Posterior uveitis II

Toxoplasmosis - OKAP says most is reactivation of congenitally acquired infection, would have old scar

 

tachyzoic and bradyzoic forms, brady is cyst form, difficult to kill

 

acquired from cats, dogs, eating uncooked meat, deer, unpasturized milk

 

ARN - treated with IV foscarnet and IV acyclovir

Toxo can look like ARN in immunocompromised host

 

check toxo antibody - if (-), it's not toxo, very few false negatives

if +, just means has prior exposure

then get MR/CT of the brain

 

Can use mepron instead of sulfa drugs (bactrim)

can present as neuroretinitis and VH

 

treat zone I - use leukovorin, oral steroids, pyrimethamine (consider CBC check)

check HIV if need

if vitritis and peripheral disease, use steroids and abx coverage

treat for 3 weeks-6 weeks

 

Bartonella

spectrum of dz ranging from foci of retinitis to choroidal granuloma

most pts have systemic sxs

most common lesion is retinitis or choroiditis foci - presumed to be infectious emboli

 

can see disc edema, macular star, retinal folds

small vitritis

treat if systemically ill - don't have to treat if limited and not visually threatening

 

Lymphoma

large b cell non-hodgkins lymphoma

usual subretinal/sub-RPE with spillover into vitreous

 

most commonly exists in cns-ocular axis; rare to extend elsewhere

systemic lymphoma while more common, uncommonly involves the eye

 

patients in 50s and 60s

most common sxs are floaters and mild blurring of vision that can evolve for years

can present with unilateral dz but will become bil if untreated

may present as a vitritis but most have some involvement at level of RPE

"masquerade syndrome"

 

may spontaneously resolve

 

dx:

sensitivity of vitrectomy ranges from 11-60%

reasons for false neg:

-poor processing of specimen

- lack of experienced pathologist

-no viable lymphoma cells present in vitreous

should biopsy if have lesion

 

treatment:

radiation to eye plus/minus whole brain radiation

high rate of relapse

high rate of leukoencephalopathy if chemo later used

radiation usually only palliative in treatment in other locations?

can do MTX as first line, radiation only in recurrences