Search

Background: Inherited primary open-angle glaucoma (POAG) in Beagle dogs is a well-established large animal model of glaucoma and is caused by a G661R missense mutation in the ADAMTS10 gene. Using this model, the study describes early clinical disease markers for canine glaucoma. Methods: Spectral-domain optical coherence tomography (SD-OCT) was used to assess nine adult, ADAMTS10-mutant (median age 45.6 months, range 28.8–52.8 months; mean diurnal intraocular pressure (IOP): 29.9 +/− SEM 0.44 mmHg) and three related age-matched control Beagles (mean diurnal IOP: 18.0 +/− SEM 0.53 mmHg). Results: Of all the optic nerve head (ONH) parameters evaluated, the loss of myelin peak height in the horizontal plane was most significant (from 154 +/− SEM 38.4 μm to 9.3 +/− SEM 22.1 μm; p < 0.01). There was a strong significant negative correlation between myelin peak height and IOP (Spearman correlation: −0.78; p < 0.003). There were no significant differences in the thickness of any retinal layers evaluated. Conclusions: SD-OCT is a useful tool to detect early glaucomatous damage to the ONH in dogs before vision loss. Loss in myelin peak height without inner retinal thinning was identified as an early clinical disease marker. This suggests that initial degenerative changes are mostly due to the loss of myelin. [ABSTRACT FROM AUTHOR]

Objective s : To identify canine breeds at risk for ocular melanosis and to compare the clinical and histologic features between affected Cairn Terriers (CTs) and non‐Cairn Terriers (NCTs). Design: Relative risk (RR) analysis and retrospective cohort study of dogs histologically diagnosed with ocular melanosis. Procedures: The COPLOW archive was searched for globe submissions diagnosed with ocular melanosis. Six hundred fifty globes were included, and RR analysis was performed to identify at‐risk NCT breeds. A cohort of 360 CT and NCT globes diagnosed from 2013 to 2023 were included in the retrospective cohort study. Clinical data were collected from submission forms, medical records, and follow‐up surveys. One hundred fifty‐seven submissions underwent masked histologic review. Immunohistochemical staining for CD204 was performed to determine the predominance of melanophages in affected uvea from five NCTs. Results: At‐risk NCT breeds included the Boxer, Labrador Retriever, and French Bulldog. Glaucoma was the reported reason for enucleation in 79.4% of submissions. At enucleation, clinical features less prevalent in NCTs than CTs included pigmentary abnormalities in the contralateral eye (33.7% vs. 63.1%, p =.0008) and abnormal episcleral/scleral pigmentation in the enucleated globe (25.4% vs. 53.6%, p =.0008). Histologic involvement of the episclera was also less frequent in NCTs than in CTs (39.7% vs. 76.9%, p =.008). Concurrent melanocytic neoplasms arising in melanosis were more common in NCTs (24.4%) than CTs (3.9%). Melanophages were not predominant in any samples evaluated immunohistochemically. Conclusions: Several popular NCT breeds carry risk for ocular melanosis, and some clinicopathologic disease features may differ from those described in CTs. [ABSTRACT FROM AUTHOR]

Captive fish populations, such as those encompassing aquarium and pet fish, offer significant economic value and are integral to conservation, research, and education. However, these ornamental fish exhibit a reduced ability to protect their ocular surfaces, and our understanding of the ocular diseases that affect them remains limited. Although corneal neoplasms in carp are uncommon, identifying their distinct characteristics is crucial in selecting appropriate therapeutic interventions that aim to preserve vision, prevent the ocular loss, and ultimately ensure the survival of the affected fish. This study provides clinical and histopathological details of various proliferative corneal masses in Cyprininae species, including five koi (Cyprinus carpio) and four goldfish (Carassius auratus). It discusses a spectrum of neoplasms, including soft tissue sarcoma, spindle cell sarcoma, chromatophoroma, and papilloma, in addition to conditions like exuberant granulation tissue and proliferative carp pox. These findings bear significant implications for clinical decision‐making and treatment, offering valuable insights into the incidence and characteristics of corneal tumors in captive fish, which could inform further studies in this area. [ABSTRACT FROM AUTHOR]

Purpose: Angle closure glaucoma (PACG) is highly prevalent in dogs and is often refractory to medical therapy. We hypothesized that pathology affecting the post‐trabecular conventional aqueous outflow pathway contributes to persistent intraocular pressure (IOP) elevation in dogs with PACG. The goal of this study was to determine the potential for aqueous angiography (AA) and optical coherence tomography (OCT) to identify abnormalities in post‐trabecular aqueous outflow pathways in canine PACG. Methods: AA and anterior segment OCT (Spectralis HRA + OCT) were performed ex vivo in 19 enucleated canine eyes (10 normal eyes and 9 irreversibly blind eyes from canine patients enucleated for management of refractory PACG). Eyes were cannulated and maintained at physiologic IOP (10–20 mmHg) prior to intracameral infusion of fluorescent tracer. OCT scleral line scans were acquired in regions of high and low perilimbal AA signal. Eyes were then perfusion fixed and cryosections prepared from 10/10 normal and 7/9 PACG eyes and immunolabeled for a vascular endothelial marker. Results: Normal canine eyes showed segmental, circumferential limbal AA signal, whereas PACG eyes showed minimal or no AA signal. AA signal correlated with scleral lumens on OCT in normal dogs, but lumens were generally absent or flattened in PACG eyes. Collapsed vascular profiles were identified in tissue sections from PACG eyes, including those in which no lumens were identified on AA and OCT. Conclusions: In canine eyes with PACG, distal aqueous outflow channels are not identifiable by AA, despite normalization of their IOP, and intra‐scleral vascular profiles are collapsed on OCT and histopathology. [ABSTRACT FROM AUTHOR]

Objective: Investigate histopathology and spectral‐domain optical coherence tomography (OCT) imaging of wild owls with chorioretinitis and identify any potential correlation with an infectious etiology. Materials and Methods: Ophthalmic examination and retinal OCT imaging were performed on fifteen great horned (Strix varia) and barred (Bubo virginianus) owls (30 eyes) with chorioretinitis and five owls with normal eyes (10 eyes). Testing to investigate the presence of potential infectious diseases included a complete blood count, biochemistry, protein electrophoresis, West Nile virus (WNV) plaque reduction neutralization test, Toxoplasma gondii modified direct agglutination test, WNV RT‐PCR, and Avian Influenza RT‐PCR. A necropsy was performed on all owls, including ocular histopathology. Results: Fundus lesions included retinal detachment (7/15 owls), depigmented lesions (12/15), pigment clumping (8/15), and retinal tear (4/15). All birds were negative for WNV and Avian Influenza on RT‐PCR. Of the owls with chorioretinitis, 3/15 were seropositive for WNV and 7/15 for T. gondii. Optical coherence tomography of 25/30 affected eyes revealed outer retinal lesions (19/25 eyes), retinal detachment (16/25), and retinal tears (3/25). Histopathological examination revealed outer nuclear layer atrophy (19/30 eyes), retinal detachment (18/30), retinal tears (7/30), suprachoroidal hemorrhage (12/30), scleral rupture (3/30), and ossicle fracture (3/30). Conclusions: Although 20% of birds were seropositive for WNV and 46.6% for T. gondii, histopathologic findings supported that the posterior segment lesions in the study group were likely due to blunt ocular trauma rather than an infectious etiology. The results of OCT imaging and histopathology documented retinal changes most consistent with blunt ocular trauma. [ABSTRACT FROM AUTHOR]

The objectives of this retrospective study were to evaluate the histopathologic changes associated with porcupine ocular quill injuries in dogs, to discuss the various methods of quill detection when quills are not grossly visible, and to discuss the pathogenesis of delayed ocular quill injuries in dogs. Seventeen globes sustaining ocular quilling injuries from 17 dogs (1986‐2018) were identified in the COPLOW archives and the gross and histologic changes tabulated and compared. All cases were dogs, with one whole globe submitted from each patient. Sixteen of 17 cases had known or suspected porcupine encounters in the weeks or years preceding enucleation. Histopathologic findings included retinal detachment, hyphema, cataract, granulomatous to pyogranulomatous inflammation (uveitis, endophthalmitis, panophthalmitis), lens capsule rupture, suppurative phakitis, scleral perforation, stromal keratitis, breaks in Descemet's membrane, preiridal fibrovascular membrane, anterior and posterior synechia, Schnabel's cavernous atrophy, and periorbital fibrosis. Quill‐associated ocular trauma can have a significant deleterious effect on vision and result in enucleation. The time from initial quilling to the manifestation of ocular signs may be prolonged (weeks to years). Any dog presenting for ocular signs with a history of a previous porcupine encounter should be carefully checked for quill migration into the globe as the source of ocular disease. Quills may not be visible grossly, and ancillary imaging techniques can be utilized with various rates of success. [ABSTRACT FROM AUTHOR]

Objective: To describe the historical, clinical, and diagnostic features of small animal patients affected by cactus‐induced keratoconjunctivitis and their response to therapy. Animals studied: Three dogs and one cat. Procedures: Ophthalmic examination directed subsequent selected diagnostic tests in each case including light microscopy of extracted foreign bodies, in vivo confocal microscopy (IVCM), corneal histopathology, and corneal bacterial culture. Treatments consisted of foreign body surgical extraction with concurrent medical therapy (three cases), or medical therapy alone (one case). Results: Clinical histories obtained supported acute cactus injury in all cases. Ophthalmic abnormalities were unilateral in each case and included ulcerative keratoconjunctivitis associated with linear, microscopic conjunctival and/or corneal penetrating cactus spines, known as glochids. Light microscopy and IVCM showed glochids to be heavily barbed, consistent with the spine morphology Prickly Pear (Opuntia) cactus species. Bacterial culture yielded Proprionicimonas sp. in one case with keratomalacia. Surgical extraction of spines was challenging, and residual conjunctival and/or corneal glochids were present in all cases. Patient discomfort resolved at a median of 21 days (range 10‐51 days). Vision‐threatening complications were not observed in any case at the time of last follow‐up examination. Epithelial downgrowth, demonstrated by IVCM and histopathology, was present in one case at 108‐day follow‐up. Conclusions: Cactus‐induced keratoconjunctivitis should be considered as a differential in regions in which Opuntia cacti are prevalent, and microscopic ocular foreign bodies are observed. Although glochids are difficult to extract, positive clinical outcomes can occur in small animal patients despite the presence of residual organic corneal foreign material. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the clinical, histopathological, and immunohistochemical features of 17 cases of ocular surface xanthogranuloma (OSX) in dogs. Methods: Archived records from the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) were searched for cases of canine OSX. Cases were evaluated for lipid‐laden macrophages and Touton giant cells. Seventeen cases matching those criteria were identified (1993‐2018). Clinical and epidemiological data were collected from the submission forms and additional follow‐up survey. Results: Ocular surface xanthogranuloma in dogs presented as small bland nodules. OSX commonly occurred at the limbus (8/17) or cornea (4/17). Three of 17 affected animals were less than 1‐year‐old and the average age was 6.9 years (range 0.7‐14 years). Fourteen of 17 cases did not report any lipid or metabolic abnormalities. Histologically, lesions were composed mainly of dense sheets of vacuolated lipid‐laden macrophages and Touton giant cells with scant additional inflammatory cells and an intact overlying epithelium. No recurrence was noted in cases where complete surgical resection was achieved, and medical treatment either pre or post‐resection led to only partial resolution. Conclusions: Xanthogranulomas are histiocytic lesions characterized by abundant lipid‐laden macrophages. The authors use the term, ocular surface xanthogranuloma, to describe nodules with rigidly defined cellular characteristics. Although these lesions share characteristics with human limbal xanthogranulomas, further investigation is needed to suggest the different subsets that have been reported in the medical literature. Complete surgical excision is the most effective treatment for OSX in dogs, and intralesional triamcinolone and topical steroids can be useful adjunctive therapies to surgery. [ABSTRACT FROM AUTHOR]

This retrospective study aimed to describe and classify cats with intraocular lymphoma, determine the proportion of cases with presumed solitary ocular lymphoma (PSOL) compared with ocular manifestations of multicentric disease and assess the clinical outcomes of these patients. One hundred seventy‐two cases identified through biopsy submissions were reviewed histologically; 163 of these cases were subtyped according to the WHO classification system. Cases were categorized as having PSOL or ocular lymphoma with suspected systemic involvement (SSI) based on submission forms and follow‐up data. The majority of cases exhibited concurrent uveitis (75%) and secondary glaucoma (58%). Diffuse large B‐cell lymphoma was the most common subtype (n = 86; 53%), followed by peripheral T‐cell lymphoma (n = 44; 27%). Other subtypes included anaplastic large T‐ (n = 8; 5%) and B‐cell (n = 4; 2.5%) lymphomas, and 15 cases (9%) were negative for all immunohistochemical markers. In sixty‐nine cases (40%), adequate clinical data and sufficient survival data were obtained to distinguish PSOL from SSI. PSOL comprised the majority of cases (64%), while 36% had SSI. When covarying for age at diagnosis, the median survival time was significantly higher (P = 0.003) for cases of PSOL (154 days) versus those with SSI (69 days); hazards ratio of 0.47 for PSOL (95% CI: 0.241‐0.937). The subtype of lymphoma did not affect survival time. Cats with PSOL represent a greater proportion of the disease population, and this subset of cats with intraocular lymphoma has a better clinical outcome. [ABSTRACT FROM AUTHOR]