15 - Retina/Choroid3 Flashcards
Histoplasmosis
- epidemiology
- pathophys
Ohio-Mississippi river valley, chicken poo (e.g. farmer), rare in AAs
Infection by Histoplasma capsulatum, FUNGUS that grows in soil, material contaminated with bird/bat droppings
- recurrences (30%) through pre-existing HISTO SPOTS
- if spots are present in disc/macular area, chance of symptomatic recurrence is ~20% in 3 years
Histoplasmosis
-signs/symp
Signs: BILATERAL CHOROIDITIS
- clinical TRIAD: PERIPAPILLARY ATROPHY, MULTIFOCAL PERIPHERAL LESIONS, MACULOPATHY (incl cnvm (late stage, 20-45))
- vitreous is always clear (vs toxo headlights in fog)
Symp: asymptomatic unless maculopathy develops (metamorphopsia)
Toxo vs histo
- laterality
- lesion(s)
- vitreous
- causitive organism
T: one eye, one lesion, cloudy vitreous, parasite
H: bilateral, multiple lesions, clear vitreous, fungus
Pathological/degenerative/high myopia
- epidemiology
- pathophys
- symp
Genetic predisposition, females, young adulthood, 2% pop
RE > -6D spherical equivalent
Axial length >/= 26.5mm
Asymptomatic; decr vision, metamorphopsia
Pathological/degenerative/high myopia -signs —macular/posterior pole (5) —peripheral (4) —non-retinal (3)
M/PP:
- posterior staphyloma (hallmark) = post bulging of WEAK SCLERA
- oblique optic nerve insertion
- FUCHS SPOTS = focal hyperpig secondary to scarring/cnvm
- LACQUER CRACKS
- macular holes/ERMs
Peripheral: think DEGENERATIONS
- LATTICE degen = thinned retina
- SNAIL-TRACK degen (recall PPMD (cornea) is train track lesions)
- PAVINGSTONE degen
- retinal breaks/detachments
Non-ret:
- premature cataracts (PSC > NS)
- extensive syneresis
- PVD
Pathological/degenerative/high myopia
-lacquer cracks
5%, esp young males
Fine, YELLOW, irregular spokes from the macula
Represent large BREAKS IN BRUCHS
Pathological/degenerative/high myopia
-pavingstone degeneration
aka Cobblestone
Discrete, CIRCULAR, areas of YELLOW-WHITE chorioretinal atrophy in periphery
No clincal importance
Epiretinal membrane
- epidemiology
- pathophys
aka macular pucker (advanced)
Females, incr with age
Often idiopathic, may be from PVDs (#1), retinal breaks, cataracts, other intraocular surgeries/trauma
Result from GLIAL CELL* PROLIFERATION on the ILM
*from posterior hyaloid or inside the retina
Epiretinal membrane
-signs/symp
Signs:
- mild: fine, glistening membrane (cellophane maculopathy)
- advanced: thick, gray-white membranes with assoc retinal folds (macular pucker)
Symp: asymptomatic; decr vision and/or metamorphopsia
Macular hole
- epidemiology
- pathophys
Aging (50-70), women
From POSTERIOR VITREOUS TRACTION on macula
IDIOPATHIC/senile (#1), trauma, surgery, CME, inflammation
BILATERAL ONSET 25-30%
-risk of development in fellow eye varies (none if PVD occurred)
Macular hole
-signs/staging/symp
Signs: ROUND, RED, WELL-DELINEATED SPOT
- stage 1: YELLOW spot/ring at fovea, impending hole
- stage 2: round, small, full-thickness hole with PSEUDO-OPERCULUM
- stage 3: large, full-thickness hole with OPERCULUM, (+)WATZKE-A*
- stage 4: stage 3 + PVD
- positve watzke-allen = complete break in middle of thin line
Symp: decr vision and/or metamorphopsia
-full-thickness = 20/200 or worse
Macular photostress test
Determine BCVA prior to starting
Hold bright light @2cm from eye, look at for 10sec
Measure time it takes for pt to read one line less than his/her BCVA
Normal: <60sec
Choroidal folds
- what/app
- common causes
Waves within choroid/bruchs/RPE secondary to mechanical stress on/within choroid
-alternating light/dark striations within fundus
Tumor, post scleritis, choroidal detach/inflamm, orbital pseudotumor, thyroid-related ophth, orbital myositis, hypotony, intracranial HTN
Albinism
- pathophys
- signs/symp
UNDERDEVELOPED IRIS, CORNEA, ONH, FOVEA
Group of disorders, mutation in genes responsible for MELANIN production
Signs: hypopigmentation, optic nerve/FOVEAL HYPOPLASIA (poor vision), MICROCORNEA, nystagmus, strabismus, mis-routing of temporal nerve fibers thru chiasm (most fibers cross), HIGH HYPEROPIA + ASTIG
Symp: photophobia, reduced VA
Retinitis pigmentosa
- epidemiology
- pathophys
Most common RETINAL dystrophy
Sporadic or AD (usually inherited)
Assoc systemic condn = Usher’s (AR, hearing loss)
Avg age dx 9-19yo
Group of condns, progressive loss of PR/RPE function
Rods damaged»_space;> cones
Tremendous variability in presentation
Retinitis pigmentosa
-signs/symp
Signs:
- TRIAD: bone-spicule pigmentation, arteriolar attenuation, waxy optic disc pallor
- PSC CATARACTS, optic DISC DRUSEN (VF loss), MACULAR CHANGES (atrophy, CME, ERM), keratoconus, myopia
- REDUCED SCOTOPIC ERG (early stages)
Symp: NYCTALOPIA (#1), PERIPHERAL VISION LOSS, by age 30 over 75% symptomatic
Stargardt’s disease
- epidemiology
- pathophys
Most common hereditary MACULAR dystrophy
Onset 1st-2nd decade (esp 6-20yo)
AUTO RECESSIVE inheritance, no sex predilection
Stargardt’s disease
-pathophys
Most often due to mutation in ABCA4 transmembrane protein - responsible for moving all-transAL from disc lumen to cytoplasm
-this leads to toxic accumm of all-transAL in the discs -> degeneration of PRs/RPE
Stargardt’s disease
-vs fundus flavimaculatus
FF and SD are considered variants of the same disorder
FF: dx is reserved for pts WITHOUT macular dystrophy signs, often presents LATER in life (4th-5th decade vs 6-20yo), commonly ASYMPTOMATIC
Stargardt’s disease
-signs/symp
Signs:
- early: bilateral YELLOW FLECKS in PISCIFORM configuration, non-specific RPE MOTTLING of macula, normal ERG
- late: classic “BEATEN BRONZE” macula (“BULL’S EYE”) and “SALT AND PEPPER” pigmentary changes, abnormal ERG
Symp: rapid vision loss and color vision abnormalities
- level of vision loss is often OUT OF PROPORTION* with fundus app in early stages; typically 20/200 by third decade, stable/slowly progressive thereafter
- early SD is the “acanthamoeba of the retina”
Choroideremia
- epidemiology
- pathophys
XL-RECESSIVE, males, 1st decade
Deficiency in rab geranyl-geranyl transferase - enzyme utilized in membrane metabolism -> atrophy of choroid
Choroideremia
-signs/symp
Signs: progresive, bilateral, diffuse atophy of RPE/choriocapillaris -> exposure of underlying sclera
-macula often spared until late
Symp: night-blindness, peripheral vision loss
- most have good vision until 50-60yo
- in females the condn is benign, non-progressive
Ddx for night-blindness (3)
Gyrate atrophy
Choroideremia
Retinitis pigmentosa
Cone dystrophy
- epidemiology
- signs/symp
Onset 1st-3rd decade, AD inheritance
Signs:
- early: normal fundus app + low VA, abnormal photopic ERG
- late: CENTRAL GEOGRAPHIC ACTROPHY, BULL’S EYE MAC, VESSEL ATTENUATION, TEMPORAL DISC PALLOR, FINE NYSTAGMUS, severe deutan-tritan color defect, abnormal photopic ERG, THINNED PR LAYER ON OCT
Symp: SLOWLY PROGRESSIVE DECR CENTRAL VISION, severe photophobia and color vision loss
-poor prognosis: 20/400 by 40yo
Ddx for bull’s eye maculopathy (3)
Stargardt’s
Progressive cone dystrophy
Hydroxy/chloroquine or Thioridazine toxicity
Best’s disease
- epidemiology
- pathophys
Uncommon, AD inheritance, presents early childhood (5-10yo)
Abnormal accum of lipofuscin in the RPE
Best’s disease
- signs/symp
- stages
Signs: BILATERAL, yellow, round, SUBFOVEAL “egg-yolk” lesion
-will have normal ERG but abnorm EOG, even prior to vision loss/fundus signs
Symp: majority are detected with little/no pt symptoms (75% better than 20/40), eventually complain of decr vision
Stages:
1) pre-vitelliform = abnormal EOG (arden <1.8), normal fundus, fam hx
2) vitelliform = 2 eggs, usually ages 3-15
3) pseudohypopyon = entire lesion absorbed, little/no effect on vision
4) vitelliruptive = breaks up -> “scrambled egg” app, MILD VISION LOSS
5) end-stage* = MOD-SEVERE VISION LOSS due to CNV, hemorrhage, atrophy, and/or macular scarring
* Best’s is best to have until ~50yo
Adult foveomacular vitelliform dystrophy
Presents in pts 30-50
Signs similar to Best’s
Overall prognosis better - minimal metamorphopsia, mild acuity loss, normal EOG and ERG, slight tritan color defect
