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 chosenand 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. Keywords: eyelids, agenesis, cryosurgery, feline, congenital

Comparação entre a fotometria e a contagem em câmara hemocitométrica para a determinação da concentração espermática do sêmen equino

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Conjunctival Melanoma in a Horse Treated by Tumor Resection and Cryotherapy

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 extended, it was located only in the conjunctiva without involvement of the sclera and the eyelid. Therefore the decision was made to perform an excisional biopsy associated with cryotherapy. The purpose of such adjuvant therapy is to kill all residual tumor cells and prevent the recurrence of malignant tumors. In the present case, the surgical wound was cured one week after surgery. The surgical procedure in the case reported was performed under local anesthesia and sedation with the horse standing. To make this decision, consideration should be given to patient health, anesthetic risk, and additional risks during recovery from general anesthesia. In this case, surgical excision of the mass associated with cryotherapy was effective in the treatment of conjunctival melanoma in a horse.Keywords: ocular, equine, melanocytic neoplasia, cryosurgery

Avaliação do endotélio corneano de equinos após exposição à indocianina verde 0,5% : estudo in vitro

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.O 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

CRIOCIRURGIA USANDO O DIMETHYL ETHER NO TRATAMENTODA CERATITE PIGMENTAREM CÃES DA RAÇA PUG

Corneal pigmentation and vascularization eventually result in blindness in dogs. Pigmentary keratitis describes a relatively common presentation comprising the deposition of melanin in the cornea and conjunctival surface associated with chronic inflammation. Cryosurgery is indicated as a treatment for pigmentary keratitis in dogs. Due to melanocytes sensitivity to cold, cryosurgery is a viable treatment for severe refractory corneal pigmentation. The aim of this work was to evaluate the use of dimethyl ether in the treatment of pigmentary keratitis in 14 eyes of seven Pug dogs. Follow-up occurred after 30 days in four animals and six months in three animals. In all treated animals, there was a reduction in corneal pigmentation. Cryosurgery causes intracellular and extracellular ice crystal formation and other mechanisms that result in rupture and death of the melanocytes. The technique used was easy to perform, has a low cryogen cost and has few undesirable or serious side effects. However, after 30 days repigmentation occured in treated patients. Cryosurgery shows good results in the first four weeks, but partial recurrence occurred in all cases.A pigmentação e a vascularização da córnea eventualmente resultam em cegueira em cães. A ceratite pigmentar é descrita com uma apresentação relativamente comum que compreende a deposição de melanina na córnea e na superfície conjuntival associada à inflamação crônica. A criocirurgia é indicada como tratamento para ceratite pigmentar em cães. Devido à sensibilidade dos melanócitos ao frio, a criocirurgia é um tratamento viável para pigmentação corneana refratária grave. O objetivo deste trabalho foi avaliar o uso do éter dimetílico no tratamento da ceratite pigmentar em 14 olhos de sete cães da raça Pug. O acompanhamento foi de 30 dias em quatro animais e seis meses em três animais. Em todos os animais tratados, houve redução da pigmentação da córnea. A criocirurgia causa a formação de cristais de gelo intracelular e extracelular e outros mecanismos que resultam na ruptura e morte dos melanócitos. A técnica utilizada foi de fácil execução, baixo custo de criogenia e poucos efeitos colaterais indesejáveis ou graves. No entanto, após 30 dias, ocorreu repigmentação nos pacientes tratados. A criocirurgia apresenta bons resultados nas primeiras quatro semanas, mas ocorreu recidiva parcial em todos os casos

Evaluation of equine corneal endothelium after exposure to 0.5% indocyanine green - in vitro study

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