White Spots In Retina Flashcards
What causes toxoplasmosis
Parasite toxoplama gondii causing a unilateral retinochoroiditis (focal fluffy yellow white lesion adjacent to inactive scar) + vitritis (headlights in fog)
Congential toxoplasmosis
90%, transplacental
- mother infected DURING pregnancy
- 10% of cases have severe systemic involvement-convulsions and cerebral calcification
- most common infectious retinitis
Acquired toxoplasmosis
10%
Inhalation of parasite in cat feces, eating undercooked meat or cheese
Treatment of toxoplasmosis
Small peripheral lesions
-observation or Bactrim
Mod-severe vitritis or sight threatening lesions
-systemic steroids + one anti-toxo agent x 5-6 weeks (pyramethamine, sulfadiazine)
Histoplasmosis cause
Fungal infection from histoplasma gondii
Signs of histo
Bilateral, multifocal chorioditis + PPA + maculopathy and NO VITRITIS
How do you get histo
Transmitted by inhalation of spores insoil (contaminated with bird or bat droppings)
OH/MS river valleys
Symptoms of histo
Asymptomatic unless mac invovled
-20% recurrence of CNVM over 3 years if mac invovled
Treatment for histo
AntiVEGF if CNMV
Bests disease
AD, abnormal accumulation of lipofuscin in RPE cells
Bilateral “egg yolk” subfoveal lesions
Dx in early childhood (5-10yo)
-75% have VA >20/40 at time of Dx
-only mild VA decrease (20/30-20/50) through midlife
Stage 1 bests
EOG < 1.8
Stage 2 bests
2 egg yolks
Stage 3 bests
Pseudohypopyon
Stage 4 bests
Scrambled eggs
Stage 5 bests
End stage, mod/severe VA loss d/t CNVM, mac atrophy
Treatment for bests
None, low vision if needed
Dominant drusen
Bilateral scattered drusen in posterior pole Asymptomatic unless mac involved Drusen in mac may cause CNVM or atrophy Decreased VA in 50-60yo TX=antivegf, low vision if needed
Adult foveomacular vitelliform dystrophy
Presents age 30-50. Signs similar to bests, but the overall prognosis is better; patients classically present with minimal metamorphopsia, mild VA loss, a normal EOG and ERG, and a slight tritan color defect
Stargardts disease
Most common hereditary mac dystrophy
AR
Age of Dx=6-20yo
Early stage Stargardts
Bilateral pisciform yellow flecks in posterior pole/mid periphery, no specific RPE molting in the macula, loss of FLR, normal ERG, decreased VA more than expected
Late stage Stargardts
Beaten bronze mac (bulls eye mac) and “salt and pepper” changes in periphery + abnormal ERG=VA 20/200 by 30, then stable ish
Treatment for Stargardts
None
Low vision
Fundus flavimaculatus
- Stargardts variant without macular dystrophy
- dx 40-50yo
- bilateral pisciform yellow flecks in post pole
- asymptomatic unless flecks in macula
- no treatment-low vision is needed
Clinical use of ERG
Detecting retinal abnormalities that affect a significant portion of the retina
MfERG can be used to detect maculopathies
