Publications by authors named "Hans Westermeyer"

Objective: To determine whether novel pre- and postsurgical ultrasound biomicroscopy (UBM) measurements of the canine ciliary cleft (CC) are associated with postoperative ocular hypertension (POH) following cataract surgery and to explore the relationship between intraocular pressure and CC UBM measurements.

Methods: Following pharmacologic mydriasis, UBM images were obtained from 31 client-owned dogs before elective cataract surgery, immediately postsurgery, and 4 to 6 hours following surgery or while experiencing POH ≥ 25 mm Hg. Presurgery and the pre- to postsurgery change in CC measurements were assessed for association with POH using individual mixed-effects logistic regression models and forward variable selection models.

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Objective: The objective of this study was to analyze the use of rebound tonometry, as a noninvasive diagnostic tool, in arachnids.

Methods: 5 juvenile (yearling) female and 1 juvenile male curlyhair tarantulas (Tliltocatl albopilosus, previously Brachypelma albopilosum) were used to track estimated ventral opisthosoma pressures over a 9-month period of time. Younger, growing animals were selected as they are more likely than adults to go through multiple molts throughout the 9 months of the study length.

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Objective: To determine the predictive value of corneal ultrasound biomicroscopy (UBM) findings for the outcome of equine corneal disease.

Animals: 46 horses with a clinical diagnosis of either infectious ulcerative keratitis or stromal abscess.

Methods: Corneal UBM (VevoMD; UHF70; VisualSonics) of horses with infectious corneal disease presenting to the North Carolina State University Equine Ophthalmology Service from 2019 to 2023 were evaluated.

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Objective: To determine the mydriatic effect of topical 10% phenylephrine with 10 mg/mL rocuronium bromide and compare this protocol with and without pretreatment with proparacaine.

Animals Studied: Ten client-owned pet adult eastern box turtles (Terrapene carolina carolina).

Procedures: All turtles were sedated with 8 mg/kg alfaxalone intramuscularly.

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Purpose: To determine the association between age and retinal full-field electroretinographic (ERG) measures in companion (pet) dogs, an important translational model species for human neurologic aging.

Methods: Healthy adult dogs with no significant ophthalmic abnormalities were included. Unilateral full-field light- and dark-adapted electroretinography was performed using a handheld device, with mydriasis and topical anaesthesia.

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Objective: This study compared the quality of retrobulbar anesthesia using a blind inferior-temporal palpebral approach (ITP) with an ultrasound-guided supratemporal (ST) technique in dogs undergoing unilateral enucleation.

Animal Studied: Twenty-one client-owned dogs were undergoing enucleation.

Procedures: Dogs were randomly assigned to receive ITP (n = 10) or ST (n = 11) with 0.

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Objective: To describe a modified ab externo method of sulcus intraocular lens (IOL) fixation and report outcomes of eyes treated with this approach.

Procedures: Records of patients with lens instability or luxation that underwent a lensectomy and sulcus IOL implantation from January 2004 to December 2020 were reviewed.

Results: Nineteen eyes of 17 dogs had a sulcus IOL placed via a modified ab externo approach.

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Purpose: To evaluate the correlation between equine pectinate ligament descemetization and ocular disease.

Methods: The pathology database of the North Carolina State University Veterinary Medical Center was searched from 2010-2021 for all equine globes. Disease status was then assigned as affected by glaucoma, uveitis, or "other" based upon clinical records.

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Background: Aging dogs may suffer from canine cognitive dysfunction syndrome (CCDS), a condition in which cognitive decline is associated with amyloid pathology and cortical atrophy. Presumptive diagnosis is made through physical examination, exclusion of systemic/metabolic conditions, and completion of screening questionnaires by owners.

Objective: This study aimed to determine whether cognitive function could be quantified in aging pet dogs, and to correlate cognitive testing with validated questionnaires and plasma neurofilament light chain (pNfL) concentration.

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The pink land iguana, Conolophus marthae, is one of four species of iguanas (three terrestrial and one marine) in the Galápagos Islands, and the only one listed as critically endangered by the IUCN. The species can only be found on the north-west slopes of the highest volcano on Isabela Island and was first described to science in 2009. As part of a population telemetry study, a health assessment was authorized by the Galápagos National Park.

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Purpose: Determine optimal iontophoresis times for riboflavin delivery to the corneal stroma across different species and compare these to corneal injection.

Methods: Ex vivo horse, dog, rabbit, and pig globes were treated with riboflavin administered with either iontophoresis for 2.5-20 minutes with or without corneal epithelium; or with purpose-designed precise corneal injection (PCI) application with intact epithelium.

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Purpose: To investigate the relationship between gonioscopic iridocorneal angle (ICA) morphology and the incidence of postoperative ocular hypertension (POH) and postoperative glaucoma in dogs undergoing cataract surgery.

Animals Studied: Retrospective analysis of 138 eyes of 78 canine patients who underwent phacoemulsification at North Carolina State University from December 1, 2015 through April 30, 2017.

Methods: Medical records of all phacoemulsification patients with preoperative RetCam gonioscopic images were reviewed for preoperative, intraoperative, and postoperative variables.

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Purpose: To explore the effects of chronic, uncontrolled glaucoma on pressure sensitivity in dogs before and after enucleation of the painful globe.

Methods: Client-owned dogs undergoing enucleation for chronic glaucoma with no other sources of pain were enrolled. Normal dogs of similar breeds and skull morphology were enrolled as controls.

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An eight-year-old female spayed Boston Terrier presented to the North Carolina Veterinary Hospital with glaucoma in the left eye (OS). Initial ophthalmic examination revealed moderate ocular hypertension, a diffusely and markedly shallow anterior chamber with anteriorly displaced iris and lens, vitreal prolapse, and a normal iridocorneal angle (ICA) morphology. The patient displayed a paradoxical response to topical latanoprost with an increase in intraocular pressure.

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Sudden acquired retinal degeneration syndrome (SARDS) in dogs is proposed to have an immune-mediated etiology. However, there is conflicting evidence regarding the presence of antiretinal antibodies, as assessed by western blotting, in the serum of SARDS patients. Because of the possibility that antibodies recognize only conformational epitopes, we hypothesized that a more sensitive method to investigate circulating retinal autoantibodies in SARDS is immunofluorescence.

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Purpose: Investigate nociception differences in dogs undergoing enucleation administered bupivacaine either via preoperative retrobulbar block (pRB) or intraoperative splash block (iSB).

Methods: Prospective, randomized, double-masked, clinical comparison study. Dogs undergoing unilateral enucleation were randomized to two groups: one received bupivacaine pRB and saline iSB of the same volume, and the other received saline pRB and bupivacaine iSB.

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Objective: To determine the combined mydriatic effects of topical rocuronium bromide and phenylephrine in juvenile loggerhead turtles and identify any adverse effects associated with treatment.

Animals Studied: Eleven juvenile loggerhead turtles (Caretta caretta).

Procedures: Four 20 μL drops of rocuronium bromide and four 20 μL drops of 10% phenylephrine were placed into the right eye at 2-minute intervals of 5 turtles, while the same volume of saline was administered to six control turtles.

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Objective: To document ocular lesions present in cold-stunned sea turtles and determine the impact of these lesions on their release.

Animals: All sea turtles (Caretta caretta, Chelonia mydas, and Lepidochelys kempii) presenting to rehabilitation centers in North Carolina over two cold stun seasons.

Procedures: Complete ophthalmic examination using slit-lamp biomicroscopy, fluorescein stain, rebound tonometry, and occasionally binocular indirect funduscopy was performed within 1 week of presenting to the rehabilitation centers.

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Purpose: To evaluate the effect of increasing storage time on the inhibitory effects of canine and feline plasma on matrix metalloproteinases (MMP) 2 and 9 in vitro.

Methods: Matrix metalloproteinases 2 and 9 activity in the presence of canine plasma stored for 57, 155, 222, 316, 367, and 438 days, and feline plasma stored for 17, 198, 565, and 954 days was assayed using a commercially available colorimetric assay kit.

Results: For canine plasma, the MMP 2 activity for older samples was not significantly different than the 57-day sample (P = 0.

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Ophthalmoscopy is an important examination technique in the diagnosis of disease. Although it is difficult to learn, practice increases confidence and proficiency. Practicing ophthalmoscopy on live animals presents an additional level of complexity, so we sought to evaluate how students would respond to practicing ophthalmoscopy on an ocular fundus model.

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Cataract removal using phacoemulsification was performed in 10 loggerhead turtles being rehabilitated after stranding. All turtles had significant systemic abnormalities and had cataracts either at the time of rescue or developed them during rehabilitation. Surgical difficulties encountered included an extremely soft globe that did not allow for a partial thickness corneal incision, incomplete topical anesthesia of the ocular surface with proparacaine, inability to dilate the pupil pharmacologically, a markedly shallow anterior chamber, a thick posterior capsular plaque in most cases, and difficulty creating a watertight closure with sutures.

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Objective: To evaluate tissue levels, safety, and efficacy of topical ophthalmic 0.5% and 1% pirfenidone in decreasing subconjunctival fibrosis.

Animal Studied: Twelve normal beagle dogs PROCEDURES: A 5 × 1 mm diameter silicone disk was implanted subconjunctivally in one eye, and then dogs were treated with topical 0.

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Purpose: To investigate factors associated with long-term visual outcome in cats with hypertensive chorioretinopathy.

Animals Studied: Eighty-eight client-owned cats diagnosed with hypertensive chorioretinopathy.

Procedure: Medical records from cats with systemic hypertension and associated retinal lesions were reviewed.

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