OBJECTIVE To evaluate the frequency of ophthalmic disorders in 7 brachycephalic dog breeds referred to an academic veterinary ophthalmology service. ANIMALS 970 client-owned dogs of 7 brachycephalic breeds that were evaluated by the ophthalmology service in a veterinary teaching hospital from January 2008 through December 2017. PROCEDURES Medical records of 7 brachycephalic breeds (ie, Boston Terriers, English Bulldogs, French Bulldogs, Lhasa Apsos, Pekingese, Pugs, and Shih Tzus) were reviewed to collect data regarding patient signalment, ophthalmic diagnoses, affected eyes, and number and dates of visits. RESULTS Median age at the first examination was 7 years (range, 23 days to 22 years). The number of dogs seen for a first examination increased with age. Corneal ulcers, keratoconjunctivitis sicca, corneal pigmentation, immature cataracts, and uveitis were each diagnosed in ≥ 100 dogs and represented 40.4% (1,161/2,873) of all diagnoses. On the basis of anatomic location, 66.3% (1,905/2,873) of all disorders were located in either the cornea (1,014/2,873 [35.2%]) or adnexa (891/2,873 [31%]). There was a significant difference in breed proportion in the study population; of the 7 breeds studied, Shih Tzus (34.3% [333/970]), Pugs (20.8% [202/970]), and Boston Terriers (16.6% [161/970]) were the most prevalent breeds. The frequency of some diseases within the referral population was associated with breed. CONCLUSIONS AND CLINICAL RELEVANCE Findings suggested that the most prevalent disorders for the brachycephalic breeds in this ophthalmic referral population were corneal ulcers, keratoconjunctivitis sicca, corneal pigmentation, immature cataracts, and uveitis. Although all dogs shared brachycephalic features, the frequency of specific ophthalmic diseases varied between breeds.

Female dogs have a significantly smaller AOD vs. males. This difference may render the female iridocorneal angle more susceptible to closure and may partially explain the 2:1 female/male predisposition to PACG. Further studies using goniodysgenic dogs are warranted.

Objective To describe clinical features of dogs diagnosed with choroidal melanocytic tumors at a veterinary teaching hospital. Animals studied Retrospective case series of 13 dogs (14 melanocytic tumors) with choroidal melanocytic tumors. Procedures Medical records of dogs evaluated by the Cornell University ophthalmology service with a clinical diagnosis of a choroidal melanocytic tumor between 2008 and 2020 were reviewed. A choroidal melanocytic tumor was clinically defined as any well‐demarcated, raised pigmented choroidal lesion underlying the retina. Histopathology results were consulted when available. Signalment and clinical features were recorded, including fundoscopic location, histopathologic findings, treatment, and outcome. Results Choroidal melanocytic tumors were identified in 14 eyes of 13 dogs. The mean (±standard deviation) of dogs was 8.6 (±3.5) years. Seven different breeds were represented, with Labrador/Labrador mix being the most common. Ten of the 14 melanocytic tumors were diagnosed incidentally. Four dogs presented for vision loss and ocular discomfort, and diagnosis was made on histopathology examination following enucleation. Pulmonary metastasis was suspected in one dog with an incidentally found choroidal melanocytic tumor OD. Fundoscopic location was available for 8 melanocytic tumors, with 6 (75%) located in the tapetal fundus. Histopathologic diagnosis was melanocytoma for 3 and malignant melanoma in 1 globe, with optic nerve head invasion in 50%. Local recurrence was not seen in any orbit following enucleation. Conclusion Choroidal melanocytic tumors are uncommon in dogs. Metastasis appears to be rare and was only suspected in one dog, but intraocular tumor growth can lead to retinal detachment, glaucoma, and necessitate enucleation.

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Objective To determine the effects of topical 0.5% tropicamide on anterior segment morphology (ASM) and intraocular pressure (IOP) in normal and glaucomatous cats. Animals used Normal cats and cats with inherited primary congenital glaucoma (PCG). Procedures Control IOP curves were performed in untreated normal and PCG cats. In the first experiment, tropicamide was applied OD in eight normal and nine PCG cats. IOP and pupillary diameter (PD) were measured at 0, 30, and 60 min, then hourly until 8 h post-treatment. In a second experiment, six normal and seven PCG cats received tropicamide OD. High-resolution ultrasound images were obtained at 0, 1, 5, and 10 h post-treatment to measure ASM changes. IOP and PD were measured OD at 0, 1, 2, 3, 5, 7, and 9 h. Results In untreated normal cats IOP OU decreased throughout the day. In PCG cats IOP OU had wide fluctuations over time. In normal cats IOP response varied in the treated eye but did not change significantly in untreated eyes. IOP significantly increased from baseline in both eyes of all treated PCG cats. Increases in IOP were associated with some ASM changes. Cats with PCG had a significantly smaller angle recess areas, diminished ciliary clefts and decreased iris-lens contact. ASM changes were not strongly correlated with IOP in all cats. Conclusions The ASM of PCG cats is markedly different from normal cats, and clinically significant increases in IOP OU occur in cats with PCG after tropicamide treatment. The mechanism for this increase remains unclear.

Different subspecies of box turtles have different normal intraocular pressures as measured by rebound tonometry, which was influenced by the animals' health status in one subspecies. Some morphometric parameters were found to be associated with IOP. Box turtles are often affected with ophthalmic abnormalities of unknown clinical significance.

Objective To describe and to establish normative data for the feline optic nerve and peripapillary retina using SD‐OCT (Spectralis® HRA+OCT2). Methods Slit‐lamp biomicroscopy and rebound tonometry were performed in seven male‐intact (0.65 ± 0.02 years;4.34 ± 0.33 kg) and seven female‐spayed (0.74 ± 0.03 years; 3.13 ± 0.28 kg) cats. All eyes were pharmacologically dilated with 1% tropicamide prior to indirect ophthalmoscopy examination. Animals were then placed under general anesthesia. Optic nerve and peripapillary retinal morphology was evaluated using SD‐OCT device by infrared imaging and volumetric scans (circle and radial). Optic disc area, optic cup depth, peripapillary retinal thickness (RT), and retinal nerve fiber layer thickness (RNFLT) were measured. The RNFLT:RT ratio was calculated in the superior, nasal, temporal, and inferior peripapillary region. Results Intraocular pressure in all cats was 20.68 ± 4.87 mm Hg (mean ± SD). Mean RT and RNFL were thickest in the superior retina (264.7 ± 13.95 µm and 70.22 ± 11.78 µm, respectively) (P < 0.0001). Inferior RT was significantly thinner than nasal and temporal retina (P = 0.0013 and P = 0.0010, respectively). The RNFLT:RT was significantly higher in the superior retina (0.27 ± 0.04) (P < 0.0001). Optic disc area OU was 1.39 ± 0.26 mm2. Optic cup depth OU was 168.36 ± 67.74 µm. All parameters tested were not affected by gender, intraocular pressure, body weight, or tested eye. Most eyes had a Bergmeister papilla that was only visible on OCT. Some animals had a recessed area over the center of the ONH meniscus. Conclusion Normative peripapillary ONH OCT data have been introduced. A Bergmeister papillae is commonly seen in young cats on OCT examination. OCT is a helpful tool to evaluate the retina in cats.

OBJECTIVE To identify genetic associations with primary glaucoma (PG) in American Cocker Spaniels using a genome-wide association study (GWAS). ANIMALS A nationwide ambidirectional case–control cohort study was performed in American Cocker Spaniels that had an ophthalmic examination performed by a veterinarian. Ninety-four dogs with PG (cases) and 111 dogs without glaucoma (controls) met phenotypic criteria and had a blood sample collected after receiving informed owner consent. PROCEDURES Genomic DNA was extracted from whole blood samples and genotyped (CanineHD BeadChip, Illumina Inc). A case–control GWAS using a linear mixed model was performed, and 3 significance thresholds were calculated (1) using a Bonferroni correction on all single nucleotide polymorphisms (SNPs) included in the GWAS, (2) using a Bonferroni correction on only the unlinked SNPs from a pruned data set, and (3) using 10,000 random phenotype permutations. RESULTS Following genotype data quality control, 89 cases and 93 controls were included in the GWAS. We identified an association on canine chromosome (CFA10); however, it did not reach statistical significance. Potential candidate genes within the surrounding linkage disequilibrium interval include coiled-coil domain containing 85A (CCDC85A) and extracellular growth factor containing fibulin extracellular matrix protein 1 (EFEMP1). CLINICAL RELEVANCE Primary glaucoma in the American Cocker Spaniel is a complex heterogeneous disease that may be influenced by a locus on CFA10. The candidate genes CCDC85A and EFEMP1 within the identified linkage disequilibrium interval have been shown to be involved in human open-angle glaucoma.