The Fundus Flashcards
what are the components of the fundus
scelera
choroid
tapetum
RPE (pigment)
neurosensory retina
what species have a holangiotic retinal vascular pattern
canine
feline
also bovine, caprine, and ovine
which retinal vascualr pattern do rabbits have
merangiotic
what are the hallmarks of fundus disease
retinal hemorrhage
rentinal detachment
vascular changes
altered tapetal reflectivity
altered pigmentation
altered optic nerve head appearance
causes of retinal hemorrhage
anemia
systemic hypertension
hyperviscosity
diabetes
chorioretinitis
coagulopathy
trauma
retinal detachment
retinal hemorrhage that has a keep boat shape is located _______
pre-retinal
retinal hemorrhage within the nerve fiber layer has what appearance
flame shaped
hemorrhage within the retina has what appearance
dot-blot
sub-retinal hemorrhage has what pattern
diffuse, irregular
looks like a coverslip that has been placed on a drop of blood
what shoud your inital work up for retinal hemorrhage include
CBC/CHEM
PT/aPTT
blood pressure
what are the 2 types of detachment
bullous = medical disease
rhegmatogenous = surgical disease
bullous detachment
multifocal
serious
common early sign of feline hypersensitive retinopathy
treatment for bullous detachment
treat underlying cause and hypertensive therapy
which breed commonly gets rhegmatogenous detachment with vitreous degeneration (vitreoretinopathy)
shih tzu
attenuation (thinning) of retinal vasculature is seen with
retinal degeneration
increased tortuosity of vasculature is commonly a result of ___
hypertension
hyperviscosity
hyperreflective tapetum is due to
retinal thinng
retinal degeneration/scarring; retinal detachment/tear
causes of hyporefelctive tapetum
increased retinal thickness
folding, edema, infiltrates, effusion
characterisitics of progressive retinal atrophy (PRA)
bilateral & symmetrical
initial night blindness
gradual loss of vision
not treatment
clinical signs of progressive retinal atrophy (PRA)
slow/incomplete PLRs
narrowing and loss of retinal blood vessels
tapetal hyper-reflectivity
optic nerve atrophy
secondary cataract formation
sudden acquired retinal degeneration syndrome (SARDS)
bilateral & symmetrical
sudden loss of vision
acute photoreceptor death
dilated pupils - PLR often (+) but sluggish
signalment of SARDS
middle/older dogs
obesity/wt gain
PU/PD/PP
CBC/CHEM abnormalities suggestive of Cushing’s (majority do not have Cushing’s disease)
Feline Central Retinal Degeneration may be associated with _____
dietary taurine deficiency
“vegan cats”
which drugs can have an adverse reaction causing retinal degeneration
enrofloxacin in cats
what dis?
Chorioretinitis - active lesion
- poorly circumscribed, raised, grey-white areas of edema or cellular infiltrate*
- hyper reflective over the tapetum*
- pale over pigmented non-tapetum*
what dis?
Chorioretinitis - inactive lesion
well circumscribed, flat, scarring
treatment of chorioretinitis
address specific cause if unknown
anti-microbial (if indicated)
anti-inflammatory
clinical findings with optic neuritis
abnormal PLR
peripheral blindness (affects part of the visual pathway that is shared with the PLR)
differential for optic neuritis
infectious (distemper, toxo, neospora, ehrilichia, fungal - blasto, cryptococcus)
inflammatory (GME, immune mediated/idiopathic)
neoplastic (lymphoma)
what is the main goal as a clinician with blindness
establish of the blindness is the result of an opthalmological or neurological disease
peripheral blindness
visual pathway shared with PLR
eye, optic nerve, optic chiasm, proximal optic tract
central blindness
visual pathway is not shared with PLR
+/- abnormal behavior, seizures, sensory or postural deficits
T/F PLR can be preserved in retinal disease that spare the inner retina
True
