Lecture 1 Flashcards Preview

PPO5 > Lecture 1 > Flashcards

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

What is the primary function of a DFE?

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


what are 2 advantages of a BIO?

quick assessment of entire retina and vitreous and stereoscopic examination


what are 3 disadvantages of a BIO?

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


what determines the magnification during BIO?

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


what are some indications for BIO?

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


what is a contraindication for BIO?

narrow angles = angle closure secondary to pupil dilation


which patients are sensitive to Tropicamide (use caution)?

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


what is the pupil dilation protocol?

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


what is vasovagal syncope?

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


when can vasovagal syncope occur?

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


what are some vasovagal syncope symptoms (warning signs)?

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


what is the vasovagal syncope treatment?

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


what is the patient education for BIO?

"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"


what type of drug is Tropicamide?

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


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

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


what type of drug is Phenylephrine?

sympathomimetic drug causing mydriasis - also acts as a vasoconstrictor


what percentages does Phenylephrine come it and which is used?

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


what is the dilation "cocktail"?

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


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

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


why is Phenylephrine not used alone to dilate?

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


what are the symptoms of an overdose of tropicamide?

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


what are some side effects of phenylephrine?

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


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

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


what should you record after dilating a patient?

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


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

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


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



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

2.2 pan-retinal (25.5D)


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

20D = 50mm
2.2 = 40mm
28D = 33mm


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

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


what is the FOV with a 20D lens?

about 8 disc diameters (inversely related to magnification)


how many disc diameters is the direct?

2 DD


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

2-3 DD


which side of the lens faces the patient?

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


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



what is the distance from lens to examiner for "tromboning"?

about 16-20 inches


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

posterior pole and mid-periphery


how do you know if your optical bench is aligned?

the front and back surface reflections are aligned


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

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


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

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


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

superior = examiner sitting
inferior = examiner standing or seated with stool raised


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

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


what are the 8 peripheral views?

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


what is the view within the condensing lens?

upside- down and reversed left to right


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

where the patient is looking = retina you are studying


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

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


why might you see double with the BIO?

vertical = BIO is tilted on head
horizontal = incorrect PD


what is a major landmark for the equator?

ampulla (spider like)


what two areas mark the periphery of the retina?

periphery = between ora serrata and equator


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

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


what do you record if everything looks normal in retina?

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


what type of lens is a condensing lens?

double aspheric with a multi-layered anti-reflective coating


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

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