João Antonio Tadeu Pigatto

Comparison of a rebound and an applanation tonometer for measuring intraocular pressure in normal rabbits

OBJECTIVE To compare intraocular pressure (IOP) measurements made on healthy adult rabbits without the effect of tranquilizers using the new applanation tonometer, Tono-Pen Avia(®), and the rebound tonometer Tonovet(®). METHODS Intraocular pressure was measured throughout the day (6:00, 9:00, 12:00, 15:00, and 18:00 h) in 38 adult New Zealand White rabbits (76 eyes). The animals were 20 males and 18 females, with a mean weight of 3.5 kg and an average age of 6 months. A complete ocular exam (including Schirmer tear test, fluorescein staining, slit-lamp biomicroscopy, and direct ophthalmoscopy) was performed on all animals at the beginning of the trial. Rebound tonometry was performed, and after 10 min, anesthetic drops were instilled and applanation tonometry was carried out. IOP values obtained using the two techniques were analyzed statistically. RESULTS The mean IOP was 9.51 ± 2.62 mmHg with Tonovet(®), and 15.44 ± 2.16 mmHg with the Tono-Pen Avia(®). Significant differences between measurements with the two tonometers were observed (P < 0.001). The linear regression equation describing the relationship between the two tonometers was y = 0.4923x + 10.754 (y = Tonovet(®) and x = Tono-Pen Avia(®)). High IOPs were recorded in the early measurements (6:00), but the average IOPs from both devices were statistically similar throughout the day (P = 0.086). The correlation coefficient was r(2) = 0.357. No significant difference in IOP regarding gender was observed. CONCLUSION The Tono-Pen Avia(®) recorded higher levels of IOP compared with the Tonovet(®). Early in the day, the IOP of rabbits was higher than later in the day, regardless of the tonometer used.

CORNEAL ENDOTHELIUM OF THE MAGELLANIC PENGUIN (SPHENISCUS MAGELLANICUS) BY SCANNING ELECTRON MICROSCOPY

Abstract The corneal endothelium is essential for the maintenance of the corneal transparency. The aim of this study was to examine the morphology of the endothelial surface and perform morphometric analysis of the normal corneal endothelial cells of the Magellanic penguin (Spheniscus magellanicus) using scanning electron microscopy. The present work demonstrates that the corneal endothelium of the Magellanic penguin is similar to those described in other vertebrates.

Morphological analysis of the corneal endothelium in eyes of dogs using specular microscopy

Both healthy eyes of 10 six-year-old male and female mongrel dogs were studied. With a contact specular microscope the corneal endothelium was examined. Endothelial cells were analyzed in the central and peripheral cornea. Morphological analysis with regard to polymegathism and pleomorphism was performed. Three images of each region with at least 100 cells were obtained. The analysis showed that polygonal cells formed a mosaic-like pattern uniform in size and shape. The predominant number of cells was hexagonal. The polymegathism index was 0.22. The study demonstrates that the morphology of the normal corneal endothelial cells of dogs is similar to that found in the human cornea.

Ultrastructural morphology and morphometry of the normal corneal endothelium of adult crossbred pig

Corneal endothelium constitutes a monolayer of polygonal cells. The integrity and health of this layer are essential for the maintenance of normal corneal transparency. This study reported by the first time in a detailed way the ultrastructural morphology and morphometry of the corneal endothelium in normal adult crossbred pigs by using scanning electron microscopy (SEM). A regular pattern of polygonal cells, with predominantly hexagonal cells and clear cell borders, was observed. An oval nucleus that bulges in the centre of the cell, cilia (2-4) in a few peripheral cells, openings of the pinocytotic vesicles, microvilli, borders bars and interdigitated cell borders were observed. The mean endothelial cell area was significantly higher (P<0.05) in the centre than in periphery, with a lower variation coefficient in the former. The mean cell density in periphery was significantly higher (P<0.05) than in centre and 43.9% higher than data formerly reported by other authors using specular microscopy, showing the significant shrinkage caused by sample processing for SEM. The mean value of cell sides (pleomorfism) was 5.9, ie. predominant hexagonal shape. The percentage of hexagonal cells was significantly higher in central region (P<0.01), determining a more homogeneous structure. The parameters obtained in this study will be a basement for future investigations about the effect on pig corneal endothelium of drugs, intracamerular surgeries and storage solutions for transplants.

Scanning electron microscopy of the corneal endothelium of ostrich

The aim of this study was to examine the endothelial surface morphology and perform a morphometric analysis of the corneal endothelial cells of ostrich (Struthio camelus) using scanning electron microscopy. Polygonality, mean cell area, cell density and coefficient of variation of mean cell area were analyzed. The normal corneal endothelium consisted of polygonal cells of uniform size and shape with few interdigitations of the cell borders. Microvilli appeared as protusions on the cellular surface. The average cell area was 269±18μm2 and the endothelial cell density was 3717±240cells mm -2 . The coefficient of variation of the cell area was 0.06, and the percentage of hexagonal cells was 75%. The parameters evaluated did not differ significantly between the right and the left eye from the same ostrich. The results of this study showed that the ostrich corneal endothelial cells appear quite similar to those of the other vertebrates.

Esofagoplastia cervical em caninos com enxerto homólogo de cartilagem conchal preservada em glicerina

The efficacy of conchal cartilage as an alternativo to correct lesions in the esophageal wall was tested. Twenty one mongrel adult dogs, whose weight rangedfrom 11 to 14kg, were randomiy divided in three groups (A, B e C). These animais were submitted to an esophageal segment excision of l x 2cm. The defect was corrected with conchal cartilage alograft. The postoperative attendance and evaluation was done with clinical observation, laboratorial and radiologic examinations during a period of twenty ( group A), forty five (group B) and sixty days (group C). At the end of these periods the animais were euthanized, necropsied and the esophageal segment was evaluated by gross an microscopic examination. It was observed an epitelial growth at the place were the conchal cartilage was sutured. This homograft can be used with sucess in the partial reconstruction of cervical esophageal wall in dogs.

Reparação traqueal em cães: transplante autógeno vs implante homógeno conservado em glicerina a 98% de cartilagem da pina

Several patologies affect the trachea, compromising the respiratory stream and the animal survival. Foreign bodies, neoplasm, ruptures, collapse and stricture are the most common ones. The effects of canine pinna cartilage implantation were evaluated in 12 dogs. Six of them were submitted to an autograft (group I) and six to homograft preserved in 98% glycerin (group II), to repair tracheal defects. One third of three cervical tracheal rings were removed and substituted for auto or homograft. These animals remained under observation and clinical evaluation in rest and moderate physical exercise during a 45 days period, without presenting any decurrent complications. At the end of the observation period, the trachea was submitted to gross and microscopic examination. Full epithelization of the grafted area was observed by macroscopic evaluation in both groups. Microscopic analyses showed granulation tissue in the transplanted area of group I, the lamina propria with moderate infiltration of neutrophile and few fibrosis with focus of epithelial hyperplasia. Animals of group II presented granulation around the area of the implantation and discrete invasion of macrophages and neomorph vases in the lamina propria, with moderate inflammation. The epithelium showed no alteration. These data suggest that the pinna cartilage homograft implant induce less aggressive response by the receiving streambed, even so this was not observed grossly.

Avaliação do endotélio corneano suíno por microscopia eletrônica de varredura após aplicação de azul brilhante a 0,05% na câmara anterior: estudo in vitro

Com o objetivo de avaliar as alteracoes ultraestruturais no endotelio corneano suino induzidas pela aplicacao intracameral do corante azul brilhante 0,05%, vinte corneas suinas foram separadas em dois grupos: olhos direitos (grupo controle) e olhos esquerdos (grupo experimental). Inicialmente todos os bulbos oculares foram avaliados por microscopia especular. As corneas dos bulbos oculares do grupo controle foram excisadas, enquanto nos bulbos oculares do grupo experimental foram injetados 0,2ml do corante vital azul brilhante 0,05% na câmara anterior e mantido por um minuto. Apos esse periodo a câmara anterior foi lavada com solucao salina balanceada e as corneas foram excisadas. Todas as corneas excisadas foram avaliadas por microscopia eletronica de varredura para verificar a ocorrencia possiveis alteracoes no endotelio corneano causadas pelo corante. Nao foram observadas diferencas ultraestruturais durante a avaliacao endotelial por microscopia eletronica de varredura das corneas do grupo controle e experimental apos a aplicacao do azul brilhante 0,05% na câmara anterior. O corante azul brilhante na concentracao 0,05% nao causou danos endoteliais apos seu uso intracameral em suinos e pode ser uma alternativa segura para a coloracao da capsula anterior da lente na cirurgia de catarata.

Neoplasmas oculares e de anexos em cães e gatos no Rio Grande do Sul: 265 casos (2009-2014)

Ocular neoplasms cause discomfort, loss of vision or may also reflect systemic diseases. A retrospective study has been performed to identify and analyze ocular and annexes neoplasms obtained by biopsies sent to the Sector of Veterinary Pathology at the Federal University of Rio Grande do Sul (SPV/ UFRGS). 265 diagnoses of ocular and annexes neoplasms, 87.5% in canine species and 12.5% in feline species, were made from January 2009 to December 2014. Neoplasms occurred more in animals over the age of 12 months and animals of old age, dogs (52/232) and cats (21/33) mixed breed were the most affected. The eyelid was most commonly affected in dogs (164/232) and feline (20/33), followed by the third eyelid in dogs (20/232) and eye orbit in cats (5/33). The most common tumor diagnosed was meibomian adenoma in dogs (82/232) and squamous cell carcinoma in cats (10/33) both in the eyelids. Twenty four tumor types have been identified in dogs and 16 in cats. Benign neoplasms in dogs represented the largest number of diagnosis (56%) whereas in cats, there were more cases of malignant neoplasms (75.8%).

Intraocular pressure measurement in sheep using an applanation tonometer

The purpose of this study was to evaluate and establish the mean values of IOP in healthy adult sheep using an applanation tonometer. Information on age, sex, and breed was obtained for all animals included in this study . Twenty five healthy sheep (Ovis aries), of the same breed (Texel), male or female, with three years of age, received an ophthalmic examination in both eyes, including pupillary reflexes, Schirmer tear test, slit lamp biomicroscopy , and fluorescein staining. For all ophthalmic testing, animals were gently physically restrained, with no pressure in the jugular area and the eyelids were carefully open. IOP was measured by applanation tonometry (Tonopen XL). The same examiner performed the tonometry; measurements were taken three times for each eye, and their average was recorded as the IOP of the animal. Statistical analysis was performed using paired t-test and values of P < 0.05 were considered significant. The mean intraocular pressure in the whole group of 50 eyes was of 16.36 +/- 2.19 mm Hg. The mean (SD) IOP in the right eye was of 15.96 +/- 2.02 mm Hg, while the mean (SD) IOP in the left eye was of 16.76 +/- 2.32 mm Hg. Significant differences in IOP were not found between right and left eyes. The applanation tonometer was adequate for measuring the intraocular pressure in sheep. Reference data will assist in diagnosing testing for ophthalmic disease in sheep, as 1 well as promote further studies in this area.