What is the slit used for?
to see elevations and depressions
What is the mag, FOV of DO?
15X 6-10 deg
What do cataracts appear like with a DO?
How would you identify a floater with DO?
casts a shadow on the retina
What happens when there is a very thick neural rim?
no to little cupping
What happens when there is a very thin neural rim?
very deep and large cup
What is the usual C/D ratio?
What is the reason for the pallour of the OD?
absence of axons
How is the mirroring in both eyes useful?
can use for differential diagnosis by comparing the two eyes
What is the lamina cribosa and what does it look like?
mesh like structure make from collagen fibres which the nerve fibres exit the optic nerve from
looks liek grey dots in the cup
Rule of vein/artery density of neural rim?
What is shelving?
when the rim acts as a shelf for the bvs to run along it then disappear under it
reappears in the cup
What is notching?
when GCs are damaged- becomes malnourished
donut of rim isnt round anymore
ISNT becomes INST
What is a temporal fundus ectasia?
bvs travel to temporal
What is a nasal fundus extasia?
bvs travel nasally
What is superior dysversion?
bvs travel superiorly
What is inferior dysversion
bvs travel inferiorly
How does the ILM look like through a DO?
retina looks shiny/wet in young px
not so much with aging
What gives the retina its colour?
the pigmentation in the RPE
What happens when there is little pigmentation?
can see other structures like choroidal vessels and vertex veins
What is a tesselated/tigroid fundus?
as you increase in age, pigmentations becomes patchy and appears tesselated
What is a RPE crescent?
termination of pigment
looks like it fades outwards from the disc edge
sometimes terminates earlier than choroid
What is a choroidal crescent?
narrow ring of pigmentation- sharp edges
no RPE or little ontop of it
or where retinal tissue has been pulled away to reveal bare choroid
What is a scleral crescent?
white crescent at disc edge
What is the difference bw and artery and a vein?
vein more blue-red and larger
artery more warm-red and smaller
What is a cilioretinal artery?
independent blood flow system deriving form the the choriocapillaries rather than the central retinal artery- just incase of a blockages
appears temporally and heads towards the macula
What happens if you see a pulse in the artery?
What can be used on a DO to see the NFL?
red free filter: green light
What are white dots on the fundus?
muller foot plate cells
What does the macula look like through the DO?
yellow brown pigmented- highly variable form person to person
bright reflex at foveola in young px
: light reflected from foveal pit
: depigmentation or pigment clumping
What is a bergmeister papilla?
embryonic structure which is a remnant of a hyaliod artery
appears as a small tuft of fibrous tissue at the centre of the OD
What is a mittendorf dot?
small dot on posterior lens: remnant of hyaloid artery
What is a vascular loop in the vitreous?
the cilioretinal artery grows into the retina, realised it is growing the wrong way and turns back leaving a loop of vascularture
What are white fluffy bunny tail spots in the fundus?
myelin sheathing of optic nerve fibres extending past the lamina cribosa
What are creamy spots?
soft hard exudates
What are some red spots on the fundus?