Parasitic Intraocular Infections

Question 1

Cause of Toxoplasmosis

Answer 1

Toxoplasmosis gondii
protozoa
ingestion of contaminated food or water or congenital

Question 2

Ocular Toxoplasmosis

Answer 2

most common cause of post seg infection and focal necrotizing retinitis
progresses from retina to choroid
self limiting

Question 3

Symptoms of Ocular Toxoplasmosis

Answer 3

unilateral
floaters
blurred vision
possible conjunctival injection and photophobia

Question 4

Signs of Ocular Toxoplasmosis

Answer 4

retinochoroiditis- focal whitish lesions with poor borders
“headlight in fog” - lesion + vitritis
mild AC rxn
retinal vasculitis

Question 5

Pathogenesis of Ocular Toxoplasmosis

Answer 5

tachyzoites cause focal necrosis and exudation that progress from retina to choroid
vitritis- hazy
inflammation clears, leaving chorioretinal scar
can reactivate

Question 6

Tx of Ocular Toxoplasmosis

Answer 6

prevention

anti-toxo and steroids

Question 7

Cause of Toxocariasis

Answer 7

Toxocara canis
Toxocara cati
roundworm in dogs/ cats

Question 8

Contraction of Toxocariasis

Answer 8

eggs via contaminated raw veggies, water, soil

infected raw or uncooked meat

Question 9

Toxocariasis causes….

Answer 9

visceral larva migrans- systemic infection

ocular toxocariasis- infection of retinal tissue

Question 10

Symptoms of Ocular Toxocariasis

Answer 10

blurry vision
floaters
mild pain and photophobia

Question 11

Signs of Ocular Toxocariasis

Answer 11

peripheral granuloma
posterior pole granuloma
vitritis

Question 12

Pathogenesis of Ocular Toxocariasis

Answer 12

larvae migrate through wall of small intestine and reach eye through bloodstream
intraocular structures damaged by immune response
macula involved

Question 13

Tx of Ocular Toxocariasis

Answer 13

none if no inflammation
steroids
vitreoretinal surgery

Question 14

Prophylaxis of Toxocariasis

Answer 14

deworm pets
dispose of pet litter
rinse raw fruits and veggies
cook meat
wash hands

Question 15

Cause of Diffuse Unilateral Subacute Neuroretinitis

DUSN

Answer 15

single nematode in subretinal space

more likely in warmer climates

Question 16

Symptoms of Diffuse Unilateral Subacute Neuroretinitis

Answer 16

insidious unilateral vision loss

Question 17

Early Signs of Diffuse Unilateral Subacute Neuroretinitis

DUSN

Answer 17

mild vitritis
mild optic disc edema
crops of gray white outer retinal lesions that come and go and appear in new locations
worm

Question 18

Late Signs of Diffuse Unilateral Subacute Neuroretinitis

DUSN

Answer 18

diffuse degenerative changes of RPE and retina
optic atrophy
narrowed retinal arterioles

Question 19

Treatment of Diffuse Unilateral Subacute Neuroretinitis

DUSN

Answer 19

photocoagulation of nematode

oral meds if cant find worm

Question 20

Cause of Onchocerciasis

Answer 20

Onchocerca volvulus helminth from black fly

mainly around equator- Africa

Question 21

Presentation of Onchocerciasis

Answer 21

dermatological lesions
sclerosing keratitis
ant uveitis w/ microfilariae in AC
chorioretinitis

Question 22

Treating Onchocerciasis

Answer 22

anti-parasitic meds
antibiotics against symbiotic bacteria
steroids for uveitis

Question 23

Control of Onchocerciasis

Answer 23

spray rivers where flies are

Question 24

Cause of Cysticercosis

Answer 24

`tapeworm from poorly cooked pork and unwashed veggies

Question 25

Ocular Cysticercosis causes….

Answer 25

intraocular or extraocular cysts- extreme inflammation upon death

Question 26

Symptoms of Ocular Cysticercosis

Answer 26

unilateral decreased vision
pain
recurrent redness

Question 27

Treatment for Cysticercosis

Answer 27

surgical removal of larvae or cysts

systemic steroids for inflammation