Veterinary ophthalmology最新文献

Objective: Cone-rod dystrophy (cord1) is a form of progressive retinal atrophy. It is linked to an RPGRIP1 genetic variant which is the third most common canine disease variant thus far. While the variant affects various breeds, it is highly prevalent in English Springer Spaniels (ESSs). Yet its clinical and pathological implications remain equivocal. Herein, we study the retinal phenotype in ESSs genetically affected with the RPGRIP1 variant.

Animal studied: Over 4 years, 494 ESSs (123 affected) were enrolled.

Procedure(s): Owner-perceived vision was collected via a questionnaire. Ophthalmic examination included fundus photography. In selected ESSs, retinal function and structure were assessed using electroretinography (ERG, 148 dogs) and optical coherence tomography (OCT, 4 dogs).

Results: Ophthalmoscopic changes included peripheral hypo-reflective lesions often with distinct borders progressing centripetally culminating in generalized retinal atrophy. Cross-sectional study revealed declining photopic ERG amplitudes with age in the affected group but not in controls. OCT indicated progressive photoreceptor loss. Despite ophthalmoscopic, ERG, or OCT abnormalities, most affected dogs were not visually impaired per their owners. In a fraction of afflicted ESSs, vision/globe-threatening complications were documented including cataracts, lens luxation, and glaucoma.

Conclusions: In ESSs, the RPGRIP1 variant is associated with insidious pathology with delayed-onset visual defects. The subtle phenotype without apparent visual deficit until the final years of life, if at all, may have caused underdiagnosis of cord1. Still, DNA testing remains informative, and ERG and OCT indicate progressive pathology. Peripheral fundus examination and photopic ERG are particularly useful for early detection and monitoring of cord1.

Purpose: To describe the first report of third eyelid cartilage eversion in an adult American Quarter Horse mare.

Case presentation: A 22-year-old American Quarter Horse mare presented to the University of Missouri Veterinary Health Center Equine Hospital for a 2-week history of a third eyelid cartilage abnormality of the left eye with no known recent trauma. Complete ophthalmic examination revealed third eyelid cartilage eversion of the left nictitans. The abnormal scrolled cartilage was surgically excised using a handheld cautery unit and submitted for histopathologic evaluation.

Results: Histopathologic findings displayed normal third eyelid cartilage, without evidence of neoplasia or inflammation. Mucosal hyperplasia and increased vascularity of the submucosa were observed. The horse healed well after electrocautery excision and normal third eyelid conformation was restored.

Conclusion: To the authors' knowledge, this is the first report of an acquired, presumed spontaneous, third eyelid cartilage eversion in a horse.

Objective: To determine the replication kinetics and cytopathic effect (CPE) of feline calicivirus (FCV) in feline corneal epithelial cells (FCEC).

Animals studied: Seven archived FCV isolates and one archived feline herpesvirus type 1 (FHV-1) isolate, previously obtained from eight domestic short hair cats.

Procedures: FCV RNA was extracted for sequencing using Illumina MiSeq, to identify three genomically diverse isolates for further testing. Following reference-based assembly, viral genomes were annotated and assessed. Superficial keratectomies were performed to isolate the corneal epithelium of cats and the cells were cultured in vitro. FCEC were infected with the three chosen FCV isolates and one FHV-1 isolate at two different multiplicity of infection ratios (MOIs, 0.1 and 0.01 PFU/cell) and virus titration was assessed at 0, 2, 6, 12, 24, and 48 h post-infection (hpi). Viral identity was confirmed by RT-qPCR.

Results: Three genomically diverse FCV isolates were chosen for further assessment in the FCEC model. All infections of FCEC with FCV led to visible CPE, characterized by epithelial cell rounding and detachment from the plate by 24 hpi, while FHV-1 led to visible CPE within 48 hpi. All three of the FCV isolates replicated effectively in FCEC at both 0.1 and 0.01 MOI, with a peak increase in titer approximately 12-24 hpi.

Conclusions: The results support the possible role of FCV as a primary pathogen of the feline ocular surface. FCV replicates in FCEC in vitro, leading to profound CPE.

The surgical reconstruction of severe corneal ulcers is a common and crucial component of the clinical practice of veterinary ophthalmology. Numerous surgical techniques are used in dogs for corneal reconstruction, and these techniques may be categorized by the material used to repair the corneal lesion. The first part of the present review described procedures that utilize autogenous ocular tissues, homologous donor tissues, and heterologous donor tissues. In this second part of the review, the categories of biomaterials and keratoprosthetics will be summarized. Biomaterials that are reported for use in dogs include amniotic membrane, porcine urinary bladder acellular matrix, porcine small intestinal submucosa, acellular porcine corneal stroma, and other miscellaneous soft tissue and cartilage grafts (e.g., preserved equine renal capsule, autologous omentum, autologous buccal mucosa membrane, bovine pericardium, and homologous peritoneum). Descriptions of keratoprosthesis surgery in dogs are currently limited, but the use of artificial corneal transplants hold promise for dogs with severe, vision-compromising corneal disease that is not amenable to other reconstruction techniques. This review describes the results of experimental studies evaluating these graft materials in dogs, and it will summarize the findings and outcomes of the clinical articles published in each material category. Reporting inconsistencies and areas where additional research is required will be highlighted to help guide future studies in this area. A major aim of this review is to help identify potential subjects that could be evaluated in future investigations and that might lead to refinements in clinical practice.

Corneal reconstruction is a key part of veterinary ophthalmic practice and numerous reconstructive techniques have been described for use in small animals in the peer-reviewed veterinary literature written in English. Despite the evidence accrued over the last six decades in over 40 clinical articles and numerous other publications on ocular surface health, several key areas require further study. The comparison between studies is difficult due to elements that go beyond common factors, such as the indication for surgery, the reconstructive technique preferred by the surgeon or the availability of reconstructive materials. However, the differences in reporting style adopted by different authors between similar studies and the lack of data found in retrospective studies add to this complexity. The present review is divided into three parts. One covers the use of autologous materials for reconstruction and corneal transplants, as well as corneal clarity. A second part focuses on biomaterials and keratoprosthetics, while the third part focuses on the use of corneal sutures and report of ocular discomfort/pain in the veterinary literature. The review focuses on the main findings of each reconstruction technique. It aims to identify areas where key information about common procedures is missing so that general guidelines may be provided for the planning of patient record keeping and future retrospective or prospective studies, while it also aims to highlight the presence of knowledge gaps that deserve further attention.

The surgical reconstruction of severe corneal disease is a common and crucial component of the clinical practice of veterinary ophthalmology. The first part of the present review described procedures that utilize autogenous ocular tissues, homologous donor tissues, and heterologous donor tissues in dogs, while the second part reviewed the use of biomaterials and keratoprosthetics in this species. This third part is dedicated to the review of the use of corneal sutures including suture type and suture pattern in corneal reconstruction of small animals including dogs and cats. The review also focused on the way studies report postoperative ocular discomfort/pain and how this is treated. Lastly, the author briefly presents the simple but effective techniques available to bury corneal knots for corneal reconstructive surgery in small animal patients, such as the "tugging" and "deep-superficial-superficial-deep" methods for simple interrupted sutures, and the adaptation of the latter for simple continuous sutures.

Objective: To determine the impact of chronic dental disease on the nasolacrimal duct of chinchillas using contrast CT dacryocystorhinography.

Animals studied: Two 12-year-old female chinchillas with uni- or bilateral ocular discharge and a history of chronic, moderate (Chinchilla 1, one-year) or severe (Chinchilla 2, three-years) dental disease.

Procedures: Contrast CT dacryocystorhinography was performed to identify abnormalities in the nasolacrimal duct and dentition, and to correlate those changes.

Results: Chinchilla 1 had a focal soft tissue attenuating expansion of the maxillary bone rostral to the first left premolar interpreted as possible abscessation causing deviation of the nasolacrimal duct over its dorsomedial margin. The right nasolacrimal duct appeared normal. Chinchilla 2 had periapical abscessation of a retained subgingival left maxillary incisor fragment which extended into the nasal cavity causing focal narrowing and distal dilation of the left nasolacrimal duct. Complete contrast infusion of the right nasolacrimal duct could not be completed on Chinchilla 2. A focal area of superficial corneal fibrosis ipsilateral to the obstructed nasolacrimal duct was also identified in Chinchilla 2. Treatment consisted of occlusal adjustments to correct the coronal elongation, systemic antibiotics (metronidazole and either marbofloxacin or azithromycin), and topical tear replacement therapy and diclofenac as needed. Ocular discharge decreased in both chinchillas but did not resolve long-term in either animal.

Conclusions: Chronic dental disease including periapical abscessation in chinchillas can obstruct the nasolacrimal duct, leading to impaired tear drainage. Management of dental disease is crucial to maintain patency of the nasolacrimal duct.

Objective: To evaluate the effects of topical application of 0.5% tropicamide and 1% atropine on pupil diameter (PD), intraocular pressure (IOP), and tear production (TP) in healthy pet rabbits.

Animals studied: Ten healthy client-owned rabbits.

Procedures: A prospective, randomized, blinded, crossover study was conducted. Each animal received one drop of 0.5% tropicamide or 1% atropine in a randomly selected eye. PD, IOP, and TP were evaluated before drug instillation and at 0.25 h, 0.5 h, 0.75 h, 1 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 24 h, 36 h, 48 h, 60 h, and 72 h post-instillation. Data were analyzed using a paired two-sample repeated measures T-test with Bonferroni correction.

Results: In both tropicamide and atropine treated eyes, the mean PD significantly increased from 15 min until 12 h after treatment with a maximum PD at 45 min (+2.7 mm and + 2.4 mm respectively). Following tropicamide and atropine instillation, IOP increased significantly in treated eyes at 45 min (+2.9 mmHg) and 15 min (+5.2 mmHg) respectively, compared to untreated eyes. No significant effects were found on TP, in both tropicamide and atropine treated eyes at any time. No effects were observed in the untreated eyes on any of the parameters evaluated for both drugs.

Conclusions: Topical treatment with 0.5% tropicamide and 1% atropine induced mydriasis in healthy pet rabbits and could be considered as effective options when mydriatic/cycloplegic drugs are required.

Objective: To describe morphological features of Megaptera novaeangliae eyes using ultrasonography and histology.

Animal studied: A total of 21 globes from 19 M. novaeangliae were used for the study, including two animals with bilateral assessment. Nine stranded animals were found alive, 10 dead.

Procedures: Carcasses were classified according to decomposition state. Globes were assessed ultrasonographically, biometric measurements were taken and then the tissues were sectioned for histological analysis.

Results: Seventeen carcasses were classified as decomposition code 2 and two as code 3. Fifteen animals were calves, three juveniles and one adult, twelve males, and five females. The cornea was thinner in the center of the eye and thicker at the periphery. The lens had an oval shape. Fourteen animals showed a structure in the vitreous body which looked triangular and filamentous by ultrasonography and, histologically, originated in the central part of the optic nerve and extended to the posterior region of the lens, composed of connective tissue. The most common abnormalities found by ultrasonograph were retinal detachment (n = 13) and displacement of the lens into the vitreous (n = 4), along with alterations suggestive of hemorrhage, fibrin deposits, and increased echogenicity in the optic nerve (n = 2).

Conclusions: An intraocular structure not previously described in cetaceans was found in this investigation; its function remains unknown. Circulatory changes that were evident in the histopathological analysis may be due to the stranding process and raise the need to consider ophthalmic examinations before reintroducing stranded mysticetes.