Veterinary ophthalmology最新文献

Purpose: To investigate antibiotic usage practices in ophthalmic surgeries in Germany.

Materials and methods: An online questionnaire was sent to veterinary surgeons (general veterinarians and veterinarians with additional qualification in ophthalmology) inquiring about their antibiotic preferences, administration methods, and factors affecting antibiotic usage in ophthalmic surgical procedures.

Results: A total of 417 questionnaires were analyzed. Postoperative antibiotics (systemic/topical in percent when used) were used all or most of the time by 69% of veterinarians following enucleation (99/6), by 62% after eyelid surgery (54/69), by 68% after third eyelid (TEL) surgery (19/92) and by 80% after keratectomy (6/99). The most commonly used systemic antibiotic was amoxicillin with clavulanic acid and the most commonly used topical antibiotic was chloramphenicol. WHO "watch-group" antibiotics were infrequently administered systemically but frequently utilized topically; including in 13% of eyelid surgery, 15% of TEL surgery, and 35% of keratectomies. Factors influencing antibiotic use included fear of complications (67%), personal experience (63%), diagnostic uncertainty (21%), and owner expectations (9%). Participants following institutional guidelines used fewer antibiotics in enucleations (p = .002) and were less likely to choose fluoroquinolones post-eyelid surgery (p = .044).

Conclusion: The potential for reducing antibiotic use following ophthalmic soft tissue surgery is significant. Addressing barriers such as concerns about postoperative complications and the reliance on individual clinical experience, the implementation of standardized guidelines could facilitate a shift toward more judicious antibiotic practices.

Objective: To further investigate quantitative and qualitative tear-film dynamics through tear-film osmolarity, meibometry, meibography, and non-invasive tear-film break-up time and to describe a survey of parameters in normal eyes of healthy non-brachycephalic dogs.

Animals studied: Thirty-two veterinary hospital staff and student owned dogs between 1 and 7 years with no known comorbidities or ocular disease.

Procedure: Complete ophthalmic examination, tear-film osmolarity (I-PEN® VET), meibometry (Meibometer MB560), meibography, and non-invasive tear-film break-up time (handheld Ocular Surface Analyzer) were performed. Significance threshold was 0.05. Q-Q plots and histograms were used to assess normality of measurements. Data were summarized descriptively with mean, standard deviation, median, and interquartile range (IQR). Pearson and Spearman's correlations were used to test for correlations between diagnostics with each other and tear-film break-up times.

Results: Thirty-two dogs (64 eyes) met the inclusion criteria. Mean tear-film osmolarity level was 293.6 ± 14.1 mOsm/L (IQR 282.5-302.3). Median meibomian lipid level was 30.4 Meibometry Units (MU) (IQR 11.5-59.1). Median percent loss of meibomian glands in the upper eyelids was 25.3% (IQR 13.5-26.8). Median percent loss of meibomian glands in the lower eyelids was 26.0% (IQR 13.5-52.3). Automatic assessment of meibomian gland loss showed that grade 0 was present in 4/128 (3.1%) eyelids, grade 1 in 78/128 (60.9%) eyelids, grade 2 in 30/128 (23.4%) eyelids, and grade 3 in 16/128 (12.5%) eyelids.

Conclusions: Tear-film osmolarity, meibometry, meibography, and non-invasive tear break-up time can easily be incorporated into routine ophthalmic examinations to provide clinical information about meibomian gland morphology and function.

Purpose: To determine the load at failure of canine intact cadaveric eyes and to describe the anatomic location and length of the rupture following external compression.

Animals studied: Sixty-six canine cadaveric globes.

Procedures: Globes were subjected to an axial force impacting the cornea or equator using a commercially available mechanical testing unit. Following rupture, eyes were inspected to document the anatomical site and length of rupture.

Results: The mean ± SD force necessary to induce scleral rupture was 310 ± 120 N OD and 294 ± 113 N OS. Increasing body weight (OD p = .000015, OS p = .0074) as well as cranial-to-caudal (OD p = .000045, OS p = .0075) and medial-to-lateral (OD p = .00027, OS p = .0083) globe diameter were associated with a higher force necessary to induce rupture. The median (25%, 75%) length of the scleral rupture was 8.5 (7.0, 11.0) mm OS and 10 (7.0, 12.5) mm OD. The median location was 8.0 (5.0, 10.0) mm posterior to the limbus at the most cranial extent OS and 6.5 (3.3, 10.0) mm OD. Rupture orientation in relation to the limbus was perpendicular (n = 35), parallel (n = 13), or other (n = 16). Globe laterality (i.e., OD or OS), sex, and age did not have a significant influence on the force necessary to induce rupture (p > .05).

Conclusions: Following external compression, the canine globe frequently ruptures in a region approximating the equator extending 1 cm posteriorly, which may not be readily apparent on clinical examination.

Objective: To analyze bacterial isolates associated with canine bacterial keratitis and their antibiotic susceptibility patterns in Korea, focusing on multidrug resistance (MDR) and identifying effective antibiotic combinations for clinical treatment.

Animal studied: A total of 146 dogs diagnosed with suspected bacterial keratitis between October 2022 and October 2023 in Korea, with 157 eye samples collected for analysis.

Procedure: Eye samples were cultured to isolate bacteria, and antibiotic susceptibility testing was performed using the minimum inhibitory concentration (MIC) method. Bacterial identification was conducted using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF). The study assessed the efficacy of individual antibiotics and combination therapies.

Results: Bacteria were isolated in 55.4% of the samples. The most common genera were Staphylococcus species (48.5%, 48/99), Streptococcus species (13.1%, 13/99), Pseudomonas species (9.1%, 9/99), and Escherichia coli (9.1%, 9/99). Amikacin (84.8%) showed the highest antibiotic susceptibility, while doxycycline exhibited the lowest (17.2%). The most effective antibiotic combinations were amikacin-moxifloxacin (93%). MDR isolates accounted for 52.5% (52/99) of the total bacterial samples.

Conclusions: Staphylococcus species were the most common isolates, with 52.5% showing MDR, underscoring the need to curb antibiotic misuse. While antibiotics like amikacin demonstrated high susceptibility rates, their use should be reserved for resistant infections to prevent further resistance development. Rather than focusing solely on finding effective combinations of antibiotics, it is crucial to consider alternative treatment strategies that offer more sustainable solutions. Rather than relying on antibiotic combinations, attention should shift to sustainable alternatives to treat bacterial keratitis and reduce antibiotic dependence in clinical practice.

Objective: To describe a novel surgical approach to conjunctivorhinostomy for feline nasolacrimal duct obstruction.

Animal studied: A client-owned 4-year-old female spayed domestic shorthair cat presented with chronic unilateral nasolacrimal duct obstruction of the right eye.

Methods: Following obstruction confirmation via complete ophthalmic examination and dacryocystorhinography, conjunctivorhinostomy was performed under general anesthesia, and an indwelling sub-palpebral lavage (SPL) line was placed to facilitate the formation of a new pathway for tear drainage. Specifically, the SPL footplate was sutured to the ventral conjunctival fornix with 5-0 nylon and 6-0 vicryl while the tubing was passed through the new pathway and the distal end of the tubing trimmed and tucked into a perinasal subcutaneous pocket. Two skin sutures closed the perinasal pocket and were removed 2 weeks postoperatively.

Results: No immediate postoperative complications occurred. At 6 weeks and 6 months postoperatively, the distal SPL tubing was dislodged and visible out of the right nostril. This was uneventfully trimmed shorter, and no further complications occurred. The SPL component was easily removed 11 months postoperatively without complication. The patient's clinical signs dramatically improved; she was comfortable over 2 years after surgery.

Conclusion: To the authors' knowledge, this is the first report of using an SPL as an indwelling catheter for nasolacrimal duct surgery via conjunctivorhinostomy in a cat. This technique eliminated external stent sites for the patient, which was associated with a short use of an e-collar, and utilized materials readily available in a specialty hospital.

Objective: Prospective observational study with preregistered study protocol to assess interexaminer agreement using the 2022 European College of Veterinary Ophthalmologists Hereditary Eye Disease (ECVO-HED) gonioscopy grading scheme.

Animals studied: Sixty client-owned dogs presented for gonioscopy as part of the required certification process prior to breeding.

Procedure: Two ECVO diplomates with comparable clinical experience performed gonioscopy with a Koeppe gonioscopy lens and slit-lamp biomicroscope at 10x magnification on all eyes in a randomized fashion.

Results: One hundred and eighteen of 120 eyes (60 dogs) were included. In 110/118 eyes (93%), both examiners provided the same breeding recommendation (yes/no). This translated into an agreement on the final breeding recommendation in 58/60 dogs (97%). Examiners disagreed on pectinate ligament abnormality (PLA) grading in 19/118 eyes and iridocorneal angle width (ICAW) grading in 9/118 eyes. PLA grading disagreement was mostly observed between neighboring grades. Disagreement between PLA and ICAW grading sometimes occurred within the same eye accounting for an observed disagreement in iridocorneal angle abnormality (ICAA) grading in 19/118 eyes in total. Cohen's kappa was Κ = 0.62 (95% TI 0.34-0.89), whereas maximum kappa was maxΚ = 0.82 (95% TI 0.59-1). Mixed model analysis suggested no significant examiner influence on breeding recommendations (OR 0.17; 95% CI 0.02-1.12, p = .09).

Conclusions: Although examiners disagreed on ICAA grading in 19/118 eyes, this resulted in a different breeding recommendation (yes/no) in eight eyes and in two dogs only. Therefore, the use of the 2022 ECVO-HED gonioscopy grading scheme seems to result in examiners providing the same breeding recommendations in most cases.

Objective: To describe a case of presumed band keratopathy in a young cat with no known history of corneal disease who was not receiving topical phosphate-based steroids.

Animal studied: A 10-month-old domestic shorthair cat was evaluated for severe ocular discomfort that did not improve despite the initiation of topical antibiotic treatment.

Methods: A complete ophthalmic examination and ancillary tests such as biomicroscopy and corneal cytology were performed at the time of presentation. A superficial lamellar keratectomy was excised, and the corneal button was sent for histopathology. In addition to routine hematoxylin-eosin staining, sections were stained with Gram, PAS, von Kossa, and trichrome stains.

Results: Biomicroscopic examination revealed an extensive corneal epithelial ulcer with a hard white plaque in the central area of the right cornea with associated superficial neovascularization. Ultrasound biomicroscopy showed a 0.63 mm, slightly hyperechoic band in the anterior corneal stroma. Corneal cytology evidenced numerous neutrophils with toxic changes and few macrophages. Histopathologic analysis excluded corneal sequestration as a differential diagnosis and confirmed superficial corneal mineralization. At the last follow-up, 16 months after surgery, corneal transparency had returned, and visual acuity was good with some corneal conjunctivalization.

Conclusions: In this case report, the presumptive diagnosis is calcific band keratopathy. To the best of the author's knowledge, this is the first presumed case in a cat not receiving topical phosphate-based steroids and without previous corneal damage. Lamellar keratectomy represents a curative approach that successfully resolved the clinical signs, with no reported recurrence.

Objective: To evaluate the success and failure rate of photoactivated chromophore for keratitis-corneal cross-linking (PACK-CXL) therapy in a single population of dogs and cats. To identify the usefulness of the PACK-CXL based on ulcer depth and establish a cutoff at which this procedure could be recommended. To analyze the influence of the different variables in corneal healing time and to report the presence of secondary endothelial damage and cataract formation.

Materials and methods: Medical records of dogs and cats with presumptive infectious keratitis which underwent accelerated epithelium-off PACK-CXL between 2016 and 2023 were reviewed and analyzed.

Results: Records for 369 animals were included, and the overall success rate for healing was 97% (range 4-74 days and no rescue procedure). The second success (re-epithelialization <30 days and no rescue procedure) rate was 86%, and a total of 40 eyes needed more than 1 month for the corneal repair. Corneal ulcers were classified in three categories based on the depth: 0%-33% (46%), 34%-66% (37.4%), and 67%-100% (16.5%). The cutoff at which PACK-CXL had a higher probability of failure was with ulcer depth >66.5%. Animals who suffered from keratomalacia and hypopyon at presentation, or were treated with topical serum or gentamicin after PACK-CXL showed an increase in epithelial healing time (EHT). Increasing age, brachycephalic conformation, keratomalacia alone, and deeper ulcers were identified as risk factors for the treatment outcome. Secondary endothelial injury or cataract formation was not noted in this study.

Conclusions: Accelerated PACK-CXL is a non-invasive, adjunctive treatment to medical therapy, which can be used in presumed infectious keratitis with a high probability of success. However, it is important to take in consideration the patient age, skull conformation, presence of keratomalacia, and the ulcer depth.

Objective: To map the disease locus for familial ocular melanosis (OM) in the Cairn Terrier.

Animals studied: Cairn Terriers with OM and normal control dogs.

Procedure: A genome-wide association study (GWAS) was performed using 63 OM-affected and 31 control Cairn Terriers, followed by haplotype analysis. A significantly associated single-nucleotide polymorphism was genotyped in a larger group of OM-affected and control Cairn Terriers. The coding and splice-site regions of genes mapping within the confidence interval were sequenced.

Results: A ~9.2 Mb region of chromosome 11 was significantly associated with OM. Haplotype analysis narrowed the region to 1.49 Mb. Genotyping of a SNP within the region showed 86% of OM-affected dogs were homozygous or heterozygous for the risk allele, whereas 78% of unaffected dogs were homozygous for the nonrisk allele. Sequencing of the coding regions and splice sites of four genes (c9orf72, IFNK, the 5' end of MOB3B, and the 3' end of LINGO2) and of a microRNA (MIR876) did not detect any genetic variants unique to OM-affected dogs.

Conclusion: OM in Cairn Terriers maps to a 1.49 Mb region of chromosome 11. This accounts for 86% of OM cases in our DNA bank. A second locus may account for the OM phenotype in the remaining 14% of cases. Sequencing of coding regions and splice sites of positional candidate genes and a microRNA did not reveal any genetic variants unique to affected dogs. Further studies are required to elucidate the DNA variant causal for OM in Cairn Terriers and to understand the disease mechanism.

Purpose: The purpose of this study is to describe modification of the lateral enucleation technique without ligation or clamping of the optic nerve, document the incidence of complications, estimate intraoperative blood loss and identify possible risk factors for the developments of complications.

Methods: Medical records of dogs, cats, and rabbits undergoing lateral enucleation without clamping of the optic nerve were identified and retrospectively reviewed for post-operative complications (2000-2022). The significance of possible risk factors for the development of complications, including species, sex, age, eye, surgeon, presumed ocular surface infection, cultures, follow-up, antibiotics, NSAIDs, complications and diabetes mellitus was examined in a subset of these patients (2019-2022). As a prospective study, intraoperative blood loss was estimated by gravimetric analysis in an additional subset.

Results: Records of 1296 enucleations were retrospectively reviewed and detailed evaluation regarding potential risk factors was performed in 446 enucleations. The overall complication rate and surgical site infection rate was 2.31% and 2.08% respectively. Only Pseudomonas spp. bacterial culture was associated with development of complications. Estimated relative intraoperative blood loss was 2.2% and 4.1% in 43 dogs and 29 cats respectively.

Conclusions: The modified lateral enucleation technique is a safe and fast procedure with minimal risk of postoperative complications in dogs, cats, and rabbits. Based on the anatomy of the orbital vasculature ligation or clamping of the optic nerve and surrounding tissue is contraindicated.