Eyes Flashcards
Anophthalmos
Developmental defect —> absence of eyes
Buphthalmos
Enlargement/distension of fibrous coats of eye
Coloboma
Absence or defect of some ocular tissue, usually due to failure of fetal fissure closure
Endopthalmitis
Inflammation of ocular cavities and adjacent structures (uvea, retina)
Exophthalmos
Abnormal protrusion of eyeball
Glaucoma
Disease characterized by increase in intraocular pressure —> pathological changes in eye
A diverse group of pressure dependent neurodegenerative disorders that results in loss of normal function of retinal ganglion cells and axons in optic nerve —> loss of vision
Most consistently recognized feature is elevation in intraocular pressure
Microphthalmos
Congenitally small eye(s)
Panopthalmitis
Inflammation of structures or tissues of eye (including sclera)
Phthisis bulbi
Shrinking, wastage, hypotony of eyeball
Blepharitis
Inflammation of eyelids
Chalazion
Chronic granulomatous inflammation of eyelid gland (meibomian gland)
Lipogranulomatous inflammation
Dacryoadenitis
Inflammation of lacrimal glands
Causes: viral (MCF, FIP, canine distemper, SDAV), immune mediated (—> KCS)
Distichiasis
Presence of a double row of eyelashes on eyelid (at least one turned inward)
Ectropion
Eversion of edge or margin (i.e. eyelid)
Entropion
Inversion of edge or margin (e.g. eyelid)
Hordeolum
(Style)
Localized Purulent inflammation of one or more meibomian glands
External - cutaneous surface at edge of lid
Internal - conjunctival surface of lid
Suppurative adenitis
Conjunctivitis
Inflammation of conjunctiva
Descemetocele
Herniation of Descemet’s membrane (usually outward)
Dermoid / choristoma
Congenital lesion on cornea or bulbar conjunctival surface resembling skin
Keratitis
Inflammation of cornea
Keratoconjunctivitis
Inflammation of cornea and conjunctiva
Keratoconjunctivitis sicca
Inflammation of cornea + conjunctiva with drying (usually decreased tear production)
Pannus
Superficial vascularization of cornea with infiltration of granulation tissue
Aphakia
Absence of lens
Cataract
Opacity of lens
Causes: congenital or acquired (intraocular disease, trauma, metabolic disease, age)
Lenticonus
Conical protrusion of substance of lens
Microphakia
Abnormally small lens
Nuclear sclerosis
Age related compression of lens fibers —> central lens opacity
Does not affect vision
Chorioretinitis
Inflammation of choroid / retina
Choroiditis
Inflammation of choroid
Hypopyon
Accumulation of neutrophils in anterior chamber
Iritis
Inflammation of iris
Iridocyclitis
Inflammation of iris and ciliary body
Synechia
Adhesion of parts (i.e. iris to other structures)
Anterior: iris to cornea
Posterior: iris to capsule of lens
Uveitis
Inflammation of uveal tract (iris, ciliary body, choroid)
Anterior: iris/ciliary body (usually anterior and posterior chambers)
Posterior: choroid (usually retina)
Panuveitis: usually all structures inside sclera (diffuse uveitis)
Papilledema
Hydropic swelling (edema) of optic disc
Causes: inc CSF pressure, inflammation, decreased intraocular pressure
Retinitis
Inflammation of retina (usually involves choroid)
May occur with neurotrophic viral infections (CSF, Teschen, scrapie, CDV)
Scleral ectasia
Bulging of sclera (often related to coloboma)
Staphyloma
Partial or full thickness defect in cornea or sclera lined by protruding uveal tissue
Layers of the eye
Outer fibrous tunica: cornea, sclera
Middle vascular tunic: iris, ciliary body, choroid
Inner neuro sensory tunic: retina
Developmental origin of ocular tissues
Neuroectoderm - photoreceptors, retinal epithelium, optic nerve
Ectoderm - corneal epithelium lacrimal apparatus, epithelial portion, lens
Mesenchyme - endothelium, stroma, iris, ciliary body
Cyclopia
Single median orbit containing a single globe (failure of division of optic primoridium)
Synophthalmos
Incomplete separation or early fusion in eye development - some duplication or pairing (more common than full cyclopia)
Cystic eye and retinal nonattachment
Result of persistence of optic vesicles cavity
Choroidal hypoplasia
Induction failure by defective retinal pigment epithelium
(Part of collie eye anomaly)
Collie eye anomaly
Choroidal hypoplasia + colobomas + retinal separation
Iris hypoplasia
Rare defect
Most often found in horses
Persistent pupillary membrane
Incomplete atrophy of mesenchyme during development - may block vision / lead to corneal or lens opacity
Cats!
Anterior segment dysgenesis
Anomalies of cornea, lens, anterior uvea
Goniodysgenesis
Maldevelopment of filtration angle
A primary cause of glaucoma
Persistent hyaloid artery
Developmental anomaly —> focal cataracts
Trichiasis
Abnormally directed cilia that contact cornea
Causes of corneal irritation
Entropion
Ectopic cilia
Trichiasis
Distichiasis
(Large or small palpebral opening)
Retinal dysplasia
Abnormal retinal differentiation characterized by retinal folds, rosettes, jumbling of retinal layers, loss of cells, glial proliferation
Most common in dogs and cattle - developmental failure, necrosis or dysplasia of developing retina by viruses (BVDV, blue tongue, CHV1, panleukopenia, FeLV)
Optic nerve hypoplasia
Most common anomaly of optic nerve
Inherited in mini poodles, material hypovitimainosis A in cattle, utero panleukopenia (kitten) or BVD (calves)
Prolapse of gland of the 3rd eyelid
Cherry eye, excision may contribute to KCS
Malignant catarrhal fever
Systemic disease in cattle (ruminants?) —> conjunctivitis/corneal edema
Viruses: gammaherpesviridiae, ovine herpesvirus-2 (most common in NA)
Chemosis
Edema and swelling of conjunctiva
Infectious causes of conjunctivitis in cats
Upper respiratory often associated with conjunctivitis
Herpesviruses, Mycoplasma felis/gatae, Chlamydia psittaci, calicivirus
Conjunctivitis in horses
Chronic —> lymphoid hyperplasia —> lymphoid follicles common in horses
Causes: Thelazia spp, Habronema spp, Onchocera
Causes of corneal injury
Chemical - caustics, medication, etc
Physical - temperature, penetration
Microbial - bacteria, virus, fungi
Immunologic - type III hypersensitivity
Glaucoma
Lysosomal storage disorders
Corneal reaction to injury
Edema
Erosion
Ulcer
Neovascularization
Fibrosis
Epithelial sliding/proliferation
Epithelial metaplasia/pigmentation
Keratitis
Corneal deposits
Pigment or lipid (congenital or acquired)
Corneal dystrophy
Endothelial or stroma distrophy
Breed-specific conditions
Feline corneal sequestrum
Orange brown discoloration of central cornea
Persian / Himalayan cats
necrosis of stroma cells —> sloughing —> healing by granulation tissue
Spontaneous chronic corneal epithelial defects
Boxer ulcer
Recurrent shallow central corneal erosion / ulcers, epithelial cells unable to anchor
Mycotic keratitis
Destructive, Suppurative, deep stroma inflammation due to fungal infection; most commonly Aspergillus in horses
Infectious bovine Keratoconjunctivitis
Bovine pinkeye - Moraxella bovis
Classifications of uveitis
Serous - protein rich fluid “aqueous flare”
Suppurative - usually bacterial
Granulomatous - fungal, algae, helminthes, mycobacteria, lens rupture, VKH
Lymphoplasmacytic - most common in cats
Feline lymphoplasmacytic uveitis
Unknown etiology
Possibly toxoplasma or bartonella
Lens induced uveitis
Phacolytic - lymphocytic uveitis associated with cataracts
Phacoclasic - 10-14 days after lens rupture
Canine adenovirus 1
Immune-mediated uveitis and corneal edema in dogs (convalescent phase or post vaccine - MLV)
Type III hypersensitivity
Equine recurrent uveitis
Hypersensitivity to exogenous agent (often cited as leptospira and dead onchocerca)
Canine uveodermatologic syndrome
Akitas
Autoimmune disease targeting melanin —> bilateral granulomatous uveitis
Sequelae of uveitis
Corneal opacities
Anterior/posterior synechia
Glaucoma
Retinal degeneration/seperation
Cataracts
Pre-iridium fibrovascular membranes —> intraocular hemorrhage
Phthisis bulbi
Degenerative lesions of uvea
Iris atrophy
Iridociliary cysts (labs, golden retrievers) - common
Diabetic cataract
90% of spontaneously diabetic dogs develop cataracts
Positional changes of lens
Ectopic lens
Subluxation/luxation
Configuration (congenital)
Retinal separation
Separation between photoreceptors and pigmented epithelium
Remains attached at ora ciliaris and optic disc
Causes of retinal degeneration
Inherited
Senile changes
Nutritional deficiencies
Toxic retinopathies
Misc (diabetes, hypertensive retinopathy, storage disease)
Idiopathic
Optic neuritis
Inflammation of optic nerve
Causes: spread of meningitis, meningoencephalitis; spread of endothalmitis, virus (FIP, canine distemper, GME), chronic (gliosis, astrocytosis, Axonal degeneration)
Nodular granulomatous scleritis
Nodular proliferative inflammation in sclera of dog
Acts like locally infiltrative neoplasm
Orbital cellulitis
Extension of inflammation from adjacent non-ocular tissues + foreign bodies
Retrobulbar abscess
Tooth root abscess —> orbit
Orbital myositis
Syndrome in dogs with autoantibodies to type 2M muscle fibers
Prevalence of glaucoma
Dogs»_space;cats>horses>ruminants
Primary glaucoma
Goniodysgenesis
Primary open angel glaucoma
no other primary ocular disease
Secondary glaucoma
Secondary to:
Uveitis
Synechiae
Pre-iridium fibrovascular membrane
Lens luxation
Intraocular neoplasia
Intraocular hemorrhage
Sequelae of glaucoma
Buphthalmia
Scleral thinning
Corneal edema
Corneal striae (breaks in Descemet’s membrane)
Exposure keratitis
Lens luxation or subluxation
Cataract (malnutrition?)
Atrophy of iris/ciliary body
Retinal atrophy, separation
Optic disc cupping
Eyelid / conjunctival neoplasms
Squamous cell carcinoma
Meibomian gland neoplasms
Melanocytoma
Hemangioma / hemangiosarcoma
Intraocular neosplasms
Melanocytoma / malignant melanoma
Iridociliary adenoma / carcinoma
Feline post-traumatic sarcomas
Lymphoma
Metastatic neoplasia
Orbital neoplasms
Optic nerve meningioma
Sarcomas
Carcinomas
Squamous cell carcinoma
Bovine > equine > feline > canine
Pathogenesis: UV light —> plaque —> papilloma —> carcinoma in situ —> carcinoma (invasive, may metastasize)
Meibomian gland neoplasms
Adenoma / epithelioma very common (70% lid tumors) in dogs
Carcinoma - rare
Melanocytoma of eyelid/conjunctiva
Common in dogs
Intraocular Malignant melanoma/Melanocytoma
Canine: 90% benign
Feline: diffuse iris melanoma > solitary masses, may obstruct filtration angle —> glaucoma; greater rise of metastatic
Iridocilliary adenoma / carcinoma
Most common primary intraocular tumor after melanomas
Feline post-traumatic sarcomas
Arise from metaplasia of lens epithelium follow injury with long latency period (months to years)
Aggressive locally infiltrative behavior - can extend along optic nerve to brain
Forms: fibrosarcoma, osteo/chondrosarcoma, B-cell lymphoma
Solitary intraocular lymphoma vs metastatic lymphoma to eye
Solitary better prognosis than metastatic
Metastatic intraocular neoplasias
Lymphoma
Histiocytic sarcoma
Pulmonary, mammary carcinoma