Severe orbital hematoma with third eyelid swelling and prolapse following a blind maxillary nerve block in a horse.

A 20-year-old quarter horse gelding was presented for routine dental examination. Periodontal disease and luxation of tooth 108 was diagnosed and oral extraction was planned. After an unsuccessful blind maxillary nerve block, it was elected to perform the procedure under total intravenous anesthesia. Following recovery, a focal superficial corneal ulcer, severe retrobulbar swelling, mild exophthalmos, and marked swelling and prolapse of the third eyelid (nictitating membrane) were observed. Clinical signs persisted beyond 48 h despite the use of systemic anti-inflammatories and topical ocular anti-inflammatories and antibiotics. A temporary tarsorrhaphy was subsequently done at 48 h and the horse was discharged after 5 d of hospitalization and regression of clinical signs. Although it is very useful for easing dental extractions, the blind maxillary nerve block is associated with potential complications due to inadvertent vascular puncture. This case report describes a rare complication of prolapse of the third eyelid in a horse after a maxillary nerve block and successful treatment with a temporary tarsorrhaphy. Key clinical message: This case report explains how nictitating membrane swelling and prolapse can occur following a blind maxillary nerve block in the horse and describes treatment with a temporary tarsorrhaphy.

Hématome orbitaire sévère avec gonflement de la troisième paupière et prolapsus à la suite d'un bloc du nerf maxillaire à l'aveugle chez un cheval. Un hongre quarter horse de 20 ans a été présenté pour un examen dentaire de routine. Une maladie parodontale et une luxation de la dent 108 ont été diagnostiquées et une extraction orale a été planifiée. Après l'échec d'un bloc du nerf maxillaire à l'aveugle, il a été décidé d'effectuer la procédure sous anesthésie intraveineuse. Après la guérison, un ulcère cornéen superficiel focal, un gonflement rétrobulbaire sévère, une légère exophtalmie ainsi qu'un gonflement et un prolapsus marqués de la troisième paupière (membrane nictitante) ont été observés. Les signes cliniques ont persisté au-delà de 48 heures malgré l'utilisation d'anti-inflammatoires systémiques et d'anti-inflammatoires oculaires topiques et d'antibiotiques. Une tarsorraphie temporaire a ensuite été réalisée à 48 heures et le cheval est sorti après 5 jours d'hospitalisation et de régression des signes cliniques. Bien qu'il soit très utile pour faciliter les extractions dentaires, le bloc du nerf maxillaire à l'aveugle est associé à des complications potentielles dues à une ponction vasculaire involontaire. Ce rapport de cas décrit une complication rare de prolapsus de la troisième paupière chez un cheval après un bloc nerveux maxillaire et un traitement réussi par tarsorraphie temporaire.Message clinique clé:Ce rapport de cas explique comment un gonflement et un prolapsus de la membrane nictitante peuvent survenir à la suite d'un bloc du nerf maxillaire à l'aveugle chez le cheval et décrit le traitement par tarsorraphie temporaire.(Traduit par Dr Serge Messier).

Evaluation of conjunctival graft procedures and factors that lead to graft complications in canine cases.

PURPOSE: To describe the complications of conjunctival graft surgery occurring in cases at a referral ophthalmic service and evaluate factors that lead to occurrence of complications in canine cases. METHODS: A retrospective case-control study was completed using data from the Veterinary Medical Center at the Western College of Veterinary Medicine, Saskatoon, Canada, between May 2015 and March 2020. Case records from dogs that underwent conjunctival pedicle graft surgery and subsequently either did or did not develop a conjunctival graft complication were reviewed. RESULTS: One hundred and six dogs undergoing conjunctival graft surgeries were identified. Sixteen conjunctival graft complications occurred, of which, eight led to negative outcomes. Univariable analysis comparing canine eyes that developed complications to control eyes revealed potential (p ≤ .05) differences between the groups in post-operative fluoroquinolone use, Streptococcus canis isolation, intraoperative intravenous cefazolin use, corneal stromal white cell infiltrate, and mean ulcer diameter. The use of intraoperative cefazolin could not be effectively evaluated with available data; however, no dogs (n = 22) receiving intraoperative cefazolin developed complications. Multivariable analysis revealed that dogs that were treated with a second-generation fluoroquinolone and that had S. canis isolated had higher odds of experiencing complications than dogs that were not treated with a second-generation fluoroquinolone and that were S. canis negative (Odds ratio = 64.7 [95% CI 6.3-669], p < .0001). CONCLUSIONS: Streptococcus species played a role in conjunctival graft complications in our study. Empiric selection of second-generation fluoroquinolone monotherapy may need reconsideration given the frequent isolation of Streptococcus spp. from canine ulcers. The use of intraoperative cefazolin may be associated with a lower complication rate.

Contouring in the optic plane improves the accuracy of computed tomography-based segmentation of the optic pathway.

Canine optic pathway structures are often contoured on CT images, despite the difficulty of visualizing the optic pathway with CT using standard planes. The purpose of this prospective, analytical, diagnostic accuracy study was to examine the accuracy of optic pathway contouring by veterinary radiation oncologists (ROs) before and after training on optic plane contouring. Optic pathway contours used as the gold standard for comparison were created based on expert consensus from registered CT and MRI for eight dogs. Twenty-one ROs contoured the optic pathway on CT using their preferred method, and again following atlas and video training demonstrating contouring on the optic plane. The Dice similarity coefficient (DSC) was used to assess contour accuracy. A multilevel mixed model with random effects to account for repeated measures was used to examine DSC differences. The median DSC (5th and 95th percentile) before and after training was 0.31 (0.06, 0.48) and 0.41 (0.18, 0.53), respectively. The mean DSC was significantly higher after training compared with before training (mean difference = 0.10; 95% CI, 0.08-0.12; P < 0.001) across all observers and patients. DSC values were comparable to those reported (0.4-0.5) for segmentation of the optic chiasm and nerves in human patients. Contour accuracy improved after training but remained low, potentially due to the small optic pathway volumes. When registered CT-MRI images are not available, our study supports routine addition of an optic plane with specific window settings to improve segmentation accuracy in mesaticephalic dogs ≥11 kg.

Phacoemulsification and intraocular lens implantation in a Canada lynx with phacoclastic uveitis.

A 4-year-old male Canada lynx (Lynx canadensis) was referred to the ophthalmology service at the University of Saskatchewan with a 7-month history of cataract and chronic phacoclastic uveitis secondary to penetrating trauma from a lynx claw. Ophthalmic examination of the right eye revealed a corneal scar, marked aqueous flare, extensive fibrovascular membranes extending from the iris to the lens, anterior and posterior synechiae, immature cataract, and anterior vitritis; the fundus was not visible. Phacoemulsification surgery and intraocular lens implantation using a custom lens of D+46 and 14 mm (An-vision, West Jordan, Utah, USA) was performed. Post-operative medications included sub-conjunctival injections of atropine, cefazolin, and triamcinolone, and oral doxycycline and prednisolone. At the 5-month follow-up, the uveitis was controlled, and a normal fundus was visualized; at 21 mo, the eye remained comfortable and visual. This is the first case report to describe phacoemulsification in a wild felid as a treatment for a traumatic cataract and severe phacoclastic uveitis. Key clinical message: Despite chronic phacoclastic uveitis, phacoemulsification surgery can provide a positive outcome for mature wild felids with traumatic lens rupture, even when topical treatment cannot be administered.

Phacoémulsification et implantation de lentilles intraoculaires chez un lynx du Canada atteint d'uvéite phacoclastique. Un lynx du Canada mâle de 4 ans (Lynx canadensis) a été référé au service d'ophtalmologie de l'University of Saskatchewan avec une histoire de 7 mois de cataracte et d'uvéite phacoclastique chronique secondaire à un traumatisme pénétrant d'une griffe de lynx. L'examen ophtalmique de l'oeil droit a révélé une cicatrice cornéenne, un phénomène de Tyndall marqué, des membranes fibrovasculaires étendues s'étendant de l'iris au cristallin, des synéchies antérieure et postérieure, une cataracte immature et une vitreite antérieure; le fond d'oeil n'était pas visible. Une chirurgie de phacoémulsification et une implantation de lentille intraoculaire à l'aide d'une lentille personnalisée de D+46 et 14 mm (An-vision, West Jordan, Utah, USA) ont été réalisées. Les médicaments postopératoires comprenaient des injections sous-conjonctivales d'atropine, de céfazoline et de triamcinolone, ainsi que de la doxycycline et de la prednisolone par voie orale. Au suivi à 5 mois, l'uvéite était contrôlée et un fond d'oeil normal était visualisé; à 21 mois, l'oeil restait confortable et visuel. Il s'agit du premier rapport de cas décrivant la phacoémulsification chez un félin sauvage comme traitement d'une cataracte traumatique et d'une uvéite phacoclastique sévère.Message clinique clé:Malgré l'uvéite phacoclastique chronique, la chirurgie de phacoémulsification peut donner un résultat positif pour les félins sauvages matures présentant une rupture traumatique du cristallin, même lorsqu'un traitement topique ne peut pas être administré.(Traduit par Dr Serge Messier).

Ophthalmic Parameters and Ophthalmoscopy of Burrowing Owls (Athene cunicularia).

Twelve adult burrowing owls (Athene cunicularia) maintained in a managed environment underwent complete bilateral ophthalmic examinations to assess ocular parameters and, if present, describe lesions (n = 24 eyes). Tear production was measured with a Schirmer tear test (STT), and intraocular pressure (IOP) was measured with rebound tonometry using established calibration settings (D = dog/cat, P = other species). Retinography was performed for all birds after application of topical rocuronium bromide, and corneal diameter was measured. Menace response was absent bilaterally in 7 of 12 (58.3%) owls; however, this did not appear to be related to the presence of fundic lesions. Ocular lesions were visualized in 6 of 12 (50%) owls. The most common ophthalmic abnormality noted was mild multifocal fundic pigment clumping, suggestive of chorioretinal scarring. Other ocular lesions included 1 retinal tear and 1 incipient cataract. Mean tear production was 6.1 ± 3.0 mm/min. Mean IOPs were 11.6 ± 1.8 mm Hg and 7.1 ± 1.3 mm Hg for the D and P settings, respectively, and these were significantly different (P < 0.001). The IOP results did not differ significantly based on patient age or between the right and left eyes, but a higher mean was obtained from males versus females using the D setting (P < 0.039; male mean 12.1 ± 1.9 mm Hg; female mean 10.9 ± 1.2 mm Hg). Measurements obtained from the STT were not affected by either age or sex. Corneal height was 11 mm and width was 12 mm, regardless of age or sex. The rebound tonometer D setting is recommended for measuring IOP values in this species. Burrowing owls had inconsistent mydriasis following topical rocuronium bromide application to the eye; however, a complete fundic examination was possible with or without complete mydriasis.

In vivo imaging comparison of unilateral circular retinal plaques in retriever dogs to dysplasia and detachment in the English Springer Spaniel.

PURPOSE: To compare the scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT), and fluorescein angiography (FA) findings in retrievers with a single unilateral circular retinal plaque to those of an English springer spaniel with bilateral retinal dysplasia. PROCEDURES: A retrospective record review identified three dogs with circular retinal plaques that underwent SLO and OCT; in two of the three dogs, FA was also completed. Morphologic changes, lesion measurements, and angiogram characteristics were documented. An English springer spaniel with bilateral retinal dysplasia that had undergone SLO, OCT, and FA was used for comparison. RESULTS: Scanning laser ophthalmoscopy of the retriever dogs revealed circular retinal plaques with a dark periphery located in the tapetal retina. OCT revealed a thickening of the nerve fiber layer corresponding to the circular pattern observed on SLO. Within the circular plaque, the retina was predominantly of normal architecture. FA revealed variable hypofluorescence of both the rim and the center of the circular lesion throughout the early angiogram phases. In the late recirculation phase, small multifocal areas of hyperfluorescence were observed. OCT of geographic retinal dysplasia in the English springer spaniel revealed disorganization of both inner and outer retinal layers, and retinal detachment. CONCLUSIONS: Circular plaques observed in the tapetal retina are predominantly formed by a thickening of inner retina, while retinal dysplasia has disorganization of both inner and outer retinal layers. Further etiologic research is needed, including pedigree mapping to determine whether retinal plaques are an acquired or inherited condition.

Bacterial isolates of indolent ulcers in 43 dogs.

PURPOSE: To determine whether bacteria are isolated from canine indolent ulcers and evaluate their influence on clinical outcomes. METHODS: Swabs for anaerobic and aerobic culture were collected from indolent ulcers of 43 client-owned dogs presenting to the University of Saskatchewan Veterinary Medical Centre. Outcomes were compared between ulcers with bacterial isolates and those without. Medical therapy was reviewed. RESULTS: Bacteria were isolated in 8/43 ulcers: Three cultured two isolates and five cultured single isolates. Staphylococcus was the most common genus isolated and was present in six ulcers: Species included unspecified [2], pseudintermedius [2], schleiferi [1], and hominis [1]. Streptococcus was the second most common isolate present in two ulcers: Species included canis and agalactiae. Tobramycin was the most common antibiotic used in ulcers with bacterial isolates prior to referral (n = 3). One case did not have conclusive follow-up data from the referring veterinarian and was therefore excluded from further analysis. All seven culture-positive ulcers were recorded as healed without complication: six healing after one procedure and one healing after two procedures. Thirty-five ulcers were culture-negative. There was no difference in outcome between indolent ulcers with bacterial isolates and those with negative cultures (P = .7475). CONCLUSIONS: Bacteria were isolated from 19% of indolent ulcers, and Staphylococcus was the most common isolate. Bacterial isolation did not influence outcome.

Effect of intracameral epinephrine on heart rate, post-operative ocular hypertension, and long-term outcome following canine phacoemulsification.

PURPOSE: To determine the effect of intrsacameral epinephrine on heart rate, blood pressure, post-operative ocular hypertension, and complications following canine phacoemulsification. PROCEDURES: A prospective, double-blinded, controlled trial was carried out using 30 client-owned dogs undergoing phacoemulsification. Eyes were randomly assigned to a treatment group receiving intracameral (IC) epinephrine (n = 31) or balanced salt solution (n = 25) at the beginning of surgery. Heart rate, post-operative intraocular pressures, and outcomes were compared between treatment groups. RESULTS: No adverse reactions to IC epinephrine or saline were observed. Post-operative ocular hypertension developed at the 2 and/or 4 hours pressure reading in 35% and 46% in the epinephrine and saline groups, respectively (P = .5072). There were 9.7% and 23.1% eyes that developed complications in the IC epinephrine and saline groups, respectively (P = .2373). CONCLUSIONS: Intracameral epinephrine is safe to use, and non-significant decreases in post-operative ocular hypertension and long-term complications were observed.

Evaluation of retinal morphology of canine sudden acquired retinal degeneration syndrome using optical coherence tomography and fluorescein angiography.

PURPOSE: To describe the optical coherence tomography (OCT) and fluorescein angiography changes in dogs with sudden acquired retinal degeneration syndrome (SARDS). METHODS: Retinal OCT was performed on 10 SARDS dogs and eight control dogs. Tomograms were collected in four quadrants around the optic nerve. Measurements were collected from the photoreceptor layer, the outer nuclear layer, the outer retina, the inner retina and the whole retina thickness in all quadrants. Sodium fluorescein was injected intravenously and serial fundic photographs were collected for a 5 minute period post-injection. RESULTS: In all quadrants, the outer nuclear layer (dorsal temporal P = 0.0000, dorsal nasal P = 0.0001, ventral temporal P = 0.0002, ventral nasal P = 0.000) and outer retina (dorsal temporal P = 0.0001, dorsal nasal P = 0.0002, ventral temporal P = 0.0054, ventral nasal P = 0.0084) measurements were significantly decreased in SARDS dogs. The whole retina thickness was significantly decreased in the dorsal temporal (P = 0.0082) and ventral temporal (P = 0.0428) retina. There were no significant differences in the photoreceptor layer thickness or inner retinal thickness between SARDS and control dogs. All SARDS dogs had a loss of definition of all of the photoreceptor bands on OCT. Two SARDS dogs had multifocal small retinal detachments and one of these dogs exhibited fluorescein leaking at the detachment sites. CONCLUSIONS: The significant reduction in the outer nuclear layer and the loss of band signals in the photoreceptor layers in dogs with SARDS identified on OCT support the previous histopathology findings. Small detachments may occasionally be detected on OCT and they may leak fluorescein.

Peripheral cranial neuropathies consistent with cavernous sinus syndrome caused by extracranial nasopharyngeal lymphoma in a cat.

Cavernous sinus syndrome is a unique constellation of cranial nerve deficits occurring typically as a result of pathologic infiltration of the cavernous sinus, which is located in the lateral sellar compartment of the calvarium. This case report describes a polyneuropathy consistent with cavernous sinus syndrome as a result of a lesion outside of the cavernous sinus. The cat was presented with right internal and external ophthalmoplegia, loss of right corneal sensation, inspiratory stridor, dysphagia, dysphonia, tongue weakness, and weight loss. Magnetic resonance imaging identified a large nasopharyngeal mass along the base of, but without extension into, the calvarium. The histologic diagnosis was nasopharyngeal lymphoma. Focal extracranial masses should be considered as differential diagnoses for multiple cranial nerve deficits, including the constellation of clinical signs recognized as cavernous sinus syndrome.

Neuropathies crâniales périphériques compatibles avec un syndrome du sinus caverneux causé par un lymphome nasopharyngé extra-crânial chez un chat. Le syndrome du sinus caverneux est une constellation unique de déficits des nerfs crâniens se produisant typiquement comme le résultat d'une infiltration pathologique du sinus caverneux, qui est situé dans le compartiment sellaire latéral du calvarium. Le présent rapport de cas décrit une polyneuropathie compatible avec un syndrome du sinus caverneux résultant d'une lésion à l'extérieur du sinus caverneux. Le chat fut présenté avec une ophtalmoplégie interne et externe droit, perte de sensation au niveau de la cornée droite, stridor inspiratoire, dysphagie, dysphonie, faiblesse de la langue, et perte de poids. Un examen d'imagerie par résonnance magnétique permis d'identifier une large masse nasopharyngée suivant la base du calvarium, mais sans extension à l'intérieur. Le diagnostic histologique en fut un de lymphome nasopharyngé. Les masses focales extra-crâniales devraient être considérées dans le diagnostic différentiel lors de déficits de plusieurs nerfs crâniens, incluant la multitude de signes cliniques reconnus comme le syndrome du sinus caverneux.(Traduit par Dr Serge Messier).

Odontogenic parakeratinized cyst resulting in exophthalmos and palatine, maxillary, and zygomatic bone erosion in a dog.

A novel case of a canine odontogenic parakeratinized cyst (COPC) that resulted in exophthalmos and palatine, maxillary, and zygomatic bone erosion in a 5-year-old Chihuahua dog is reported. Final diagnosis was aided by cross-sectional imaging (magnetic resonance imaging and computed tomography) and confirmed with histologic examination of the cyst wall.

Congenital nuclear cataracts in a Holstein dairy herd.

This report describes congenital nuclear cataracts and posterior lenticonus in a closed purebred Holstein dairy herd in Canada. Ophthalmic examinations were completed on 30 male and 249 female cattle aged newborn to 10 years old. Nutritional, infectious, and toxic etiologies were investigated. Necropsies of 3 affected calves were performed and eyes of 2 additional affected calves were examined with light microscopy. Bilateral nuclear cataracts were identified in 53/279 (19%) animals. Additional congenital anomalies observed included posterior lenticonus, iris to lens persistent pupillary membranes (n = 7), and lenticular colobomata (n = 1). Heifers did not give birth to calves with congenital nuclear cataracts (0/105), whereas the incidence of affected calves born to multiparous cows was 31% (53/171). The animals with nuclear cataracts ranged from newborn to 8 years old. The cataracts appeared to be non- or minimally progressive. Light microscopic examination of 10 affected globes confirmed nuclear cataract with posterior lenticonus (n = 10). Pedigree analysis was inconclusive. Polymerase chain reaction and sequence analysis for the NID1 gene deletion were negative. The etiology of the congenital lenticular anomalies was not determined.

Cataractes nucléaires congénitales dans un troupeau laitier Holstein. Cette étude rapporte les résultats d'une enquête sur des cataractes nucléaires congénitales et des lenticônes postérieurs dans un troupeau laitier fermé Holstein pur-sang au Canada. Des examens ophtalmiques ont été réalisés sur 30 bovins mâles et 249 bovins femelles qui étaient âgés de nouveau-né à 10 ans. Les étiologies nutritionnelles, infectieuses et toxiques ont été étudiées. Des nécropsies ont été effectuées pour trois veaux touchés et les yeux de deux veaux affectés additionnels ont été examinés à l'aide de microscopie photonique. Des cataractes nucléaires bilatérales ont été identifiées chez 53/279 (19 %) des animaux. Les anomalies congénitales additionnelles observées incluaient le lenticône postérieur, des membranes pupillaires persistantes de l'iris à la lentille (n = 7) et le colobome lenticulaire (n = 1). Les taures n'ont pas donné naissance à des veaux avec des cataractes nucléaires congénitales (0/105), tandis que l'incidence des veaux affectés nés de vaches multipares était de 31 % (53/171). Les animaux avec des cataractes nucléaires étaient âgés de nouveau-né à 8 ans. Les cataractes semblaient être non progressives ou minimalement progressives. Un examen à l'aide d'un microscope photonique de 10 globes affectés a confirmé la cataracte nucléaire avec un lenticône postérieur (n = 10). L'analyse du pedigree a été non-concluante. Une réaction d'amplification en chaîne par la polymérase et une analyse de séquence pour la suppression du gène NID1 ont été négatives. L'étiologie des anomalies lenticulaires congénitales n'a pas été déterminée.(Traduit par Isabelle Vallières).