The objective of this study was to evaluate the morphology of different regions of the equine cornea using optical microscopy. Both

The purpose of this study was to verify the effect of the upper lip twitch restraint on intraocular pressure (IOP) of healthy horses. In this study, forty five Criollo horses, aged between two to

The purpose of the study was to investigate whether indocyanine green (ICG) dye damages the corneal endothelium of horses. Twenty-four corneas of 12 healthy equines, males or females, of different ages were used in this study. Only eyes with no ocular findings were used. Randomly, one eye was included in the treatment group and one in the control group. The eyes of the treatment group were exposed for 1 minute to dye ICG 0.5%. After that the endothelium of all eyes was stained with trypan blue and alizarin red S and analyzed and photographed under an optical microscope. Areas with damaged endothelial cells were manually measured and quantified using software for morphometric analysis and expressed as a percentage of cell damage. In all eyes examined areas of cell damage were observed in both corneas of the control group and the treatment group. The mean endothelial damage was 0.8 ± 0.37% in the treatment group and 0.97 ± 0.39% in the control. The Qui-square test stated that treatment and control group were not different. The ICG 0.5% did not cause acute damage to equine corneal endothelium. Key words: Cataract. Indocyanine green. Corneal endothelium. Alizarin red. ResumoO objetivo do estudo foi investigar se indocianina verde (ICG) induz dano nas células do endotélio da córnea de equinos. Vinte e quatro córneas de 12 equinos saudáveis, machos ou fêmeas, de diferentes idades foram estudadas. Somente olhos hígidos foram utilizados. Aleatoriamente, um olho foi incluído no grupo controle e outro no grupo tratamento. Os olhos do grupo tratamento foram expostos durante um minuto à indocianina verde a 0,5%. Posteriormente, o endotélio da córnea foi corado com azul de tripano e vermelho de alizarina, analisado e fotografado usando microscópio óptico. As áreas com células endoteliais danificadas foram aferidas e quantificadas utilizando um software para análise morfométrica. Os valores encontrados foram expressos como percentual de perda celular. Em todos os olhos examinados foram observadas áreas de dano celular, tanto no grupo controle quanto no grupo tratamento. A perda celular endotelial média foi de 0,8±0,37% no grupo tratamento e 0,97 ± 0,39% no grupo controle. O teste Qui-quadrado confirmou que os grupos tratamento e controle não diferiram. Foi possível concluir que a ICG 0,5% não causou dano agudo nas células do endotélio da córnea de equinos. Palavras-chave: Catarata. Indocianina verde. Endotélio corneano. Vermelho de alizarina.

Background: Ocular melanoma is very rare compared to cutaneous melanoma in horses. Definitive diagnosis is made through histopathological examination and treatment options include surgical excision associated with cryotherapy, radiation therapy, and chemotherapy. In this report, we describe a case of conjunctival melanoma in a horse that has been treated successfully with surgical excision associated with cryotherapy. Case: A 15-year-old male Percheron male was referred to the Ophthalmology Veterinary Section of the Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil, with a history of a pigmented mass located on the lower eyelid of the left eye. Ophthalmologic examination revealed ocular discomfort, secretion and a pigmented mass in the left inferior bulbar conjunctiva. The dermatological examination revealed other melanomas in the perineal region. Complete blood count and serum chemistry profile were within normal ranges and prior to surgery the horse was treated with flunixin meglumine (1.1 mg/kg, IV, q 12 h). Sedation was performed with xylazine (0.4 mg/kg, IV) and detomidine hydrochloride (0.01 mg/kg, IV) and then the animal was placed in a retention trunk. The conjunctival mass was resected with a margin of safety. Liquid nitrogen was applied to the tumor site and the adjacent conjunctiva with a copper cryoprobe with one unit of liquid nitrogen. Histopathological examination revealed neoplastic cells containing pigmented melanocytes in the conjunctival submucosa, confirming the diagnosis of conjunctival melanoma. Postoperative treatment was performed with flunixin meglumine (1.1 mg/kg, IV, q 12 h) for 3 days and topical ophthalmic ointment containing neomycin, polymyxin B sulfate and dexamethasone twice daily for one week. Seven days after surgery, the lesion was healed. The patient was followed for 24 months after excision and there was no evidence of recurrence. Discussion: Older horses are considered more predisposed to melanoma development, possibly because of the proliferation of melanocytes as a manifestation of aging, and in addition, cutaneous melanomas are common in gray horses and rare in other horse colors. In this case, the horse was a 15-year-old Percheron horse with gray hair. In horses, there is only one case of conjunctival melanoma documented in the literature. In both cases, the ophthalmic examination revealed a large, raised, heavily pigmented mass protruding from the bulbar conjunctiva. The only difference is that in the present case the location of the mass was in the inferior bulbar conjunctiva and in the case cited in the literature. The mass was located in the bulbar conjunctiva under the lateral comer. In this case, the diagnosis of conjunctive melanoma was based on clinical signs and confirmed by histopathological examination. It was decided to perform an excisional biopsy for treatment and to confirm the diagnosis of conjunctival melanoma. The choice of treatment depends very much on the clinical presentation, that in this animal, despite the neoplasia being exte...

The aim of this study was to evaluate the morphology of endothelial cells from different areas of the cornea of dogs. Twenty healthy eyes from 10 dogs, females or males, of different ages were studied. Corneal endothelium morphology of superior, inferior, central, nasal and temporal areas was assessed by 0.2% alizarin red staining using an optic microscope. One hundred endothelial cells from each corneal area were analyzed. In all areas of the cornea studied were found endothelial cells with four sides, five sides, six sides and seven sides. There was no significant difference regarding endothelial cell morphology in all corneal regions evaluated. Thus, the morphology of the central cornea area represents the entire endothelial mosaic and may be applied to peripheral areas. Therefore, analysis of the central area is sufficient to estimate the shape of endothelial cells of peripheral areas of healthy dog corneas.

The aim of this study was to evaluate the immediate effects of 0.05% brilliant blue on corneal endothelium of horses. Thirty-eight corneas of 19 horses, male or female, of different ages were studied. Corneas were randomly divided into two groups. Group 1: Corneal endothelium was covered with 0.3mL of brilliant blue 0.05% for 60 seconds followed by rinsing with a balanced salt solution. Group 2: Corneal endothelium was covered with BSS for 60 seconds. The corneas were excised with an 8mm trephine and prepared to analyze posterior endothelial surface using a light microscope (24 corneas) and a scanning electron microscope (14 corneas). The equine posterior corneal endothelium surface observed by optical microscopy and scanning electron microscopy revealed a continuous layer of polygonal cells of uniform size and shape in both the control and treatment groups. Due to non-normal residuals at ANOVA mean comparison, a generalized linear model was utilized at 5% level of significance. The chi-square test stated that treatment and control group were not different statistically. The 0.05% brilliant blue did not cause damage to equine corneal endothelium.