Final: Ophthalmology - Lens, Glaucoma, Fundus Flashcards
What is the therapy for cataracts?
Topical NSAIDs and corticosteroids (to help control/prevent lens-induced uveitis)
Phagoemulsification - sx where lens is broken up using ultrasound energy and aspiration
What is the therapy for lens induced uveitis?
Topical +/- systemic anti-inflammatories
What is the etiology of lens luxation? How is it treated?
Primary: Inherited (Terrier breeds) causng abnormal degeneration of zonular ligaments; more common in dogs
Secondary: Chronic uveitits (most common in cats), trauma, chronic glaucoma (enlargement of globe can stretch/break zonular ligaments)
When is latanoprost indicated with lens instability? When is it counterindicated?
Indicated: Anterior lens luxation when surgery IS NOT possible, subluxation
C/O’d: Anterior lens luxation when surgery IS possible
Latanoprost = Miotic to trap lens
What is the term for the hardening of the lens that occurs naturally in animals and causes increased reluceny such that the lens appears cloudy? At what age is it evident in dogs and cats? Does it cause vision loss?
Nuclear sclerosis
7 yrs
Does not cause vision loss
What is a cataract?
Any opacity of the lens or lens capsule
What is used to determine where the opacity is located in the lens?
Parallax - using the appearance of one object relative to another to determine depth
Where do lens zonules attach? What are they?
Equator of the lens
Small collagen fibrils arising from ciliary body that secure the lens’ position within the eye (ligaments of the ciliary body)
What type of cataract formation is driven by osmotic effects due to entrapped sorbital (converted from glucose by aldose reductase) and fructose in the lens capsule? What animals is this type common in?
Intumescent cataract
Diabetics
When do you see an aphakic crescent?
Lens subluxation
What is the movement of the iris that occurs secondary to lens instability? What about the movement of the lens secondary to lens instability?
Iridonesis
Phacodonesis
Cataract or nuclear sclerosis:
Can see the fundus through a lens attenuation
Can see fundus around a lens attenuation
Nuclear sclerosis: Can see the fundus through a lens attenuation
Cataract: Can see fundus around a lens attenuation
What is the most common cause for cataract formation in dogs? Cats and horses?
Dogs: Inherited
Cats, Horses: Chronic uveitis
Dogs with ____ will lose rod photoreceptor function and display ____ blindness, often before developing ______.
Progressive retinal atrophy (PRA)
Night
Cataracts
Important to exclude retinal disease as an etilogy of cataract prior to pursuing cataract surgery
What are the 2 types of lens-induced uveitis? Which is more severe and how are they caused?
Phacoclastic (more severe)- caused by traumatic tears of the lens capsule
Phagolytic (milder)- leakage of lens proteins from a cataract