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.     

Multi‐channel visual evoked potential as an ancillary tool to diagnose intraorbital optic nerve lesions

Multi‐channel visual evoked potential (MVEP) recording method was used to assist in diagnosing a 4‐month‐old Chinese Albino rabbit with an intraorbital mass. Subcutaneous MVEP of its both eyes were recorded simultaneously using 16 electrodes (4 × 4) multi‐channel array. Analysis of the cortical potential landscapes (CPL) showed that the conduction function of right eye was remarkably impaired in terms of decreased amplitudes and prolonged latencies. Specific side‐dominant distribution asymmetry of the decreased MVEP amplitudes indicated that the temporal side of the optic nerve (ON) was severely involved. Overall prolonged latencies of the CPL without side differences suggested that the functional impairment could have been caused by the mechanical compression exerted by an intraorbital mass. Surgical removal procedures confirmed that the mass was located temporally to the ON. Pathological examination provided a final diagnosis of a giant polycystic mucocele. Beyond its significance as a standard tool to assess functional changes of the visual pathway, MVEP recordings might assist locating intraorbital lesions that involve the ON by careful analysis of abnormal CPLs.     

Orbital fibroma in a horse

An 11-year-old American Quarterhorse gelding presented for moderate periorbital swelling and exophthalmia of the left eye. The menace response, and direct and consensual pupillary light reflexes were absent in the left eye. Conjunctival hyperemia, blepharedema, a mydriatic pupil, resistance to retropulsion, and an increased intraocular pressure were present. A soft-tissue mass could be palpated in the left retrobulbar space by pressing onto the orbit over the supraorbital fossa. Incomplete surgical resection of the mass was performed and histopathologic evaluation was consistent with a fibroma. Normal pupillary light reflexes and vision returned following surgery. The mass has not recurred 14 months after surgery.     

COMPARISON BETWEEN ULTRASONOGRAPHIC AND CLINICAL FINDINGS IN 43 DOGS WITH GALLBLADDER MUCOCELES

Cholecystectomy is the current standard recommended treatment for dogs with gallbladder mucoceles. However, medical management with monitoring has also been recommended for asymptomatic dogs. The purpose of this retrospective study was to compare ultrasonographic patterns of gallbladder mucoceles with clinical disease status in a group of dogs. For each included dog, the ultrasonographic pattern of the mucocele was classified into one of six types: type 1, immobile echogenic bile; type 2, incomplete stellate pattern; type 3, typical stellate pattern; type 4, kiwi like pattern and stellate combination; type 5, kiwi like pattern with residual central echogenic bile; and type 6, kiwi like pattern. A total of 43 dogs were included. Twenty‐four dogs, including 11 dogs with gallbladder rupture, were symptomatic. Nineteen dogs were asymptomatic. Cholecystectomy (n = 19), medical therapy (n = 17), or monitoring (n = 6) treatments were applied according to clinical signs and owners’ requests. One dog suspected of having gallbladder rupture was euthanized. Frequencies of gallbladder mucocele patterns were as follows: type 1 = 10 (23%), type 2 = 13 (30%), type 3 = 5 (12%), type 4 = 11 (26%), type 5 = 4 (9%), and type 6 = 0. In dogs with gallbladder rupture, type 2 (8/13) was the most common. No significant correlations were found between ultrasonographic patterns of gallbladder mucoceles and clinical disease status or gallbladder rupture. Findings indicated that ultrasonographic patterns of gallbladder mucoceles may not be valid bases for treatment recommendations in dogs.     

Effect of acute intraocular pressure elevation on blood flow velocity and resistance in the rabbit ophthalmic artery

Objective To determine the effect of intraocular pressure (IOP) on blood flow velocity and resistance in the rabbit ophthalmic artery. Animals Ten adult New Zealand White rabbits were used. Procedures Right eyes were cannulated and the IOP was raised in a stepwise manner from 20 to 70 mmHg. Peak systolic velocity (PSV), end diastolic velocity (EDV) and resistive index (RI) in the ophthalmic artery were measured by color Doppler imaging. Values of PSV, EDV and RI were compared at various IOPs via the analysis of variance (anova ) of a randomized block design with post hoc Bonferroni test. Results Significant differences of PSV, EDV and RI at different IOP points (all P < 0.001) were observed. Over the entire IOP range, linear regression showed a negative correlation between IOP and both PSV and EDV (β = ?0.07434, P = 0.0020 and β = ?0.07829, P < 0.001, respectively), as well as a positive correlation between the RI and IOP (β = 0.00221, P < 0.001). Moreover, line plots identified a point with IOP = 40 mmHg, splitting the IOP range with different regression slopes. Piecewise linear regression indicated no correlation between PSV, EDV, RI and IOP when the IOP was elevated from 20 to 40 mmHg (P = 0.1832, P = 0.5932 and P = 0.5819, respectively). However, piecewise linear regression detected a stronger negative correlation between PSV, EDV and IOP (β = ?0.15760, P = 0.0011 and β = ?0.11872, P = 0.001, respectively) and a stronger positive correlation between RI and IOP (β = 0.00273, P = 0.0015) during the stage from 40 to 70 mmHg. Conclusions The ophthalmic artery in the rabbits was capable of maintaining normal blood velocity and resistance when IOP was below 40 mmHg. However, the autoregulatory capacity was greatly limited when IOP was over 40 mmHg.     

Macrophakia in three cats

This report describes three cases of bilateral macrophakia in 3-, 5-, and 9-year-old cats, respectively. All cats were presented because of visual deficits. Ophthalmic examination revealed macrophakia (the vitreous was replaced by the lens) and retinal changes (tapetal hyper-reflectivity, attenuation of retinal vessels, and retinal folds) in all cats. In addition, bilateral subconjunctival orbital fat prolapse in one cat and microphthalmos in another cat were present. To confirm the ophthalmologic diagnosis of macrophakia, gross pathology examination in one cat and ultrasound examination in another cat were performed.