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Ophthalmology > Unit 2 > Flashcards

Unit 2 Flashcards

1
Q

What is the Uveal Anatomy (aka vascular tunic)

A

Anterior uvea- iris ciliary body
Posterior uvea- choroid

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2
Q

Where does the aqueous humor exit

A

The iridocorneal angle at the base of the iris

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3
Q

What are the functions of the iris (4)

A

Protection, nutrition, controls light entry, removes waste and aqueous humor

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4
Q

What are the functions of the ciliary body

A

Produces aqueous humor and lens accommodation

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5
Q

Where can persistent pupillary membranes bind the iris to

A

Iris to iris, iris to cornea, iris to lens

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6
Q

Which persistent pupillary membrane location formation is generally benign

A

The iris to iris

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7
Q

What can persistent pupillary membranes that bind the iris to the cornea cause

A

Corneal opacities, chronic corneal edema, and may interfere with vision

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8
Q

What uveal disease is acquired but some breeds predisposed to, may rupture and cause pigment dispersion but are generally not clinically significant

A

Iris cysts

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9
Q

Is iris atrophy a congenital disease and is it clinically significant?

A

No it is an acquired disease of older dogs that isn’t usually clinically significant

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10
Q

What are the clinical signs of uveitis

A

Miosis (look for asymmetry), change in iris color (red or dark), low IOP or >5mm difference between eyes), sclera injection and maybe conjunctival hyperemia, pain, aqueous flare

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11
Q

What are the potential causes of aqueous humor flare (the actual substances)

A

Increased cells and protein, hypopyon (pus in the AC), Hyphema (blood in the AC), Fibrin

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12
Q

Explain the Tyndall effect

A

The ability to see light passing through a liquid becuase of the dispersion of light in colloidal solutions

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13
Q

What are potential sequelae of uveitis

A

Glaucoma, synechia (lens sticking to other areas), cataracts, retinal detachments, loss of vision, blindness, enucleation

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14
Q

T/F most causes of uveitis are secondary

A

True

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15
Q

List examples of primary causes of uveitis

A

Lens-induced uveitis (cataracts), blunt injury, reflex uveitis from corneal ulceration, intraocular tumors

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16
Q

T/F diabetes can cause uveitis

A

True

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17
Q

T/F cataracts can cause uveitis but uveitis can also cause a cataract

A

True

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18
Q

How does a cataract cause uveitis

A

The lens proteins leak through the capsule and cause inflammation

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19
Q

What is the first step when treating uveitis

A

Looking for the underlying cause

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20
Q

How should you treat uveitis

A

Treat the underlying cause and also control the inflammation with topical NSAIDS or steroids (if there are no ulcers)

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21
Q

Should you use systemic anti inflammatories for uveitis and why or why not

A

Not without a work up because it may worsen the uveitis or obscure diagnostics

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22
Q

How should you treat iris melanosis in a cat

A

You should monitor or enucleate if the eye is inflamed or there is increased pressure.

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23
Q

Is iris melanoma always malignant

A

No it can be benign, but there is no way to tell early in the disease without enucleation and benign can later become a tumor

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24
Q

What are the three structural elements of the lens. Which part becomes the lens fibers and which is the barrier

A

There is the lens capsule which is the barrier, the lens epithelium which multiplies to become the lens fibers, and the lens fibers (they are antigenic protein)

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25
Q

A normal lens should have what 3 features

A

Absence of blood vessels, lack of pigmentation, and perfect orderly arrangement of lens fiber cells

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26
Q

What is the primary source of nutrition for the lens

A

The aqueous humor

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27
Q

What is retroillumination and what can it detect

A

When light is reflected from the iris or tapetum to help detect subtle structures in the anterior segments or lens. The abnormalities will appear dark against the light background

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28
Q

How will cataracts impact retroillumination

A

They will alter/interrupt the tapetal/red reflex

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29
Q

How does nuclear sclerosis differ from cataracts

A

Nuclear sclerosis is a normal age related change because the lens nucleus increases in density because of lens fiber addition. Looks like a lens within a lens. Nuclear sclerosis does not significantly affect vision in animals nor does it block the tapetal/red reflex

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30
Q

What is a lens coloboma

A

A notch defect (missing tissue) seen at the equator of the lens that is congenital

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31
Q

What is microphakia

A

A small lens, is congenital

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32
Q

What is Spherophakia

A

A rounded lens, it is congenital

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33
Q

What is the most common cause of cataracts in dogs

A

Genetics/ inherited

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34
Q

How does diabetes cause cataracts

A

Hyperglycemia—> hexokinase pathway becomes over saturated and the glucose is shunted to aldose reductase which turns it into sorbitol with alters the osmotic gradient. Causes lens fiber swelling, rupture, vacuole formation and cataracts

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35
Q

What is more likely to develop cataracts from diabetes dogs or cats

A

Dogs

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36
Q

What disease causes bilateral cataracts, that are complete, develop rapidly, and cause blindness

A

Diabetes

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37
Q

What is the most common cause of cataracts in cats and horses and are they good candidates for cataract surgery

A

Uveitis/ post-inflammatory cataracts, usually not good candidates

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38
Q

What is lens capsule rupture associated with in cats and knowing this how should you treat it

A

Associated with risk of post-traumatic sarcoma development so you should consider enucleation

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39
Q

What classification is the earliest stage of cataract disease

A

Punctate cataracts

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40
Q

Describe what classifies a cataract as incipient

A

When <10% of the lens is affected and there is no vision loss and the tapetal reflection is apparent

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41
Q

What describes a cataract that is incomplete/immature

A

10-99% of the lens is affected but the tapetal reflection is still apparent

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42
Q

Will a complete cataract have a menace

A

No, there is vision loss

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43
Q

What is a resorting/hypermature cataract

A

There may be a tapetal reflection and it appears “sparkly and wrinkled”

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44
Q

What is the only surefire way to cure a cataract

A

Surgical removal of the opacity- use ultrasonic energy with irrigation and aspiration to remove the lens and replace it with an intraocular lens implant

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45
Q

What must you do with a post-op cataract surgery patient

A

Control the uveitis with topical anti-inflammatories, monitor the IOPs, systemic antibiotics and anti0inflammatories and recheck them frequently

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46
Q

What causes a primary lens luxation and what breeds are predisposed

A

Anomalous zonules and terriers

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47
Q

What are causes of secondary lens luxation

A

Chronic inflammation, glaucoma/ buphthalmia (enlargement of the eye), intraocular mass, trauma

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48
Q

Where can lens luxate to

A

Anteriorly (in front of the iris)
Posteriorly (falls back into the vitreous)

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49
Q

What is a hallmark sign of a lens luxation

A

An aphakic crescent

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50
Q

What is glaucoma

A

A group of diseases united by elevated intraocular pressure impairing normal optic nerve and retinal health and function

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51
Q

What is normal intraocular pressure and what is it usually dictated by

A

10-25 mmHg and dictated by a balance between aqueous humor production and outflow

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52
Q

Where and how is aqueous humor made

A

The ciliary body through passive diffusion and also active diffusion which uses carbonic anhydrase to release HCO3 into the posterior chamber which Na and water follow

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53
Q

Describe the flow of the aqueous humor

A

Posterior chamber—> through pupil—> into anterior chamber—> through iridocorneal angle into venous sinuses OR via the uveoscleral pathway (Supra-ciliary/choroidal space) OR through the iris/ciliary body stroma to the choroidal circulation

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54
Q

What are the two causes of primary elevated IOP

A

Iridocorneal angle closure and accumulation of proteoglycans in trabecular meshwork (in the ciliary cleft)

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55
Q

What are the five secondary causes of elevated IOP

A

Infiltration of iridocorneal angle (ICA) with inflammatory or neoplastic cells, neovascularization of iris spanning the IC angle, Synechiation (iris sticking to other things), lens luxatio/subluxation, vitreous pupillary block or obstruction of ICA

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56
Q

How fast can elevated intraocular pressure cause irreversible damage to the optic nerve

A

Within 24-48 hours

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57
Q

T/F acute glaucoma isn’t a “neurologic” emergency

A

False

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58
Q

If you control the intraocular pressure will damage to the optic nerve stop?

A

No it can still continue because a cascade of apoptosis has begun

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59
Q

What is staphyloma and what is it a clinical sign of

A

Uveal bulging via thinned sclera from chronic stretching/atrophy, clinical sign of glaucoma

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60
Q

What is gonioscopy and what can it be used to evaluate

A

Evaluation of intracorneal angle with special lenses to assess the angle opening and abnormalities to help determine if there is primary glaucoma

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61
Q

What signs may tell you if there is potential for restoration of vision with glaucoma?
What would indicate a bad prognosis?

A

If the glaucoma is acute, there is a positive menace, dazzle reflex, or consensual PLR to the fellow eye, and a normal optic nerve head these are all good signs
Chronic glaucoma (>72hr), buphthalmic, absent reflexes and a grey/dark, round and cupped optic nerve head are all bad signs

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62
Q

What are signs glaucoma may be primary in nature (inherent angle problem)

A

No other ocular disease, breed predisposition, abnormal drainage angle (gonioscopy)

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63
Q

What are ocular diseases that can result in secondary glaucoma

A

Lens luxation, intumescent cataract, uveitis, neoplasia, vitreous prolapse

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64
Q

What are differences in how primary and secondary glaucoma are treated

A

Primary usually involves therapy to open the angle and decrease aqueous production and secondary involves treating the underlying cause and therapy to decrease aqueous production

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65
Q

American cocker spaniel, chows, huskies, bouviers, and basset hounds are prone to what

A

Primary angle closure glaucoma

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66
Q

T/F primary glaucoma acute attacks may spontaneously return to normal and vision may return

A

True

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67
Q

When is a likely time of day that a primary angle closure glaucoma cause may experience an acute attack

A

At night (dim light), because the pupil dilates and obstructs the angle

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68
Q

What is goniodysgenesis

A

There is dysplasia of the pectinate ligaments, they do not develop normally and instead of delicate strands they form broad thickened fibers that are large sheets with “flow holes”

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69
Q

What makes up the posterior segment

A

Vitreous, choroid (tapetum), retina, optic nerve

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70
Q

What is the primary vitreous

A

The hyaloid vessel system that becomes the vitreous but during development is vascular and provides nutrients to the lens, the vessels all but go away in development

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71
Q

What accounts for 75% of the volume of the globe

A

Vitreous

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72
Q

What is the vitreous mostly made of

A

Water

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73
Q

What are the functions of the vitreous

A

Provides structure and keeps the retina pressed against the back of the eye (mechanical support), metabolic support for the retina and lens, some refraction

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74
Q

What is the common developmental abnormality of the vitreous

A

Persistent hyaloid artery or remnant

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75
Q

What is a bergmeister’s papilla and what is it common in

A

A small tuft of tissue at the optic nerve head that is a remnant of the hyaloid artery and is a normal finding often in large animals

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76
Q

What is persistent tunica vasculosa lentis, what can occur from it

A

A network of fine, white strands extending from posterior lens capsule that is the remnants of embryonic blood supply, inherited in Dobermans and Stanford shire terriers and sporadic in other breeds but can become hyperplastic

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77
Q

What is asteroid hyalosis

A

Condensed calcium phospholipid particles suspended in vitreous, look like sparkly or starry pin-point opacities (snow globe appearance), an aging change

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78
Q

What is syneresis

A

Liquification of vitreous

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79
Q

What is notable about vitreal hemorrhage

A

Will be very slowly resorted (months), but the underlying cause is a sequela to trauma, systemic disease, etc.

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80
Q

Neurosensory retina layers look like what

A

Nothing!

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81
Q

What part of the retina can you see in the neurosensory retina layers

A

The blood vessels

82
Q

What part of the retina has opacity to it so you can see it

A

Retinal pigmented epithelium

83
Q

Where do retinal detachments occur and why

A

The space that is formed between the neurosensory retina and retinal pigmented epithelium because these layers are formed separately so they aren’t attached

84
Q

Do birds have retinal blood vessels

A

No, only mammals do

85
Q

What part do the retinal blood vessels nourish

A

The inner third of the retina (the outer 2/3 nourished by choroid)

86
Q

In an albino animal what can you see instead of the retinal pigment

A

The choroid behind it and its blood vessels

87
Q

Which retinal pattern is poorly vascularlized

A

Paurangiotic retinal pattern

88
Q

What retinal pattern is a zigzag of the retina and choroid because there are no retinal blood vessels and is seen mostly in birds
What do they also have for nourishment

A

Anangiotic retinal pattern
There is also a pectin

89
Q

What are the outermost cells of the sensory retina

A

Photoreceptors (rods and cones)

90
Q

What cells are highly light sensitive but provide minimal detail

A

Rods

91
Q

What cells are less light sensitive but good detailed vision and color

A

Cones

92
Q

What receives input from the photoreceptors and transmits it to the ganglion cells

A

Integrating neurons

93
Q

What transmits visual info to the brain and the axons form the nerve fiber layer and optic nerve

A

Ganglion cells

94
Q

Describe how the electrical signal travels through the eye

A

It is generated by the photoreceptor cells and transmitted to the integrating neurons and to the ganglion cells to the nerve fiber layer to optic nerve moving in a posterior direction

95
Q

What are the supporting cells of the retina

A

Retinal muller cells

96
Q

What is the outermost later of the retina

A

The retinal pigmented epithelium

97
Q

Is it normal for the retinal pigmented epithelium to have pigment over the tapetum

A

No, normally there is not pigment over the tapetum

98
Q

The optic nerve head is also known as

A

Optic disk or optic papilla

99
Q

What does the choroid contain

A

Blood vessels (choriocapillaris and choroidal vessels), pigment, and tapetum

100
Q

What is the job of the tapetum

A

It is posterior to reflect the light photons back to the retina to enhance light sensitivity

101
Q

Because the tapetum is between the retina and the choroid how does blood supply get through to the retina

A

Vessels that travel through the tapetum (creates stars of Winslow)

102
Q

What reflexes assess light reflexes and perception (not vision)

A

Pupillary light reflexes and dazzle reflex

103
Q

What tests assess vision

A

Behavior (history, cotton bal tracking, maze testing), menace response

104
Q

What is uses to assess retinal electrical activity (retinal function only)

A

Electroretinography

105
Q

How can you visualize the posterior segment when the anterior segment is opaque

A

Ocular or orbital ultrasonography

106
Q

How can you look at the vessels of the retina

A

Fluorescein angiography

107
Q

What is ophthalmoscopy

A

Looking at the fundus/back of the eye- the composite image of layered structures of the posterior segment

108
Q

What are the three major layers of the fundus

A

Fiberous tunic, vascular (uveal) tunic, nervous tunic

109
Q

What is the outermost and innermost layer of the fundus

A

Outermost- sclera
Innermost- retinal vessels

110
Q

Pigment and vascular variations can vary, in eyes with little pigment in the choroid (like blue eyes) what does the eye normally look like

A

You will see lots of retinal and choroidal vessels and may even see some sclera poking through

111
Q

The tapetum is always what (position wise)

A

Superior (when present)

112
Q

What color is the tapetum normally in dogs and cats

A

Dogs- yellow, green, orange, blue, purple (as puppies)
Cats- yellow, green

113
Q

What animals often lack a tapetum

A

Color dilute animals like merles, because fundus color varies with coat color

114
Q

T/F large dogs often have small tapetums

A

False, tapetal size varies with size of dog, large dog= large tapetum

115
Q

In primary glaucoma therapy what therapeutics are used to decrease aqueous humor production

A

Carbonic anhydrase inhibitors, betel blockers, or cyclo-destructive procedures (laser, cryo, chemical)

116
Q

In primary glaucoma therapy what therapeutics are used to enhance drainage

A

Mitotics- prostaglandins, pilocarpine
Goniovalve implantation

117
Q

When are miotics contraindicated for glaucoma

A

Secondary glaucoma and/or lens luxation

118
Q

What are two glaucoma therapies that are emergency “band-aids” to allow other treatments time to work or give time to get to surgery

A

Osmotic diuretics (mannitol) or aqueocentesis (tap the eye)

119
Q

T/F topical steroids are contraindicated for glaucoma but NSAIDS are not

A

False, topical NSAIDS are contraindicated but steroids are not. Systemic steroids and NSAIDS are sometimes used

120
Q

If one eye has primary glaucoma what is the likelihood the other eye will get it too

A

The “good” eye will develop glaucoma usually within 8 months

121
Q

Betaxolol (beta blocker) or Demecarium bromide (acetylcholinesterase inhibitor) are used how

A

As prophylactic therapy for primary glaucoma, but eventually will fail

122
Q

What is more common, secondary or primary glaucoma

A

Secondary is twice as common

123
Q

What is a common sign of glaucoma associated with uveitis

A

The intraocular pressure is high when normally it is low with uveitis

124
Q

What are the common treatments for secondary glaucoma from uveitis

A

Workup and treat the uveitis and use topical carbonic anhydrase inhibitors, beta-blockers, or beta agonists

125
Q

How are two ways uveitis can cause secondary glaucoma

A

Obstruction of the filtration apparatus through inflammatory cells/fibirn accumulating in the intracorneal angle
Pre-iridal fibrovascular membrane (rubeosis iridis)- granulation tissue on the anterior surface of the iris

126
Q

What are common causes for primary instraocular tumors and are they usually benign or malignant

A

Melanoma, melanocytomas, ciliary body adenocarcinoma, adenomas
In dogs primary tumors are usually benign to the body (but can devastate the eye) but in cats they have metastatic potential

127
Q

Feline glaucoma is usually primary or secondary

A

Secondary from uveitis, neoplasia, or feline aqueous humor misdirection syndrome (FAHMS)

128
Q

What happens with feline aqueous humor misdirection syndrome (FAHMS)

A

In older cats the aqueous humor gets directed into the abnormal vitreous and shifts the lens and iris diaphragm forward

129
Q

What is often present with feline aqueous humor misdirection syndrome (FAHMS) (other than glaucoma)

A

Anisocoria and a shallow anterior chamber

130
Q

What are used to treat feline aqueous humor misdirection syndrome (FAHMS)

A

Topical carbonic anhydrase inhibitors (brinzolamide)

131
Q

Light enters the eye and travels through what (on the retina) to strike what

A

Enters the eye and travels through the sensory retina to the posterior/outer portion to strike the retinal pigment epithelium and photoreceptors to convert it to an electrical signal

132
Q

T/F the retinal muller cells help transmit the electrical impulse of light energy through the eye

A

False

133
Q

Which layer of the fundus is orange-red

A

The vascular tunic/ choroid

134
Q

What layer of the fundus varies with coat color AND can obstruct the choroid

A

The retinal pigmented epithelium of the nervous tunic, variably pigmented

135
Q

Where is the dog’s optic nerve head

A

In the tapetum or non-tapetum, usually at the junction

136
Q

Where is the cat’s optic nerve head

A

In the tapetum

137
Q

How are dog and cat optic nerve heads different in shape

A

The dog’s is myelinated so it varies in shape because it varies in myelination. The cat’s is in myelinated

138
Q

What are the only “things” that could be in the fundus that shouldn’t be and what colors would they appear

A

Infiltrate (infection, inflammation, neoplasia)- whitish, edema- grayish, hemorrhage- red

139
Q

How do active lesions in the fundus typically appear (compared to for example a scar)

A

Active processes are usually raised, have ill-defined edges, and are hyporeflective

140
Q

If a disease causes retinal thickening from infiltrate, how will it often appear during a fundus examination

A

It will be a hyporeflective area

141
Q

A dog has small gold circles on its fundus that appear to “glint” and shine at you. What are these?

A

Retinal scars

142
Q

What is a hallmark sign of retinal degeneration

A

Vascular attenuation

143
Q

When there is a retinal detachment, exactly what two layers are separating

A

The neurosensory retina and the underlying retinal pigmented epithelium

144
Q

What can cause a retinal detachment

A

Subretinal fluid (between the neurosensory retina and RPE)- can be serous, exudative/infiltrate, or hemorrhage
Or retinal tears

145
Q

You look into a dog’s eye and are able to preform a “pen-light diagnosis” because when you look into the pupil there is a vascular membrane visible. What are you diagnosing

A

A complete retinal detachment because the neurosensory layer is not pushed up against the back of the lens

146
Q

What disease is characterized by retinal and tapetal thinning and will appear hyper-reflective and there will be vascular attenuation
This disease is inherited

A

Progressive retinal atrophy

147
Q

What are the two types of progressive retinal atrophy and do they have varying clinical signs

A

Photoreceptor dysplasia and photoreceptor degeneration, the clinical signs are usually similar but the age of presentation and progression rate can vary

148
Q

A dog presents because the owner noticed it started bumping into furniture after they rearranged their living room. The owner also says they did notice the dog seemed to be struggling to see on their nightly walks a few months ago but was fine during the day. You look at the dogs eyes and it has mydriasis (larger pupils) at rest. You do a fundic exam and the dog’s tapetum is hyperreflective. What is the best diagnosis for this dog?

A

Progressive retinal atrophy, they often lose the rods first so they have dim light deficits before progressing to cones and bright light eventually becoming blind. The pupils are larger because they are stretched to try and help the eye see

149
Q

With progressive retinal atrophy might you see a PLR

A

Yes, even if the dog is blind, but it may progressively decrease

150
Q

In late stages of progressive retinal atrophy what may you see in the eye

A

Secondary cataract formation

151
Q

Describe the steps of retinal atrophy

A

Photoreceptors (and retina) dying (rods and then cones)—>retinal thinning—> tapetal hyper-reflectivity—> vascular attenuation (because retina auto regulates the blood supply)

152
Q

What happens with retinal dysplasia and how do dogs get it

A

There is abnormal formation of full thickness areas of neurosensory retina and it folds and creates wrinkles. This is commonly an inherited disease in dogs (don’t breed these dogs!)

153
Q

What breeds are prone to retinal dysplasia

A

Labradors and springer spaniels

154
Q

Are all retinal dysplasia cases the same?

A

No there is a continuum of severity, mild animals may be normal but severe animals may be blind

155
Q

How does a retinal fold appear on a fundic exam

A

Dull/dark grey-green dots or linear folds surrounding hyper-reflective tapetum

156
Q

You see a large horseshoe-shaped area of grey-green on the fundic exam with hyper-reflective foci and some pigmentation. What could this be?

A

Geographic retinal dysplasia, a severe form of retinal dysplasia

157
Q

You do a fundic exam on a dog and you don’t see any blood vessels, and you can’t see the optic nerve, you just see a big dark area blocking some of the tapetum. What is happening

A

There is compete retinal detachment and the retinal is hanging off of the optic nerve and is covering it

158
Q

A Labrador presents with retinal dysplasia and bowed legs that look like a basset hounds. What is occurring

A

This is oculochondrodysplasia and autosomal recessive disease that causes retinal dysplasia and inhibits growth of radius, ulna, tibia, and causes hip dysplasia

159
Q

What happens with Collie eye anomaly

A

A congenital lesion that causes bilateral disease that can vary from choroidal hypoplasia to optic disc coloboma to retinal detachment and if severe enough hemorrhage associated with the retina detachment

160
Q

What does an eye with choroidal hypoplasia look like

A

It has a pale yellow-white lesion (exposed sclera) with abnormal tortuous choroidal vessels and the retina may also have tortuous vessels

161
Q

A female middle aged dog presents to you becuase the owner says she suddenly started running into things, she is getting into the garbage and jumping up on counters to steal food (and she never used to), and is drinking more and having to go out more to urinate.
On presentation the dog’s pupils are dialated and you are unable to get PLRs.
What is your best diagnosis and how can you confirm this diagnosis?

A

Sudden acquired retinal degeneration syndrome
You can do an electroretinogram to differentiate if the blindness is neurologic or retinal and in this case it will be extinguished immediately (flat line)

162
Q

What bloodwork abnormalities may you see with sudden acquired retinal degeneration syndrome and what other disease will this look like

A

Elevated Alk Phos, and maybe elevated ALT, cholesterol, total bilirubin
Looks like hyperadrenocortisism

163
Q

Which is more common chorioretinitis (infection spreading from choroid and extending to retina) or the other way around, retinochoroiditis

A

Chorioretinitis is way more common

164
Q

You do a fundic exam and notice an area where the blood vessels appear raised (are in a different plane). This area is also grayish and has irregular and poorly delineated margins. What is occurring here?

A

This is likely chorioretinitis

165
Q

In active chorioretinitis how can you tell a tapetal lesion from a non-tapetal lesion

A

Tapetal lesions are often grey-ish or brown-ish areas of hyporeflectivity and non-tapetal lesions are more grey-ish to white areas

166
Q

What do inactive areas of chorioretinitis inflammation/ scarred areas look like

A

There is depigmentation with variable pigment clumping and vessel attenuation. The optic nerve may also be pale with atrophy

167
Q

T/F there are tons of infectious causes that can cause chorioretinitis

A

True! It can be from fungal, parasites, viral, bacteria, algal, and more

168
Q

If you suspect chorioretinitis what should be your first diagnostic step

A

A minimum database then maybe titers, BP

169
Q

Should you use topical medications to treat uveal inflammation from chorioretinitis

A

No they won’t penetrate

170
Q

What layers separate in a retinal detachment

A

The neuroretina separates from the retinal pigmented epithelium

171
Q

How do bullous/ exudative retinal detachments differ from Rhegmatogenous

A

Bullous are more common and are due to subretinal fluid or exudate
Rhegmatogenous is usually secondary to a retinal tear or vitreal traction bands (fibrous bands) form because of vitreal hemorrhage or inflammation and pull retina off of RPE

172
Q

You are doing a fundic exam and you see what appears to be the retina “billowing forward” and it is in a different plane of focus. The retinal vessels also appear distorted and pushed away. What could be happening

A

There is a bullous retinal detachment

173
Q

Where might you see retinal vessels in a complete retinal displacement (hint you can use a “penlight diagnosis”)

A

Displaced anteriorly so that you can see them through the pupil on the back of the lens

174
Q

What are 6 differentials for Bullous retinal displacement

A

Hypertension, hypoproteinemia, hyperviscosity, polycythemia, uveodermatologic syndrome, idiopathic/spontaneous

175
Q

How does a disinsertional Rhegmatogenous retinal detachment appear

A

The optic nerve is often obscured as the retina hangs in front of it in a grayish fold and the tapetum will be hyper-reflective and there will be a lack of retinal vessels

176
Q

What are some etiologies that are associated with Rhegmatogenous retinal detachments

A

Congenital abnormalities (ex. Collie eye anomaly)
Shah Tzus/ Lhasa apsos (primary vitreous abnormality)
Secondary to intraocular inflammation or trauma
After cataract surgery

177
Q

What are two ways to repair retinal detachment

A

Laser retinopexy (burning rows of chorioretinal adhesions around the detachment to prevent it from going further

Retinal reattachment

178
Q

What is it called when the optic nerve appears small, round, gray or is absent

A

Micropapilla or optic nerve hypoplasia

179
Q

What is a coloboma

A

A congenital defect or absence of an ocular structure

180
Q

What can be found in the Collie Eye Anomaly (hint it has to do with the optic nerve)

A

An optic nerve coloboma (a pit on or within the optic nerve)

181
Q

What is papilledema

A

Passive, non-inflammatory optic nerve disk swelling

182
Q

What is papilledema associated with and what is it not associated with

A

It is associated with increased intracranial pressure due to the mass lesion but it is not associated with vision loss

183
Q

What is inflammation of the optic nerve called

A

Optic neuritis

184
Q

T/F optic neuritis only effects one eye typically, only involves the optic disk, and causes slow progressive blindness and miosis

A

False, it can be unilateral or bilateral and it can involve any segment of the optic nerve and is associated with sudden blindness and fixed dilated pupils (mitosis)

185
Q

How does optic neuritis differ when there is intraocular involvement vs. retrobulbar involvement

A

With intraocular the disk is swollen, raised, hyperemic or has hemorrhages, and the disk margins are indistinct
Retrobulbar involvement the optic disk appears normal

186
Q

What are some infectious causes of optic neuritis

A

Fungal- Blastomycosis, crypto, histo, toxo
Canine distemper virus

187
Q

What is an immune mediated cause of optic neuritis

A

Granulomatous meningoencephalitis

188
Q

How do you do a diagnostic evaluation of optic neuritis

A

Treat and manage as a neurological disease- CBC/chem/UA, chest radiographs, titers, neurologic evaluation, MRI or CT, CSF tap

189
Q

Optic nerve head cupping is secondary to

A

Chronic glaucomatous optic neuropathy
Ganglion cell loss—> loss of optic nerve and axons

190
Q

What is optic nerve atrophy associated with

A

Chronic progressive retinal atrophy, previous optic neuritis, post proptosis, glaucoma

191
Q

What is it called when there is immediate vision loss with a PLR deficit immediately after a traumatic proptosis

A

Traumatic optic neuropathy

192
Q

What chorioretinal disease in cats is usually associated with eyelid agenesis

A

Focal chorioretinal and optic nerve colobomas

193
Q

What infectious diseases is retinal dysplasia associated with

A

Feline panleukopenia and FeLV

194
Q

What occurs when a cat has a taurine deficiency

A

Since it is an essential amino acid in the feline diet, if it is not present feline central retinal degeneration can occur

195
Q

How would a feline eye look on a fundic exam if the cat has a taurine deficiency

A

There would be two hyper-reflective lesions that coalesce to form a horizontal band over the disk resulting in retinal degeneration

196
Q

What comorbidity may you see with taurine deficiency retinal degeneration

A

Dialated cardiomyopathy

197
Q

What disease is found in Abyssinian, Persian, Siamese, and DSH cats and what will you see on a fundic exam

A

Rod-cone dysplasia and rod-cone degeneration
Tapetal hyper-reflectivity and vessel attenuation occur with feline retinal dysplasia/degeneration

198
Q

What drug can cause feline retinal degeneration (even at the recommended dose)

A

Enrofloxacin

199
Q

What are causes of chorioretinitis in cats

A

Viral (FeLV, FIP, FIV), bacterial, fungal (crypto, histo, Blastomycosis), parasitic

200
Q

What can cause hyphema, vitreal hemorrhage, retinal hemorrhages and vessel tortuosity, and varying retinal detachment in older cats (will have dilated pupils or acute vision loss)

A

High blood pressure- hypertensive chorioretinopathy

201
Q

What other diseases can hypertensive chorioretinopathy be associated with

A

Cardiac disease, renal disease, and/or hyperthyroidism

Ophthalmology (2 decks)

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