Parasitic Intraocular Infections Flashcards
Cause of Toxoplasmosis
Toxoplasmosis gondii
protozoa
ingestion of contaminated food or water or congenital
Ocular Toxoplasmosis
most common cause of post seg infection and focal necrotizing retinitis
progresses from retina to choroid
self limiting
Symptoms of Ocular Toxoplasmosis
unilateral
floaters
blurred vision
possible conjunctival injection and photophobia
Signs of Ocular Toxoplasmosis
retinochoroiditis- focal whitish lesions with poor borders
“headlight in fog” - lesion + vitritis
mild AC rxn
retinal vasculitis
Pathogenesis of Ocular Toxoplasmosis
tachyzoites cause focal necrosis and exudation that progress from retina to choroid
vitritis- hazy
inflammation clears, leaving chorioretinal scar
can reactivate
Tx of Ocular Toxoplasmosis
prevention
anti-toxo and steroids
Cause of Toxocariasis
Toxocara canis
Toxocara cati
roundworm in dogs/ cats
Contraction of Toxocariasis
eggs via contaminated raw veggies, water, soil
infected raw or uncooked meat
Toxocariasis causes….
visceral larva migrans- systemic infection
ocular toxocariasis- infection of retinal tissue
Symptoms of Ocular Toxocariasis
blurry vision
floaters
mild pain and photophobia
Signs of Ocular Toxocariasis
peripheral granuloma
posterior pole granuloma
vitritis
Pathogenesis of Ocular Toxocariasis
larvae migrate through wall of small intestine and reach eye through bloodstream
intraocular structures damaged by immune response
macula involved
Tx of Ocular Toxocariasis
none if no inflammation
steroids
vitreoretinal surgery
Prophylaxis of Toxocariasis
deworm pets dispose of pet litter rinse raw fruits and veggies cook meat wash hands
Cause of Diffuse Unilateral Subacute Neuroretinitis
DUSN
single nematode in subretinal space
more likely in warmer climates
Symptoms of Diffuse Unilateral Subacute Neuroretinitis
insidious unilateral vision loss
Early Signs of Diffuse Unilateral Subacute Neuroretinitis
DUSN
mild vitritis
mild optic disc edema
crops of gray white outer retinal lesions that come and go and appear in new locations
worm
Late Signs of Diffuse Unilateral Subacute Neuroretinitis
DUSN
diffuse degenerative changes of RPE and retina
optic atrophy
narrowed retinal arterioles
Treatment of Diffuse Unilateral Subacute Neuroretinitis
DUSN
photocoagulation of nematode
oral meds if cant find worm
Cause of Onchocerciasis
Onchocerca volvulus helminth from black fly
mainly around equator- Africa
Presentation of Onchocerciasis
dermatological lesions
sclerosing keratitis
ant uveitis w/ microfilariae in AC
chorioretinitis
Treating Onchocerciasis
anti-parasitic meds
antibiotics against symbiotic bacteria
steroids for uveitis
Control of Onchocerciasis
spray rivers where flies are
Cause of Cysticercosis
`tapeworm from poorly cooked pork and unwashed veggies
Ocular Cysticercosis causes….
intraocular or extraocular cysts- extreme inflammation upon death
Symptoms of Ocular Cysticercosis
unilateral decreased vision
pain
recurrent redness
Treatment for Cysticercosis
surgical removal of larvae or cysts
systemic steroids for inflammation
