Direct ophthalmoscopy

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Direct ophthalmoscopy

• OP1201 Basic Clinical Techniques
• Anterior eye
• Dr Kirsten Hamilton-Maxwell

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Todays goals

• By the end of todays lecture, you should be able
  to explain
• Why examining the anterior eye is important
• Basic construction and optical principles of the
  direct ophthalmoscope
• How to use it to examine the anterior eye and how
  to record results
• Have some awareness of normal and abnormal
  anterior eye conditions
• Limitations of direct ophthalmoscopy for the
  anterior eye
• By the end of the related practical, you should
  be able to
• Assess and record the health of the anterior eye
  using direct ophthalmoscopy efficiently and
  accurately

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Background

• Why ocular health assessment is important
• What is a direct ophthalmoscope?
• Basic ocular anatomy

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Ocular health

• Good ocular health is vital to good vision
• Optometrists are primary care practitioners
• Required to identify ocular health problems
• Manage or refer appropriately for treatment
• Ocular health examination is one of our primary
  functions
• Today we will look at one of the techniques used
  to examine the eye ophthalmoscopy!

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Ophthalmoscopy

• An instrument used for assessment of ocular
  health
• Posterior eye
• Can also be used for the anterior eye

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The direct ophthalmoscope

• Most contain
• Light source
• Eyepiece
• Lens rack and power dial
• Usually between -15D and 15D in 1D steps
• Jump change of 10/15D
• Total range of -30D to 30D
• Aperture selector
• Filter selector
• On/off and brightness control
• Power handle
• (We will talk more about how it all goes together
  in the next lecture)

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Basic ocular anatomy
Anterior eye
Posterior eye
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Anterior eye anatomy
Pupillary margin
Eyelashes
Lateral canthus
Medial canthus
Cornea
Conjunctiva Episclera
Lid margin
Lens
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Procedure

• When?
• How?
• A few examples
• Recording results

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When should I do direct ophthalmoscopy?

• This is probably the most important test that you
  will do
• Every patient
• Legal requirement!
• Just to clarify the eye health of every patient
  MUST be assessed, however, direct ophthalmoscopy
  is not the only method that we can use.
• There are no contraindications
• i.e. No reason that you should not attempt it on
  every patient

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How to do ophthalmoscopy

• Set up
• Remove spectacles (yours and the patients)
• Explain what you are doing
• Raise the examination chair so you are bending
  slightly
• Dim the room lighting
• Hold the ophthalmoscope in your right hand in
  front of your RE for patients RE, swap all to
  the left side for LE
• Hold as close to your eye as possible
• Tilt ophthalmoscope to about 20deg to avoid
  bumping into the patients nose

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How to do ophthalmoscopy

• Ask the patient to look at a spot about 15deg
  temporal, and up slightly
• Keep BOTH eyes open (you and the patient) and
  look through the eyepiece
• Using both eyes will help control your
  accommodation and it will be more comfortable
• This will take practice

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How to do ophthalmoscopy

• Systematic examination of
• Eyelids and eyelashes
• Conjunctiva
• Cornea
• Iris
• Pupil
• Lens

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Eyelids

• Set the ophthalmoscope lens to 10D
• The patients eye will be in focus at 10cm away
  if you are emmetropic
• At 10cm away, the magnification is 2.5x
• Adjust for your refractive error
• Use a lower power if you are a myope
  (short-sighted)
• Use a higher power if you are a hypermetrope
  (long-sighted)
• Wear your spectacles if you have high astigmatism
• The patients refractive error is not important
  for the anterior eye exam
• Use widest and brightest beam
• Look for changes in colour (especially red or
  brown), lumps, rough areas, ulcerations, loss or
  irregularity of eyelashes

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Stye (external hordeolum)
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Basal cell carcinoma
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Conjunctiva

• As for eyelids, but ask patient to look in 9
  cardinal directions of gaze
• Up, up-left, left, down-left, down, down-right,
  right, up-right
• Lift eyelid to see upper conjunctiva when eye
  looks down
• Look for changes in colour (especially redness),
  raised/rough areas, irregularity of blood vessels

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Allergic conjunctivitis
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Subconjunctival haemorrhage
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Pinguecula
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Cornea, iris and pupil

• As for the conjunctiva and lids, but ask the
  patient to look straight ahead
• The cornea
• Look for a loss of transparency, ulceration,
  presence of blood vessels
• Iris
• Look for irregularities in colour, texture,
  raised areas, blood vessels, transillumination
• Pupil
• Look for shape, size and at the pupil margin

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Corneal arcus
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Corneal ulcer
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Iris nevus
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The lens

• Is located immediately behind the iris
• When looking at the pupil, you are actually
  looking at the lens
• Direct illumination
• Shine the light onto the lens
• Look for changes in colour (especially white or
  yellow)
• Indirect illumination
• Relies on the annoying red glow seen in
  photographs!
• Look for black/grey shadows

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How to view the lens
Retro-illumination
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Cataract
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Lens - retroillumination
This technique is also good for observing corneal
lesions and iris transillumination
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Iris transillumination
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Recording your findings
Draw abnormalities
Never EVER write NAD or WNL Legally Not
Actually Done or We Never Looked!
Written description here
Written description here
Be descriptive, even when normal
Be descriptive, even when normal
Colour, size, shape
Colour, size, shape
Record cards always show the RE on the left side
of the page the way you see the patient!
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Example of lens recording
Mittendorf dot
Ant
Post
Side view
Front view
This diagram shows the position and the depth
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Example
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What to write
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Limitations
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Limitations of direct ophthalmoscopy

• Direct ophthalmoscopy of the anterior eye is a
  screening technique
• Instrument of choice is the slit lamp
• We will cover this later in the year
• Low magnification (2.5x for the anterior eye)
• No stereopsis (3D vision)
• Minimal lighting variability

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Further reading

• Elliott, Sections 6.4 to 6.5, 6.20
• Become familiar with the procedural steps
• Memorise anatomical structures