Internal Ocular Pathology

Question 1

Hypopyon

Answer 1

Purulent inflammation in anterior chamber

Question 2

Intra ocular inflammation

Answer 2

Anterior uveitis - inflammation of iris and ciliary body
Posterior uveitis - inflammation of choroid
- if retina involved too = chorioretinitis
Panuveitis - inflammation of all 3 components of uvea
Endophthalmitis - inflammation of uvea, retina, ocular cavities
Panophthalmitis - inflammation of entire globe including cornea and sclera

Question 3

Anterior uveitis

Answer 3

• inflammation of iris and ciliary body

Question 4

Posterior uveitis -

Answer 4

inflammation of choroid
- if retina involved too = chorioretinitis

Question 5

Panuveitis -

Answer 5

inflammation of all 3 components of uvea

Question 6

Endophthalmitis -

Answer 6

inflammation of uvea, retina, ocular cavities
(Anterior /posterior chamber, vitreous chamber)

Question 7

Panophthalmitis -

Answer 7

inflammation of entire globe including cornea and sclera

Question 8

Uveitis

Answer 8

Most cases reflect uveal involvement of systemic disease
- hematogenous bacterial infection
- immune mediated uveal inflammation

Question 9

Indications for Canine uveitis

Answer 9

Idiopathic
Phacolytic uveitis
Trauma
Foreign body
Blastomycosis
Phacoclastic uveitis

Question 10

Diseases of uvea

Answer 10

Lens induced uveitis
Systemic mycoses
Uveodermatologic syndrome
Feline uveitis
Equine uveitis

Question 11

Phacolytic uveitis

Answer 11

Leakage of lens protein through the lens capsule - highly anti genetic
Occurs secondary to cataracts*

Question 12

Phacoclastic uveitis

Answer 12

Release of lens protein through ruptured lens capsule
- traumatic rupture of lens capsule
- rapidly progressing diabetic cataracts*

Question 13

Systemic mycoses

Answer 13

Blastomyces - common in dogs
Cryptococcosis - common in cats
Lesion: Pyogranulomatous endophthalmitis
Exudate accumulates in choroid and sub retinal space

Question 14

Uveodermatologic syndrome aka VKH

Answer 14

“Vogt-koyanagi-harada syndrome”
Common in akitas, Siberian huskies, samoyeds
Immune mediated disease targeting melanin
- bilateral granulomatous uveitis (1st lesion)
-depigmentation of facial skin (2nd lesion)

Question 15

Indications for Feline uveitis

Answer 15

Idiopathic
Cryptococcosis
Feline infectious peritonitis

Question 16

FIP

Answer 16

Mutated enteric coronavirus
Pyogranulomatous inflammation in multiple organs
Causes immune mediated uveitis in eye

Question 17

Equine uveitis

Answer 17

Equine recurrent uveitis (moon blindness)

Question 18

Equine recurrent uveitis (moon blindness)

Answer 18

Repeated bouts of anterior uveitis occurring at unpredictable intervals; increases in severity over time
One of the most common causes of blindness in EQ

Question 19

Proposed path of moon blindness

Answer 19

Hypersensitivity reaction to
- leptospira antigen
- onchoncerca cervicalis microfilaria
Genetic susceptibility
- Appaloosa, German warm blood

Question 20

Diseases of lens

Answer 20

Lens luxation
Cataract
- diabetic cataract
-secondary cataract
-age related cataract
Glaucoma - primary/secondary

Question 21

lens luxation

Answer 21

Complete dislocation of lens
Can fall into anterior chamber or remain in posterior
Anterior luxation predisposed to glaucoma - mechanical obstruction of aqueous fluid (pupillary blockage)

Question 22

causes of lens luxation

Answer 22

Primary - no known trauma or other ocular disease
Could be congenital or aquired (spontaneous)
Secondary - blunt trauma, glaucoma

Question 23

Cataract

Answer 23

Lenticular opacity
Diabetic
Secondary - uveitis, glaucoma, neoplasia, advanced retinal degeneration
Age related

Question 24

Diabetic cataract

Answer 24

Bilateral cataracts are common (70%) in diabetic dogs
^ glucose in aqueous -> shunts to sorbitol synthesis -> excess sorbitol osmotically attracts water -> swelling & degeneration of lens fibers -> cataracts

Question 25

Glaucoma

Answer 25

Sustained increase intraocular fluid pressure -damages retina and optic nerve - leads to vision loss - results in impaired outflow of aqueous* (uveitis, inflammatory blocks outflow)

Question 26

Common development of glaucoma

Answer 26

Dogs > cats > horses Most common reason for enucleation in dogs & cats

Question 27

primary glaucoma

Answer 27

Goniodysgenesis Incomplete atrophy of ciliary cleft mesenchyme Abnormality of development Delayed onset of clinical glaucoma (5+ yr)

Question 28

Open angle glaucoma

Answer 28

No primary histo logic lesion

Question 29

Secondary glaucoma

Answer 29

Any primary lesion that obstructs aqueous flow through the pupil or trabecular mesh work (ciliary cleft)

Question 30

Pupillary block in secondary glaucoma

Answer 30

Obstruction of aqueous through pupil Anterior lens luxation Lens capsule rupture

Question 31

Trabecular occlusion in secondary glaucoma

Answer 31

Neoplasia Preiridial fibrovascular membrane Mechanical compression - cataracts, posterior chamber neoplasms

Question 32

Lesions of glaucoma

Answer 32

Result from increased intraocular pressure regardless of cause Depend on degree of pressure elevation, duration & quickness of onset

Question 33

Gross lesions of glaucoma Buphthalmos

Answer 33

Buphthalmos - stretching of globe secondary to increased intraocular pressure - can prevent eyelids from closing = corneal Dessication

Question 34

Gross lesions of glaucoma Corneal edema

Answer 34

Pressure induced injury to corneal endothelium

Question 35

Gross lesion of glaucoma Atrophy

Answer 35

Atrophy of iris and ciliary body Chronic pressure induced ischemia Late in course of disease

Question 36

Microscopic lesions of glaucoma

Answer 36

Atrophy of nerve fiber layer & ganglion cell layer Loss of neurons from inner nuclear layer Collapse of trabecular mesh work Optic nerve atrophy Optic disc cupping Corneal edema Cararacts

Question 37

Ocular neoplasia

Answer 37

Uveal neoplasms - dogs, cats, horses

Question 38

Uveal melanocytoma - dog

Answer 38

Most common primary intraocular tumor in dogs Almost always benign Can cause secondary glaucoma

Question 39

iridociliary adenoma - dogs

Answer 39

Almost always benign

Question 40

Uveal neoplasms - cat

Answer 40

Diffuse iris melanoma Iridociliary adenoma Primary ocular sarcoma

Question 41

Ocular neoplasms - horses

Answer 41

Uveal melanocytoma Topic nerve tumors Neoplasms metastatic to globe

Question 42

Diffuse Iris melanoma

Answer 42

Cat Starts as unilateral hyperpigmentation - progresses to diffuse Iris involvement

Question 43

Iridociliary adenoma

Question 44

Primary ocular sarcoma

Answer 44

Cat Post traumatic sarcoma Spindle cell sarcoma that develops secondary to lens rupture

Question 45

Uveal melanocytoma- horse

Answer 45

Common in gray horses Similarly to uveal melanocytoma in dogs

Question 46

optic nerve tumors

Answer 46

Meningiomas Most common in dogs Metastasis is uncommon

Question 47

Neoplasms metastatic to globe

Answer 47

Lymphoma Carcinomas