Peripheral Retina/BIO

What are the four BIO tips?

1. Center light onto pt's eye

2. do not move your head

3. condense light to a point thru pupil

4. align purkinje images within 20 D

Why must light be perfectly centered onto pt's eye?

if not, condensed light will not go thru pt's pupil

more critical for peripheral views b/c pupil/aperture = small

Why should you not move your head after centering light on eye?

head movement after centering light on eye -> light cannot be condensed straight into pupil

must induce prism to illuminate retina -> doc not looking where she intended

What three things happen when you induce prism?

distorts image - prentice's rule - light going thru center of lens not bent; light going thru edge of lens = 2.5 cm * 20 D (stretching image)

rainbow glare

scleral indentation (more difficult) and ora harder to find

What does condensing light to a point thru pupil mean?

focus light to smallest diameter as it goes thru pupil

requires a third person to help - lens needs to be pulled out enough for light to focus as a point by the time it hits pupil (otherwise light scatter/not focused ex. if point forms behind retina)

Does a fully condensed beam allow views of posterior pole and ora? What about a not fully condensed beam?

fully condensed beam -> views of posterior pole and ora

not fully condensed beam -> views of posterior pole BUT NOT ora (b/c smaller apertures require better skills)

Why do purkinje images need to be aligned within 20D?

otherwise lens is twisted (relative to path of BIO light and induces prism - distorts image/rainbow glare)

What color, straight/bended, location o' clock, orientation, and pigment are long posterior ciliary nerves?

yellow color

straight

3 and 9 o' clock

radial (point towards center)

choroidal pigment

Long posterior ciliary nerves contain sensory info from where? _________ fibers to ________ (__________ muscle)

Damage to LPCN can lead to what?

sensory info from cornea and iris

sympathetic fibers to pupil (dilator muscle)

damage can lead to dryness (b/c tears/blink rate may decrease) and pupil constriction

What color, straight/bended?, quadrants, pigment are short ciliary nerve?

yellow color, straight, in various quadrants, choroidal pigment

What do short ciliary nerves contain? What is their function?

parasympathetic fibers to pupil and CB

pupil sphincter for constriction

CB for accommodation

What three things may laser photocoagulation of retina affect? Why is it done?

pupil size, accommodation, K dryness (if damage LPCN and SCN)

laser photocoagulation done to reduce O2 demand to dec VEGF from creating neovascularization and damaging central vision (kills peripheral retina)

What is PVD the separation between?

posterior hyaloid/vitreous face

ILM of retina

What are the six normal vitreous attachments?

ora, crystalline lens, ONH, macula, BV, retina

What is PVD the most common cause of? What is rhegmatogenous?

rhegmatogenous retinal detatchments

what is rhegmatogenous? What is retinal detachment the separation between?

rhegmatogenous = retinal break (hole/tear)

retinal detachment = separation b/w Phr and RPE

What is a horseshoe retinal tear? Which quadrant is 60% located in? What is it walking towards

60% supero-temp

walking towards the cup

What is an operculated hole?

former flap tear

flap is avulsed (horseshoe tear pulled off)

damage is done, not pulling anywhere else (circular b/c no longer traction)

What does the shape of break tell us? more vs less circular?

strength/amount of pulling?

more circular = less vitreo-retinal traction (already pulled)

less circular = more vitreo-retinal traction (still pulling)

What is white without pressure? color, distinct or indistinct borders, shape, b/w what, elevated?, reactive hyperplasia?

optical phenomenon

abn vitreoretinal interface

white color

distinct/sharp borders

any shape

b/w ora to equator

no elevation

no reactive hyperplasia

What is white without pressure?

may have ______ border, mistaken for ____, no _________ BV, no _________, no ________

may have red border

mistaken for tear

no sheared BV

no hemes

no elevation

What is typical lattice? pigmented, white or unpigmented?, ___-shaped, parallel to _____, sup >/

retinal thinning

pigmented, white or unpigmented

cigar-shaped

parallel to ora

sup > inferior

in typical lattice: _______ BV locally (arteries and veins), manifests in _______; ____-____% of population, mirror symmetry in ___-____% , may or may not contain _______ _______, less than __% will become an RD

sheathed BV locally (arteries and veins), manifests in adolescence; 8-15% of population, mirror symmetry in 30-50%

may or may not contain atrophic holes, less than 1% will become an RD

Vitreo-retinal tufts are ______ adhesions b/w ____ and ________ found in __% of pts consisting of condensation of ______ cells and _______

color is _________ or __________, discrete ________, _____ quadrants equally, base may have ______, <__% of RD

Vitreo-retinal tufts are focal adhesions b/w vitreous and retina found in 5% of pts consisting of condensation of glial cells and vitreous

color is chalky white or grey, discrete bumps, all quadrants equally, base may have pigmentation, <1% of RD

key CHRPE signs

pigmented, depigmented halo, defined margins, round, lacunae, solitary, unilateral, flat, no malignant potential

key signs pavingstone degeneration

yellow to white

round

distinct margins

pigmented edges

far periphery

inferior

peripheral drusen color, size, shape, halo color, what two layers is it a waste produce b/w

yellow, round, small, dark halo, waste produce b/w RPE and BM

Why is there a dark halo in drusen

normally mono layer of RPE

large drusen -> RPE to stack

stacked RPE -> more pigment to absorb light