Lecture 2

Question 1

what are 3 pupil dilation contraindications?

Answer 1

anterior chamber IOL, narrow angles from gonio, and plateau iris

Question 2

what are the 2 diagnostic codes for a DFE?

Answer 2

92004 = new patient
92014 = established patient

Question 3

what are 2 exceptions for when a dilated exam is part of a comprehensive exam?

Answer 3

patient refuses and medically contraindicated

Question 4

what should you do if your patient refuses dilation at their comprehensive exam?

Answer 4

you still must assess the fundus - undilated 90D and/or direct scope (pt ed on importance of DFE and reschedule within 1-2 weeks)

Question 5

what instruments/tools give a direct view of the retina? which give indirect?

Answer 5

direct = direct ophthalmoscope and goldmann 3 mirror 
indirect = condensing lenses and BIO

Question 6

what is the difference between a direct and indirect image?

Answer 6

direct = upright image (directly on observer's retina)
indirect = inverted/reversed, aerial image located between examiner's eye and condensing lens

Question 7

what is the clinical standard for posterior pole examination?

Answer 7

using a high plus condensing lens and the slit lamp biomicroscope (dilated or un-dilated)

Question 8

what are 2 reasons why fundus biomicroscopy is advantageous over direct ophthalmoscopy?

Answer 8

stereoscopic views and variable magnification and FOV

Question 9

what is the FOV and working distance for the 90D lens?

Answer 9

FOV = 30-40 degrees and 7mm working distance

Question 10

what is the FOV and working distance for the 78D lens?

Answer 10

FOV > 90D and working distance is 8mm

Question 11

which lens has more magnification, 78D or 90D?

Answer 11

78D

Question 12

when do you use the 90D vs. the 78D?

Answer 12

90D = preferred lens for undilated views and periphery 
78D = preferred lens for glaucoma suspects and diabetic retinopathy

Question 13

what happens to the magnification as the power of the condensing lens decreases?

Answer 13

increases

Question 14

what happens to the FOV as the power of the condensing lens decreases?

Answer 14

decreases

Question 15

what is the “super 90” lens?

Answer 15

superfield lens, diameter > 90, designed to provide same mag as 90 with > FOV and 7mm working distance

Question 16

what is the “super 66”?

Answer 16

designed for high resolution of posterior pole, diameter > 78, mag >78D but same FOV and 11mm working distance

Question 17

what is the digital high mag lens?

Answer 17

ideal for posterior pole = diameter and FOV similar to 78, more mag than 78 and 13mm working distance

Question 18

what is the digital wide field lens?

Answer 18

“ultimate 90” - similar mag but larger FOV, 5-6mm working distance

Question 19

what does the proper working distance of a condensing lens allow for?

Answer 19

the back focus of the lens to be fixed right at the pupil - permitting the examiner to move the joystick and effectively scan the full field the lens provides

Question 20

what is the set-up for 90D or 78D?

Answer 20

medium-high illumination in click position, 10x (can move to 16x with 90D), parallelepiped beam height 5-6mm and with camera use polaroid filter and 1-3 aperture size

Question 21

what are the steps to 90D/78D after the slit lamp is set up?

Answer 21

give patient proper target (aperture knob), center beam in red reflex of pupil (cornea in focus), hold lens at 45-60 degree angle close to eye, and pull slit lamp towards you until image is in focus

Question 22

what is the order for scanning the posterior pole with 90/78D?

Answer 22

start with optic nerve, scan away from disc to inferior arcades, then down to superior arcades, scan nasal retina and then macula

Question 23

you are examining OS superior/temporal arcades, the view is lost as you reach the outer limit of the 90D, which way should you move to keep scanning?

Answer 23

move lens to lens to examiner’s left (direction you are scanning) - works because the views are inverted and reversed

Question 24

which vessels, temporal or nasal arc around the fovea?

Answer 24

temporal (nasal vessels radiate straight from disc to equator)

Question 25

which way should you hold your 90D lens if the patient looks up to examine superior retina?

Answer 25

you need to tilt the bottom of the lens closer to patient and top towards you

Question 26

which way should you hold your 90D lens if the patient looks down to examine inferior retina?

Answer 26

tilt the bottom of the lens away from patient (towards you) and top towards the patient

Question 27

which way should you hold your 90D lens if the patient looks left or right?

Answer 27

tilt the lens IN the direction of the patient's gaze (pt looks right = tilt lens to your right)

Question 28

it is important to keep your views centered in the 90D lens - where do you have the patient look?

Answer 28

ask patient to look into the direction you want the image to move (ex: want ONH to move to your left, ask patient to look to their right)

Question 29

what are the horizontal meridian landmarks that divide the retina into superior and inferior?

Answer 29

long posterior ciliary nerves at 3 and 9 o'clock

Question 30

what are the vertical meridian landmarks that divide the retina into nasal and temporal?

Answer 30

short ciliary nerves at 10 and 2 and 4 and 6 o'clock positions

Question 31

what divides the anterior and posterior retina?

Answer 31

the equator (vortex ampulla mark this spot)

Question 32

how many vortex ampulla are there and where are they located?

Answer 32

at least 4-6 = located at 1,5,7,11 o'clock meridians

Question 33

what is the ora serrata?

Answer 33

junction between retina and ciliary body (nasal appears serrated - dentate processes are more easily seen nasally)

Question 34

what are the different FOV (degrees) for the mirrors on the 3-mirror?

Answer 34

``` D-shaped = 60 rectangular = 66 trapezoid = 76 ```

Question 35

what are 4 indications for the 3-mirror fundus examination?

Answer 35

stereoscopic exam of retina, stable view of posterior pole, magnified view of peripheral retina, and performed after BIO

Question 36

what are 3 contraindications of using the 3-mirror?

Answer 36

severe corneal surface disease, recent eye surgery, trauma (hyphema, corneal laceration, and globe perforation)

Question 37

what view does the contact hruby lens provide?

Answer 37

a direct upright view (larger FOV than with direct scope)

Question 38

what areas of the retina are seen with the trapezoid, rectangular and d-shaped mirrors?

Answer 38

``` trapezoid = equator to PP (mid-periphery) rectangular = equator to ora (periphery) d-shaped = CB and pars plana ```

Question 39

what is the set up for the 3-mirror fundus exam?

Answer 39

same as gonio and 78/90D - place mirror 180 from retina in question, move light into mirror and push IN with scope (not pull back)

Question 40

what are the boundaries for the mid-periphery and the periphery?

Answer 40

``` mid-periphery = everything posterior of equator periphery = between the ora and equator ```

Question 41

what 5 things do you asses for the optic nerve?

Answer 41

disc size/shape, margins, contour of neuroretinal rim tissue, C/D ratio and rim tissue/NFL

Question 42

what 4 things do you examine during fundus biomicroscopy?

Answer 42

optic nerve, vessels, posterior pole retina and macula and peripheral retina

Question 43

what are you looking at when you evaluate the optic nerve head?

Answer 43

physiological cupping of the optic nerve (looking at the overall size of the disc to estimate the expected physiologic cup size)

Question 44

how do you know if the disc size is smaller or larger than average?

Answer 44

use medium aperture spot on direct scope: smaller = disc falls within spot larger = disc falls outside spot

Question 45

what is the average size of the ON?

Answer 45

disc diameter is about 1500 micrometers

Question 46

how do you measure the ON with a slit lamp?

Answer 46

use narrow beam in click with 78/90D, adjust vertical height beam across the vertical optic disc inner edge and read scale

Question 47

what are the conversion factors for 78 and 90D lenses?

Answer 47

``` 78D = 1.2x conversion 90D = 1.33x conversion ```

Question 48

what is the order from smallest to largest optic disc size with race?

Answer 48

caucasians - hispanics - asians - african americans (largest)

Question 49

how does the optic disc size change for myopia and hyperopia?

Answer 49

greater for high myopia (>5D) and smaller for high hyperopia (>5D)

Question 50

what is the cup to disc ratio?

Answer 50

the ratio of the physiological cup of the optic nerve to the overall diameter (divided into tenths) - estimated and recorded for horizontal and vertical ratios (record horizontal first)

Question 51

what are the 5 "R" rules for optic nerve evaluation?

Answer 51

scleral "ring" for ON diameter, "rim" size and color, "retinal" nerve fiber layer, "region" of the peripapillary for atopy (PPA) and "retinal" and/or optic nerve hemorrhages

Question 52

what is venous pulsation?

Answer 52

an observed pulsation of the venous arcades as they pass over the rim of the cup or at the central bifurcation

Question 53

what is a scleral crescent?

Answer 53

"white stuff" - or direct visualization of the sclera around the ONH

Question 54

what is a pigment crescent?

Answer 54

"dark stuff" - direct visualization of the RPE and choroid