Exophthalmos, Proptosis, Buphthalmos, Glaucoma Flashcards
What is the difference between Buphthalmos & Exophthalmos?
Buphthalmos=ENLARGED globe(from increased IOP)
Exophthalmos= NORMAL sized globe that PROTRUDEs
A dog comes in with the main complaint of “pawing” at its eye. On tonometry you find the IOP=28 mmHg. While the eye is firm it does retropulse.
What is your top ddx?
Bupthalmos from glaucoma
What are the 4 main things to consider when working up an exophthalmos case?
- Signalment & history are critical clues
- Complete PE
- Ophthalmic exam
- Oral exam
What surgery removes ONLY the globe?
Enucleation
What surgery removes the globe & orbital contents?
Exenteration
Swelling of the eyelid conjunctiva=
Chemosis
T/F: Orbital cellulitis due to Idiopathic inflammation causes only bilateral exopthalmos.
FALSE!
Idiopathic inflammation causes unilateral OR bilateral Orbital cellulitis
What is the main c/s & reason the owner would bring in an orbital cellulitis / retrobulbar abscess case?
“Red eye”-hyperemia
On US of the orbit of a dog that was brought in for “red eye” you find bilateral fluid pockets. What is your top ddx?
Bilateral=Orbital cellulitis
If it were unilateral think Retrobulbar abscess
What is the difference in treating exopthalmos from Orbital cellulitis vs. Retrobulbar abscess?
Orbital cellulitis- Steriods & Antibiotics
Retrobulbar abscess- Antibiotics only
A _______ may be placed on the lateral canthus of an exophthalmic eye if it protrudes so much the dog can’t blink.
Temporary tarsorrhapy
What age & type of dog does orbital cellulitis/retrobulbar abscesses affect?
Young(1-5 y/o)
Large breed
T/F: The oral exam of an orbital cellulitis case ma cause pain.
True
Waxing/waning “suprised” expression
NON-painful when mouth opened
Normal behavior
NON-hyperemic orbital tissue
Extraocular polymyositis
What is the treatment for Extraocular polymyositis?
Immunosuppressive corticosteroids-SLOW taper
What should you warn the owner of with extraocular polymyositis?
May relapse 1-2 times
What is the #1 cause of Anterior uveitis?
Infectious diseases
What are the top ddx for Peripheral lymphadenopathy cases with the following signs? Exophthalmos Anterior uveitis Ocular cloudiness Fever
Lymphoma
Tick borne dz
Fungal dz
Protozoal dz
Extreme exophthalmos to the point that they can’t close their eyes=
Proptosis
What types of dogs are predisposed to proptosis?
Brachycephalics
Trauma cases of proptosis in cats and non-brachycephalic dogs have what kind of prognosis?
SEVERE & more guarded prognosis
What is the prognosis for vision of proptosed eyes?
Gaurded-poor
only 27% of proptosed canine retained vision
What can be used to reduce proptosis?
Lateral canthotomy w/ temporary tarsorrhaphy
What is the tx for a completely avulsed proptosed eye?
Enucleate
Buphthalmos is cause by ______ or _______.
Chronic glaucoma or IO neoplasia
What is the top ddx for the following c/s? Dilation of pupil Corneal edema Subluxation or luxation of lens Vision loss Buphthalmus
Chronic Glaucoma
What is the difference between Acute & Chronic glaucoma?
Globe size
Acute: NOT enlarged
Chronic: Enlarged(bupthalmic)
What is the name for the break in Descemet’s membrane found with chronic glaucoma cases?
Haab’s striae
T/F: Acute glaucoma is unilateral.
True
What are the two types of primary glaucoma & which is more common?
Narrow/closed angle=common
-abnormal iridocorneal angle
Open angle=less common
-Normal iridocorneal angle
Which of the two types of primary glaucoma has Goniodysgenesis?
Narrow/closed angle
What are the top breeds that have the two types of primary glaucoma?
Close angle:
- Cocker
- Basset
- Chow
- Shar pei
- Boston
- WFT
Open:
-Beagle
What is the pathogenesis of glaucoma?
Aqueous humor can’t get out(obstruction)
Fluid build up–>Increased IOP, stretch of ocular structures & lens zonules–> vision loss, buphthalmus & subluxation/luxation of lens
What are the 4 main causes of secondary glaucoma?
Uveitis
Lens diseases
IO neoplasia
Trauma
What is the most common cause of glaucoma in cats?
Uveitis
Glaucoma= IOP > ____
25 mmHg
What are the 2 main treatment goals of acute primary glaucoma if vision is present & c/s
Decrease aqueous production
Increase outflow
What can be used to decrease aqueous production for acute primary glaucoma if vision is present & c/s
IV-mannitol
Carbonic anhydrase inhibitors
What are the oral vs. topical carbonic anhydrase inhibitors?
Oral:
- Methazolamide( Neptazane, Glautabs)
- Acetazolamide(Diamox)
- Dichlophenamide
Topical:
- Dorzolamide
- Brinzolamide
What can be used to increase aqueous outflow for acute primary glaucoma if vision is present & c/s
F2a prostaglandin analouge(“Prosts”: Travoprost–>miosis, inc. outflow
Beta blocker”-olol”: Timolol, Betaxolol–> dec AH production, inc. outflow
Parasymphathomimetics: Pilocarpine, Demecarium bromide–>miosis
What should you warn the owner about about with the treatment of actue primary glaucoma
CONTRALATERAL EYE! Prophylactically treat w/:
Timolol, Dorzolamide, or Demercarium bromide forever
What are the indications for salvage procedures?
- Blind PAINFUL eye
- Blind eye REQUIRING MEDS
- IO tumor
- Severe IO infection
- Severe orbital disease resulting in globe damage
What are the 3 salvage procedures?
- Enucleation
- Evisceration & intrascleral prothesis insertior
- Pharmacologic ablation of the ciliary body
What drug could be used for pharmacologic ablation of the ciliary body?
Gentamicin-vitreal injection
DNU in cats
What might pharmacologic ablation of the ciliary body with a vitreal injection of Gentamicin?
Phthisis bulbi-“Phthisical eye”
-ie. shrunken, non-functional eye
T/F: Medical management is normally enough to control glaucoma enough to maintain vision.
FALSE!!!
Medical management is RARELY enough to control glaucoma enough to maintain vision.
What surgery is recommended for tx of acute glaucoma that’s regaining vision & has an IOP
Diode laser surgery
What surgery is recommended for tx of acute glaucoma that’s regaining vision & has an IOP >20mmHg?
Ahmed shunt placement & Diode Laser
What c/s should make you want to exam an eye immediately for actue glaucoma?
Red, cloudy, painful, or blind eye
Buphthalmos indicates _____ & ______ procedures are likely needed.
Chronicity; Salvage
How is Glaucoma diagnosed?
Tonometry: IOP >25 mmHg
Applanation or Rebound= ideal
Glaucoma can be caused by an of the following EXCEPT:
A. IO neoplasia B. Lens luxation C, Uveitis D. Abnormal iridocorneal angle E. Optic nerve atrophy
E. Optic nerve atrophy
Treatment of an acute glaucoma case will involve all of the following EXCEPT:
A. Atropine B. Oral carbonic anhydrase inhibitor C. Topical miotic D. Mannitol E. Topical carbonic anhydrase inhibitor
A. Atropine
