Veterinary ophthalmology最新文献

Objective: Determine the effect of oral macrocyclic lactone heartworm-preventative medications on retinal function and chromatic pupillary light reflex (cPLR) in healthy dogs.

Animals studied: Cross-sectional retrospective: 60 dogs (n = 33 females) with heartworm medication administration status and electroretinogram (ERG) data available. Prospective clinical study: 25 dogs (n = 10 females) had ERG performed, 18 of which had cPLR performed.

Procedures: Retrospective: ERG amplitudes/peak times were compared between dogs that had or had not received oral heartworm preventatives. Bivariate and multiple variable linear regression models were used to evaluate relationships between ERG testing and heartworm preventive administration status, age, and sex.

Prospective: ERG and cPLR testing were performed at a baseline visit (minimum 14 days since last preventative administration), and a second visit where ERG/cPLR testing was performed 4 h after oral preventative administration. Mixed effects models and Mann-Whitney U statistics were performed.

Results: Retrospective: There was no association between heartworm preventive administration status and ERG amplitudes or peak times (all p-values > 0.12).

Prospective: Heartworm preventative had no effect on light- and dark-adapted ERG amplitudes or peak times (all p-values > 0.56). Similarly, there was no effect on baseline pupil size (p = 0.83), nor on cPLR (p = 0.32).

Conclusion: No significant effects of oral macrocyclic lactones on retinal/cPLR function at preventative doses were identified. While small effects on retinal/cPLR function cannot be completely ruled out, it remains unlikely that these medications cause clinically significant visual deficits at prescribed doses, and proven antiparasitic benefits likely far outweigh small potential ophthalmic risks of administration.

Objective: To describe the case of a 12-year-old male African lion (Panthera leo) presented with ocular discharge, corneal edema, and buphthalmos of the right eye.

Procedures: Ocular ultrasonography showed an intraocular mass involving the iris and ciliary body. Enucleation was performed.

Results: Subsequent histopathological analysis revealed a pleomorphic pigmented neoplastic cell population infiltrating, expanding and effacing the iris and ciliary body and occupying the ciliary cleft. The histopathological and immunohistochemical features were consistent with a diffuse iris melanoma (DIM).

Conclusion: DIM is the most common primary intraocular neoplasm of domestic cats, but rarely reported in large felids. The prognosis in large felids is unknown and warrants identifying additional cases and careful monitoring of affected individuals.

Objective: To describe the ocular findings in dogs and cats after chemical injury by the Bronze Orange Bug (Musgraveia sulciventris), which is endemic to eastern Australia in Queensland and New South Wales.

Animals studied: Medical records were reviewed for the keywords "stink bug" between February 2013 and January 2023. Signalment, clinical signs, month at presentation, and affected eye(s) were recorded. Cases were divided into confirmed and suspected cases.

Results: Twenty-four confirmed and nine suspected cases were identified, consisting of 26 dogs and seven cats. There were 19 females (57.6%) and 14 males (42.4%). Median age at presentation was 1.9 (range 0.16-12.5) years, with a median weight of 6.1 (range 1.3-25) kilograms. All cases presented between August and May, with the majority (75.7%) presenting in summer. This correlates with the breeding life cycle of the Bronze Orange Bug. Unilateral presentation was more common (97%; n = 32) than bilateral (3%; n = 1) with an increased incidence of left eyes (60.6%; n = 20) compared to right eyes (36.4%; n = 12). Presenting signs included acute onset blepharospasm (100%), superficial corneal ulceration (90.9%), conjunctival hyperemia (87.8%), chemosis (60.6%), periocular swelling (51.5%), conjunctival ulceration (39.4%), third eyelid protrusion (39.4%), miosis (36.4%), corneal edema (36.4%), and aqueous flare (24.2%). The median time to resolution of clinical signs was 13 days.

Conclusions: The Bronze Orange Bug's defensive secretion causes acute onset ocular irritation consistent with acidic chemical burns in dogs and cats. Bronze Orange Bug exposure should be considered as a differential diagnosis in endemic areas, particularly during the summer months.

Objective: To determine factors that may affect the onset of glaucoma in the unaffected, contralateral eye of dogs with primary angle-closure glaucoma (PACG).

Animal studied: One hundred and seventeen dogs unilaterally affected by PACG.

Procedures: Multicenter retrospective study. Patient factors, examination findings, prophylactic treatments, and treatment failure dates were recorded. Treatment failure was defined as glaucoma onset in the contralateral eye (IOP > 25 mmHg); death prior to a second diagnosis was treated as a competing risk. Cumulative incidence plots and Cox proportional hazard models were used to visualize and test for associations between baseline characteristics and time to treatment failure.

Results: Mean age at first diagnosis was 8.3 years and 69.2% were female. Within 5 years, 70.9% of dogs with unilateral PACG developed glaucoma in the contralateral eye. Median time to treatment failure was 2.15 years. The most common purebred dogs were the Cocker Spaniel, Basset Hound, and Shih Tzu. Dogs with an initial diagnosis in the left eye had a 1.8-fold increased risk of treatment failure of the right eye. Time to treatment failure was not different between dogs receiving prophylactic topical carbonic anhydrase inhibitors versus beta-blockers, nor in dogs receiving versus not receiving topical corticosteroids.

Conclusions: No treatment regimen was found to be superior to another for PACG prophylaxis. Future prospective studies are warranted to investigate complementary glaucoma management strategies.

Purpose: To describe five cases of orbital lipoma in which surgery was successful and no long-term recurrence was observed.

Methods: A review of the medical records of dogs presenting with signs of orbital or periorbital disease and diagnosed with orbital lipoma in different practices in Spain and France was performed.

Results: Five cases with a mean (±SD) age of 9.32 (±1.95) years and different breeds were included. Three cases were referred for periocular mass, one for conjunctival mass, and one for exophthalmos. Computed tomography (CT) was performed in all cases and showed a well-defined hypoattenuating mass, not continuous with the orbital fat, compatible with orbital lipoma. Surgical management was based on the size and location of the lipomas. In all cases, the mass could be removed by blunt dissection. Histopathology confirmed fibrolipoma in two cases (one case with associated bone metaplasia), one simple lipoma, one infiltrating lipoma, and one chondrolipoma. Postoperative follow-up was uneventful, with no recurrence over 2 years after surgery in all cases.

Conclusion: Orbital and periorbital lipomas and their variants, although rare, may occur in dogs with clinical signs of orbital neoplasia. CT scan can predict the nature of the lesion as a lipoma. Surgical treatment is successful, with no recurrence more than 2 years after surgery. Histopathology is essential to determine the type of lipoma variant.

Objective: To describe a medial orbital reconstruction using titanium mesh after surgical excision of a multilobular osteochondrosarcoma (MLO) in a dog.

Study design: Case report.

Methods: A 9-year-old, castrated, male Siberian Husky was treated for left orbital MLO causing left enophthalmia and lateral displacement of the left globe. A surgical excision was completed, with preservation of the globe. The medial orbit was reconstructed with titanium mesh.

Results: The patient recovered uneventfully. Histopathology confirmed MLO, grade II with complete excision. At the 2-week follow-up, there was persistent mild enophthalmia, but the patient was asymptomatic. No thoracic metastasis, local recurrence or enophthalmia was noted at the 6 months recheck.

Conclusion: The use of titanium mesh restored the medial orbit and provided excellent functional and cosmetic outcomes. No major complications were noted up to 6 months postoperatively.

Clinical significance: Titanium mesh can be used to reconstruct the medial aspect of the orbit in dogs.

Over 25% of people in the United States are affected by physical disabilities, leading to regular interactions between the disabled community and veterinary ophthalmology. However, various barriers hinder individuals with disabilities from accessing care for their pets, working in veterinary clinics, pursuing training as veterinarians and veterinary ophthalmologists, and continuing their careers as disabilities develop. This article explores strategies for the veterinary ophthalmology community to implement positive changes that enhance access and inclusivity within clinics and the profession at practical, institutional, and cultural levels.

Objective: To investigate the effects of a 0.02 mg/kg dose of intravenous buprenorphine on various ocular parameters in healthy dogs.

Animals: 25 healthy, client-owned dogs.

Methods: Objective parameters (intraocular pressure [IOP], pupil size [PS]) and subjective parameters (menace response, dazzle reflex, corneal reflex, globe position, and third eyelid position) were measured prior to and following administration of buprenorphine. Baseline data was first established by measuring ocular parameters 20 min prior to (T_-20) and immediately before (T₀) intravenous administration of a 0.02 mg/kg dose of buprenorphine. Data was then collected again at 10, 20, 30, and 45 min post-administration (T₁₀, T₂₀, T₃₀, and T₄₅ respectively).

Results: There was no significant change in any parameter measured in the baseline data, between T_-20 and T₀. No significant change was observed in the subjective parameters at any of the time points measured in the post-drug administration period. There was a significant decrease in PS between T₀ and T₁₀ (p < .05) which continued to decrease significantly across timepoints. Both eyes showed a significant, but transient increase in IOP. This increase was followed by a significant decrease in IOP OD and an approaching significant decrease in IOP OS. All variations in IOP remained within the normal canine range.

Conclusions: A 0.02 mg/kg dose of intravenous buprenorphine impacts both PS and IOP and, therefore, should be used with caution in select diseases where effects on pupil size and intraocular pressure may cause additional harm.

Objective: To describe a novel minimally invasive surgical approach to treatment of a nasolacrimal duct cyst in a dog and outcome.

Animal studied: A 10-year-old, male entire, Springer Spaniel with a chronic right-sided maxillary swelling and associated right eye epiphora and sneezing.

Procedure: Computed tomography with dacryocystography confirmed a cystic structure and destruction of the right maxilla and zygomatic bone with invasion of the nasal cavity. Obstruction of the nasolacrimal duct was confirmed. Rhinoscopy was performed allowing visualization of the ventromedial wall of the cyst. Under direct visualization, dacryocystorhinostomy was performed and the wall of the cyst was ablated with the aid of a thulium laser fiber.

Results: No intraoperative complications occurred during the procedure. Full resolution of clinical signs was noted within 2 weeks of treatment. No recurrence had occurred on long-term follow-up at 32 months.

Conclusions: Laser-assisted dacrocystorhinostomy under direct visualization was successful in the treatment and resolution of a nasolacrimal duct cyst (dacryops) in this case.

Purpose: To determine whether the differences in intraocular pressure (IOP) change after the topical application of 0.5% tropicamide and 0.5% phenylephrine (TP) are due to anatomical variations in the anterior chamber using ultrasound biomicroscopy (UBM).

Methods: Prospective clinical data from 27 eyes of 14 dogs with normal eye conditions were analyzed. IOP and UBM measurements were taken before and 30 min after administering a topical TP. Dogs were categorized into two groups based on an IOP increase criterion of 4 mmHg: the high group and the stable group. Parameters measured included the iridocorneal angle (ICA), angle-opening distance (AOD), ciliary cleft width (CCW), length (CCL), area (CCA), ciliary body axial length (CBAXL), and ciliary process-sclera angle (CPSA).

Results: Both groups showed a statistically significant decrease in ICA and an increase in AOD. However, in the stable group, CPSA increased, CBAXL decreased, and CCA increased, whereas in the high group, CPSA and CBAXL did not change significantly, and CCA decreased.

Conclusion: In the stable group, although the pupil dilated, the ciliary body relaxed, leading to an increase in the CCA. Conversely, in the high group, the pupil dilated, and the ciliary body remained unrelaxed, resulting in a reduction in the CCA. These iridociliary changes with pupil dilation increase the risk of elevated IOP. Therefore, an increase in IOP following TP administration may serve as a prognostic indicator for possible glaucoma risk.