Ophtho Flashcards
Exam 2
4 primary layers of the Adnexa
skin
orbicularis oculi m.
meibomian glands
palpebral conjunctiva
Orbicularis oculi muscle (purpose/ uses)
closed eyelids
responsible for blepharospasm
invervated by CN VII
surgical holding layer
Meibomian glands (purpose/ uses)
lipid layer tear film
distichiasis, ectopic cilia
duct is surgical landmark
palpebral conjunctiva (purpose/ uses)
goblet cells produce mucous for tear film
source of tissue for surgery
Superior palpebral levator muscle
open upper eyelid
innervated by CN III
Müller’s muscle
smooth muscle
sympathetic innervation
maintains palpebral fissure opening
Functions of the Adnexa
- general eye protection
- spread tear film and prevent evaporation
- produce portions of tear film
- contains portions of tear drainage system
What is blepharospasm
involuntary tight closure of the eyelid
General signs of disease of the Adnexa
redness
swelling
blepharospasm
Entropion
- rolling in of eyelid margin
- can be congenital, spastic, or cicatricial (from scar tissue)
- dogs most common (also sheep and pot-bellied pigs)
Entropion (clinical signs)
- larger dogs, lateral aspect lower lid
- belpharospasm
- epiphora (wetness along lower, lateral eyelid margin
- corneal vessels, melanosis, esp ventrolaterally
Entropion (Causes)
- inherited
- spastic
- Cictricial
- Fat deposition (pigs)
Entropion (Diagnosis)
- signalment
- clinical signs
Entropion (treatment)
- Adolescents (lubrication, tacking)
Adults (surgical repair via Hotz-Celsus or “smile”)
Chronic epiphora syndrome
- underlying problem medial entropion, lower lid
- > malposition lacrimal punctum
- > “crimping” canaliculus
- > Trichiasis
Chronic epiphora syndrome (Signs)
- chronic tear staining from medial canthus
- secondary moist dermatitis (brachycephalics)
Chronic epiphora syndrome (Cause)
- Entropion medial aspect lower lid
- breed related (chich, poodles)
Chronic epiphora syndrome (treatment)
- benign neglect
- Hotz-Celsus or “smile” surgery
Ectropion
- majority dogs, breed related ( cockers , bloodhounds, giant breeds)
- age-related
Ectropion
- loss of contact lower eyelid with eye
- leads to secondary corneal problems
- > blepharospasm
- > epiphora
- > corneal vessels
- > corneal melanosis
- > corneal ulceration
Ectropion (Causes)
- inherited
- age related
Ectropion (treatment)
- often not necessary
- lubricating ointments
- antibiotics or steroid ointments
- wedge resection
Meibomian Adenoma (Signs)
- papilloma-like projection from margin
- swelling affected gland
- upper lid more common
- variable size
- blepharospasm if ulcer
- met very rare
Meibomian Adenoma (Cause, Diagnosis)
Cause: Age-related
Diagnosis: Signalment, Signs, Biopsy
Meibomian Adenoma (treatment)
- curettage and cryotherapy
- wedge resection
Most common Adnexa Neoplasias (canine)
- meibomian adenoma
- papilloma
- melanoma
- 2ary lymphoma
Most common Adnexa Neoplasias (feline)
- squamous cell carcinoma
- fibrosarcoma
- mast cell tumor
- basal cell carcinoma
- 2ary lymphoma
Feline squamous cell carcinoma (Signs)
- ulcerative lesions
- lower lid
- white or light pigmentation
- met late
Feline squamous cell carcinoma (Cause)
- lack of eyelid pigmentation
- UV exposure
Feline squamous cell carcinoma (treatment)
- radiotherapy =)
- surgical excision
- cryotherapy
Distichiasis
- meibomian glands modified hair follicles
- undifferentiated gland produces cilia
- cilia emerges form meibomian gland duct
Distichiasis (signs)
- difficult to see without magnification
- fine hairs emerging from eyelid margin
- usually does not cause disease
Distichiasis (cause)
- inherited
- developmental
Distichiasis (treatment)
- manual epilation initially to confirm dx
- cryotherapy
Ectopic cilia
- similar to distichiasis, cilium from meibomian glands
- cilium protrudes through palpebral conjunctiva
Ectopic cilia (signs)
- 8-12 months of age
- marked blepharospasm, epiphora
- vertically linear superficial corneal ulcer
- raised papilla, 12 o’clock position on upper lid
Ectopic Cilia (cause)
- inherited
- developmental
Ectopic Cilia (Treatment)
- excision
- cryotherapy
Trichiasis
- hair from normal site in contact with ocular surface
- most frequent in dogs (bracycephalics + long facial hair breeds)
Trichiasis (signs)
- periocular hair touching ocular surface
- medial canthus, nasal folds
- usually do not cause irritation
- often “wick” tears onto face
Trichiasis (Cause, Diagnosis)
Cause: breed related, conformational
Diagnosis: signalment, clinical signs
Trichiasis (treatment)
- usually not indicated
- cryotherapy
- lid surgery
Traumatic Injuries (treatment)
- minimal debridement
- 2 layer closure for lacerations (orbicularis oculi muscle is holding; skin needs careful alignment of margins)
- reconstruction of inferior NL system
- systemic, topical antibiotics
Bacterial blepharitis
- overgrowth surface bacterial flora
- ascends into eyelid via meibomian ducts
- Staph and Strep spp.
- Staph toxins exacerbate
Bacterial blepharitis (signs)
- severe eyelid swelling
- blepharospasm
- excoriation
- alopecia
- mucopurulent discharge
- granuloma formation
- bilateral and recurrent (Dogs)
Bacterial Blepharitis (Cause and Dx)
Cause: infection from ascending bacteria, fight wounds
Dx: clinical signs, biopsy, culture and sensitivity
Bacterial Blepharitis (treatment)
- topical antibiotic/ steroid (Neomycin and Polymyxin + dexamethasone)
- oral antibiotics (cephalexin)
- oral prednisone
- warm compress
- autogenous vaccines
Chalazion
- obstructed meibomian duct
- accumulation secretion
- rupture of gland
- granulomatous reaction
Chalazion (signs)
- nodular swelling within lid
- no inflammation
- no pain
- yellow/ white appearance through palpebral conjunctiva
Chalazion (Cause)
- obstruction of meibomian gland duct
- age-related
Chalazion (treatment)
- curettage of gland
- topical antibiotic/ steroid
Eyelid Agenesis (signs)
- absence lateral 1/2 to 2/3 upper eyelid
- trichiasis
- always bilateral, but not symmetric
- may have exposure keratitis
Eyelid Agenesis (Cause)
- heritable or developmental
Eyelid Agenesis (treatment)
- topical ointments
- cryotherapy
- blepharoplastic procedures
Neonatal ophthalmia
- ankyloblepharon normal for cats and dogs 10-14 days
- infection under eyelids before opening
- Staph, strep, herpesvirus
Neonatal ophthalmia (signs)
- inflamed, distended eyelids
- purlent discharge
- conjunctival hyperemia, chemosis
- +/- corneal ulceration
Neonatal Ophthalmia (treatment)
- open lids (digital manipulation, blunt probe)
- flush dilute betadine solution
- topical antibiotics
4 Primary layers of the cornea
- epithelium
- stroma
- Descemet’s membrane
- endothelium
Corneal epithelium
- 5-10 cells thick
- constant turnover
- hydrophobic
- mechanical barrier
Corneal Stroma
- 90% thickness
- hydrophilic
- location of clinical signs
- sensory innervation from CN V
Corneal Descemet’s membrane
- basement membrane endothelium
- elastic, last barrier to perforation
- hydrophobic
Corneal endothelium
- Na/K pump removes fluid
5 factors that affect corneal transparency
- avascular
- relatively dehydrated
- orderly arrangement stromal fibrils
- lack of pigment
- non-keratinized epithelium
Corneal source of nutrition
- tear film for anterior
- aqueous fluid for posterior
Corneal functions
- transmission of light
- refraction of light
- fibrous layer for protection
Corneal ulcers (normal healing)
- sliding (migration)
- formation of new basement membrane
- dividing (mitosis)
Uncomplicated corneal ulcer (signs)
- epithelium only, no stromal loss
- heals in ~7 days
- no change in stromal character
- no extensive vascularization
- miosis due to reflex uveitis
Uncomplicated corneal ulcer (management)
- topical steroid contraindicated
- topic broad spectrum abx
- topical atropine, q24hr
Complicated corneal ulcer (signs)
- increasing depth, non-specific
- stromal infiltrate, specific
- change in stromal character (melting)
- corneal vascularization, non-specific
- hasn’t healed in 7-10 days, non-specific
- loose peripheral epithelium, specific
Complicated corneal ulcer (common causes)
- infection
- foreign bodies
- exposure
- entropion
- ectopic cilia
Signs of infected ulcer (complicated)
- all signs of complication possible
- stromal infiltrate, melting specific
Diagnosis of infected ulcer
- cytology
- culture and sensitivity
Treatment of infected ulcer
- referral
- vigorous abx (q2hr)
- topical serum
- E-collar
- warm compress
Signs of exposure ulcer (complicated)
- most frequent w/ brachycephalics
- centrally loacated
- round, firm edges
Treatment of exposure ulcer
- frequent abx ointment
- +/- topical atropine
- consider tarsorrhaphy
Signs of ersistent ulcer syndrome or SCCED
- middle-aged or older
- superficial
- redundant epithelium around periphery
Treatment of persistent ulcer syndrome
- corneal debridement
- grid keratotomy or diamond burr (dogs only)
- meidcal tx as uncomlicated
Chronic superficial keratitis
- immune-mediated
- breed related (GSD)
- environmental (UV light)
- referred to as ‘pannus’
Chronic superficial keratitis (signs)
- Acute/ Active (fibrovascular invasion, ventrolateral thickening, 3rd eyelid thickening)
- Chronic (corneal melanosis, blindness)
Chronic superficial keratitis (cause)
- genetics/ UV lights –> stromal protein alteration –> loss of immunotolerance –> inflammatory response
Chronic superficial keratitis (treatment)
- topical steroids
- topical cyclosporine
- maybe seasonal, often lifelong)
Exposure Keratitis
- usually dogs
- incomplete blinking
- eyelids ‘gap’ open while sleeping
- senile change
- cats w/ eeylid agenesis
secondary to eyelid injury
Exposure Keratitis (signs)
- corneal vessels, melanosis medially
- may lead to ulcers
Exposure Keratitis (Cause)
- conformation
- developmental
- Age related
- Eyelid inuury
Exposure Keratitis (treatment)
- if ulcer –> refer
- surgery for agenesis or lid problem
- abx/ steroid ointment QID until keratitis controlled, then reduce
- topical lube long term
Corneal Degeneration (Signs)
- crystalline to chalky deposits composed of lipids of Ca salts
- superficial w/in cornea
- older patients
Corneal Degeneration (Cause)
- aberrant healing response
- 2ary to trauma, irritation, inflammation
Corneal Degeneration (Treatment)
- topical abx treatment
- chemical keratectomy
Corneal Dystrophy (Signs)
- crystalline ‘ground glass’ deposits
- under corneal epithelium
- bilateral, not symmetric
- no pain, inflammation, vision change
- early age onset (1-2 years)
Corneal Dystrophy (cause)
- heritable
Corneal Dystrophy (treatment)
- not indicated
Feline Herpesvirus (Signs)
- blepharospasm, epiphora
- conjunctival hyperemia
- chemosis
- corneal vessels
- linear (dendritic) ulcers [pathopneumonic]
- focal, pinpoint cellular infiltrate
Feline Herpesvirus (Treatment)
- suppression of signs, not cure
- topical antivirals (cidofovir)
- oral antivirals (famciclovir)
- topical steroids contraindicated
Corneal Sequestrum (unique to what species)
- cats
Corneal Sequestrum (signs)
- dark brown plaque, represents necrotic stroma
- not melanin
- painful, can lead to rupture
Corneal Sequestrum (cause)
- herpesvirus
- chronic exposure
Corneal Sequestrum (treatment)
- slough
- keratectomy
Eosinophilic Keratitis (signs)
- cats and some horses
- fibrovascular infiltrate
- ‘caseous’ islands
Eosinophilic Keratitis (Cause)
- herpesvirus
Eosinophilic Keratitis (treatment)
- topical steroids
- topical antivirals
- megesterol acetate
Corneal Neoplasia - Canine
Primary - Limbal melanoma, hemangiosarcoma/carcinoma
Secondary - Lymphoma
Corneal Neoplasia - Feline
Primary - Limbal melanoma/ melanocytoma
[ Lymphoma and SCC very rare]
Limbal Melanoma (signs)
- dark mass, centered on limbus
- extends both ways
- unilateral
Corneal Dermoid (treatment)
- keratectomy
- reconstruct lateral canthus
Corneal Dermoid (what is it)
- normal tissue in abnormal location
Parts of the tear film
- Lipid Layer (meibomian)
- Aqueous Layer (lacrimal and 3rd eyelid gland)
- Mucous Layer (goblet cells)
Lacrimal Drainage Apparatus
- lacrimal puncta
- canaliculi
- nasolacrimal duct
- nasal punctum
Functions of the lacrimal system
- provides nutrition to occular surface
- removes metabolites, waste, debris
- provide lubrication to occular surface
A patient has presents with mucoid ocular discharge, what is the first thing you will do before any other diagnostics?
- Shirmer Tear Test
Lacrimal System Diagnostics
- Shirmer Tear Test
- Fluorescine Dye Passage
- Nasolacrimal (NL) flush
Two causes of discharge
- overproduction
- lack of drainage
Keratoconjunctivitis sicca (signs)
- mucoid discharge
- blepharospasm
- conjunctival hyperemia
- 360 corneal vessels
- corneal melansosis
Keratoconjunctivitis sicca (causes)
- immune-mediate (most common)
- drugs (TMS, atropine, anesthesia)
- ioatrogenic (removal of 3rd eyelid)
- trauma to lacrimal nerve
Keratoconjunctivitis sicca (Diagnosis)
- signs + STT
Keratonconjunctivitis sicca (treatment)
- topical cyclosporine
- topical antibiotic/ steroid
Developmental Drainage Obstruction (signs)
- dogs have epiphora from birth
- fluorescine dye passage poor or negative
- NL flush nothing from inferior punctum
- horses have chronic purulent discharge
Developmental Drainage Obstruction (treatment)
- in dogs – incise conjunctiva over imperforate punctum
- topical abx/ steroid combination
- in horses, cannulate
Foreign Body Obstruction (signs)
- blepharospasm
- mucupurulent discharge
- medial canthal swelling
- (-) fluorescin dye passage
Foreign Body Obstruction (Treatment)
- vigorous flushing +/- anesthesia
- dislodge/ retrieve fb
- cannulate NL system
- Abx/ steroids
Inflammatory Obstruction (Causes)
- descending infection w/ stagnant tear drainage
Inflammatory Obstruction (signs)
- mucopurulent discharge
- no medial canthal swelling
- (-) fluorescin dye passage
- NL flush easy, mucoid plug
Inflammatory Obstruction (Treatment)
- NL flush (+/- betadine)
- abx/ steroid
Functions of the anterior uvea
- regulate light entry
- accomodation
- produce aqueous
Anterior Uveitis (active - signs)
- Aqueous flare
- miosis
- hypopyon or hyphema
- keratic precipitates
- iris bombé
- corneal edema
- episcleral injection
- corneal vessels
- dec IOP initially
Anterior Uveitis (inactive- signs)
- corneal scarring
- posterior synechia
- iridial scarring
- cataracts
- glaucoma, buphthalmos
Anterior Uveitis (pathogenesis)
- damage to anterior uvea –> release mediators inflammation –> increase vascular permeability -> breakdown BAB –> leakage of protein, fibrin, cells into aqueous
Anteriur Uveitis (treatment)
- topical steroid, NSAIDS, atropine
Anterior Uveal Neoplasia (top 3)
1* - melanoma, ciliary body adenoma/ carcinoma
2* - Lymphoma
Treatment of Anterior Uveal Neoplasia
- enucleation
Uveal cysts (signs)
- 3 locations (posterior surface or iris/cb, pupillary margin, free floating in AC)
- +/- transillumination
Uveal Cysts (cause)
- idiopathic
- 2* to inflammation
Uveal cysts (treatment)
- not necessary
Iris Atrophy (signs)
- scalloping at pupil margin
- moth eaten appearance to iris stroma
- slow PLRs
- anisocoria
- dyscoria
Iris Atrophy (treatment)
- not indicated
Persistent pupillary membrane (signs)
- originate @ collarette region of iris (iris-iris, iris-ant lens, iris-post. cornea)
Persistent pupillary membrane (cause)
- heritable in certain breeds
- developmental defect
Persistent pupillary membrane (treatment)
- usually not indicated
- iris > lens cataract surgery
Glaucoma (progression)
- peracute onset pressure spike
- initially unilateral
- fellow eye affected 6-12 months
Glaucoma (primary mechanism)
- decreased outflow of aqueous humor
Glaucoma (signs - chronic)
- buphthalmos
- corneal striae, fibrosis
- lens (sub)luxation
- mydriasis
- ‘cupped’ optic disk
- tapetal hyper-reflectivity
- retinal vascular attenuation
Glaucoma (cause)
- iridocorneal angle increasingly compromised first few yers of life
- drainage angle collapsed
- IOP spikes
Causes of 2* Glaucoma
- Anterior Uveitis (#1 cause)
- lens luxation/ subluxation
- intraocular neoplasia
Glaucoma (treatment)
- Mannitol (acute decrease in IOP by pulling fluid out of vitreous humor)
- Methazolamide (oral carbonic anhydrase inhibitor – not really used)
- Topical Meds [Xalatan (topical prostaglandin -> miosis), Dorzolamide (CA inhibitor will dec production), Timadol Maleate (B-blocker)]
3 structural elements of the lens
- lens capsule (barrier function)
- lens epithelium (multiple through life)
- lens fiber cells (transparent d/t orderly arrangement)
Reasons for lens transparency
- absence of blood vessels
- lack of pigmentation
- orderly arrangements of lens fiber cells
Cataracts (4 classifications)
- incipient - focal, no intereference w/ vision
- incomplete - diffuse, + tapetal reflection
- complete - vision loss
- resorbing - crystalline, wrinkled ALC, deep AC, some degree of lens-induced uveitis
Cataracts (causes)
- disruption in lens-cell fibers
- -> inherited
- -> diabetes mellitus
- -> anterior uveitis (most common in cats/horses)
- -> senility (usually do not progress to vision impairment)
- -> trauma
Cataracts (treatment)
- surgery
Lens Sub-Luxation (signs)
- shalow or uneqal ant. chambers
- anisocoria
- aphakic crescent
- vitreous strands through pupil
- iridodonesis
- glaucoma
Anterior Uveitis (causes)
- infectious
- immune-mediated
- neoplastic
- metabolic (systemic hypertension)
- traumatic (blunt or perforating)
- idiotpathic (#1 cause)
