A genome-wide association study to investigate genetic loci associated with primary glaucoma in American Cocker Spaniels.

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.

Preliminary report of postoperative complications of phacoemulsification in Pugs: A multicenter retrospective study of 32 cases.

OBJECTIVE: To compare complication rates and visual outcomes following phacoemulsification in Pugs versus dogs of other breeds. ANIMALS STUDIED: Thirty-two pure-bred Pugs (55 eyes) and 32 dogs of other breeds (56 eyes) undergoing phacoemulsification. PROCEDURES: Multi-institutional retrospective medical record review of perioperative factors, postoperative complications, and visual outcomes. The reference population of dogs of varying breeds included surgical cases following each Pug case at the same institutions. Perioperative risk factors and postoperative complication rates were compared between the two populations. RESULTS: Pigmentary keratitis and diabetes mellitus were the most common preoperative comorbidities, found in 75% (P < .001) and 72% (P = .12) of Pugs, respectively. No perioperative factors were significantly associated with postoperative complications in Pugs. Postoperative complication rates were similar between groups; however, the most common complication in Pugs was corneal ulceration (15% of operated eyes), whereas glaucoma was most common in the reference population (13% of operated eyes). Three months postoperatively, vision was preserved in 91% of eyes of Pugs (50/55) and 95% of the reference population (53/56). One year postoperatively, 80% (32/40) of Pug eyes and 82% (28/34) of eyes in the reference population remained sighted. CONCLUSIONS: Comorbidities and complications of cataract surgery in Pugs of this study demonstrate a predisposition for corneal disease. This highlights the importance of preoperative evaluation of factors associated with PK and corneal clarity, and postoperative monitoring for corneal ulceration in this breed.

Sudden acquired retinal degeneration in dogs: breed distribution of 495 canines.

PURPOSE: The purpose of this study was to describe breed, age, gender, and weight distribution of dogs affected with sudden acquired retinal degeneration (SARD) and to investigate whether SARD is more common in small breed dogs. METHODS: Medical records of dogs diagnosed with SARD confirmed by an electroretinogram were reviewed. Breed, age, gender, and weight were recorded when available. The same data were obtained for dogs with SARD described in the veterinary literature. RESULTS: Three hundred and two dogs were included from the ophthalmology practices and 193 dogs from the veterinary literature. Sixty breeds were present in the study. Mixed-breed dogs were the most common at 108 dogs (21.8%), followed by the Dachshund (68, 13.7%), Chinese Pug (44, 8.9%), Miniature Schnauzer (39, 7.9%), Maltese (23, 4.6%), Cocker Spaniel (22, 4.4%), Bichon Frise (18, 3.6%), Beagle (16, 3.2%), Brittany (15, 3.0%), and Pomeranian (10, 2.0%). Fifty other breeds were represented by 1-9 dogs each. The median age was 9 years (range = 10 months-16 years). The weight was known for 197 dogs. About 60.9% of dogs were less than 25 pounds, 31.5% were between 25 and 50 pounds, and 7.6% were greater than 50 pounds. Gender was recorded in 393 dogs: 217 female dogs and 176 male dogs. CONCLUSIONS: As previously reported, SARD is most common in middle-aged to older dogs. Smaller dogs of less than 25 pounds appear overrepresented, while large/giant breed dogs of greater than 50 pounds are infrequently diagnosed. In this study, there was no statistical significance between female and male dogs.

Endogenous mycotic endophthalmitis in a dog with candiduria and Evans syndrome.

This report describes the clinical presentation, diagnosis, histologic lesions, and outcome of endogenous mycotic endophthalmitis secondary to candiduria in a three-year-old female spayed Dachshund. The dog was being treated for Evans syndrome for one month prior to being diagnosed with candiduria and fibrinous uveitis OS. The left eye was enucleated due to secondary glaucoma, and the fungal urinary tract infection was treated successfully. Uveitis developed in the contralateral eye with relapse of the urinary tract infection in the following weeks. The right eye was medically managed until secondary glaucoma developed and was subsequently enucleated. Histopathology of both eyes showed evidence of endophthalmitis with intralesional fungal organisms, consistent with Candida spp. Ocular candidiasis is rare in dogs. To the authors' knowledge, this is the first report of endogenous mycotic endophthalmitis with concurrent candiduria in a dog.

Sudden acquired retinal degeneration syndrome (SARDS) - a review and proposed strategies toward a better understanding of pathogenesis, early diagnosis, and therapy.

Sudden acquired retinal degeneration syndrome (SARDS) is one of the leading causes of currently incurable canine vision loss diagnosed by veterinary ophthalmologists. The disease is characterized by acute onset of blindness due to loss of photoreceptor function, extinguished electroretinogram with an initially normal appearing ocular fundus, and mydriatic pupils which are slowly responsive to bright white light, unresponsive to red, but responsive to blue light stimulation. In addition to blindness, the majority of affected dogs also show systemic abnormalities suggestive of hyperadrenocorticism, such as polyphagia with resulting obesity, polyuria, polydipsia, and a subclinical hepatopathy. The pathogenesis of SARDS is unknown, but neuroendocrine and autoimmune mechanisms have been suggested. Therapies that target these disease pathways have been proposed to reverse or prevent further vision loss in SARDS-affected dogs, but these treatments are controversial. In November 2014, the American College of Veterinary Ophthalmologists' Vision for Animals Foundation organized and funded a Think Tank to review the current knowledge and recently proposed ideas about disease mechanisms and treatment of SARDS. These panel discussions resulted in recommendations for future research strategies toward a better understanding of pathogenesis, early diagnosis, and potential therapy for this condition.

Preliminary evaluation of tear production in dogs hospitalized in an intensive care unit.

OBJECTIVE: To determine the tear production in dogs admitted to an intensive care unit (ICU). DESIGN: Prospective observational study from November 2010-September 2011. SETTING: Private emergency and referral hospital. ANIMALS: Thirty healthy control dogs and 30 dogs hospitalized in an ICU for treatment of systemic illness without previously diagnosed ophthalmic disorders and no recent history of anesthesia. Enrollment was based on availability of the ophthalmologist within 24 hours of admission to the ICU. INTERVENTIONS: Tear production was measured utilizing Schirmer tear test strips (STT) in healthy control animals as well as in hospitalized canine patients. All patients received an ophthalmic examination by a board-certified veterinary ophthalmologist within 24 hours of admission to the ICU. Lubrication with artificial tear gel every 2-4 hours as needed was implemented after STT was measured. MEASUREMENTS AND MAIN RESULTS: Average tear productions in the control and canine ICU populations were 24.5 mm/min and 13.2 mm/min, respectively. This was found to be statistically significant (P < 0.001). Furthermore, there was a trend toward a decrease in tear production in patients with kidney disease and a trend toward normal tear production in patients with cardiac disease but the sample size was likely too small to enable detection of a statistically significant difference. CONCLUSIONS: This study demonstrates a decrease in tear production in canine ICU patients. While further study is warranted to determine how different diseases impact tear production, these finding support the implementation of frequent ocular lubrication in all ICU patients.

Periocular cutaneous mast cell tumors in cats: evaluation of surgical excision (33 cases).

OBJECTIVE: To describe feline periocular cutaneous mast cell tumor (CMCT) clinical features, rates of local tumor recurrence and metastases, and cat survival time following surgical excision. ANIMALS STUDIED: Thirty-three cats with periocular CMCTs. PROCEDURES: Medical records of cats diagnosed with periocular CMCTs were reviewed; cats were included if CMCTs were surgically excised and the diagnosis confirmed by histopathology. The appearance, size, location and histopathology findings of CMCTs were recorded. Rates of local recurrence, metastasis, and survival time following surgical excision were collected when available. RESULTS: All periocular CMCTs were restricted to the eyelids. In addition to surgical excision, three cats were treated with adjunctive therapy (strontium-90 irradiation or cryotherapy) intraoperatively. Local tumor control was achieved in 22/23 cats with a minimum follow-up of 30 days (median follow-up time of 711 days); one cat developed disseminated CMCTs but no local recurrence. Cats with periocular CMCTs had a median survival time of 945 days. Metastatic disease involving peripheral lymph nodes or abdominal viscera was not detected in any cat at any time during the study. All periocular CMCTs were classified as low-grade based on histopathology, and complete excision was achieved in approximately 50% of cases. CONCLUSIONS: Surgical excision of periocular CMCTs in cats is an effective treatment option with rare local recurrence and metastases, even following incomplete surgical excision.

Acute blindness in dogs: sudden acquired retinal degeneration syndrome versus neurological disease (140 cases, 2000-2006).

OBJECTIVE: To evaluate dogs with amaurosis and compare signalment, history, ophthalmic examination and neurologic abnormalities between dogs diagnosed with sudden acquired retinal degeneration syndrome (SARDS) versus neurological disease (ND). Animals Studied-140 dogs with acute vision loss and ocular abnormalities insufficient to account for visual deficits. An electroretinogram (ERG) was performed on each dog. PROCEDURES: Medical records were reviewed and information was collected for all dogs meeting the inclusion criteria. Dogs diagnosed with SARDS were compared to those with ND based on signalment, duration of clinical signs, past medical problems, clinicopathologic findings, and ophthalmic and physical examination abnormalities. RESULTS: 120 dogs were diagnosed with SARDS and 20 dogs with ND based on ERG results. Mixed-breed dogs were most commonly diagnosed with SARDS as well as ND. Pure breed dogs frequently diagnosed with SARDS included the Miniature Schnauzer and Dachshund. Dogs with SARDS did not differ significantly from those with ND based on age or sex distribution. Cushing's-like symptoms were reported more frequently in SARDS dogs as well as conjunctival hyperemia and retinal vascular attenuation. Papilledema and asymmetric visual deficits were observed more frequently in dogs with ND. Dogs with ND were no more likely than SARDS dogs to have additional neurological deficits. CONCLUSIONS: Appreciable overlap of clinical signs exists between dogs with SARDS and dogs with ND resulting in acute vision loss. As a significant portion of dogs (14%) in the present study were diagnosed with ND, an ERG to rule out ND is indicated in dogs with amaurosis.

Orbital inflammatory disease and pseudotumor in dogs and cats.

Orbital disease is common in dogs and cats. Clinical signs include exophthalmos, protrusion of the third eyelid, and resistance to retropulsion of the globe. This article discusses diagnostic work-up for dogs and cats with signs suggestive of orbital disease. Diagnosis and treatment of nonneoplastic orbital diseases follows. Congenital diseases are discussed first, followed by inflammatory diseases of the orbit including orbital pseudotumor. Lastly, other less common orbital conditions are addressed.

Putative aqueous humor misdirection syndrome as a cause of glaucoma in cats: 32 cases (1997-2003).

OBJECTIVE: To characterize the clinical and morphologic aspects of aqueous humor misdirection syndrome (AHMS) in cats and provide a hypothesis regarding its pathogenesis on the basis of detailed analysis of affected cats. DESIGN: Retrospective study. ANIMALS: 32 cats (40 eyes). PROCEDURE: Medical records of cats in which AHMS was diagnosed from July 1997 to August 2003 were reviewed. In certain cats, results of additional diagnostic testing were also obtained, including A-scan, B-scan, and high-resolution ultrasonography; streak retinoscopy; video keratometry; and infrared neutralizing videoretinoscopy as well as results of analysis of flash-frozen sections and histologic examination of enucleated globes. RESULTS: Cats had a uniformly shallow anterior chamber, intact lens zonules, and a narrowed approach to an open iridocorneal angle. Mean age of affected cats was 11.7 years (range, 4 to 16 years), and female cats were significantly more often affected than male cats. Clinical signs included mydriasis, decreased pupillary light reflex, decreased menace response, and blindness. Glaucomatous changes to the optic nerve, incipient cataracts, and eventual blindness were seen. Intraocular pressure was > or = 20 mm Hg (range, 12 to 58 mm Hg) in 32 of 40 eyes. Ultrasonography and histologic examination revealed a thickened anterior vitreal face interposed between the lens and ciliary body, partial ciliary cleft collapse, and cavitated vitreal regions. Various treatment modalities were used. CONCLUSIONS AND CLINICAL RELEVANCE: AHMS affects older cats, especially females, and may result in glaucoma, vision loss, and signs of ocular pain. Topical administration of carbonic anhydrase inhibitors decreased intraocular pressure.

Combined transscleral diode laser cyclophotocoagulation and Ahmed gonioimplantation in dogs with primary glaucoma: 51 cases (1996-2004).

OBJECTIVE: To evaluate the combined diode laser cycloablation procedure and adjunctive Ahmed gonioimplant use in dogs with primary glaucoma. DESIGN: Retrospective study. ANIMALS: 48 dogs, 51 eyes with primary glaucoma. PROCEDURE: Medical records from two large private clinical ophthalmology services were reviewed. Signalment, duration of glaucoma, gonioscopic evaluation, laser power and duration settings, immediate postoperative and final intraocular pressure and visual results, short and long-term visual outcome, and surgical complications were recorded. RESULTS: The age range of affected dogs was 3.0-14.0 years, with a mean age of 7.5 +/- 2.6 years. Eleven pure breeds were represented, with the most common being the American Cocker Spaniel. The sex distribution was 22 neutered males, 1 intact male, 23 spayed females, and 2 intact female dogs. The right eye was affected in 33 cases, and the left eye in 18 cases. The average total joules, which was administered with the diode laser, was 109.6 +/- 23.6 J. Immediate surgical complications included fibrin formation in the anterior chamber (15), corneal ulcers (4), hyphema (7), and focal retinal detachment (1). Long-term complications included cataract formation (8 total, 2 of which were significant, vision-threatening), elevated intraocular pressure (IOP) (6), unstable gonioimplant (1), and glaucoma recurrence (14). Additional surgeries performed on the eyes over the course of study included: intrascleral prosthesis (4), enucleation (1), resection of fibrotic scar tissue (5), and repeat laser cycloablation (8). The dogs were examined for a mean follow-up time of 17.6 months (range: 2-83 months postoperatively). Twenty-nine cases were followed greater than one year. Vision was maintained in 42/51 eyes (82%) in the immediate short-term of this study. In all cases included in the study, good control of IOP was achieved in 39/51 (76%) of eyes, and IOP was poor or uncontrolled in 12/51 (24%) of eyes. Twenty out of 41 eyes (49%) maintained fair to excellent vision six months after surgery. Twelve months postoperative observations demonstrated that 12/29 (41%) of the eyes were still visual. CONCLUSIONS: In primary glaucoma, the combined procedure of laser diode cyclophotocoagulation and Ahmed valve implant was associated with return or maintenance of vision in 42/51 eyes (82%) in the immediate short-term of this study, and a long-term IOP control in 39/51 (76%) of the cases, with 12/29 eyes (41%) visual after 12 months.

Adnexal surgery in dogs and cats.

Abnormalities in eyelid position and function can lead to chronic irritation of cornea and conjunctiva. Corneal ulceration, vascularization and pigmentation are common consequences. Loss of vision, or loss of the globe may be the end result. The combination of ptosis and entropion of the upper eyelid is commonly seen in breeds with abundant forehead skin folds. Treatment options include surgical reduction of skin folds, suspending the brows, enforced secondary granulation of the upper eyelid, or a combination of procedures. Lid-shortening procedures reduce corneal exposure, improve functional blinking and reduce likelihood of traumatic proptosis. Although a lateral canthoplasty is technically easier to perform, a medial canthoplasty is the preferred method of eyelid shortening. An involuted lateral canthus with entropion is seen in certain dog breeds with a broad skull base and redundant facial skin. Surgical correction is by either applying traction to the lateral canthus, or by resection of the lateral canthal ligament. A combination of entropion, ectropion and macroblepharon may result in the presence of diamond shaped eyelids. Surgical correction involves the combination of several procedures. Upper eyelid agenesis is a congenital absence of part of the upper eyelid in cats. Treatment options include a skin-orbicularis flap from the lower eyelid with a conjunctival pedical graft, the transposition of the lower eyelid to the upper eyelid, cross lid flap and subdermal plexus flap, and subdermal collagen injection. Several techniques for reconstruction of upper and lower eyelid defects are described.