ACVO Veterinary Ophthalmology flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Schirmer tear test I

Measures reflex tear production using a standardized paper strip placed in the conjunctival fornix for one minute. Normal canine values are approximately 15-25 mm/min, and values below 10 mm/min support keratoconjunctivitis sicca.

Intraocular pressure reference range

Normal canine IOP is roughly 10-25 mmHg measured by applanation or rebound tonometry. Values above 25-30 mmHg suggest glaucoma, while values below 10 mmHg suggest uveitis or globe rupture.

Menace response pathway

A learned cortical response requiring intact optic nerve, visual cortex, and facial nerve. It is absent in very young puppies and can be absent in normal cats, so interpretation depends on age and species.

Pupillary light reflex pathway

Afferent limb is the optic nerve and efferent limb is the oculomotor nerve. The reflex is subcortical and present earlier than the menace response, making it useful in neonates.

Aqueous humor outflow

Aqueous humor is produced by the ciliary body and drains mainly through the iridocorneal angle and pectinate ligament into the scleral venous plexus in dogs, with minor uveoscleral flow.

Tapetum lucidum location

A reflective structure in the dorsal fundus that enhances dim-light vision. The optic disc lies in the nontapetal, pigmented fundus in dogs and cats, which matters for orientation on fundic examination.

Topical atropine effects

A muscarinic antagonist producing mydriasis and cycloplegia lasting one to three days. Systemic absorption through the nasolacrimal duct can cause tachycardia, dry mouth, and ileus, especially in small patients.

Tropicamide duration

A short-acting anticholinergic mydriatic and cycloplegic used for fundic examination. Mydriasis lasts roughly four to six hours, substantially shorter than atropine, reducing recovery time.

Timolol mechanism

A nonselective beta-adrenergic antagonist that lowers intraocular pressure by reducing aqueous humor production. It is contraindicated in patients with cardiac disease or asthma because of systemic beta blockade.

Latanoprost mechanism

A prostaglandin F2-alpha analog that increases uveoscleral outflow to reduce intraocular pressure. Common side effects include conjunctival hyperemia and periorbital changes with chronic use.

Pilocarpine action

A direct muscarinic agonist causing miosis and increased trabecular outflow. It can produce ocular irritation and systemic cholinergic signs such as salivation, vomiting, and diarrhea.

Topical corticosteroid risk

Corticosteroids reduce ocular inflammation but delay corneal epithelial healing and increase risk of corneal melting and fungal infection when applied to an ulcerated cornea.

Fluorescein stain use

A dye that stains exposed corneal stroma but not intact epithelium, used to detect corneal epithelial defects. Seidel testing uses it to detect aqueous leakage from a full-thickness wound.

Ivermectin toxicity in MDR1 dogs

Dogs with an ABCB1 mutation have impaired drug efflux at the blood-brain barrier, so ivermectin causes mydriasis, hypersalivation, ataxia, and tremors from GABA-gated chloride channel overactivity.

Keratoconjunctivitis sicca signs

Characterized by mucoid discharge, corneal vascularization, and low Schirmer tear test values. Treatment includes tear stimulants such as cyclosporine or tacrolimus and topical lubrication.

Corneal ulcer depth grading

Ulcers are graded as superficial epithelial loss, deep stromal loss, or descemetocele where stroma is lost to Descemet membrane. Descemetoceles require surgical stabilization.

Indolent ulcer features

A chronic superficial corneal ulcer with loose epithelial edges that fails to heal within seven to ten days. Treatment options include debridement, grid keratotomy, or diamond burr superficial keratectomy.

Uveitis clinical signs

Signs include miosis, aqueous flare, hypopyon, ciliary spasm, and low intraocular pressure. Treatment targets the underlying cause with topical corticosteroids and atropine.

Primary angle-closure glaucoma

An emergency presentation with a fixed dilated pupil, episcleral congestion, corneal edema, and intraocular pressure often above 40 mmHg. Rapid treatment is needed to preserve vision.

Cataract grading stages

Cataracts are graded as incipient, immature, mature, or hypermature by extent. Lens capsule rupture causes phacoclastic uveitis from exposure to lens proteins.

Entropion correction

Inward rolling of the eyelid margin causes trichiasis and corneal irritation. Young dogs may need temporary tacking before definitive surgical correction once facial conformation matures.

Cherry eye treatment

Prolapse of the third eyelid gland is treated by gland replacement rather than excision. Excision removes a major source of tear production and increases risk of keratoconjunctivitis sicca.

Sudden acquired retinal degeneration

Causes acute blindness with mydriasis and absent menace in older dogs, often with a normal fundus initially. Electroretinography confirms loss of retinal function.

CAER registry purpose

The Companion Animal Eye Registry, run by the American College of Veterinary Ophthalmologists, screens breeding dogs for heritable eye disease using standardized examination and reporting forms.

CAER examination components

Performed by board-certified veterinary ophthalmologists using indirect ophthalmoscopy, slit-lamp biomicroscopy, and tonometry. Findings are coded on standardized forms for registry submission and breeding decisions.

Collie eye anomaly genetics

An autosomal recessive disorder associated with a NHEJ1 gene variant causing choroidal hypoplasia, coloboma, and retinal detachment. Genetic testing and breeding guidance reduce prevalence in predisposed breeds.

Progressive retinal atrophy inheritance

Many forms are inherited and progressive, with the prcd form being autosomal recessive in several breeds. Genetic testing guides breeding decisions and supports CAER screening.

Retinal dysplasia in screening

Multifocal retinal dysplasia and other inherited developmental anomalies are recorded on CAER forms. Breed-specific guidance may treat them as breeding exclusions depending on severity and inheritance.

Persistent hyperplastic primary vitreous

A congenital anomaly involving persistent fetal vasculature behind the lens, often with persistent hyperplastic tunica vasculosa lentis. It is recorded on CAER examinations in predisposed breeds.

CAER result categories

Results are reported as normal, affected, or breeder option. The registry database supports tracking of heritable ocular disease prevalence and trends across breeds over time.

Breed-specific screening intervals

The ACVO Genetics Committee maintains breed-specific recommendations for screening age and frequency. Some breeds require examination at defined intervals to remain eligible for registry reporting.

Gonioscopy in screening

A technique using a contact lens to visualize the iridocorneal angle and pectinate ligament. It identifies angle abnormalities that predispose dogs to primary angle-closure glaucoma and informs breeding guidance.