To describe the morphological features of corneal dystrophy in Siberian Huskies using invivo confocal microscopy (IVCM). Twenty-one dogs. A prospective case-control study was performed. Siberian Huskies with (n = 13 dogs) and without (n = 8) corneal dystrophy were evaluated. Complete ophthalmic and IVCM examinations (Heidelberg Retina Tomograph and Rostock Cornea Module) were performed for each case. All dogs with corneal dystrophy demonstrated characteristic bilateral, round-to-oval, refractile, crystalline corneal opacities visible within the stroma by slit-lamp biomicroscopy. The median age of dogs with corneal dystrophy was 5.0 years (range: 2-13 years), with eight females and five males included. During IVCM, dense accumulations of fine, needle-like, tapered, hyperreflective structures were present within the axial corneal stroma of each dog. The length of the spindles varied from several μm to > 400 μm and the structures were commonly present in dense clumps. Amorphous, thicker, crystalline deposits with blunted ends were present less frequently and intermixed with the needle-like structures. Other corneal anatomic features were generally obscured by the deposits, but the surrounding regions appeared morphologically normal, including the epithelium, keratocytes, corneal nerves, and endothelium. Siberian Huskies without corneal dystrophy were presented for various other ophthalmic conditions, including cataracts and primary glaucoma. The median age of control dogs was 1.5 years (range: 1-9 years), with five females and three males included. Similar hyperreflective deposits were not detected by IVCM in any dogs from the control group. Application of IVCM can aid in the characterization of corneal dystrophies in Siberian Huskies.

To retrospectively investigate the outcome of a modified Morgan pocket technique that included temporary ventral scleral gland fixation to treat prolapse of the nictitans gland. The files of 101 client-owned dogs (126 eyes) between 2015 and 2024 were retrospectively analyzed. All the surgeries were completed in under 10 min. Follow-up was between 180 to 3285 days (mean 1190 days) in 119/126 (94%) eyes and three years in 81/126 (64.3%) eyes. The technique achieved successful surgical repositioning in 125/126 (99.2%) eyes after one surgery, with only one eye (1/126 (0.8%)) having a recurring prolapse that was successfully managed by repeating the technique. Seven other immediate postoperative complications (7/126, 5.6% of the eyes) were recorded, including lacrimal cysts in 5/126 (4%) eyes and corneal ulceration in 2/126 (1.6%) eyes. All cysts were treated with local drainage, two under general anesthesia and three under sedation and topical anesthesia. Additional complications occurred in 14/101 (13.9%) of the animals, including keratoconjunctivitis sicca and ulcerative keratoconjunctivitis of different degrees of severity. Given the long follow-up and low number of cases affected, it was not known if these problems might have been associated with some aspects of the surgical treatment. The technique described included a temporary fixation of the gland before closure of the pocket with successful long-term repositioning of the gland in 99.2% of eyes after the first attempt. Cysts and recurrence were infrequent complications. Further studies could investigate if the technique might be adapted to minimize complications.

The objective of this study is to present high-quality and up-to-date ocular ultrasonographic images and videos of a posterior lenticonus with concomitant mature cataract in a cat. Additionally, the clinical findings, surgical treatment, and outcome are reported for completeness and to confirm the diagnosis. An 8-year-old castrated male domestic shorthair cat presented due to unilateral cataract. Ophthalmological examination revealed a mature cataract without clinically detectable uveitis. Hematological and biochemical analyses were unremarkable, and tests for common infectious diseases associated with feline uveitis were negative. Electroretinography and ocular ultrasound were performed as part of the presurgical planning for phacoemulsification. Retinal function was normal. Ultrasonographic examination revealed a severely distorted shape of the posterior lens capsule (PLC) with hyperechoic material protruding into the vitreous body. Neither a PLC fibrovascular plaque nor a persistent hyaloid artery was identified. These findings were interpreted as a possible rupture of the posterior lens capsule with lens material extruding into the vitreous body. Posterior lenticonus was considered a less likely differential diagnosis. The owner elected to proceed with phacoemulsification surgery. Intraoperatively, the posterior lens capsule was found to be intact. An axial posterior lenticonus with cataractous lens material bulging together with the capsule into vitreous was identified. An intraocular lens was successfully implanted. Given the better surgical prognosis compared to capsule ruptures, posterior lenticonus, although rare, should be considered a differential diagnosis, particularly when a cone-shaped protrusion lacking Doppler signal is identified at the posterior lens capsule extending into the vitreous body.

To utilize previously published tonometer correction formulae to investigate whether true intraocular pressure (IOP) is relatively conserved across a diverse range of vertebrate species. Tonometer correction formulae for 21 species. A literature search was performed to identify prior studies containing correction formulae for non-invasive tonometers used in normal animal and human subjects. In all cases, direct manometry was compared to non-invasive tonometry values. Where necessary, multiple correction regression formulae were combined to generate a single representative formula using a meta-analysis generic inverse variance method. A subsequent literature search was then performed to collect uncorrected IOP values of normal animals and humans using a variety of non-invasive tonometers. These IOP values were then corrected using the relevant correction formula. Sixty-five tonometer correction formulae and 104 studies containing IOP values in normal animals and humans acquired using non-invasive tonometry met the inclusion criteria. Corrected IOP values were calculated for 21 species using 13 types of non-invasive tonometers. Overall corrected and uncorrected mean IOP values were typically within a range of 10 to 25 mmHg (corrected: 16/21 species, uncorrected: 14/21 species). Differences between overall mean corrected and uncorrected IOP values ranged from 0.2 to 15.3 mmHg with an average of 6.1 mmHg difference. True normal IOP is relatively conserved across a diverse range of vertebrate species despite uncorrected values from individual tonometers suggesting otherwise. Maintaining true IOP between 10 and 25 mmHg appears to be important in ocular physiology in many vertebrates.

ABSTRACTObjectiveTo evaluate the evolution of corneal sensitivity in healthy beagle puppies during the first weeks of life, compare these results with adult corneal sensitivity, and determine the age at which adult corneal sensitivity levels are reached.Animals StudiedTwelve puppies and five adult females.ProceduresCorneal sensitivity was assessed in puppies weekly from 2 to 7 weeks of age and in their mothers by measuring the corneal touch threshold (CTT) in the central cornea using a Cochet–Bonnet esthesiometer. Hygrometric and temperature measurements were recorded throughout the study period.ResultsIn puppies, esthesiometry indicated a progressive decrease in corneal sensitivity with age. Sensitivity was higher between 2 and 4 weeks, which stabilized between 5 and 7 weeks, with a median CTT values of 0.5, 0.5, 0.8, 1.4, 1.2, and 1.4 g/mm2 at 2, 3, 4, 5, 6, and 7 weeks, respectively. The median CTT in puppies reached the adult median value (1.4 g/mm2) at 5 weeks. The median CTT at 2 weeks was significantly different from the median CTT at 7 weeks (0.5 vs. 1.4 g/mm2). Humidity and temperature were not significantly associated with corneal sensitivity in adults.ConclusionsIn this study, corneal sensitivity in beagle puppies was higher during the first 3 weeks of life compared to 7 weeks. During this early period, puppies exhibited corneal sensitivity levels exceeding those of adults, which subsequently decreased to adult‐equivalent values between 5 and 7 weeks of age.

To describe the findings of computed tomography (CT) used to investigate signs of ophthalmic disease in pet rabbits. Retrospective review of records of patients with signs of ophthalmic disease that underwent CT scans in three referral centers between 2001 and 2022. Signalment, presenting ophthalmic and nonophthalmic complaints, CT findings, and restrain modality were recorded. There were 85 rabbits representing 14 breeds including 28/85 (32.9%) crossbreed/unknown and 25/85 (29.4%) Dwarf rabbits. The top presenting ophthalmic complaints were ocular discharge (48/85, 56.5%), exophthalmos (34/85, 40%), and epiphora (14/85, 16.5%), while 38/85 (44.7%) rabbits also had nonophthalmic complaints. Anesthetic complications forced 1/85 (1.18%) CTs to be stopped. There were ophthalmic abnormalities in the remaining 81/84 (96.4%) CTs with exophthalmos and/or nasolacrimal duct disease affecting 76/81 (93.8%) rabbits and 68/81 (84%) also showing nonophthalmic abnormalities. Ophthalmic abnormalities were seen with nonophthalmic disease in 64/81 (79%) rabbits with dental disease being the most common (52/64, 81.3%) although only 20/52 (38.5%) had presented with dental complaints. No association was found between the presence of exophthalmos and/or NLD disease and dental disease. There were no obvious image artifacts in the 4/84 (4.8%) physically restrained patients. Examination with CT in the present study mainly supported the investigation of ocular discharge, exophthalmos, and epiphora, and of possible local and systemic involvement in one eye with intraocular neoplasia. Adnexal disease was often seen with previously unknown, nonophthalmic pathology, which warrants prospective, controlled studies. Image quality studies in a large number of physically restrained patients are also warranted.

To determine the intraocular pressure (IOP) reference values in healthy male camels using two rebound tonometers: TonoVet (TV) and TonoVet Plus (TV+), and to compare measurements between both devices and in different body positions. Thirty-four healthy, captive, adult (8-24 years and a median age of 14), male camels belonging to a zoological collection in Fuerteventura, Spain. All camels underwent general physical examination, slit lamp biomicroscopy, and tonometry, under minimal physical restraint (headstall and chute). Three consecutive readings were acquired with TV and/or TV+ in the right and/or left eyes in standing and/or sitting positions, whenever possible. Comparisons between groups were made when paired data for the test variable was available for the same eye (for tonometer and body position) or for the same animal (for left and right eyes) using paired t-tests. The mean IOP (± standard error and range) in standing position was 18.51 mmHg (0.52, 10.33-24.33 mmHg) for TV and 19.53 mmHg (0.50, 12.33-26.33 mmHg) for TV+. In sitting position, the IOP was 14.70 mmHg (0.49, 11.33-18.33 mmHg) for TV and 16.28 mmHg (0.47, 13-19.66 mmHg) for TV+. Measurements for both TV and TV+ were significantly higher (p = 0.003 and p = 0.011, respectively) in standing position. Recordings with TV+ were significantly higher than with TV, in any body position (p < 0.001 and p = 0.006, respectively). There were no statistically significant differences between right and left eyes, except for TV+ in standing position, with the IOP in the left eye being significantly higher (20.58 mmHg versus 18.51 mmHg, p = 0.004). To the authors' knowledge, this is the first report estimating the IOP reference values in male camels comparing two different rebound tonometers. Measurements for both TV and TV+ were significantly higher in the standing position. Recordings with TV+ were significantly higher than with TV (in any body position). Further studies with female individuals and different age groups are warranted.

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 hours 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. Whilst 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.

PurposeThis study aims to inform about the clinical image, diagnostic possibilities, and treatment options for cats and dogs diagnosed with ocular encephalitozoonosis.Materials and MethodsMedical records of 7 dogs and 75 cats with ocular encephalitozoonosis presented at the Clinical Unit of Ophthalmology of the University of Veterinary Medicine Vienna between 08/2006 and 02/2022 have been compiled. Diagnosis was based on the presence of cataracts and positive antibody titer against Encephalitozoon cuniculi. Patient history, details on the characteristics of the cataracts, level of antibody titers, and the treatment regimen were summarized, as are the results of histological stainings of surgical samples to determine the presence of Encephalitozoon cuniculi, as well as PCR analyses to identify its sub‐strains.ResultsOur analysis of the clinical data shows that focal cortical anterior cataracts often associated with anterior uveitis and lesions in the fundus are the most prevalent manifestation of ocular encephalitozoonosis in cats and dogs.ConclusionSerological testing and PCR analysis of lens material are the most important diagnostic tools. Timely phacoemulsification with adjuvant anti‐inflammatory and antiparasitic medication is the most promising therapy for Encephalitozoon cuniculi‐induced cataracts.