Radiotherapy in combination with exenteration and partial orbitectomy for orbital multilobular tumor of bone in a Cocker Spaniel.

Background: Multilobular tumor of bone or multilobular osteochondrosarcoma is a tumor of flat bone in the skull. The treatment of choice for a multilobular tumor of bone is local aggressive surgical excision. Case Description: A female Cocker Spaniel dog aged 11 years presented with a history of globe displacement of the right eye for 3 months. Ophthalmic examination revealed exophthalmos, third eyelid protrusion, and slightly increased intraocular pressure OD (oculus dexter; right eye). Computed tomography (CT) revealed a mass effect in the right retrobulbar, maxilla, zygomatic, and temporal areas. Right zygomatic and temporal bone lysis were observed. Physical examination, hematology, and blood chemistry results were within normal limits. Exenteration with zygomatic arch removal was performed. During surgery, a firm 2-lobed mass (4.8 × 3.7 and 1.6 × 1.4 cm) adhered to the mandible was found in the retrobulbar area OD. Histopathological findings revealed a multilobular tumor of bone. CT imaging was performed for the remaining tumor and an extended part of the right retrobulbar mass was found. Hypofractioned radiotherapy with 6 fractions of 6 Gy was performed on days 0, 7, 14, 21, 28, and 35. At 1-month and 4-month follow-up inspections, the mass gradually reduced in size. At 8 months and 11 months after radiotherapy, the mass was unremarkable. The dog was alert during all follow-up periods to 1 year and 8 months after hypofractioned radiotherapy combined with exenteration and partial orbitectomy. Conclusion: Hypofractioned radiotherapy combined with exenteration and partial orbitectomy extended the patient's survival and decreased the size of the remaining tumor for the management of orbital multilobular tumor of bone in this dog for at least 1 year and 8 months.

Retrobulbar respiratory epithelial orbital cyst in a dog: A case report.

A 10-month-old female, neutered French Bulldog presented with a history of unilateral right-sided intermittent conjunctivitis and exophthalmos. The patient suffered blunt force trauma to the right eye after a tennis ball impact approximately five months prior to presentation. Examination identified the patient was visual with exophthalmos, lateral strabismus, conjunctival hyperaemia, episcleral congestion, and papilloedema. Magnetic resonance imaging and ultrasonography identified an approximately two centimeter diameter fluid-filled structure directly posterior to the globe leading to displacement of the optic nerve and distortion of the posterior globe wall. Centesis of the lesion demonstrated neutrophilic and macrophagic inflammation with evidence of prior hemorrhage. Within four weeks, the structure had re-filled to its original size and was subsequently excised in its entirety, via a lateral orbitotomy. Histopathologic findings indicated a non-keratinising orbital cyst, the lining of which was consistent with a respiratory epithelial cyst. Recurrence had not occurred seven months' post-surgery. To the author's knowledge, previous reports of retrobulbar respiratory epithelial cysts have not been documented in animals.

Tumours involving the retrobulbar space in cats: 37 cases.

OBJECTIVES: The aim of this multicentre retrospective study was to describe the clinical presentation, imaging findings, diagnosis and outcomes of cats with retrobulbar neoplasia. METHODS: A total of 37 cats that were diagnosed with retrobulbar neoplasia and underwent advanced imaging were recruited from searches of the clinical records of two referral hospitals. All cats had neoplasia confirmed via cytology or histopathology. Data relating to the signalment, presentation, results of investigations, treatment and outcome were recorded. A review of imaging studies was performed where possible. RESULTS: In total, 23 cases (62%) were presented with respiratory signs. Exophthalmos was the most common ophthalmological examination finding, present in 18 cases (49%). Thirty-two cases (86%) had secondary extension of neoplasia to the retrobulbar space (most commonly from the nasal cavities), present in 20 cases (54%), of which 12 were lymphoma. In cases where contrast was administered, 28/35 (80%) had contrast-enhancing masses. Orbital extension was detected in 21 cases (57%), exophthalmos in 22 (59%), globe deformation in 12 (32%) and local lymphadenomegaly in 22 (61%). In total, 36 (97%) retrobulbar tumours were malignant. Thoracic imaging, where it was performed, was concerning for metastasis in 8/25 cases (31%), with abdominal imaging suggestive of metastasis in 5/12 (42%). The most common diagnosis was lymphoma with 19 cases (51%), with nasal lymphoma representing 12 of these, followed by carcinoma in 10 (27%). The median survival time, for cases where death was recorded, was 85 days (range 1-263 days). CONCLUSIONS AND RELEVANCE: To the authors' knowledge, this is the largest study of neoplasia affecting the feline retrobulbar space. Retrobulbar tumours in cats are overwhelmingly malignant, and commonly due to secondary extension of tumours originating elsewhere. Lymphoma, particularly arising from the nasal cavities, was the most common cause. Cats presenting with signs suggestive of retrobulbar disease should be assessed for disease affecting any of the structures of the head.

Medical management and resolution of perinatal bilateral exophthalmia and secondary corneal ulcers in an Antillean manatee (Trichechus manatus manatus) neonate from Puerto Rico.

OBJECTIVE: To present a novel case of perinatal bilateral exophthalmos and corneal ulcers in a neonate Antillean manatee and describe the medical treatment that led to the resolution of the observed clinical signs and vision restoration. ANIMAL STUDIED: A manatee stranded alone in Puerto Rico on July 5, 2020. RESULTS: The manatee was found in critical condition with pronounced exophthalmos, lagophthalmos, and corneal opacification of both eyes (OU). Vision impairment was evident due to the lack of ocular menace reflex and bumping into the tank's walls. Biomicroscopy revealed conjunctival hyperemia and chemosis, limited third eyelid movement, but had viscous tears present OU. Dense, full-thickness, white to cream-colored cellular infiltrates affected 70% of the cornea with peripheral active vascularization OU. Rubeosis iridis was also present OU. Treatment consisted of supportive medical management, including nutritional support and topical treatment for ulcerative keratitis. Resolution of the corneal ulcers and functional vision were achieved after 6 weeks of therapy. Currently, bilateral, mild, intermittent exophthalmos is observed with no adverse clinical signs, and the calf is in good health. CONCLUSIONS: The extent of bilateral corneal disease on a neonatal calf may be a result of an intrauterine infection or possible trauma at or right after birth. While the latter may have led to exophthalmia and consequent corneal disease, the exact cause could not be determined. Supportive therapy and medical management of infectious keratitis were successful and led to vision recovery. This is the first report of ocular pathology in a neonatal manatee.

Outcome of 25-gauge pars plana vitrectomy via a lateral approach without proptosis of the globe: A retrospective study in 72 dogs (78 eyes).

OBJECTIVE: To evaluate the postoperative visual outcome and complications of 25-gauge pars plana vitrectomy (PPV) via a lateral approach without proptosis of the globe in dogs. PROCEDURES: We reviewed the medical records of dogs diagnosed with giant rhegmatogenous retinal detachment (RRD) at Yokohama Animal Eye Clinic from 2016 to 2019 and treated by 25-gauge PPV. Medical records included signalment, follow-up time, etiology and duration of RRD, angle between the outermost trocar ports, immediate postoperative anatomic success rate, pre- and postoperative visual status, and postoperative complications. RESULTS: Seventy-two dogs (78 eyes, 13 breeds) were included. The most common breed was the Toy Poodle (48.6%), and the mean follow-up time was 690.6 days. The most common etiology of RRD was cataract surgery (46.2%). The mean angle between the outermost trocar ports was 71.4º. Immediate postoperative anatomic success was noted in all eyes. Vision was regained or maintained in 87.2% of eyes, and the mean time to return of vision was 28.5 days. Maintenance of vision until the last known follow-up was noted in 73.5% of eyes. The most common postoperative complication was glaucoma (40.3%), and glaucoma was the most common etiology of postoperative vision loss (88.9%). CONCLUSION: Twenty-five gauge PPV via a lateral approach without proptosis of the globe is a successful method for treating canine giant RRD.

GWAS Hits for Bilateral Convergent Strabismus with Exophthalmos in Holstein Cattle Using Imputed Sequence Level Genotypes.

Bilateral convergent strabismus with exophthalmos (BCSE) is a malformation of the eyes and is recognized as a mild but progressive disorder that affects cattle in the first two years of life. This most likely inherited disorder is rarely described in cattle resembling autosomal dominantly inherited forms of human progressive external ophthalmoplegia (PEO). In German Braunvieh cattle, two linked genome regions were found that could be responsible for the development and/or progression of BCSE. The goal of this study was to phenotypically characterize BCSE in Holstein cattle from Germany and Switzerland as well as to identify associated genome regions by GWAS. The clinicopathological phenotype of 52 BCSE-affected Holstein cattle was in accordance with the phenotype described in German Braunvieh cattle, but in addition, signs of degeneration and cellular infiltration in the eye muscles were found. By using imputed sequence level genotype data, three genome-wide significant GWAS hits were revealed on different chromosomes that were not detected by initial GWAS based on high density SNP array data highlighting the usefulness of this approach for mapping studies. The associated genome regions include the ABCC4 gene as well as markers adjacent to the NCOR2 and DNAJC3 genes all illustrating possible functional candidate genes. Our results challenge a monogenic mode of inheritance and indicate a more complex inheritance of BCSE in Holstein cattle. Furthermore, in comparison to previous results from German Braunvieh cattle, it illustrates an obvious genetic heterogeneity causing BSCE in cattle. Subsequent whole genome sequencing (WGS)-based analyses might elucidate pathogenic variants in the future.

Diagnosis and surgical management of a retrobulbar abscess causing unilateral exophthalmos in a Boer goat.

A 10-year-old Boer goat wether presented for unilateral exophthalmos of 2- to 3-week duration. Ocular ultrasonography and computed tomography (CT) were utilized in the diagnosis of the patient's orbital disease and surgical planning. Exenteration was performed under the same general anesthetic event as CT. Cytology, culture, and histopathology were performed after exenteration. Cytology was consistent with a mixed bacterial infection. Culture confirmed the presence of Streptococcus ovis. Histopathology on the enucleated globe and mass revealed no evidence of tumor and confirmed intraocular extension of retrobulbar inflammation. Histopathologic diagnosis was consistent with severe chronic orbital pyogranuloma and fibrinosuppurative endophthalmitis confined to the subretinal space. The abscess recurred in the orbital space 2 weeks postoperatively; the orbit was explored. Repeat culture was consistent with S. ovis, Staphylococcus schleigeri subspecies coagulans, and Fusobacterium necrophorum. Complete resolution was obtained after drainage and lavage of the orbit. Abscess is cited as a cause of exophthalmos in small ruminants, but no individual case reports exist. Advanced imaging allowed presumptive diagnosis and surgical planning. Histopathology confirmed intraocular extension of retrobulbar disease.

Intraocular extraskeletal osteosarcoma in a rabbit (Oryctolagus cuniculus).

An 8-year-and-9-month-old male, lop-eared rabbit (Oryctolagus cuniculus) presented with gradual enlargement of the left eye to 4 × 4 × 4 cm and exophthalmos. The animal died 3 months later, and necropsy was performed. On gross pathology, the intraocular tissue was effaced and occluded by a hard, light-gray mass. Histologically, the mass comprised spindle-shaped to angular cells arranged in interlacing bundles with abundant production of osteoid, bone and cartilage, consistent with osteosarcoma. Limited cases of intraocular neoplasm have been reported in pet rabbits. To the best of our knowledge, this represents the first pathologic documentation of intraocular osteosarcoma in a rabbit.

Role of cytokines in the clinical manifestation of exophthalmia in newborn calves with tropical theileriosis.

The present study aimed to evaluate the pathology of the exophthalmia and the host-immune response in naturally Theileria annulata-infected calves. The newborn calves detected positive for theileriosis were grouped into calves with theileriosis and absence of exophthalmia (n = 30), and calves with theileriosis and the presence of exophthalmia (n = 13). Sixteen healthy calves, free from any haemoprotozoal infection, were kept as healthy controls. A significantly (P ≤ .001) higher circulating levels of tumour necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were estimated in diseased calves with and without exophthalmia as compared to healthy controls. Contrarily, significantly (P ≤ .01) lower interferon-γ (IFN-γ) level was estimated in diseased calves. The diseased calves with exophthalmia revealed significantly higher levels of TNF-α (P ≤ .001) and IL-10 (P ≤ .006) as compared to the diseased calves without exophthalmia. The diseased calves were not found to have an elevated intraocular pressure; rather they had significantly (P ≤ .001) lower intraocular pressure compared to the healthy controls. An elevated systemic TNF-α level might be attributed to the exophthalmia in calves with tropical theileriosis. The elevated circulatory IL-10 and reduced IFN-γ levels could be one of the strategies of Theileria annulata to escape the host immunity.

Cause and Treatment of Exophthalmos in Aged Cotton Rats (Sigmodon hispidus).

Aged cotton rats (Sigmodon hispidus) from an established breeding colony displayed signs of spontaneous exophthalmos. Of a total of 118 colony animals that were older than 6 mo of age, 37 (31%) displayed signs of exophthalmos. These rats were clinically healthy and had no other signs of disease. Ophthalmic exams, molecular and microbiologic testing, and histopa- thology were performed to determine the cause of the exophthalmos and to provide appropriate treatment. Environmental monitoring records were also reviewed for vivarium rooms in which the cotton rats were housed. Histopathology findings supported that the exophthalmos in these cotton rats was secondary to retro-orbital thrombosis associated with cardiomyopathy. The exophthalmic eyes were treated by either removal of the affected eye (enucleation) or surgical closure of the eyelids (temporary tarsorraphy). Enucleation of the exophthalmic eye was the best intervention for these aged cotton rats. These findings demonstrate the potential for a high incidence of ocular problems occurring secondary to cardiomyopathy in aged cotton rats. Enucleation as a therapeutic intervention for exophthalmic eyes in aged cotton rats prolongs the morbidity-free time span during which these aged animals can be used experimentally.

Canine retrobulbar lipoma excision through a ventral transpalpebral anterior orbitotomy.

A 5-year-old spayed female German shepherd dog was referred for diagnostic evaluation and treatment of progressive exophthalmos, conjunctival hyperemia, and protrusion of the third eyelid of the left eye. Computed tomography revealed a retrobulbar mass of the orbit, exhibiting radio attenuation consistent with adipose tissue and well-defined margins. No evidence of metastasis was detected on thoracic radiographs or abdominal ultrasound. Cytological evaluation of ultrasound-guided fine-needle aspirates was inconclusive. A ventral transpalpebral anterior orbitotomy approach facilitated excision of the abnormal retrobulbar tissue. Histopathology revealed mature adipose cells compatible with a lipoma. The patient regained normal appearance and function 3 months after surgery. Key clinical message: While rare, consider a lipoma as a differential diagnosis for a retrobulbar mass. The ventral transpalpebral orbitotomy has been described in only 3 cases in the veterinary literature, and this is the only known report of utilizing this approach for excision of a neoplastic condition.

Excision d'un lipome rétrobulbaire canin à travers une orbitotomie antérieure ventrale transpalpébrale. Une chienne Berger Allemand stérilisée âgée de 5 ans fut référée pour évaluation diagnostique et traitement d'exophtalmie progressive, d'hyperémie conjonctivale et de protrusion de la troisième paupière de l'oeil gauche. Un examen par tomodensitométrie révéla une masse rétrobulbaire de l'orbite, montrant de la radioatténuation compatible avec du tissu adipeux et des bordures bien définies. Aucune évidence de métastase ne fut détectée sur les radiographies thoraciques ou une échographie abdominale. Une évaluation cytologique d'aspirations écho-guidées à l'aiguille fine était non-concluante. Une orbitotomie antérieure par approche transpalpébrale ventrale facilita l'excision du tissu rétrobulbaire anormal. L'examen histopathologique mis en évidence des cellules adipeuses matures compatibles avec un lipome. Le patient retrouva une apparence et une fonction normales 3 mois après la chirurgie.Message clinique important :Bien que rare, un lipome doit être considéré comme un diagnostic différentiel lors de masse rétro-bulbaire. L'orbitotomie ventrale transpalpébrale a été décrite dans seulement trois cas dans la littérature vétérinaire, et le présent rapport est le seul connu utilisant cette approche pour l'excision d'une condition néoplasique.(Traduit par Dr Serge Messier).

Prognostic indicators and outcome in dogs undergoing temporary tarsorrhaphy following traumatic proptosis.

PURPOSE: Retrospectively evaluate prognostic indicators and outcome in dogs undergoing temporary tarsorrhaphy following traumatic proptosis. METHODS: Medical records (2004-2017) were reviewed for signalment, cause and duration of proptosis, and clinical findings on admission. The operating faculty member, post-operative medications, and ophthalmic findings at last recheck were recorded. Owners of dogs with blinded eyes were surveyed regarding final outcome and satisfaction. Data were analyzed using Fisher's exact, Likelihood ratio, and Mann-Whitney tests. RESULTS: At last recheck, 17.5 ± 7.3 (mean ± SD) days post-operatively, vision was present in 12/43 eyes (28%). Vision at last recheck was not correlated with breed, cause or duration of proptosis, or post-operative medications (P > .05), but was correlated with presence of direct and indirect pupillary light reflexes (PLRs) on admission (P = .001 and .02, respectively), and with assessment and surgery performed by veterinary ophthalmologists rather than surgery or emergency personnel (P = .015). Mean satisfaction scores (graded 0-10) of 22 owners contacted 59.6 ± 48.2 months after last recheck were 7.8 ± 2.6 (n = 6), 5.7 ± 4.9 (n = 3), and 8.8 ± 1.3 (n = 13) for dogs with phthisical eyes, eyes requiring long-term medications, and blind but otherwise normal eyes, respectively (P = .284). CONCLUSIONS: Contrary to previous studies, breed, and cause and duration of proptosis, did not significantly affect outcome. Testing of direct and indirect PLR is a simple and significant prognostic indicator. Patients assessed and operated by a veterinary ophthalmologist have better prognosis.

Clinical findings of traumatic proptosis in small-breed dogs and complications associated with globe replacement surgery.

Background: Proptosis is a serious traumatic disease commonly affecting small breed dogs and possibly causing loss of vision, with globe replacement surgery (GRS) being essential in most of the cases after stabilizing the patient's condition. Aim: To determine the common dog breeds and clinical findings associated with traumatic proptosis and demonstrate the short-term complications following GRS. Methods: The study was performed on 15 client-owned small-breed dogs presented with unilateral traumatic proptosis. Dogs were examined at initial presentation to determine the concurrent abnormalities associated with globe prolapse. The globe was replaced within the orbit and avulsed extraocular muscles were identified and sutured. Endoscopic examination of the ocular fundus was achieved 1 and 3 weeks after GRS in one Pekingese diagnosed with glaucoma. Complications following GRS were recorded. Results: Pekingese (53.3%) and Griffon (26.7%) were the most affected dogs with proptosis in Egypt. Bruised, hyperemic and swollen conjunctiva and periorbital tissue, lateral globe retraction, cloudy cornea, and miosis were common clinical findings associated with proptosis. Exposure keratitis, keratoconjunctivitis sicca, and exotropia were identified in all 15 patients at presentation. Complications following GRS included phthisis bulbi (53.3%), strabismus (26.7%), and lateral exotropia (20%). Intraocular pressure was reduced to 22 mmHg 3 weeks after GRS in the only patient diagnosed with glaucoma, and endoscopic evidence of optic nerve cupping was identified. Conclusion: Clinical findings associated with proptosis at initial presentation may have influenced the outcome of GRS. Favorable prognosis may be given to patients with relatively high potential for vision at initial presentation and ≤2 extraocular muscle avulsions. Immediate surgical intervention following the occurrence of proptosis should be advised to achieve favorable disease prognosis.

[Intraocular melanoma in a 10-year-old female llama (Lama glama)]. / Intraokuläres Melanom bei einer 10 Jahre alten Lamastute (Lama glama).

A 10-year-old female llama was presented with a continually growing mass of the left eye. It displayed exophthalmus. The nictitating membrane was hyperemic. The cornea was completely opaque, vascularised, ulcerated and covered with abnormal tissue. Deeper structures of the eye were not visible. The right eye was unaffected. The left eye was removed under general anaesthesia. On histological examination, an amelanotic melanoma was diagnosed. The cornea, sclera, vitreous body and lens could not be differentiated. Fourteen months later, the llama was presented to the clinic because of a mass in the left orbita and right-sided blindness. Because of its poor general condition, the animal was euthanised. Histopathological examination revealed recurrence of the amelanotic melanoma with metastases to the regional lymph nodes and infiltration of the optical nerve, leading to the rightsided blindness.

Exophthalmos due to sterile neutrophilic dermatosis in a dog.

An 8-year-old castrated male Bichon Frise was presented to the Kansas State University Veterinary Health Center for evaluation of unilateral right-sided exophthalmos, suspected secondary to a retrobulbar abscess. The dog had acutely developed right-sided periorbital swelling, exophthalmos with pain on retropulsion, as well as multiple cutaneous exudative plaques on the feet and tail base. On ophthalmic examination, the dog also exhibited mild left-sided exophthalmos with decreased, nonpainful retropulsion. Orbital ultrasound and CT were performed to evaluate the extent of bilateral orbital disease. Incisional biopsies were obtained from the affected right periorbital tissues and skin of the feet, and histopathology revealed severe neutrophilic inflammation of the dermis with no organisms detected. Histologic changes were consistent with sterile neutrophilic dermatosis. The dog achieved clinical remission following treatment with initial immunosuppressive doses of corticosteroids and subsequent long-term maintenance therapy using oral cyclosporine.

Experimental infection by Yersinia ruckeri O1 biotype 2 induces brain lesions and neurological signs in rainbow trout (Oncorhynchus mykiss).

Pathological manifestations in rainbow trout (Oncorhynchus mykiss) following experimental waterborne infection with Yersinia ruckeri serotype O1 biotype 2 (strain 07111224) were investigated. Rainbow trout were exposed to 8 × 107  CFU/ml of Y. ruckeri by bath for 6 hr, and mortality was then monitored for 22 days post-infection (dpi). Organs were sampled at 3 dpi and also from moribund fish showing signs of severe systemic infection such as bleeding, exophthalmia or erratic swimming behaviour. Y. ruckeri was observed in the meninges and diencephalon of the brain, and lamina propria of olfactory organ at 3 dpi. At 12 dpi, Y. ruckeri had spread throughout the brain including cranial connective tissues and ventricles and the infection was associated with haemorrhages and an infiltration with leucocytes. Y. ruckeri infection and associated with leucocyte infiltration were observed at 13 dpi. In conclusion, Y. ruckeri strain 07111224 causes encephalitis in the acute phase of infection, which could explain why Y. ruckeri-affected fish show exophthalmia and erratic swimming known as signs of ERM.

Ocular localization of mycobacterial lesions in tank-reared juvenile cobia, Rachycentron canadum.

Severe clinical mycobacteriosis with consistent ocular lesion localization was diagnosed in a population of 800 juvenile tank-reared Cobia (Rachycentron canadum) which experienced a sudden increase in mortality approximately 5 months after arriving into Trinidad and Tobago from Florida, USA. Moderate daily mortality (15-20 animals per day) persisted for just over 1 month. Moribund fish displayed circling behaviour and had an open-mouth gape upon death. Fish consistently presented with bilateral exophthalmia, corneal cloudiness and hyphema. Non-branching acid-fast rods were detected in aqueous humour touch preparations. Histological analysis revealed severe bilateral intra-ocular granulomatous responses in all specimens. Mycobacterium sp. was identified using a real-time PCR assay detecting the RNA polymerase ß-subunit (rpoB) gene in different tissue samples. Specimens did not present with characteristic granulomatous responses usually seen in viscera. To the best of our knowledge, this represents only the third documentation of piscine mycobacterial infection presenting with only localized ocular lesions, and the second documented case of mycobacteriosis in cobia. It is, however, the first documentation of an ocular presentation of mycobacteriosis in a marine species and is the first documentation of such a presentation in cobia.

Recurrence after exenteration for canine orbital malignant schwannoma.

A 14-year-old Maltese dog presented with progressive exophthalmos and external deviation of the right eye. Ultrasonography revealed the presence of a retrobulbar mass and fine-needle aspiration cytology was performed, which detected a malignant mass. There was no evidence of metastasis on thoracic and abdominal radiography. Computed tomography showed no invasion into the bony orbit and no metastasis to the lung or lymph nodes. Exenteration was performed to remove the mass completely. Malignant peripheral nerve sheath tumor was confirmed by histopathological examination.