Retina Flashcards
(40 cards)
Layers of Bruch’s membrane
- RPE basement membrane
- Collagen
- Elastic tissue
- Collagen
- Basement membrane of choriocapillaris
Areas of adhesion between choroid and sclera
ONH, SS, EXIT point of vortex veins, Long and short posterior ciliary vessels
Areas of adhesion between retina and vitreous
Optic nerve, vessels, vitreous base, Macula
Also: edges of lattice, chorioretinal scars, enclosed Ora bays
Layers Of choroid
Bruch’s membrane, choriocapillaris, stroma, Suprachoroidal space
ERG components
A-wave: negative waveform; photoreceptors
B-wave: Muellers and bipolar cells
C-wave: RPE: positive deflection; occurs in dark adapted state
Amplitude: bottom of a to top of b
Implicit time: time from light flash to peak of B
Oscillatory potential: wavelets on ascending b wave of the scotopic and photopic bright flash ERG; generated in middle retinal layers (IPL)
ERG findings in a. CRAO b. CRVO c. RP d. X-linked RP carrier E. cone dystrophy
A. Normal a wave absent b wave
B. Reduced b wave amplitude; prolonged implicit time; reduced b:a wave ratio
C. Early-Reduced amplitude and prolonged implicit time: Late-Extinguished
D. Prolonged photopic b wave implicit time, reduced scotopic b wave amplitude
E. Abnormal photopic and Flicker, normal scotopic
ERG findings in: A. JXLR B. RD C. MEWDS D. CSNB E. congenital rubella
A. Normal a wave until late, reduced b, especially scotopic
B. Reduction in amplitude corresponds to extent of detachment
C. Reduced a wave
D. Normal a wave, poor b
E. Normal
ERG findings: A. LCA B. microvasc dz C. Glc D. Optic neuropathy
A. Flat
B. loss Of oscillatory potential
C. Normal
D. Normal
Normal ERG with abnormal EOG
Best disease and carriers, pattern dystrophies, chloroquine toxicity
Abnormal ERG with normal EOG
CSNB, X-linked retinoschisis
Occurs with abnormal bipolar region but normal rods
Fluorescein light characteristics
ICG light characteristics
A. Absorbs light at 465 to 490 nm; Emits at 520-530 nm
B. Absorbed at 805 nm (IR), Emits at 835 nm (near-IR)
Traumatic retinal breaks (Friedman 338)
- Dialysis (IT > SN); 10% initially, 80% by 2y
- GRT
- Flap tear
- Tear around lattice
Can also get traumatic MH
DDX CME
DME Epinephrine Pars planitis RP Irvine Gass Vein occlusion E2 prostaglandin
Other (non-leaking): Nicotinic acid, JXLR, Goldmann-Favre, RP
Other: XRT, vitreous wick, JXT
JXT
Type 1: M > F, middle age, on coats’ spectrum
1a: congenital: temp macula, ME & HE
1b: idiopathic, minimal leakage, va >
20/25
Type 2a (most common): m=f, bilateral, symmetric, minimal ME, glistening white dots (singerman spots), right angle venules; can develop RPE hyperplasia, pseudovitelliform Mac degen, ME 2/2 ischemia, 33% c abnl GTT
-FA c leakage, risk of CNV
Type 3: m=f, cap occlusion predominates;
3a: ret only
3b: + CNS vasculopathy
DDX blood in every retinal layer
macroaneurysm, AMD, cap hemangioma, tersens, sickle, melanoma, trauma, CNV (rare), CRVO (rare)
Peripheral retinal Degenerations associated with RD/Break
Ora Bay
Meridional fold
Meridional complex
Cystic retinal tuft & Zonular traction tuft (Both are types of vitreoretinal tuft; noncystic retinal tufts not a/w RD)
Lattice
Degenerative retinoschisis (only if hole extends to inner retina)
Etiology of choroidal folds
2/2 shrinkage of inner choroid or Bruch’s; causes undulations of overlying RPE & outer retina
THIN RPE: Tumors, hypotony, inflammation/idiopathic, neovascular membrane, retrobulbar mass, papilledema, extraocular hardware
High risk features in choroidal nevi
Thickness > 2 mm Fluid Sx Orange pigment Margin < 3 mm from ONH
Other: u/s shadowing, absent halo
DDX peripapillary or ppole lesion
Pigmented: Nevus, melanoma, melanocytoma, CHRPE, Adenma/adenocarcinoma, BDUMP
Variable or non-pigmented: astrocytoma, choroidal osteoma, combined hamartoma of retina/RPE, mets, RB, SRH, granuloma, posterior scleritis
Vascular: retinal capillary hemangioma, retinal cavernous hemangioma, race owe hemangioma, cavernous hemangioma of choroid (diffuse or circumscribed)
Most commonly affected intra ocular structure in leukemia
Optic nerve
Layer of schisms in JXLR vs senile
JXLR- nfl
Senile- opl
Cellular rxn when light strikes photoreceptors
Dec cGMP, Na channels close
Treatable RP variants
Bassen-Kornzweig (abetalipoproteinemia; tx c vit A & E) Refsum's (inc phytanic acid; restrict animal fats, leafy greens) Gyrate atrophy (inc ornithine; tx arginine restriction, b6 supp)
DDX eye problems and hearing loss
RP (H-CAUL): hallgrens, cockayne, alstroms, ushers, Laurence-moon-bardet-beidl
Cogans, sticklers, waardenberg, duanes, rubella
