Veterinary ophthalmology最新文献

Objective: To determine plasma concentrations of ophthalmic 0.1% (w/v) diclofenac sodium and 0.5% (w/v) ketorolac tromethamine following 4 times daily ophthalmic administration in healthy dogs.

Animals studied: Eight healthy research Beagles.

Procedures: A prospective, masked, randomized, crossover study was conducted. Eight dogs were randomly assigned to a diclofenac or ketorolac group (4 dogs per group). Plasma was collected before drug administration (time 0/baseline). Each dog received 0.05 mL, equivalent to one drop of diclofenac or ketorolac into both eyes 4 times daily for 5 days (4 am, 8 am, 12 pm, and 4 pm). Plasma samples were collected at 5, 15, 30, 60, 120, 240, and 360 min after the 4 pm treatment on Days 1 and 5. Plasma concentrations (ng/mL) were quantified by liquid chromatography-mass spectrometry and analyzed with noncompartmental pharmacokinetic analysis. A Wilcoxon signed rank test was used to determine statistical significance (p < 0.05).

Results: After ophthalmic administration of 0.1% diclofenac, mean t_1/2, T_max, and C_max occurred at 3.08 ± 0.9 h, 121.4 ± 2.8 h, 0.12 ± 0.05 μg/mL, respectively. The mean t_1/2, T_max, and C_max after 0.5% ketorolac administration were 18.5 ± 14.6 h, 121.6 ± 2.0 h, 1.8 ± 1.7 μg/mL, respectively. The AUC_0-∞ for diclofenac and ketorolac was 8.97 ± 3.73 μg/mL*h and 98.2 ± 43.3 μg/mL*h, respectively.

Conclusions: Diclofenac and ketorolac were rapidly absorbed systemically after ophthalmic administration. The half-life of topical ketorolac is six times longer than that of diclofenac.

Socioeconomic privilege significantly impacts access to the veterinary profession by creating barriers related to educational resources, exposure, mentorship, and financial challenges. Individuals from low socioeconomic backgrounds face systemic inequities that result in disparities in demographic representation, professional opportunities, and overall wellbeing within the profession. Addressing these challenges can bridge gaps in care, enhance recruitment, and cultivate a workforce that better reflects the communities it serves. These findings underscore the urgent need for innovative strategies to foster a more diverse and inclusive veterinary profession.

Objective: To describe the use of transcorneal iris photocoagulation (TCIP) to improve intraocular visualization of intended incision lines, reduce hemorrhage, and facilitate excision of pigmented iridal tumors in four canine eyes and one feline eye.

Materials and methods: A Rhodesian Ridgeback (treated bilaterally), a German Shepherd, a Labrador Retriever, and a Scottish Fold underwent sector iridectomy due to rapidly growing, pigmented, raised, iridal tumors affecting 1/4-1/3 of the iris circumference (3- to 4-clock hours). A diode laser was used to delineate the intended sector iridectomy incision lines, approximately 1-2 mm away from the grossly visible tumor margins, with the aim of improving visualization to achieve tumor-free margins and reduce tissue handling/trauma.

Results: All iridal tumors were removed en bloc with tumor-free margins on histopathology. The most common histologic diagnosis was iris melanocytoma (3/5 eyes). The most common intra- and postoperative complications included hyphema and fibrin clot formation (5/5), posterior synechia formation of iris wound margins (5/5 eyes), and photophobia (3/5 eyes). Two eyes required intracameral tissue plasminogen activator (tPA) injections within 2 weeks of surgery. The follow-up period for all operated eyes ranged from 5 to 14 months. Vision was retained in all eyes, with no grossly apparent tumor regrowth within the follow-up times included for each case in the present series.

Conclusions: The use of TCIP to delineate intended incision lines improved intraocular visualization of sector iridectomy surgical margins in this case series. While hyphema and fibrin clot formation still occurred, they were successfully managed.

This report describes the clinical, gross, histopathological, immunohistochemical, and therapeutic aspects of a spontaneous melanocytic iris melanoma in a rabbit, representing the first documented case of this condition in the species in the semiarid region of the state of Rio Grande do Norte, Brazil. A 2-year-old, mixed-breed female rabbit was referred to the Wildlife Department presenting an inadequate diet based on food intended for human consumption. According to the anamnesis, the patient had previously received ocular treatment but later developed bleeding in the right eye. On ophthalmic clinical examination, there was active hemorrhage and ocular rupture, leading to an indication for surgical enucleation. A transpalpebral enucleation was performed, and the eyeball was fixed in 10% buffered formalin and submitted for histopathological evaluation. Histopathological analysis revealed a moderately cellular, unencapsulated, and poorly demarcated neoplasm of the iris and ciliary body, composed of spindloid and anaplastic melanocytic cells containing brown granular pigment, with 12 mitotic figures observed in 2.37 mm². For immunohistochemical evaluation, melanin bleaching was performed, and a melanoma cocktail (HMB-45, Melan-A/MART-1, and Tyrosinase) along with the proliferation marker Ki-67 was used. The neoplastic cells showed diffuse cytoplasmic immunoreactivity for all melanocytic markers and nuclear labeling for Ki-67, with a nuclear proliferation index of 38%, confirming the diagnosis of melanocytic iris melanoma. Excision of the eyeball using the transpalpebral technique was effective in the treatment of this neoplasm, providing a favorable prognosis. This case highlights the importance of considering iris melanoma as a differential diagnosis for ocular lesions in rabbits.

Objective: To report the first documented case of high-grade optic chiasm and nerve oligodendroglioma in a young dog and contribute to the comparative study of gliomas in humans and canines.

Animal studied: A 29-month-old male intact German Shepherd.

Procedures: Over 2 months, the patient underwent repeated physical and ophthalmic examinations, systemic health assessments (complete blood count, serum biochemistry, urinalysis, and infectious disease testing), anesthetized MRI, ultrasound-guided biopsy of the left retrobulbar mass, and necropsy. Histopathologic and immunohistochemical analyses, including OLIG2 and GFAP immunohistochemistry, were performed.

Results: MRI evaluation identified a large, lobulated, asymmetric mass with retrobulbar involvement and compression of the optic chiasm and optic nerves. The mass exhibited hyperintense signals on T2-weighted and T2-FLAIR sequences, mixed intensity on T1-weighted imaging, and heterogeneous contrast enhancement, with areas of necrosis and meningeal enhancement suggestive of an aggressive neoplasm. Gross necropsy findings and histopathologic examination of post-mortem tissues confirmed the diagnosis of a high-grade oligodendroglioma, with tumor cells demonstrating marked nuclear atypia, high mitotic activity, and OLIG2 nuclear immunoreactivity.

Conclusions: The tumor's localization and histological characteristics suggested a primary origin within the optic pathway, differing from typical canine oligodendrogliomas. This case emphasizes the rarity of canine optic pathway oligodendrogliomas, a diagnosis that is similarly uncommon in human medicine. Dogs have been proposed as an intermediate animal model for human gliomas, and this case underscores the need for further molecular characterization of canine gliomas to improve diagnostic accuracy, therapeutic strategies, and comparative oncology insights.

Objective: Evaluate the efficacy of a therapeutic approach combining tacrolimus and hyaluronate-based lubricant for the management of evaporative dry eye disease (EDED) in dogs, compared to hyaluronate monotherapy.

Procedures: Fifty-four client-owned dogs with EDED were randomly assigned to three groups (n = 18 each): Group 1 received 0.03% tacrolimus and 0.3% hyaluronate twice daily; Group 2 received 0.3% hyaluronate four times daily; and Group 3 received 0.3% hyaluronate twice daily. Blink rate, clinical scoring, corneal esthesiometry, Schirmer tear test, tear film breakup time (TFBUT), punctate fluorescein staining, lissamine green staining, and owner-reported symptoms were assessed at baseline, 15, and 45 days after initiating therapy.

Results: Group 1 showed the most significant improvements, with TFBUT increasing by +57% by Day 15 and + 93% by Day 45, accompanied by notable reductions in ocular discharge and conjunctival hyperemia. Most ocular changes and owner-reported symptoms improved more rapidly and with greater amplitude in Group 1. Although Groups 2 and 3 also improved, changes were less pronounced despite the higher dosing frequency in Group 2. Neither corneal sensitivity nor corneal changes (fibrosis, neovascularization, pigmentation, and edema) showed significant variation in any group.

Conclusions: Dogs receiving combined tacrolimus and hyaluronate treatment showed faster and more pronounced improvements in both objective and subjective assessments of ocular health. These findings underscore the importance of addressing both the immunologic aspects and tear film instability associated with EDED, particularly in cases where inflammation plays a significant role. Future studies should directly evaluate tacrolimus monotherapy and explore different tacrolimus formulations and vehicles.

Objective: To visualize corneal endothelial cells in enucleated porcine eyes using slit-lamp imaging with a mobile smartphone (SLiM), determine optimal illumination conditions, and explore agreement between SLiM and vital dye stained imaging.

Animals studied: Twelve enucleated porcine eyes.

Procedures: Corneal endothelium imaging conditions of the SLiM were varied by adjusting the angle between the illumination unit and microscope unit (AIM), slit-width (SW), and light intensity (LI). Subsequently, the corneal endothelium was stained with a vital dye as a reference. SLiM image quality was graded to identify optimal conditions. Endothelial cell density (ECD), percentage of hexagonal cells (HEX), and the coefficient of variation in cell area (CV) were compared between SLiM and stained images.

Results: The cumulative link mixed model showed that AIM, SW, and LI significantly influenced the image quality. Image quality grades were significantly higher with 60° AIM than with 40° or 80° AIM (p < 0.001) and lower with 7 mm SW than with 3 or 5 mm (p < 0.001). High and medium LI produced higher grades than full LI (p < 0.05), whereas Low LI significantly reduced image quality (p < 0.001). SW and LI had a statistically significant interaction effect on image quality grades. Best-performing conditions were 60° AIM, 3 mm SW, and high LI. ECD, HEX, and CV values obtained from SLiM and vital dye stained images were comparable in three selected eyes.

Conclusions: SLiM was feasible for imaging porcine corneal endothelial cells, with optimal image quality achieved under specific illumination conditions.

Objective: To evaluate the accuracy and clinical applicability of the handheld autorefractor Retinomax K+ Screen in comparison to manual streak retinoscopy in non-cyclopleged dogs.

Methods: Thirty-four dogs (68 eyes) of 15 different breeds underwent comprehensive ophthalmic examination and refractive assessment using streak retinoscopy and handheld autorefraction. Statistical analyses included the Wilcoxon signed-rank test, Bland-Altman analysis, and Spearman's rank correlation (α = 0.05).

Results: Autorefraction was successfully performed in 57 of 68 eyes; 11 eyes were excluded due to insufficient measurement quality. Retinoscopy yielded a mean spherical equivalent of 0.13 ± 1.04 diopters (D), while autorefraction produced significantly more hyperopic values (mean 0.98 ± 1.66 D; p < 0.001). Bland-Altman analysis demonstrated wide limits of agreement (-2.52 to +4.10 D), indicating substantial variability. A moderate positive correlation was found between methods (ρ = 0.49; p < 0.001).

Conclusions: The Retinomax K+ Screen provides rapid, non-invasive refractive measurements but systematically overestimates hyperopia and exhibits considerable variability compared to retinoscopy. Despite fast acquisition, inconsistent results and reduced reliability under suboptimal conditions limit the clinical precision of the autorefractor and its use as a screening tool appears questionable under clinical conditions.

Objective: To describe the ocular morphological characteristics and establish clinical and ophthalmic reference standards for Nile tilapia.

Animals studied: Fresh carcasses were used for diaphanization, optical and electron microscopy, and computed tomography analyses. For clinical and ultrasonographic evaluations, 75 adult Nile tilapias of undetermined sex were examined.

Procedure: Standard diaphanization, optical and electron microscopy, and computed tomography techniques were applied to fresh carcasses of Nile tilapia. Live fish were chemically restrained using propofol. Ophthalmic evaluations included slit-lamp biomicroscopy, direct ophthalmoscopy, fluorescein staining, and rebound tonometry for intraocular pressure measurement. Ocular ultrasonographic measurements were obtained from both eyes of three individuals.

Results: The diaphanization technique revealed a scleral ring composed of two cartilaginous ossicles (dorsal and ventral) connected by two bony ossicles (rostral and caudal). Microscopic analysis identified the fibrous tunic (comprising the cornea and sclera), the vascular tunic (including the iris and choroid), and the nervous tunic (represented by the retina). Clinical evaluation of Nile tilapia showed no ocular lesions, with a mean intraocular pressure of 7.74 mmHg. Ultrasonography effectively assessed intraocular and retrobulbar structures, while computed tomography enabled visualization and measurement of the eyeballs, lens, and vitreous chamber in sagittal, axial, and coronal planes.

Conclusions: The ocular structures of Nile tilapia, including the cornea, lens, retina, and iris, are similar to those observed in other teleost species. Clinical evaluation methods, such as ultrasonography, slit-lamp biomicroscopy, and rebound tonometry appear to be reliable diagnostic methods in fish ophthalmology. The data presented in this study are novel for Nile tilapia.