What are the components of vascular tunic/uveal tract?
What tunic is comprised of the retina?
What cranial nerves are involved in menace response?
- IN: 2 (optic)
- OUT: 7 (facial)
- determines if pt is visual
What cranial nerves are involved in pupilary light reflex?
- IN: 2 (optic)
- OUT: 3 (oculomotor)
- *if pt fails menace but passes PLR, must be Cr.N.7 problem
What cranial nerves are involved in palpebral reflex?
- IN: 5 (Trigeminal)
- OUT: 7 (facial)
- *if pt fails menace but passes palpebral, must be Cr.N2 problem
what tests are done after these nerve exams? what test must be done first?
- Schirmer tear test
- Fluorescein stain
What is defined as globe to rostral in orbit (globe is normal size)? What is globe of normal size that is too caudal in orbit?
- rostral: exophthalmos
- caudal: enophthalmos
what is term for equator of globe rostral to palpebral fissure? What is term for globe that is too large?
- large globe = buphthalmos
when is retropulsion contraindicated as part of exam? what is retropulsion helpful in detecting?
- don't do with deep ulcers or damaged cornea
- detects mass behind eye
What are some clinical signs of orbital disease?
- Decreased retropulsion
- Increased/Decr. scleral show
- Elevated Nictitans
- Pain/discomfort when open mouth
What are examples of congenital enophthalmos? what is prognosis?
- Microphthalmos (associated w/merle coat)
- Anophthalmos (rare!)
- Poor for both
What is phthisis bulbi?
- globe too small for orbit
- acquired enophthalmos as end stage to other disease of globe
What are reasons for acquired enophthalmos where globe is normal size?
- emaciation (fat loss)
- dehydration (fluid loss)
- soft tissue atrophy
What are 2 basic reasons for exophthalmos?
- Increased fluid (inflammation, hyperplasia, neoplasia)
- Increased cells (blood, cyst, lipids)
With eye diseases, what is difference between pain when opening mouth and non-painful?
- Pain = likely inflammatory cause/abscess/FB
- Not painful = slow growing mass/neoplasia
What is acute recurrent episodes of facial muscle inflammation associated with bilateral exophthalmos, nictitans elevation and pain when try to open mouth? what do eyes do in chronic cases?
- masticatory muscle myositis
- chronic: enophthalmos and muscle atrophy
What test for MMM is diagnostic if results are positive? How do you treat?
- 2M autoantibody test (serum)
- immunosuppresion via steroids +/-azathioprine
What is another autoimmune myositis associated with bilateral exophthalmos except NO nictitans elevation and NON painful when open mouth?
- extraocular muscle myositis --> immunosuppression therapy
- (chronic is enophthalmos like MMM)
Is orbital neoplasia rapid or gradual onset? exoph- or enophthalmos? other presenting signs? Is there usually pain when open mouth?
- Gradual Onset
- Nictitans elevation
- Decr. retropulsion
- No pain when open mouth
Is orbital neoplasia generally benign or malignant? what is prognosis for orbital neoplasia?
- malignant 95%
- poor to guarded
distinguish evisceration, enucleation, and exenteration.
- Evisceration: removal of intraocular contents (then prosthesis)
- Enucleation: removeal of globe
- Exenteration:remove globe + ALL of orbital contents
enucleation can be either subconjunctival or transpalpebral. which is better for histopath? which is indicated with infected eyes?
- histo: subconjunctival (include nictitans +conjunctiva)
- infected: transpalpebral
with proptosis, what are some positive indicators?
- + consensual PLR
- voluntary movement of globe (some mm. still attached)
- ***pupil size is NOT reliable
with proptosis, what are some negative indicators?
- hyphema = retinal detach/uveal trauma
- corneoscleral laceration
- rupture 3+ extraocular mm.
- transected optic n.
- **prog. worse in cats w/deep orbits, dolicephalic dogs, and spp. w/complete orbit like equine/bovine
what are some complictions following proptosis?
- phthisis bulbi
how do you treat eyelid laceration?
- minimal debride (no scissors!) to preserve tissue then suture and clean w/betadine or saline
- suture w/4 or 5-O vicryl in figure 8 pattern
- (heals fast due to blood supply)
what is principle of repair for wedge resection of lid laceration?
- can only remove up to 1/3 eyelid margin
- use 2 layer closure; apposition critical
Ankyblepheron, a congenital eyelid lesion can be due to what etiology?
what is a coloboma? more in cats or dogs? what is a tx option?
- partial abcense of palpebral fissure
- congenital eyelid lesion leads to inability to blink --> exposure keratitis
- cats > dogs
- pedicle graft
what is choristoma?
- dermoid; congenital eyelid lesion
- normal tissue in abnormal location
- resection may be indicated
distinguish trichiasis, distichiasis, and ectopic cilia. Which are associated with ulcers/+fluorescein stain?
- T: normal hair in normal location going in wrong direction
- D: cilia from mybomian gland
- E:cilia from bulbar surface of (upper) eyelid; young dog
- **D and E assoc. w/ulcers and pos. fluorescein stain
List 4 features of brachycephalic ocular syndrome.
- macropalpebral fissures
- medial trichiasis (nasal trichiasis)
- medial lower lid entropion
- pigmentary/exposure keratitis