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Flashcards in Exotic animal Deck (41)
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1
Q

avian orbit

A

incomplete

very little orbital fat

poor developed extraocular muscles

orbital lacrimal gland in ventrolateral orbit

harderian gland at base of third eyelid

2
Q

Pecten

A
3
Q

Avian adnexa

A

lower eyelid mobile than upper

no meibomian glands

feathers instead of eyelashes

4
Q

Avian nictitans

A

very active

innervated by CN VI

movements controlled by pyrimidalis muscle

from dorsomedial orbit sweeps ventrolaterally

5
Q

Avian globe

A

large-outweighs brain

sclera contains cartilage & 10-18 scleral ossicles

6
Q

avian globe shapes

A

globose-passerines, raptors, Anterior-posterior diameter simialr to equatorial diameters

flat-aquatic birds, flattened cornea, shortened AP diameter

tubular-owls, goatsuckers, longest AP diameter

7
Q

Avian anterior segment

A

striated iris muscles-PLR still present but need neuromuscular blockage for mydriasis

annullar pad-accommodation, compressed by Brucke’s and Crampton’s muscle to deform lens

8
Q

Avian posterior segment

A

no tapetum

pecten-pigmented vascular structure, protrudes into vitreous, overlies optic nerve, nutrition

9
Q

avian retina and optic nerve

A

avascular retina (anagiotic)

Four retinal visual pigments-increased color spectrum including UV light

densely packed PR, thicker retina-increase visual acuity and processing

double cone with oil droplets-act as light filter to enhance color vision, reduce chromatic aberration and glare

rapid flicker fusion rate-can detect more rapid movement in more detail

Fovea-in spp with high acuity vision, high conc of PR, mono vs bi

complete decussation at optic chiasm-direct PLR only

10
Q

avian ophtho exam

A

menace response absent

Direct PLR only

Tonometers not validated

STT, use phenol red in smaller sp

examination without mydriasis

optic nerve most often not visible due to overlying pecten

11
Q

avian trauma clin sxs

A

blepharitis, eyelid lacerations

conjunctivitis, hemorrhage

ossicle fx

corneal ulceration-ant uveitis, hyphema

secondary cataract formation

penetrating injury to lens, lens (sub)luxation

choriorentitis, retinal tears or detachment

pecten avulsion

12
Q

avian trauma course of action

A

evaluate and stablize systemic injuries

ophtho exam

manage uveitis-topical or systemic NSAIDs

topical abx if corneal ulcer present

assess px for return to vision

13
Q

avian enucleation

A

traditional techniques not poss due to ossicles and large globe volume within orbit

attention to hemostasis

avoid traction on optic nerve

smaller sutures

14
Q

transaural enucleation

A

birds

facilitates exposure and removal of the globe

owls

15
Q

globe collapse enucleation

A

birds

incision and collapse of globe

eases removal from orbit

histopath-more difficult

16
Q

blepharitis and conjunctivitis in birds

A

most common reason for presentation in captive birds

clin sxs: blepharoedema, conjunctival hypermia, chemosis, ocular d/c, exophthalmos, corneal ulceration

everything causes this

17
Q

Course of action when bird presents with blepharitis or conjunctivitis

A

PE

thorough hx, incl hsubandry and housing

conjunctival cyto, bx

conjunctival C&S

Chlamyophila PCR

skin scrapings

18
Q

reptilian ocular anatomy

A

very similar to birds

Hardedrian gland, poorly developed extraocular muscles, +/- third eyelid

+/- NDL or puncta

eyelids-similar to birds except spectacles on snakes

19
Q

reptilian globe and anterior segment

A

cornea and sclera-cartilage in sclera

anterior uvea-striated muscle in iris and ciliary body

lens-annular pad

20
Q

reptilian posterior segment

A

most do not have tapetum

conus papillaris-like pecten but less developed

retina-anangiotic, cones with oil droplets, foveate

complete decussation

21
Q

reptilian ophtho exam

A

meance response absent

direct PLR only

normal values for STT & tonometry not known

exam with mydriasis

optic nerve not visible due to overlying conus papillaris

22
Q

reptilian ocular disease

A

usually attributes to husbandry practices

corneal ulcers common-tx similar to mammals

conjunctivits-dx an tx similar to birds

23
Q

retained spectacle

A

dysecdesis-abnormal shedding of skin and spectable, insufficient humidity

appearance-dry, wrinkled opaque spectacle

tx: increase humidity to 50-60%, soak in water, rarely surgical removal req

24
Q

pseudobuphthalmos

A

obstruction of nasolacrimal duct

accumulation of Harderian secretions in subspectacular space

25
Q

subspectacular abscess

A

infection within subspectacular space and accumulation of purulent debris

26
Q

obstruction of NLD

A

stomatitis

infection

create drainage

27
Q

hypovitaminosis A

A

due to unbalanced diet

squamous metaplasia of ductal epithelium and subsequent ductal occlusion

clin sxs: blepharedema, conjunctivitis, narrowed palpebral fissure

tx: early dz: diet change, more advanced-req vit A supplementation

28
Q

fibropapilloma

A

green sea turtles

involving eyelids and conjunctiva

herpes virus?

tx: sx removal +/- strontium radiation tx

29
Q

Rabbit orbital anatomy

A

laterally laced globes

venous sinus extending from globe equator to orbital apex

lacrimal gland, acessory lacrimal gland, Harderian gland, third eyelid gland

30
Q

Rabbit lacrimal system

A

ventral punctum only

tortuous NLD route through lacrimal and maxillary bones

areas of narrow diameter

adjacent to apices of maxillary molars and incisors

31
Q

rabbit retina and optic nerve

A

merangiotic fundus

retinal vessels and myelin radiate horizontally from optic disc

nearly 100% decussation of optic nerve

32
Q

Rabbit ophtho exam

A

menace response absent

Direct PLR only

STT value variable

PRT more useful

33
Q

rabbit blepharitis

A

very common-differentiate from dacryocysitis

causes: Pasteurella & Staph, trauma, environmental irritants, viral
dx: conjunctival cyto, C&S, bx

tx dictated by cause

34
Q

pseudopterygium

A

bulbar conjunctiva grows centripetally over cornea but is nonadherent

unknown cause

tx: trim excessive conjunctiva, tack leading edge to conjunctival fornix, topical cyclosporine A

35
Q

Dacryocystitis in rabbits

A

inflm of nasolacrimal sac

tortuous NLD, sudden narrowing or proximity to tooth roots predisposes to obstruction

dental disease, secondary bacterial inf

clin sxs: conjunctivitis, purulent ocular d/c expressed from puncta

dx: clin sxs, negative jone’s test, skull rads/CT, C&S
tx: treat dental disease, Flush NLD, systemic abx

36
Q

exophthalmos in rabbits

A

orbital dz

retrobulbar abscess

due to pasteurella multocida-secondary to dental dz

less common: parasitic cyst, orbital neoplasia, thymoma

37
Q

retrobulbar abscess in rabbit

A

dx: clinical appearance, skull rads/CT, CBC-heterophilia

aggressive medical management-parenteral penicillin,

many need exenteration-caution with vascular plexus

recurrence common

38
Q

encephalitozoon cuniculi

A

obligate intraocular protozoa

vertical transmission in utero

causes neurologic dz

ocular dz: iris granuloma secondary to lens capsule rupture, phacoclastic anterior uveitis, cataract

dx: clin sxs, serology, PCR lens tissue
tx: uveitis therapy, phacoemulsification, albendazole

39
Q

ferret anatomy and exam

A

very similar to dogs and cats-more laterally places, retrobulbar venous sinus

STT and IOP

indirect ophthamoscopy

40
Q

ferret conjunctivitis

A

common

usually ocular manifestation of systemic dz-k9 distemper, Human influenza, mycobacteriosis, salmonellosis

dx: clin sxs, PE, conjunctival cyto, C&S, bx, serology, PCR

tx-underlying disease

41
Q

ferret exophthalmos

A

first sign of lymphoma

dx: PE, CBC, Chem, UA, Thoracic rads, Abdominal u/s