Direct Ophthalmoscopy Flashcards
if you see black dots in fundus reflex against motion, it is:
in front of lens
cells, flare, hyphema
if you see black dots in fundus reflex with no motion, it is:
at plane of lens
mittendorf dot, PSC, vacuoles
if you see black dots in fundus reflex with motion, it is:
vitreous hemorrhage, asteroid hyalosis
color and cause of:
RPE crescent
black, proliferation of RPE
color and cause of:
choroidal crescent
dark grey, RPE is not formed flush against ONH during development (allowing underlying choroid to show through)
color and cause of:
scleral crescent
variation of white, RPE and choroid fall short in development, revealing white sclera
peripapillary atrophy (PPA) is caused from:
degeneration of the posterior short ciliary artery
ISNT rule for rim tissue states:
thickest to thinnest part of rim tissue
Inf - Sup - Nas- Temp
causes of pale nerve tissue (pallor)
endstage glaucoma, CRAO, CRVO, AION, Optic Neuritis, chronic papilledema, tumor, aneurysm, trauma
characteristics of pallor
pale nerve, reduced BCVA, APD (afferent pupillary defect), VF defect, color desaturation, lack of or compromised circulation
signs of rim tissue thinning
enlargement of the cup, receding rim tissue
cause of rim tissue thinning
progressive endstage glaucoma
when does SVP or CRVP occur?
when IOP in normals is higher than the retinal venous pressure
what is the normal disc size
1.5mm (medium aperture)
what is the normal disc shape
oval vertically (cup elongated more vertically than horizontally)
what is tilted disc and how does it occur?
bilteral, congenital anomaly with developmental hypoplasia of the inferior nasal rim tissue
appearance and possible sign of tilted disc:
ONH appears like its rotated, pseudo-disc edema appearance and may have VF defect in superior or superior temporal area
how does oblique insertion of the disc occur?
unilateral or bilateral malinsertion of ONH through scleral canal that pierces globe at greater than 15 degrees (seen in axial myopes and astigmats)
appearance of oblique insertion disc:
raised nasal rim tissue, stretched and flattened temporal rim tissue, kidney beam appearance
describe normal cup appearance
C/D ratio from .2-.4, centered and round, round laminar dots, symmetrical to fellow eye
what do you look for when examining the retinal nerve fiber layer?
use red free filter to examine along course of retinal vasculature about 0 to 3DD away from the nerve and look for rows of shimmering nerve fiber
what do retinal nerve fiber layer (RNFL) defects appear as?
dark, dull, matte-finished appearance, retinal vessels more apparent, associated with rim tissue thinning
arteries are ___ than veins by approx. ___
arteries are smaller than veins by 1/3
arteries lie ____ (above/below) veins
arteries lie above veins
veins are subject to compression by:
overlying hardened arteries
how far is the macula from the ONH
2DD temporally
proliferation of melanin at the level of the choroid is called:
benign choroidal melanoma (nevus)
proliferation of melanin in the RPE cells is called:
RPE Hyperplasia
enlargement of the RPE cells in size is called:
congenital hypertrophy of the RPE (CHRPE)
