Lecture 10 2/20/25

Question 1

What are the characteristics of anterior uveal tract anatomy?

Answer 1

-iris and ciliary body are extremely vascular
-iris consists of sphincter muscle, dilator muscle, and stroma
-ciliary body has muscle for accomodation
-non-pigmented epithelium of ciliary body produces aqueous humor
-pigmented and non-pigmented epithelium of ciliary body compose part of blood-ocular barrier

Question 2

What determines pupil size in a normal eye?

Answer 2

balance between tonic activity of parasympathetic nervous system activating sphincter muscle and tonic activity of sympathetic nervous system activating dilator muscle

Question 3

What happens when light falls on the retina in a normal eye?

Answer 3

-photoreceptors are activated
-reflex pathway involving midbrain structures loops through parasympathetic pathway to constrict pupil

Question 4

What are persistent pupillary membranes?

Answer 4

strands of tissue that extend from the iris collarette to the lens, cornea, and/or to another area on the iris

Question 5

Which species/breeds most commonly exhibit persistent pupillary membranes?

Answer 5

*dogs
-basenjis
-corgis
*horses

Question 6

What is heterochromia iridis?

Answer 6

multi-colored iris; often seen in animals with dilute colors that may also lack fundic pigment and tapetum

Question 7

What is the treatment for persistent pupillary membranes?

Answer 7

none needed

Question 8

What is the treatment for heterochromia iridis?

Answer 8

none needed

Question 9

What is anterior uveitis?

Answer 9

inflammation of the iris or ciliary body leading to breakdown of blood-ocular barrier

Question 10

Which clinical sign is pathognomonic for anterior uveitis?

Answer 10

aqueous flare

Question 11

Which clinical signs are highly suggestive or anterior uveitis?

Answer 11

-decreased intraocular pressure
-miosis

Question 12

What is aqueous flare?

Answer 12

leaking of cells and protein from uveal vessels

Question 13

How is aqueous flare detected?

Answer 13

-shine a focused light source from the front
-observe from the side; beam of light traversing anterior chamber will be visible if there are appreciable quantities of protein

Question 14

What is hypopyon?

Answer 14

chronic manifestation of aqueous flare in which precipitate settles out and collects at the bottom of the eye

Question 15

What are keratic precipitates?

Answer 15

a form of aqueous flare in which precipitate appears to dot the eye

Question 16

What is miosis?

Answer 16

small/contracted pupil that results due to inflamed tissues releasing prostaglandins, causing the sphincter muscle to constrict

Question 17

What are the signs of pain due to anterior uveitis?

Answer 17

-blepharospasm
-photophobia
-enophthalmos/sunken eyeball
-prolapse of third eyelid
-depression

Question 18

What causes pain in anterior uveitis?

Answer 18

ciliary muscle spasm

Question 19

What can cause redness of the eye in anterior uveitis?

Answer 19

-ciliary flush
-episcleral congestion

Question 20

What are the two common causes of episceral injection?

Answer 20

-anterior uveitis
-glaucoma

Question 21

What is the mechanism of corneal edema?

Answer 21

inflammatory cells damage corneal endothelium, decreasing efficacy of ATPase pumps

Question 22

What causes decreased intraocular pressure in anterior uveitis?

Answer 22

ciliary body inflammation leads to decreased aqueous production and increased non-conventional outflow from dilated leaky vessels

Question 23

What is synechia?

Answer 23

when the iris adheres to the lens (posterior, more common) or to the cornea (anterior) due to sticky fibrin

Question 24

What does secondary glaucoma develop from?

Answer 24

iris bombe/cells in angle

Question 25

What is iris bombe?

Answer 25

-pupil becomes synechiaed posteriorly to the lens for all 360 degrees, preventing aqueous humor flow through the pupil -aqueous builds up behind iris, causing it to bow forward -peripheral iris adheres to cornea and obliterates iridocorneal angle

Question 26

Why do cataracts develop in anterior uveitis?

Answer 26

due to abnormal metabolism in the lens due to abnormal aqueous

Question 27

Which iridial changes can be seen in anterior uveitis?

Answer 27

-darkening -congestion -swelling -rubeosis iridis/abnormal blood vessels on iris

Question 28

What are the goals of treatment for anterior uveitis?

Answer 28

-decrease pain by stopping ciliary spasm -prevent synechia by dilating and/or moving pupil -decrease cellular and protein exudation to prevent glaucoma (use anti-inflammatories)

Question 29

Which parasympatholytic drugs can be used in anterior uveitis treatment?

Answer 29

-atropine (can lead to glaucoma) -tropicamide (used in patients with secondary glaucoma)

Question 30

What are the characteristics of corticosteroid treatment for anterior uveitis?

Answer 30

-immunosuppressive -inhibit arachidonic acid metabolism -anti-fibrotic -inhibit neovascularization -must use pred. or dexamethasone; hydrocortisone does not penetrate -can be used in eyes despite systemic dz, but do NOT use with corneal ulcers

Question 31

What are the general indications for corticosteroid treatment?

Answer 31

-inflammatory dz -immune-mediated dz -reduction of neovascularization/scarring in corneal dz

Question 32

What are the contraindications for corticosteroid treatment?

Answer 32

-corneal ulceration -active infection

Question 33

What are the side effects of corticosteroid treatment?

Answer 33

-slowed corneal epithelialization -activate latent collagenase/MMPs -can encourage infection -can have systemic side effects

Question 34

What are the topical preparations of NSAIDs?

Answer 34

-ketorolac -flurbiprofen -suprofen -diclofenac

Question 35

What are the indications for NSAID therapy?

Answer 35

-inflammatory disorders in which steroids are contraindicated -adjunct to corticosteroid therapy (can use NSAIDs with steroids here!)

Question 36

What is the contraindication for NSAID therapy?

Answer 36

can inhibit ulcer healing