Approach to Immune-mediated Ocular Diseases.

Immune-mediated ocular inflammation is a common clinical diagnosis reached for horses with keratitis and uveitis. This diagnosis is made as a diagnosis of exclusion following a thorough effort to rule out an underlying cause for the inflammation, most importantly infectious and neoplastic disease. Practically, response to ophthalmic and systemic anti-inflammatory or immunomodulatory medications is used to support a diagnosis of immune-mediated ocular inflammation; however, such medications are often contraindicated in the face of infection or neoplasia.

An evaluation of intracapsular lens extraction and transcorneal lens reduction for treatment of anterior lens luxation in dogs.

Objective: The aim of the study was to evaluate success rate, complications, and outcomes in dogs with anterior lens luxation (ALL) treated with intracapsular lens extraction (ICLE) or transcorneal lens reduction (TCLR).

Procedure: Medical records of dogs with ALL undergoing ICLE or TCLR from 2014 to 2021 were reviewed. Signalment, presenting complaint, history, ophthalmic examination findings, short-term complications, and outcomes were analyzed.

Ultrasound biomicroscopy of the equine iridocorneal angle.

Background: The iridocorneal angle (ICA) is the major pathway of aqueous humour outflow from the anterior chamber of the eye. Ultrasound biomicroscopy (UBM) has been utilised to characterise the morphology of this drainage pathway in numerous species. UBM may allow for early recognition of aqueous humour outflow obstructions in horses, allowing for earlier recognition of risk for glaucoma, a vision-threatening and painful disease.

Corneal thickness and anterior chamber depth of the normal adult horse as measured by ultrasound biomicroscopy.

Objective: To determine corneal thickness (CT) and axial anterior chamber depth (ACD) using ultrasound biomicroscopy (UBM) in normal adult horses. To compare corneal thickness measurements between UBM and ultrasonic pachymetry.

Animals Studied: Sixty eyes of 30 healthy adult horses aged 8-24 years.

Additional Evidence for T338M as a Genetic Risk Factor for Ocular Squamous Cell Carcinoma in Horses.

Squamous cell carcinoma (SCC) is the most common periocular cancer in horses and the second most common tumor of the horse overall. A missense mutation in (, c.1012 >, p.

Horses with equine recurrent uveitis have an activated CD4+ T-cell phenotype that can be modulated by mesenchymal stem cells in vitro.

Equine recurrent uveitis (ERU) is an immune-mediated disease causing repeated or persistent inflammatory episodes which can lead to blindness. Currently, there is no cure for horses with this disease. Mesenchymal stem cells (MSCs) are effective at reducing immune cell activation in vitro in many species, making them a potential therapeutic option for ERU.

Equine eosinophilic keratoconjunctivitis in California: retrospective study of 47 eyes from 29 cases (1993-2017).

Objective: (a) To evaluate the epidemiology of equine eosinophilic keratoconjunctivitis (EK) in the western United States, (b) to ascertain the efficacy of keratectomy and diamond burr debridement vs medical management alone, (c) to determine the efficacy of various medical therapies, and (d) to further characterize the histopathologic findings of the disease in horses.

Animals Studied: Twenty-nine horses (47 eyes) diagnosed with EK from 1993 to 2017.

Procedure: Retrospective medical record review; owner questionnaire.

Limbal squamous cell carcinoma in a Rocky Mountain Horse: Case report and investigation of genetic contribution.

Objective: To document a case of limbal squamous cell carcinoma (SCC) in a Rocky Mountain Horse stallion determined to be homozygous for the genetic risk factor (DDB2 c.1013C>T) strongly associated with the disease in Haflinger and Belgian horses, and to determine the frequency of this allele in a larger population of Rocky Mountain Horses.

Animals Studied: One privately owned Rocky Mountain Horse and 84 Rocky Mountain Horses screened for allelic frequency.

Effect of topical application of 0.5% proparacaine on corneal culture results from 33 dogs, 12 cats, and 19 horses with spontaneously arising ulcerative keratitis.

Objective: To investigate the effect of topically applied proparacaine on bacterial and fungal culture results and to compare cytologic and culture results in patients with ulcerative keratitis.

Procedure: Corneal samples were collected from 33 dogs, 19 horses, and 12 cats with spontaneously arising ulcerative keratitis. Samples for bacterial (dogs, cats, horses) and fungal (horses) cultures were collected prior to and following application of 0.

Traumatic phacocele in an American Miniature Horse.

An 18-year-old American Miniature Horse mare was presented with a complaint of a scleral swelling affecting the right eye and a history of suspected trauma 6 weeks prior to evaluation. Clinical findings included severe blepharospasm, a bulbous swelling of the dorsotemporal bulbar conjunctiva, and phthisis bulbi. Ocular ultrasound was recommended but declined.

Ocular and periocular hemangiosarcoma in six horses.

Objective: To determine the characteristics of and prognosis for ocular and periocular hemangiosarcoma in horses.

Animal Studied: Six horses treated for ocular or periocular hemangiosarcoma.

Procedure: A retrospective review of medical records from 2007 to 2015 was performed to identify horses with a histologic diagnosis of ocular or periocular hemangiosarcoma.

Corneal sensitivity and tear production in 108 horses with ocular disease.

Purpose: To compare corneal sensitivity and tear production in horses with keratitis to horses with other ocular disease.

Method: Retrospective medical record review was used to identify equine patients presented during a 1-year period for an ocular complaint who had Schirmer Tear Test (STT) or Corneal Touch Threshold (CTT) measured. Variables studied included patient age and sex; affected eye; category of presenting ocular complaint (keratitis vs.

Interval prevalence of and factors associated with colic in horses hospitalized for ocular or orthopedic disease.

OBJECTIVE To determine interval (1-year) prevalence of and factors associated with colic in horses hospitalized for ocular or orthopedic disease. DESIGN Cross-sectional study. ANIMALS 105 horses with ocular disease and 197 horses with orthopedic disease admitted to a veterinary teaching hospital between July 1, 2011, and June 30, 2012.

Corneal edema in four horses treated with a superficial keratectomy and Gundersen inlay flap.

Objective: To describe the clinical presentation, treatment, and outcome of four horses with severe corneal edema caused by suspected endothelial disease treated with a superficial keratectomy and Gundersen inlay flap and to determine whether this procedure (i) reduces corneal edema, (ii) reduces ocular pain, (iii) eliminates recurrent corneal ulceration, and (iv) improves vision in these horses.

Animals Studied: Four horses met inclusion criterion of (i) diagnosis with endothelial disease by a board-certified veterinary ophthalmologist and (ii) surgical treatment with a superficial keratectomy and Gundersen inlay flap.

Procedure: Retrospective medical record review of included horses was used to determine breed, age and sex of included horses, as well as details of medical and surgical therapy, and visual outcome.

Porcine urinary bladder extracellular matrix grafts (ACell Vet® Corneal Discs) for keratomalacia in 17 equids (2012-2013).

Objective: To describe the clinical course, outcomes, and complications associated with use of commercially available porcine urinary bladder extracellular matrix (ECM) grafts (ACell Vet(®) Corneal Discs) in equid patients with keratomalacia, and to evaluate the efficacy of ECM grafts as a viable alternative to other biomaterials for corneal grafting in equid patients.

Animals: Sixteen horses and one donkey (17 eyes) with unilateral keratomalacia severe enough to warrant surgical repair between August 2012 and September 2013.

Procedure: Retrospective medical record review to identify equid patients meeting inclusion criteria of (i) diagnosis with keratomalacia severe enough to warrant surgical repair and (ii) surgical repair with an extracellular matrix graft.

Limbal squamous cell carcinoma in Haflinger horses.

Objective: To describe the prevalence of LSCC in Haflinger horses and to analyze affected horses' pedigrees investigating the genetic mode of inheritance.

Animals: Fifteen horses met inclusion criterion of (i) being of the Haflinger breed, as confirmed by North American Haflinger Registry pedigree and (ii) being diagnosed with LSCC, as confirmed by clinical examination by a veterinary ophthalmologist or by histopathology. Pedigrees could not be obtained for four additional horses diagnosed with LSCC that had been identified as Haflingers.

Equine amniotic membrane transplantation for corneal ulceration and keratomalacia in three horses.

Purpose: Amniotic membrane has antifibrotic, anti-angiogenic and antiprotease properties. This retrospective study was designed to investigate the use of equine amniotic membrane transplants (AMT) at preserving vision, maintaining the structural integrity of the globe and maximizing cosmesis in equine eyes with corneal ulceration and severe keratomalacia.

Methods: Equine amnion had previously been aseptically harvested from a 12-year-old Thoroughbred mare during an elective Cesarean section.

Orbitotomy for retrobulbar malignant fibrous histiocytoma in a dog.

A retrobulbar malignant fibrous histiocytoma was diagnosed in a 12-year-old castrated male Keeshond dog. The mass was excised with a lateral orbitotomy and zygomatic arch resection. Vision was preserved in the affected eye, and no recurrence was noted up to 10 months postoperatively.

Evaluation of various compounds to inhibit activity of matrix metalloproteinases in the tear film of horses with ulcerative keratitis.

Objective: To examine in vitro effects of various antiproteolytic compounds on activity of matrix metalloproteinase (MMP)-2 and -9 in the tear film of horses with active corneal ulcers.

Sample Population: Samples of tear film obtained from the eyes of 34 horses with active ulcerative keratitis.

Procedure: Horses were sedated, and tear samples were collected from the lower fornix of 34 ulcerated eyes by use of capillary tubes.