV superior a 2,66m/s está associada à catarata normal ou incipiente, apresentando sensibilidade de 94% e especificidade de 84%. O método qualitativo permitiu a diferenciação entre lentes normais de olhos saudáveis e afetadas e a classificação dos estágios evolutivos. A elastografia se mostrara uma ferramenta viável para avaliar as lentes de cães, caracterizando os tipos de catarata e demonstrando maior rigidez das lentes doentes.(AU)

Accuracy of ARFI elastography in the differentiation of cataract stages in dogs / Acurácia da elastografia ARFI na diferenciação dos estágios da catarata em cães

Objective was to evaluate the accuracy of elastography in the differentiation between normal and cataract lenses One hundred forty-five eyes of 98 dogs were divided into groups according to cataract stage. Forty-twoeyes were submitted to phacoemulsification. Biometric parameters, echogenicity and echotexture patterns of the anterior, posterior and vitreous chambers, lens and retina-choroid-sclera complexes were evaluated by ocular ultrasound in modes A and B. Deformability, and color (blue color = indicated less rigid structures, color red = more rigid structures) of the lenses were evaluated by the elastogram. The shear wave velocity (SWV; m/s) was calculated in three regions of the lens, both in the cortex and in the nucleus. The SWV of nucleus was statistically different between the normal lenses and with cataracts, and between the stages of cataract (P<0.001). Healthy lenses and incipient cataracts had a more rigid nucleus. Mature cataracts presented lowest nuclear rigidity (P<0.001). On cortical region the SWV was significantly higher (P<0.01) in intumescent and incipient cataracts. SWV less than 2.67m/s indicates cataract with a sensitivity of 72% and specificity of 94%. Values lower than 2.23m/s suggest mature cataract, with sensitivity of 71% and specificity of 76%. SWV greater than 2.66 m/s are associated with normal lenses or incipient cataract, presenting sensitivity of 94% and specificity of 84%. Qualitative method allowed differentiation between healthy and affected lenses and the classification of evolutionary stages. There was a correlation between the degree of stiffness of lens in cortical and nuclear regions (p=00165, r=0.37) and between the balanced saline solution quantitative and surgical time (P<0.01, r=0.73). Degree of stiffness of lens did not correlate with parameters of phacoemulsification. Elastographic proved feasible for evaluating the lens of dogs, characterizing the types of cataracts, and demonstrating increased stiffness of the diseased lenses.(AU)

O objetivo foi avaliar a precisão da elastografia na diferenciação entre lentes normais e de catarata. Cento e quarenta e cinco olhos de 98 cães foram divididos em grupos de acordo com o estágio de maturação da catarata. Quarenta e dois olhos foram submetidos à facoemulsificação. Parâmetros biométricos, ecogenicidade e padrões de ecotextura das câmaras anterior, posterior e vítrea, lente e complexos retina-coróide-esclera foram avaliados por ultrassonografia ocular nos modos A e B. A deformabilidade e a coloração (cor azul = indicou estruturas menos rígidas, cor vermelha = estruturas mais rígidas) das lentes foram avaliadas pelo elastograma. A velocidade da onda de cisalhamento (SWV; m/s) foi calculada em três regiões da lente, tanto no córtex quanto no núcleo. A SWV do núcleo foi estatisticamente diferente entre as lentes normais e com catarata e entre os estágios da catarata (P<0,001). Lentes saudáveis e cataratas incipientes tinham um núcleo mais rígido. Cataratas maduras apresentaram menor rigidez nuclear (P<0,001). Na região cortical, a SWV foi significativamente maior (P<0,01) nas cataratas intumescentes e incipientes. Uma SWV menor que 2,67m/s indica catarata com sensibilidade de 72% e especificidade de 94%. Valores inferiores a 2,23m/s sugerem catarata madura, com sensibilidade de 71% e especificidade de 76%. Uma SWV superior a 2,66m/s está associada à catarata normal ou incipiente, apresentando sensibilidade de 94% e especificidade de 84%. O método qualitativo permitiu a diferenciação entre lentes normais de olhos saudáveis e afetadas e a classificação dos estágios evolutivos. A elastografia se mostrara uma ferramenta viável para avaliar as lentes de cães, caracterizando os tipos de catarata e demonstrando maior rigidez das lentes doentes.(AU)

Facoemulsificação com implante de lente intraocular em cão / Phacoemulsification technique with dog intraocular lens implant

As afecções oculares são diagnosticadas rotineiramente em clínica de animais domésticos, tornando a oftalmologia um relevante seguimento na Medicina Veterinária. A catarata é caracterizada pela opacidade progressiva docristalino que interfere na absorção de luz que chegará à retina. O objetivo deste trabalho é relatar o caso de tratamento cirúrgico de catarata imatura pela técnica de facoemulsificação com implante de lente intraocular em canino. Um canino, macho, não castrado, da raça poodle, com 14 anos de idade, foi atendido em uma clínica veterinária, na cidade de Manaus, Amazonas. Após diagnóstico, optou-se pela cirurgia através da técnica de facoemulsificação, visando a remoção por meio da fragmentação e aspiração do cristalino, com posterior implante da lente intraocular. Decorridos 30 dias da cirurgia, o paciente retornou para a avalição da evolução do tratamento. Observou-se melhora significativa na visão do animal. Por conseguinte, conclui-se que a técnica foi eficiente no processo de recuperação, de acordo com o progresso significativo dos testes de reflexo, colocação de obstáculos em ambientes escuros e claros.

Eye disorders are routinely diagnosed in domestic animal clinic, which makes ophthalmology a relevant follow up in Veterinary Medicine. Cataracts are characterized by a progressive opacity of the lens that interferes with the absorption of light reaching the retina. The objective of this work is to report the case of surgical treatment of immature cataract using the phacoemulsification technique with intraocular lens implant in canines. A 14-year-oldmale poodle, uncastrated, was seen at a veterinary clinic in the city of Manaus, Amazonas. After diagnosis, surgery was performed using the phacoemulsification technique, aiming at the removal through fragmentation and aspiration of the lens with subsequent implantation of the intraocular lens. After 30 days of the surgery, the patient returned to evaluate the progress of the treatment. A significant improvement in the animal's vision was observed. Therefore, it was concluded that the technique used was an efficient in the recovery process according to significant advances, two reflection tests, placing obstacles in dark and light environments.

Facoemulsificação com implante de lente intraocular em cão / Phacoemulsification technique with dog intraocular lens implant

As afecções oculares são diagnosticadas rotineiramente em clínica de animais domésticos, tornando a oftalmologia um relevante seguimento na Medicina Veterinária. A catarata é caracterizada pela opacidade progressiva docristalino que interfere na absorção de luz que chegará à retina. O objetivo deste trabalho é relatar o caso de tratamento cirúrgico de catarata imatura pela técnica de facoemulsificação com implante de lente intraocular em canino. Um canino, macho, não castrado, da raça poodle, com 14 anos de idade, foi atendido em uma clínica veterinária, na cidade de Manaus, Amazonas. Após diagnóstico, optou-se pela cirurgia através da técnica de facoemulsificação, visando a remoção por meio da fragmentação e aspiração do cristalino, com posterior implante da lente intraocular. Decorridos 30 dias da cirurgia, o paciente retornou para a avalição da evolução do tratamento. Observou-se melhora significativa na visão do animal. Por conseguinte, conclui-se que a técnica foi eficiente no processo de recuperação, de acordo com o progresso significativo dos testes de reflexo, colocação de obstáculos em ambientes escuros e claros.(AU)

Eye disorders are routinely diagnosed in domestic animal clinic, which makes ophthalmology a relevant follow up in Veterinary Medicine. Cataracts are characterized by a progressive opacity of the lens that interferes with the absorption of light reaching the retina. The objective of this work is to report the case of surgical treatment of immature cataract using the phacoemulsification technique with intraocular lens implant in canines. A 14-year-oldmale poodle, uncastrated, was seen at a veterinary clinic in the city of Manaus, Amazonas. After diagnosis, surgery was performed using the phacoemulsification technique, aiming at the removal through fragmentation and aspiration of the lens with subsequent implantation of the intraocular lens. After 30 days of the surgery, the patient returned to evaluate the progress of the treatment. A significant improvement in the animal's vision was observed. Therefore, it was concluded that the technique used was an efficient in the recovery process according to significant advances, two reflection tests, placing obstacles in dark and light environments.(AU)

Exigência de triptofano digestível para codornas japonesas / Digestible tryptophan requirements for Japanese quais

A coturnicultura é uma parte do setor avícola que vem ganhando cada vez mais espaço, pois possui inúmeras vantagens e entre elas a alta densidade na criação, redução no custo com mão-de-obra, alta prolificidade, rusticidade, precocidade, rápido ganho de peso, longevidade na vida produtiva, alta produtividade e rápido retorno do capital investido. Assim, torna-se necessário o fornecimento de rações que atendam às exigências nutricionais do animal, atrelado à disposição dos aminoácidos essenciais digestíveis na dieta, pois dos 20disponíveis as aves conseguem sintetizar apenas 10. O triptofano é um aminoácido essencial que atua no aumento do consumo, em uma possível redução no estresse e em várias vias metabólicas, tais como a via da serotonina, da melatonina e do ácido nicotínico, além de ter função também na biossíntese proteica. A serotonina é um neurotransmissor que influencia o comportamento, a secreção do hormônio do estresse e não pode atravessar a barreira hematoencefálica, mas o triptofano através de um transportador tem essa capacidade, tal fator promove uma melhor sinalização da serotonina. A melatonina é um neuro-hormônio sintetizado principalmente pela glândula pineal e pela retina, e está relacionada com a regulação do sono e do ritmo circadiano. O triptofano é precursor do ácido niacínico, que pode ser convertido em niacina, uma vitamina hidrossolúvel que atua como precursora das coenzimas NAD e NADP. Este estudo permitirá um maior conhecimento da atuação e metabolismo do triptofano, bem como suas exigências nutricionais para codornas de postura japonesas.

Quail farming is a part of the poultry sector that has been gaining more and more space, as it has numerous advantages and among them the high density in the creation, reduced labor costs, high prolificity, rusticity, precocity, rapid weight gain, longevity in productive life, high productivity and quick return on invested capital. Thus, it is necessary to provide rations that meet the animal's nutritional requirements, linked to the availability of digestible essential amino acids in the diet, since birds can synthesize only 10 of the 20 available. Tryptophan is an essential amino acid that acts in increasing consumption, a possible reduction in stress and in several metabolic pathways, such as the serotonin, melatonin and nicotinic acid pathways, in addition to having a role in protein biosynthesis. Serotonin is a neurotransmitter that influences the behavior, secretion of stress hormone and cannot cross the blood-brain barrier, but tryptophan through a transporter has this capacity, such a factor promotes better signaling of serotonin. Melatonin is a neurohormone synthesized mainly by the pineal gland and the retina and is related to the regulation of sleep and circadian rhythm. Tryptophan is a precursor to niacinic acid, which can be converted into niacin, a water-soluble vitamin that acts as a precursor to the NAD and NADP coenzymes. This study will allow a greater understanding of the performance and metabolism of tryptophan, as well as its nutritional requirements for Japanese quails.

Exigência de triptofano digestível para codornas japonesas / Digestible tryptophan requirements for Japanese quais

A coturnicultura é uma parte do setor avícola que vem ganhando cada vez mais espaço, pois possui inúmeras vantagens e entre elas a alta densidade na criação, redução no custo com mão-de-obra, alta prolificidade, rusticidade, precocidade, rápido ganho de peso, longevidade na vida produtiva, alta produtividade e rápido retorno do capital investido. Assim, torna-se necessário o fornecimento de rações que atendam às exigências nutricionais do animal, atrelado à disposição dos aminoácidos essenciais digestíveis na dieta, pois dos 20disponíveis as aves conseguem sintetizar apenas 10. O triptofano é um aminoácido essencial que atua no aumento do consumo, em uma possível redução no estresse e em várias vias metabólicas, tais como a via da serotonina, da melatonina e do ácido nicotínico, além de ter função também na biossíntese proteica. A serotonina é um neurotransmissor que influencia o comportamento, a secreção do hormônio do estresse e não pode atravessar a barreira hematoencefálica, mas o triptofano através de um transportador tem essa capacidade, tal fator promove uma melhor sinalização da serotonina. A melatonina é um neuro-hormônio sintetizado principalmente pela glândula pineal e pela retina, e está relacionada com a regulação do sono e do ritmo circadiano. O triptofano é precursor do ácido niacínico, que pode ser convertido em niacina, uma vitamina hidrossolúvel que atua como precursora das coenzimas NAD e NADP. Este estudo permitirá um maior conhecimento da atuação e metabolismo do triptofano, bem como suas exigências nutricionais para codornas de postura japonesas.(AU)

Quail farming is a part of the poultry sector that has been gaining more and more space, as it has numerous advantages and among them the high density in the creation, reduced labor costs, high prolificity, rusticity, precocity, rapid weight gain, longevity in productive life, high productivity and quick return on invested capital. Thus, it is necessary to provide rations that meet the animal's nutritional requirements, linked to the availability of digestible essential amino acids in the diet, since birds can synthesize only 10 of the 20 available. Tryptophan is an essential amino acid that acts in increasing consumption, a possible reduction in stress and in several metabolic pathways, such as the serotonin, melatonin and nicotinic acid pathways, in addition to having a role in protein biosynthesis. Serotonin is a neurotransmitter that influences the behavior, secretion of stress hormone and cannot cross the blood-brain barrier, but tryptophan through a transporter has this capacity, such a factor promotes better signaling of serotonin. Melatonin is a neurohormone synthesized mainly by the pineal gland and the retina and is related to the regulation of sleep and circadian rhythm. Tryptophan is a precursor to niacinic acid, which can be converted into niacin, a water-soluble vitamin that acts as a precursor to the NAD and NADP coenzymes. This study will allow a greater understanding of the performance and metabolism of tryptophan, as well as its nutritional requirements for Japanese quails.(AU)

Comparative retinal histomorphometry and visual acuity of three bat species of the genus Artibeus (Phyllostomidae: Stenodermatinae) / Histomorfometria comparada da retina e acuidade visual de três espécies de morcegos do gênero Artibeus (Phyllostomidae: Stenodermatinae)

This study performed a histomorphometric analysis of the retina and estimated the visual acuity of three fruit-eating bats of the genus Artibeus, including Artibeus lituratus, Artibeus planirostris and Artibeus obscurus. In total, 13 animals were used for this study, in which the retinas were hemidisected, fixed, cut, and stained. The visual acuity was determined by the density of ganglion cells in the retina and the retinal layers were also measured from histological sections. The retinas of these bats are avascular, do not present tapetum lucidum in any quadrant, and have the 10 retinal layers common in mammals. Moreover, it was observed that the thickness of the retina in the central region was significantly higher in all measured parameters (p<0.001), except for the outer plexiform layer (OPL) which was significantly higher in the peripheral region (p<0.001). The retinas of the three species showed a horizontal visual streak with a higher concentration of retinal ganglion cells (RGCs) at the inferotemporal region. In addition, the species A. lituratus exhibited extras areas of high cell density in the retina. Thus, A. lituratus showed the highest visual acuity (1.92 cycles/degree), while A. planirostris showed a visual acuity of (1.77 cycles/degree) and A. obscurus exhibited the lowest visual acuity (1.50 cycles/degree). All these characteristics are related to the echolocation system and the eating habits of each species. Therefore, it can be concluded that bats of the genus Artibeus have a high visual acuity value compared to other echolocating bats and all these differences might be directly linked to the phylogeny of the genus.(AU)

Este estudo realizou uma análise histomorfométrica da retina e determinou os valores de acuidade visual de três espécies de morcegos do gênero Artibeus, incluindo Artibeus lituratus, Artibeus planirostris e Artibeus obscurus. Em total, 13 animais foram usados para esse estudo, no qual as retinas foram hemidissecadas, fixadas, cortadas e coradas. A acuidade visual foi determinada pela densidade de células ganglionares na retina e também foi realizado a mensuração das camadas retinianas a partir de cortes histológicos. As retinas dessas três espécies são avasculares, não apresentaram tapetum lucidum em nenhum quadrante e possuem as 10 camadas retinianas comum em mamíferos. Verificou-se também que a espessura da retina na região central foi significativamente maior em todos os parâmetros mensurados (p<0,001), com exceção da camada plexiforme externa (OPL) que foi significativamente maior na região periférica (p<0,001). As retinas das três espécies exibiram uma especialização retiniana em forma de faixa visual horizontal apresentando a maior concentração de células ganglionares na região inferotemporal. Além disso, a espécie A. lituratus exibiu áreas extras de alta densidade celular na retina. Assim, a espécie A. lituratus exibiu a maior acuidade visual (1,92 ciclos/grau), A. planirostris mostrou um valor intermediário entre essas duas espécies (1,77 ciclos/grau) e A. obscurus exibiu a menor acuidade visual (1,50 ciclos/grau). Todas estas características estão relacionadas aos padrões de ecolocalização e hábitos alimentares de cada espécie. Portanto, pode-se concluir que os morcegos do gênero Artibeus têm um alto valor de acuidade visual em comparação com outros morcegos ecolocalizadores e todas essas diferenças devem estar diretamente ligadas à filogenia do gênero.(AU)

Comparative retinal histomorphometry and visual acuity of three bat species of the genus Artibeus (Phyllostomidae: Stenodermatinae) / Histomorfometria comparada da retina e acuidade visual de três espécies de morcegos do gênero Artibeus (Phyllostomidae: Stenodermatinae)

This study performed a histomorphometric analysis of the retina and estimated the visual acuity of three fruit-eating bats of the genus Artibeus, including Artibeus lituratus, Artibeus planirostris and Artibeus obscurus. In total, 13 animals were used for this study, in which the retinas were hemidisected, fixed, cut, and stained. The visual acuity was determined by the density of ganglion cells in the retina and the retinal layers were also measured from histological sections. The retinas of these bats are avascular, do not present tapetum lucidum in any quadrant, and have the 10 retinal layers common in mammals. Moreover, it was observed that the thickness of the retina in the central region was significantly higher in all measured parameters (p<0.001), except for the outer plexiform layer (OPL) which was significantly higher in the peripheral region (p<0.001). The retinas of the three species showed a horizontal visual streak with a higher concentration of retinal ganglion cells (RGCs) at the inferotemporal region. In addition, the species A. lituratus exhibited extras areas of high cell density in the retina. Thus, A. lituratus showed the highest visual acuity (1.92 cycles/degree), while A. planirostris showed a visual acuity of (1.77 cycles/degree) and A. obscurus exhibited the lowest visual acuity (1.50 cycles/degree). All these characteristics are related to the echolocation system and the eating habits of each species. Therefore, it can be concluded that bats of the genus Artibeus have a high visual acuity value compared to other echolocating bats and all these differences might be directly linked to the phylogeny of the genus.(AU)

Este estudo realizou uma análise histomorfométrica da retina e determinou os valores de acuidade visual de três espécies de morcegos do gênero Artibeus, incluindo Artibeus lituratus, Artibeus planirostris e Artibeus obscurus. Em total, 13 animais foram usados para esse estudo, no qual as retinas foram hemidissecadas, fixadas, cortadas e coradas. A acuidade visual foi determinada pela densidade de células ganglionares na retina e também foi realizado a mensuração das camadas retinianas a partir de cortes histológicos. As retinas dessas três espécies são avasculares, não apresentaram tapetum lucidum em nenhum quadrante e possuem as 10 camadas retinianas comum em mamíferos. Verificou-se também que a espessura da retina na região central foi significativamente maior em todos os parâmetros mensurados (p<0,001), com exceção da camada plexiforme externa (OPL) que foi significativamente maior na região periférica (p<0,001). As retinas das três espécies exibiram uma especialização retiniana em forma de faixa visual horizontal apresentando a maior concentração de células ganglionares na região inferotemporal. Além disso, a espécie A. lituratus exibiu áreas extras de alta densidade celular na retina. Assim, a espécie A. lituratus exibiu a maior acuidade visual (1,92 ciclos/grau), A. planirostris mostrou um valor intermediário entre essas duas espécies (1,77 ciclos/grau) e A. obscurus exibiu a menor acuidade visual (1,50 ciclos/grau). Todas estas características estão relacionadas aos padrões de ecolocalização e hábitos alimentares de cada espécie. Portanto, pode-se concluir que os morcegos do gênero Artibeus têm um alto valor de acuidade visual em comparação com outros morcegos ecolocalizadores e todas essas diferenças devem estar diretamente ligadas à filogenia do gênero.(AU)

Altered retina and cornea of Clarias gariepinus (Siluriformes: Clariidae) under the effect of bright and dim lights

The purpose of this study was to investigate the influence of constant bright light on the cornea and retina of Clarias gariepinus (Burchell, 1822) and to examine whether it can change after constant exposure to dim light. Twenty-one adult individuals of C. gariepinus were divided into three groups (n = 7). The first group was maintained under normal light (NL). The second group was exposed to the intense bright light (BL) (3020 Lux) of white light lamps for seven days. The third group was exposed to dim light for seven days (DL) following the previous exposure to intense bright light for seven days. The eyes of each fish group were removed and fixed. The following aspects of the eye were investigated: histopathological, immunohistochemical (GFAP and BAX) staining and biochemical study for lactic dehydrogenase (LDH), superoxide dismutase (SOD), malondialdehyde (MDA) and glucose-6-phosphate-dehydrogenase (G6PDH). Also, isoenzyme electrophoresis of LDH, G6PDH and SOD were performed. The present study found that, seven-days BL exposure caused damage to both cornea and retina. However, after exposure to dim-light after bright light there was partial improvement in corneal and retinal structure and an increase in the assayed SOD and G6PDH levels, along with a reduction in MDA content and activity of LDH. These findings demonstrate a plasticity that may help C. gariepinus survive disturbances in the aquatic environment.

Altered retina and cornea of Clarias gariepinus (Siluriformes: Clariidae) under the effect of bright and dim lights

The purpose of this study was to investigate the influence of constant bright light on the cornea and retina of Clarias gariepinus (Burchell, 1822) and to examine whether it can change after constant exposure to dim light. Twenty-one adult individuals of C. gariepinus were divided into three groups (n = 7). The first group was maintained under normal light (NL). The second group was exposed to the intense bright light (BL) (3020 Lux) of white light lamps for seven days. The third group was exposed to dim light for seven days (DL) following the previous exposure to intense bright light for seven days. The eyes of each fish group were removed and fixed. The following aspects of the eye were investigated: histopathological, immunohistochemical (GFAP and BAX) staining and biochemical study for lactic dehydrogenase (LDH), superoxide dismutase (SOD), malondialdehyde (MDA) and glucose-6-phosphate-dehydrogenase (G6PDH). Also, isoenzyme electrophoresis of LDH, G6PDH and SOD were performed. The present study found that, seven-days BL exposure caused damage to both cornea and retina. However, after exposure to dim-light after bright light there was partial improvement in corneal and retinal structure and an increase in the assayed SOD and G6PDH levels, along with a reduction in MDA content and activity of LDH. These findings demonstrate a plasticity that may help C. gariepinus survive disturbances in the aquatic environment.(AU)