Birefringence Analyses Reveal Differences in Supramolecular Characteristics of Corneal Stromal Collagen Fibrils Between Falconiformes and Strigiformes.

This study aimed to assess the birefringent properties of corneal stromal collagen fibrils in birds of the orders Falconiformes (diurnal) and Strigiformes (predominantly nocturnal) to compare their supramolecular organizations. In total, 22 corneas of Falconiformes (Caracara plancus, n = 8; Rupornis magnirostris, n = 10; and Falco sparverius, n = 4) and 28 of Strigiformes (Tyto furcata, n = 16; Pseudoscops clamator, n = 6; and Athene cunicularia, n = 6) were processed histotechnically into 8-µm thick sections. Corneal optical retardation (OR) values related to the form and intrinsic fractions of the total birefringence of collagen fibrils were measured using a polarized light microscope equipped with phase compensators. In addition, the coherence coefficients that inform the local orientation of the fibrils were calculated through video image analysis. All assessments were conducted both in the anterior and posterior stroma of the cornea. Differences were significant when P < 0.05. The results showed supraorganizational differences between fibrils in the anterior stroma of Falconiformes and Strigiformes. The OR values were greater (P < 0.0001) for Falconiformes, indicating that the corneas of these birds contain more collagen fibrils or more aggregated collagen fibrils. In contrast, the coherence coefficients were higher (P = 0.016) for Strigiformes, indicating that the corneal collagen fibers in these birds are highly aligned and have few undulations. A multivariate data matrix constructed for Euclidean distance calculations showed that the dissimilarity between Falconiformes and Strigiformes corneas, in terms of the supraorganization of stromal collagen fibrils, was 4.56%. In conclusion, it is possible that the supraorganizational differences reported in this study may be sources of variation in the visual quality of Falconiformes and Strigiformes. This study provides the necessary evidence to encourage further research associating corneal optical performance to supramolecular characteristics of corneal stromal collagen.

The use of tear ferning test in cats for evaluation of ocular surface.

BACKGROUND: The tear film is a trilaminar fluid composed mainly of lipids, electrolytes, proteins and water. It is responsible for lubrication, nutrition and protection against microbial and toxic agents. Disruption of any these components may weaken the ocular surface, making it more susceptible to disease. Increasing evidence suggests that qualitative tear film deficiencies are an important predisposing factor or cause of some of the most common and challenging ocular diseases in cats, including conjunctivitis, corneal ulcer, spontaneous chronic corneal epithelial defects (SCCED), pigmentary keratitis, corneal sequestrum and dry eye syndrome. The aim of this study was to describe the tear ferning test in healthy cats and to compare the results by using two grading scales for humans. Tear samples were collected using Schirmer tear test (STT) strips from 60 healthy cats, and, after centrifuging the strips to obtain the samples, the aliquot was placed on clean microscope glass until it dried and the tear ferning patterns were observed under a polarized light microscope and classified according to the Rolando and Masmali grading scales. RESULTS: Ferning patterns in the lower grades showed full crystallization with high density, without gaps between the ferns and branches, forming several nuclei that were easily distinguished. According to the Rolando scale, 50% (60/120), 46.6% (56/120) and 3.4% (4/120) of eyes showed type I, II and III patterns, respectively. According to the Masmali scale, 15% (18/120), 56.6% (68/120 eyes) and 28.4% (34/120) of eyes showed grade 0, 1 and 2 patterns, respectively. No difference was observed between the right and left eyes for both Rolando (P = 0.225) and Masmali (P = 0.683) scales. CONCLUSIONS: The tear ferning test is a qualitative test that can be used in cats as a complementary evaluation of the ocular surface. While the Rolando scale showed an increased prevalence of types I and II, the Masmali scale showed an increased prevalence of grades 1 and 2. This can be attributed to the species-specific differences between human and feline tear film. So Masmali grade 2 can be considered a normal tear pattern for the species, because all the cats used in study were clinically healthy. For this reason, future complementary studies are necessary for comparing healthy eyes and eyes with different ocular surface disease in cats. Both scales can be feasible options for grading tear crystallization in cats, but as Rolando scale included 96.6% of the samples in the 2 types that are considered normal for humans, we think that this scale seemed to be more precise to classify crystallization pattern in cats. The crystallization patterns observed in this study can form the basis for standardizing ocular surface parameters in cats.

Tear meniscometry test in wild animals / Teste de meniscometria lacrimal em animais silvestres

ABSTRACT: This study aimed to describe strip meniscometry test values for Amazona aestiva (turquoise-fronted amazon), Ara ararauna (blue-and-yellow macaw) and Caiman latirostris (broad-snouted caiman). Twenty-one Amazona aestiva and 11 Ara ararauna, healthy, adults of unknown sex, and 37 healthy adult Caiman latirostris (27 males and 10 females), were used in this investigation. All animals were manually restrained and I-Tear® Test strip was inserted for 5 s at the edge of the lower tear meniscus, without touching the eyelid or ocular surface, immediately followed by measurement (millimeter per 5 seconds). No differences were reported between left and right eyes for Amazona aestiva (P = 0.824), Ara ararauna (P = 0.262) and Caiman latirostris (P = 0.679). Median and confidence interval were 2.0 (2.25-3.56) mm/5s for Amazona aestiva, 3.0 (2.93-4.15) mm/5s for Ara ararauna and 3.0 (2.55-4.90) mm/5 s for Caiman latirostris. These values for strip meniscometry tear test can be used as parameters for each species and may be helpful for diagnosis and treatment of tear-production disorders in birds and reptiles.

RESUMO: O objetivo deste estudo foi descrever os valores do teste de meniscometria lacrimal para Amazona aestiva (papagaio-verdadeiro), Ara ararauna (arara-canindé) e Caiman latirostris (jacaré-de-papo-amarelo). Vinte e um Amazona aestiva, 11 Ara ararauna adultos, de sexo desconhecido, e 37 Caiman latirostris adultos (27 machos e 10 fêmeas), foram utilizados nesta investigação. Todos os animais foram contidos manualmente e uma tira do I-Tear® test foi inserida por 5 segundos na borda do menisco inferior, sem tocar a pálpebra ou a superfície ocular, e imediatamente mensurada (milímetro por 5 segundos). Não foram encontradas diferenças entre os olhos esquerdos e direitos para Amazona aestiva (P = 0,824), Ara ararauna (P = 0,262) e Caiman latirostris (P = 0,679). Mediana e intervalo de confiança foram de 2,0 (2,25-3,56) mm/5 s para Amazona aestiva, 3,0 (2,93-4,15) mm/5 s para Ara ararauna e 3,0 (2,55-4,90) mm/5 s para Caiman latirostris. Estes valores para o teste de meniscometria podem ser utilizados como parâmetros para estas espécies e podem ser úteis para diagnosticar e tratar distúrbios de produção lacrimal em aves e répteis.

CONJUNCTIVAL BACTERIAL FLORA, ANTIBIOGRAM, AND LACRIMAL PRODUCTION TESTS OF COLLARED ANTEATER (TAMANDUA TETRADACTYLA).

The collared anteater ( Tamandua tetradactyla ) is adapted to a variety of habitats. It is a solitary species for which no reference values for ophthalmic tests have been established. Eight animals ranging from 1 to 4 yr of age, two males and six females, were manually restrained for assessment. Ophthalmic tests included evaluation of tear production by Schirmer tear test 1 (STT1), endodontic absorbent paper point tear test (EAPPTT), palpebral fissure length (PFL), culture of the conjunctival bacterial flora, and antimicrobial susceptibility test. Median ± semi-interquartile range (S-IQR) STT1, EAPPTT, and PFL were 8.50 ± 4.13 mm/min, 14.13 ± 3.24 mm/min, and 15.91 ± 2.51 mm, respectively. Bacterial growth was present in 100% of the samples, with predominance of Gram-positive bacteria (70.27%). Staphylococcus spp. was the most frequently isolated genus. Antimicrobial susceptibility test showed sensitivity of Staphylococcus epidermidis and Staphylococcus spp. to neomycin, tobramycin, and gentamicin. The results in this study can benefit the determination of reference values for different diagnostic techniques, and may be used as a guide for diagnosis and treatment of ocular diseases in collared anteaters.

Corneal sensitivity in five horse breeds / Sensibilidade corneana em cinco raças de equinos

ABSTRACT: This study aimed to determine and compare corneal sensitivity values in different regions of the cornea in five horse breeds. One hundred and forty five healthy horses, adults of both sexes, of the following breeds - Arabian horse (AH; n=20), Mangalarga Marchador (MM; n=50), Pure Blood Lusitano (PBL; n=35), Quarter Horse (QH; n=20), Brazilian Sport Horse (BSH; n=20)-were investigated. Corneal touch threshold (CTT) was measured with a Cochet-Bonnet esthesiometer in five different corneal regions. Measurements of the median central CTT were: 4.50±0.50cm (AH), 3.50±0.56cm (MM), 3.00±0.25cm (PBL), 2.50±0.44cm (QH) and 2.50±0.00cm (BSH). The central region was the most sensitive and the dorsal region the least sensitive corneal region for all breeds. CTT values differed for corneal regions and horse breeds. The CTT values were different among the corneal regions and the horse breeds. Arabian horses presented higher sensitivity values being the most sensitive in all of the corneal regions.

RESUMO: Objetivou-se com o presente estudo, determinar e comparar valores de sensibilidade corneana em diferentes regiões da córnea em cinco raças de equinos. Foram investigados 145 equinos hígidos, adultos de ambos os sexos, das raças: Puro Sangue Árabe (PSA; n=20), Mangalarga Marchador (MM; n=50), Puro Sangue Lusitano (PBL; n=35), Quarto de Milha (QH; n=20) e Brasileiro de Hipismo (BSH; n=20). O limiar táctil da córnea (LTC) foi mensurado com o auxílio do estesiômetro de Cochet-Bonnet, em cinco diferentes regiões da córnea (central, nasal, ventral, temporal e dorsal). Os valores médios das mensurações do LTC central foram: 4,50±0,50cm (PSA), 3,50±0,56cm (MM), 3,00±0,25cm (PSL), 2,50±0,44cm (QM) e 2,50±0,00cm (BH). A região central foi a mais sensível e a região dorsal a menos sensível para todas as raças. Os valores de LTC diferiram para as regiões da córnea e entre as raças dos cavalos, sendo a raça Puro Sangue Árabe o que apresentou valores maiores de sensibilidade, desta forma sendo o mais sensível em todas as regiões corneanas.

Orbital multilobular osteochondrosarcoma in a dog / Osteocondrossarcoma multilobular em órbita de cão

Retrobulbar tumors may arise from any orbital tissue. Some are primary and others may extend from adjacent structures or derived from metastases. Multilobular osteochondrosarcomas are regarded as slowly growing and potentially malignant neoplasms in dogs. This tumor is of rare occurrence on retrobulbar region. This paper aims to report a rare case of female dog, Shih Tzu, spayed, five-year-old, that was referred to the Hospital of Veterinary Medicine, Federal University of Bahia, Brazil, with an increased volume in the orbital space, after enucleation for exophthalmia of unknown etiology. This animal was evaluated clinic and the diagnosis image (radiography and computed tomography) demonstrated a large formation of bone predominantly in the region of the right orbit and zygomatic arch, with invasion and destruction of adjacent bones. Due to her poor quality of life, the dog was submitted to euthanasia and after necropsy. On gross examination, an encapsulated nodular mass with an irregular surface, measuring 5.6 x 4.6 x 3.9 cm, was located in the right lateral skull, occupying the orbit with displacement of the zygomatic arch. The tumor was identified by histopathology as a malignant mesenchymal neoplasm, multilobular osteochondrosarcoma. Thus, differential diagnoses for exophthalmos should include cancers, including the multilobular osteocondrossarcoma.

Tumores retrobulbares podem originar-se de qualquer tecido orbital. Alguns são primários e outros podem estender-se a partir de estruturas adjacentes ou derivados de metástases. O osteocondrosarcoma multilobular é um tumor considerado de crescimento lento, potencialmente maligno e sua ocorrência é considerada rara em região orbital. Este trabalho objetiva descrever um caso de uma cadela, Shih Tzu, castrada, com cinco anos, atendida no Hospital de Medicina Veterinária da Universidade Federal da Bahia, Brasil, com apresentação de aumento de volume no espaço orbital, após enucleação devido a exoftalmia de etiologia desconhecida. O animal foi avaliado clinicamente e por exames de imagem (radiografia e tomografia computadorizada), os quais demonstraram uma grande formação óssea predominantemente na região da órbita direita e arco zigomático, com invasão e destruição dos ossos adjacentes. Devido às más condições de sobrevida apresentada pelo animal, foi indicado o procedimento de eutanásia e por fim, submetido à necropsia. No exame macroscópico, uma massa nodular encapsulada de superfície irregular, medindo 5,6 x 4,6 x 3,9 centímetros, foi localizada no crânio lateral direito, ocupando a órbita com deslocamento do arco zigomático. O tumor foi identificado por exame histopatológico como neoplasia mesenquimal maligna, osteocondrossarcoma multilobular. Desta forma, diagnósticos diferenciais para exoftalmia devem incluir neoplasias, dentre elas o osteocondrossarcoma multilobular.