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An approximately 26‐year‐old, suspected female, red‐tailed hawk (Buteo jamaicensis) was presented with a history of chronic ocular changes of the left eye likely secondary to blunt trauma resulting in blindness and phthisis bulbi. Ophthalmic evaluation of OS revealed a large intraocular mass, 3+ aqueous flare indicating anterior uveitis, and severely decreased intraocular pressure measuring 5 mmHg. Ocular ultrasound revealed an abnormal, spherical shaped and hyperechoic lens, as well as hyperechoic material or a mass lesion in the posterior segment. An enucleation procedure was performed, and histopathology of the eye revealed no signs of neoplasia but instead intraocular osseous metaplasia with bone marrow and adipose tissue replacing the lens. Similar mass lesions were found in the retina and choroid. Multiple fractures in the scleral ossicle and cartilage correlated the intraocular lesions with a blunt traumatic event. A bioresorbable disk of porcine small intestine submucosa (BioSIS Vetrix®) was incorporated to relieve tension during closure. The graft sloughed during healing process, revealing a healed wound underneath. The BioSIS was not incorporated into the wound as designed but may have facilitated healing. This is the first report of intraocular osseous metaplasia in a raptor and the use of BioSIS Vetrix® with enucleation in an avian species. [ABSTRACT FROM AUTHOR]

A 21‐year‐old, suspected female captive ferruginous hawk (Buteo regalis) was followed for 3 years due to an iridial mass of the left eye (OS) that progressively increased in size. Enucleation of OS was eventually recommended due to the iridial mass taking up approximately 75% of the anterior chamber, and the bird seemed less active. A complete physical examination, complete blood cell count, biochemistry, and survey radiographs were performed pre‐surgery with no findings indicating metastasis. A subconjunctival enucleation was performed and the globe was submitted for histopathology through the Comparative Ocular Pathology Lab of Wisconsin. The histopathologic evaluation determined the mass to be consistent with an iris melanocytoma, which has not been previously reported in this species. The patient recovered well from surgery and has remained comfortable and active for 117 days post‐surgery. This case report aimed to review the current available information on avian ocular neoplasms as well as describe the clinical presentation, medical management and surgical procedure, and long‐term follow‐up for this patient to enhance clinical understanding of the behavior of iris melanocytic tumors in avian species. [ABSTRACT FROM AUTHOR]

A juvenile to young adult, male, great horned owl (Bubo virginianus,GHOW) was presented to the wildlife rehabilitation hospital at Lindsay Wildlife Museum (WRHLWM) due to trauma to the right patagium from barbed wire entanglement. On presentation, both corneas were irregular, dry, and no movement of the third eyelid was noted. A severe corneal enlargement/globoid appearance was the predominant ophthalmic feature. The fundus was normal in both eyes (OU). Over the course of several days, both corneas developed edema combined with further dessication at the ocular surface associated with diffuse dorsal fluorescein stain uptake. Repeated ophthalmic examinations found normal intraocular pressures and an inability to move the third eyelid over the enlarged corneas. The bird was deemed nonreleasable due to severe wing damage and poor prognosis associated with eye abnormalities and was humanely euthanized. Postmortem CT, enucleation, and histopathology were performed to evaluate the ocular anatomical abnormality and confirm the suspected diagnosis of keratoglobus. This GHOW represents the first reported case of presumptive keratoglobus in a raptor.

Objective: To determine long‐term outcome of phacoemulsification in raptors at the University of Tennessee Veterinary Medical Center. Animals Studied: Seven nonreleasable diurnal raptors including, four bald eagles (Haliaeetus leucocephalus), two red‐tailed hawks (Buteo jamaicensis), and one peregrine falcon (Falco peregrinus) that had undergone phacoemulsification. All birds showed behavioral changes attributable to visual deficits prior to surgery. Procedures: All birds underwent phacoemulsification for cataracts. Four underwent bilateral phacoemulsification, and three had unilateral surgery. Due to a low sample size, statistics were not done. Results: Six raptors (nine eyes) had long‐term follow‐up (median 75 months, range 28 to 105 months). Seven of these eyes (78%) were visual at last examination. Of those visual eyes, two developed mild to moderate posterior synechiae, four had mild to moderate capsular opacities, and one developed a lipid keratopathy. The remaining two eyes with long‐term follow‐up were from the same red‐tailed hawk. Both eyes developed fibropupillary membranes that were blinding. One eye was pseudophakic, and the other was aphakic and also developed a rhegmatogenous retinal detachment. Another bald eagle was euthanized two months after surgery due to refractory glaucoma; one eye was pseudophakic. Conclusions: Phacoemulsification is a viable treatment for captive raptors with cataracts. The most severe complications occurred relatively soon after surgery. Captive raptors appear to adapt well to aphakia. [ABSTRACT FROM AUTHOR]

Objective: To determine endothelial cell density (ECD) and morphology and morphometry of corneal endothelial cells in the tawny owl (Strix aluco), as well as to report the effects of aging on these parameters. Animal study and procedures: Twenty tawny owls were included in the study and classified into 2 groups according to their age: fledglings (<1 year old) and adults (>1 year old). Central corneal endothelium was studied by means of noncontact specular microscopy (Specular Microscope SP‐2000P; Topcon, Tokyo, Japan), and results for ECD (cells/mm2), mean cell area ((MCA (μm2)), polymegathism (CV), and pleomorphism (% hexagonal cells) were obtained. Results are described by median, interquartile range (25th, 75th percentiles), and absolute range for ECD, MCA, pleomorphism, and polymegathism. In addition, inferential analyses by Mann‐Whitney U test were also performed. A two‐tailed Type I error of 5% was established. Results: Results in fledglings were as follows: ECD = 2864 cells/mm2, MCA = 348 μm2, % hexagonal cells = 72.75%, and CV = 21. Results in adults were as follows: ECD = 2602 cells/mm2, MCA = 384 μm2, % hexagonal cells = 78.83%, and CV = 16. No significant differences in ECD and MCA were seen between the groups (P > .05), although there were significant differences in % hexagonal cells and CV (P < .05). Conclusions: Tawny owls present a uniform endothelium in cell size and shape, although ECD and MCA differ greatly from other bird species. Differences in ECD and MCA could not be found between fledglings and adults probably because of the youth of adult specimens, although there were differences in pleomorphism and polymegathism. [ABSTRACT FROM AUTHOR]

Objective To evaluate aqueous humor viscosity in the raptor, dog, cat, and horse, with a primary focus on the barred owl ( Strix varia). Animals studied Twenty-six raptors, ten dogs, three cats, and one horse. Procedure Animals were euthanized for reasons unrelated to this study. Immediately, after horizontal and vertical corneal dimensions were measured, and anterior chamber paracentesis was performed to quantify anterior chamber volume and obtain aqueous humor samples for viscosity analysis. Dynamic aqueous humor viscosity was measured using a dynamic shear rheometer (AR 1000 TA Instruments, New Castle, DE, USA) at 20 °C. Statistical analysis included descriptive statistics, unpaired t-tests, and Tukey's test to evaluate the mean ± standard deviation for corneal diameter, anterior chamber volume, and aqueous humor viscosity amongst groups and calculation of Spearman's coefficient for correlation analyses. Results The mean aqueous humor viscosity in the barred owl was 14.1 centipoise (cP) ± 9, cat 4.4 cP ± 0.2, and dog 2.9 cP ± 1.3. The aqueous humor viscosity for the horse was 1 cP. Conclusions Of the animals evaluated in this study, the raptor aqueous humor was the most viscous. The aqueous humor of the barred owl is significantly more viscous than the dog ( P < 0.0001). The aqueous humor viscosity of the raptor, dog, cat, and horse can be successfully determined using a dynamic shear rheometer. [ABSTRACT FROM AUTHOR]

Objective To evaluate the achievement of a bilateral mydriasis in raptors induced by a concurrent topical application of rocuronium bromide and to assess any side effects that might result from its use. Animals studied Ten healthy adult common buzzards ( Buteo buteo) and 10 healthy adult little owls ( Athene noctua). Procedures Common buzzards (Group 1) received a single dose of 0.40 mg of rocuronium bromide in each eye (total dose 0.80 mg/bird), whereas the little owls (Group 2) received a single dose of 0.20 mg in each eye (total dose 0.40 mg/bird). The drug was topically instilled in all the birds of both groups. The pupil diameter was measured with a pupillary gauge and the assessment of the pupillary light reflexes was performed using a standard light source. Results Maximal pupillary diameter was 8.10 ± 0.56 mm in the right eye and 8.05 ± 0.59 mm in the left eye for Group 1 and 10.0 ± 0.75 mm in both eyes for Group 2. No statistical differences were evidenced between the achieved pupillary diameters of both eyes in each group. The maximal pupillary diameter was achieved at T110 min and T40 min for Groups 1 and 2, respectively. The drug did not cause noticeable adverse effects in the examined birds. Conclusions A single concurrent topical administration of rocuronium bromide to the eyes of the examined birds induced a complete bilateral mydriasis in both eyes without causing any adverse effect. [ABSTRACT FROM AUTHOR]

Objective To evaluate the mydriatic efficacy of a neuromuscular blocking agent (rocuronium bromide) applied topically to only one eye of nocturnal birds of prey and to assess for any general and/or local adverse effects due to its use. Animal studied Twelve healthy adult tawny owls ( Strix aluco) were randomly divided in two groups. Procedures Six birds (Group 1) received a single dose of 0.35 mg of rocuronium bromide. The second group of subjects (Group 2) received two doses of 0.35 mg of rocuronium bromide (total 0.70 mg/eye). In both groups, the curariform agent was instilled topically. Pupil diameter was measured with a pupillary gauge in 10 min intervals for a total of 100 min and then every 20 min for a total of 240 min. The assessment of the pupillary light reflex was performed using a standard light source during pupillary size recording. Results Maximal pupillary diameter was 11.5 ± 0.3 mm for Group 1 and 11.0 ± 0.6 mm for Group 2 and no statistically significant differences were detected among the two groups. The maximal pupillary diameter was achieved at T80 for Group 1, and at T60 for Group 2. A complete fundus examination was possible on all treated eyes of subjects of both groups. The drug did not cause any noticeable adverse effects in any of the examined birds. Conclusion Results of the present study suggest that a single topical administration of 0.35 mg of rocuronium bromide to the eyes of healthy tawny owls results in sufficient mydriasis to allow for a complete examination of the fundus. [ABSTRACT FROM AUTHOR]

Abstract A young adult great horned owl (Bubo virginianus ) was examined following presumed trauma. The owl had soft tissue injury to its left wing as well as corneal protrusion, lens subluxation, and iridodialysis of the right eye. The bird's eye was treated surgically with a large, rectangular penetrating keratoplasty. Following escape from housing, the bird was found with partial wound dehiscence and iris prolapse 12 days post operation. Surgical repair was performed and healing progressed for 14 days, at which time the transplant dehisced and the globe was exenterated. The patient rehabilitated well until escaping from its cage again 4 weeks later, at which time it sustained an open comminuted humeral fracture and was euthanized. [ABSTRACT FROM AUTHOR]