PC - Binocular Indirect Ophthalmoscopy - Week 2

Question 1

Describe the following for a BIO:
Image of the fundus
Image orientation
Stereopsis
Field of view
Magnification
Limitation

Answer 1

Image - real
Orientation - Reversed and inverted
Stereopsis - yes
Field of view - 25 degrees
Magnification - 2x
Limitation - Posterior pole to ora serrata and vitreous

Question 2

Are cataracts an indication for a BIO exam?

Answer 2

Yes

Question 3

Name 3 general indications for a BIO exam.

Answer 3

Indications for DFE
1st presentation
Reduced best corrected VA

Question 4

Name 15 PC indications for a BIO exam.

Answer 4

Reported visual disturbance
Photopsia
Floaters
Metamorphosia
Metachromatopsia
Shadows
Veils
Curtain of reduced vision
Scotoma
VF deficit
HA
Diplopia
Ptosis
Pupil abnormalities
Trauma (hyphaema)

Question 5

Name 5 GH indications for a BIO exam.

Answer 5

Diabetes
Hypertension
Cancer
High cholesterol
Lupus

Question 6

Aside from general, PC, GH, and cataracts, name 4 indications for a BIO exam.

Answer 6

Known PVD
Previous RD
Retinal/choroidal lesion

Question 7

How can a patients entire retina be seen through a BIO?

Answer 7

Need to direct their gaze to see everything.

Question 8

Which method views better through media opacities, BIO or direct?

Answer 8

BIO

Question 9

Name 2 advantages of the BIO.

Answer 9

Provides 2x magnification

Large field of view

Question 10

Compare the magnification of the BIO to a fundus lens.

Answer 10

Lower magnification compared to a fundus lens

Question 11

Name 3 disadvantages of the BIO.

Answer 11

Image is reverse and inverted
Requires mydriasis
Illumination may be uncomfortable

Question 12

Are higher power condensing lenses better for smaller or larger pupils?

Answer 12

Smaller

Question 13

Do higher power condensing lenses provide better or poorer steropsis?

Answer 13

Poorer

Question 14

Do higher power condensing lenses provide higher or lower magnification?

Answer 14

Lower

Question 15

Do higher power condensing lenses provide a greater or smaller field of view?

Answer 15

Greater

Question 16

Must higher power condensing lenses be held closer to or further from the eye?

Answer 16

Closer

Question 17

Briefly explain the BIO procedure.

Answer 17

Explain the procedure
Dilate the pupils
Dim the lights
Patient at eye level
Begin with direct gaze
Then direct patient to additional gaze positions

Question 18

If during BIO the patient looks up from direct gaze, what are you seeing?

Answer 18

Superior retina

Question 19

How can the vitreous be seen during BIO?

Answer 19

Increase working distance or move the lens in slightly

Question 20

How would you troubleshoot reduced or no view during BIO?

Answer 20

Tilt the lens

Question 21

How would you troubleshoot excessive reflections during BIO?

Answer 21

Reduce intensity, tilt lens, change aperture

Question 22

How would you troubleshoot limited peripheral retinal view during BIO?

Answer 22

Stand opposite to the retinal area examined
Rotate the chair
Tilt or turn the patient’s head

Question 23

How many disc diameters is the ora serrata from the optic disc?

Answer 23

~10DD

Question 24

Give a template for a BIO recording

Answer 24

Technique
Drops (name, %, dose, eye, time)
Mid-periphery NAD (or tick)
Periphery NAD (or tick)
Vitreous NAD (or tick)
If abnormality, then size (DD), shape, colour, raised/flat, location (DD & sector)

Question 25

Describe scleral indentation, and when it is typically used.

Answer 25

A means of elevating the retina, used when retinal tearing/hole is suspected.
The patient is asked to look up, the indentor is placed between the eye and orbit.
Done with the other gaze directions as well.