Lecture 1 Flashcards Preview

PPO5 > Lecture 1 > Flashcards

Flashcards in Lecture 1 Deck (52)
Loading flashcards...
1
Q

What is the primary function of a DFE?

A

to evaluate the peripheral retina in search of “rhegmatogenous” conditions - prone to tearing

2
Q

what are 2 advantages of a BIO?

A

quick assessment of entire retina and vitreous and stereoscopic examination

3
Q

what are 3 disadvantages of a BIO?

A

lower magnification than SLEx and direct (3x), requires a dilated pupil, and light is very bright for patient

4
Q

what determines the magnification during BIO?

A

the power of the condensing lens (moving closer to the patient will not increase magnification)

5
Q

what are some indications for BIO?

A

every comprehensive exam, flashes/floaters, myopia > 4D, systemic diseases

6
Q

what is a contraindication for BIO?

A

narrow angles = angle closure secondary to pupil dilation

7
Q

which patients are sensitive to Tropicamide (use caution)?

A

Down’s syndrome patients (sensitive to anti-cholinergic effects)

8
Q

what is the pupil dilation protocol?

A

review hx, acuities OD/OS, pupils (EOMs), SLEx (VH), IOP, gonio (as needed), pt education (ask allergies) and instill drops

9
Q

what is vasovagal syncope?

A

sudden temporary loss of consciousness caused by transient cerebral hypoperfusion as a result of drop in HR and BP (vagus n)

10
Q

when can vasovagal syncope occur?

A

when body over-reacts to certain triggers = eye drops, tonometry, gonio, BIO, etc.

11
Q

what are some vasovagal syncope symptoms (warning signs)?

A

nausea, pale, light-headed, warm, clammy/sweaty

12
Q

what is the vasovagal syncope treatment?

A

recline patient and elevate feet, alternate (sit with knees up and head between knees), take BP and pulse, alert lab instructor - keep in position until BP and pulse increase to normal

13
Q

what is the patient education for BIO?

A

“I am going to use this bright light to get a good view of the back of your eye and make sure that it is healthy”

14
Q

what type of drug is Tropicamide?

A

anti-cholinergic drug which blocks the sphincter muscle of the iris and the ciliary muscle resulting in dilation and moderate cycloplegia

15
Q

what are the percentages for Tropicamide and when are each used?

A
1% = brown eyes 
0.5% = shallow angles (used alone) and blue/green eyes
16
Q

what type of drug is Phenylephrine?

A

sympathomimetic drug causing mydriasis - also acts as a vasoconstrictor

17
Q

what percentages does Phenylephrine come it and which is used?

A

2.5% and 10% (use 2.5% for dilation)

18
Q

what is the dilation “cocktail”?

A

anesthetic (proparacaine or fluress), 2.5% phenylephrine and tropicamide

19
Q

what is the purpose of the anesthetic in the dilation cocktail?

A

prevents burning and watering (which flush the drug out) and creates a more permeable corneal surface (loosens tight junctions)

20
Q

why is Phenylephrine not used alone to dilate?

A

doesn’t produce as much dilation as Tropicamide and doesn’t induce any blur (cycloplegic)

21
Q

what are the symptoms of an overdose of tropicamide?

A

headache, fast heartbeat, dry mouth and skin, unusual drowsiness, and warmth/redness of skin

22
Q

what are some side effects of phenylephrine?

A

dizziness, fast/irregular/pounding heartbeat, increased sweating, increase BP, paleness, and trembling

23
Q

what side effects should be explained to the patient before dilation?

A

blur near&raquo_space; distance for 2-6 hours, photophobia, may wish to have a driver and cycloplegia may wear off before dilation of pupil

24
Q

what should you record after dilating a patient?

A

which drop, how much, which eye(s), and what patient ed was given

25
Q

what happens when you increase the dioptric power of a condensing lens?

A

increased FOV, decreased magnification, and decreased working distance (the lower power lens = farther away from eye)

26
Q

which condensing lens gives the best balance between magnification and FOV?

A

20D

27
Q

which lens has a diameter and magnification similar to the 20D?

A

2.2 pan-retinal (25.5D)

28
Q

what is the working distance for the 20D lens, 2.2 pan-retinal and 28D lens?

A
20D = 50mm
2.2 = 40mm
28D = 33mm
29
Q

what is the image magnification for the 15D, 20D, 30D and “2.2” lens?

A
15D = 4x
20D = 3x
30D = 2x
2.2 = 2.5x
30
Q

what is the FOV with a 20D lens?

A

about 8 disc diameters (inversely related to magnification)

31
Q

how many disc diameters is the direct?

A

2 DD

32
Q

what is the distance from the optic nerve head to the macula?

A

2-3 DD

33
Q

which side of the lens faces the patient?

A

the side with the silver ring or the pointed side of the “V” on VOLK (open side faces you) = less convex surface towards patient

34
Q

what is it called when you pull the lens towards you until the entire lens fills with a view of the fundus?

A

tromboning

35
Q

what is the distance from lens to examiner for “tromboning”?

A

about 16-20 inches

36
Q

what 2 parts of the retina can you fill the entire lens with a view of the fundus?

A

posterior pole and mid-periphery

37
Q

how do you know if your optical bench is aligned?

A

the front and back surface reflections are aligned

38
Q

how do you know if you are at the correct “tromboned” distance?

A

there should be a pinpoint light on the cornea (center of pupil) and entire lens is filled

39
Q

what should you do each time you have the patient look in a different direction?

A

move yourself to maintain a position about 180 degrees from the patient’s fixation

40
Q

what is the set-up for viewing the superior and inferior retina?

A
superior = examiner sitting
inferior = examiner standing or seated with stool raised
41
Q

how many views are there for the periphery and how many for the pole/mid-periphery?

A

8 peripheral and 4 posterior pole/mid-periphery (overlap with scanning)

42
Q

what are the 8 peripheral views?

A

temporal, superior temporal, superior, superior nasal, nasal, inferior nasal, inferior, and inferior temporal

43
Q

what is the view within the condensing lens?

A

upside- down and reversed left to right

44
Q

how do you know what part of the retina you are studying?

A

where the patient is looking = retina you are studying

45
Q

if you are looking at superior retina and the vortex veins are centered in lens, which edge will the ora serrata be near?

A

near the edge by your thumb (equator will be near index finger)

46
Q

why might you see double with the BIO?

A
vertical = BIO is tilted on head
horizontal = incorrect PD
47
Q

what is a major landmark for the equator?

A

ampulla (spider like)

48
Q

what two areas mark the periphery of the retina?

A

periphery = between ora serrata and equator

49
Q

what 4 things do you record if you see something in the retina?

A

which eye or both, anatomical location (use clock positions), size and shape (size in DD), and contour (flat or elevated)

50
Q

what do you record if everything looks normal in retina?

A

Record OD and OS separately (not OU) = flat and intact, no holes, no tears 360 degrees

51
Q

what type of lens is a condensing lens?

A

double aspheric with a multi-layered anti-reflective coating

52
Q

what do BIO’s have that helps relax the accommodation of the examiner?

A

convex lenses built into the eyepieces (range from +1.75 to +2.50D)