Prior to Lab

1. Read your BIO manual, and become familiar with its various components
2. Charge your BIO
3. Clean your 20D lens
4. Know how to put on/take off your teaching mirror
5. If you have a Heine BIO, learn the location of the small pupil selector lever, and MOVE IT TO THE FAR RIGHT as it sits on your head.  Failure to do so will often result in a poor image
6. Know how to adjust the coronal height (using the adjustment knob on top of the BIO)
7. Know how to adjust the occipital fit (using the adjustment knob on the back of the BIO)
8. Know how to turn on the unit and adjust the intensity of the light
9. Know how to adjust the head of the unit (the part that contains the illumination/observation system) to select a light beam size, to select a light beam filter, to move the oculars closer to and further away from the user, to change the ocular height of the system relative to the user, to move the light beam up and down, and to adjust the PD to the user’s PD.

BIO Setup

Make sure that you are able to quickly and accurately set up your BIO.  Failure to do so can result in discrepancies between what you see and what the observer sees in the teaching mirror.

1. Loosen the coronal and occipital straps
2. Place BIO on your head; tighten the coronal strap until you can see through oculars
3. Tighten the occipital strap to hold BIO firmly in place
4. Loosen BIO head, and move up and down until oculars are vertically aligned with your eyes
5. Move/tilt BIO head so that oculars are as close to your eyes as you can comfortably get them.
6. Turn on unit, select largest light circle (no filters) and change PD for each eye such that a centered image of the light circle is seen on your palm when held directly in front of you at arm’s length (which is approximately your working distance)
7. Move light to slightly above horizontal (you’re trying to clear your teaching mirror here – failure to do so can result in tons of glare)

Obtain an Image

1. With your patient dilated, situate them at eye level.  Indicate where you want them to fixate
2. Shine the BIO light on the patient’s face such that the light is centered horizontally and vertically over the eye to be examined
3. With you hand braced on the patient’s face, place the lens (with the silver ring toward the patient) in front of their eye as close to their face as possible and find the red reflex.  Pull back the lens to its proper working distance (the point at which magnification/minification switches; watch the iris as you pull the lens back – this is also the point at which the image will completely fill the lens).  Learn to use your fingers to move the lens in and out.  Note that there is no focusing in this procedure – you either have an image or you don’t
4. Observe the retina

Perform an Examination

1. Start with the right eye at the 10:00 o’clock position (patient looks up and to their right) and examine the retina
2. Continue at the 12:00 o’clock position (patient looks straight up) and examine the retina
3. Continue at the 2:00 o’clock position (patient looks up and to their left) and examine the retina
4. Continue at the 3:00 o’clock position (patient looks straight to their left) and examine the retina
5. Continue at the 9:00 o’clock position (patient looks straight to their left) and examine the retina
6. Continue at the 4:00 o’clock position (patient looks down and to their left) and examine the retina
7. Continue at the 6:00 o’clock position (patient looks straight down) and examine the retina
8. Continue at the 8:00 o’clock position (patient looks down and to their right) and examine the retina
9. Finish by examining the central retina (patient looks right at your light)
10. Examine the other (left) eye using steps 1 through 9

Examination Tips

1. Maintain proper vertical position
   • If patient is looking up, your forehead should roughly align with the patient’s chin (placing you lower than the patient)
   • If the patient is looking at the 3:00, 9:00, or straight ahead positions, your eyes should line up vertically with the patient’s eyes (placing your eyes at the same height as the patient’s eyes)
   • If the patient is looking down, your  chin should roughly align with the patient’s forehead (placing you higher than the patient)
2. Maintain proper horizontal position
   • If patient is looking right, your left ear should roughly align with the patient’s left ear (placing you to the patient’s left)
   • If the patient is looking at the 12:00, 6:00, or straight ahead positions, your eyes should be directly in front of the patient’s as they look straight ahead
   • If the patient is looking left, your right ear should roughly align with the patient’s right ear (placing you to the patient’s right)
3. Make sure the patient fixates correctly.  If they are not, it’s usually best to hold out a hand or finger and say, “look here”, as opposed to “can you look a little bit further up”.  Watch to ensure that their nose is always pointed straight ahead.
4. Hold open lids if necessary.  This may be especially true with patient down gaze, where the pupil buries itself in the lower lid and the upper lid covers the top of the eye