Transcript File - Optometry Peer Tutoring

Direct ophthalmoscopy
OP1201 – Basic Clinical Techniques
Anterior eye
Dr Kirsten Hamilton-Maxwell
Today’s goals
 By the end of today’s 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
Background
Why ocular health assessment is important
What is a direct ophthalmoscope?
Basic ocular anatomy
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!
Ophthalmoscopy
 An instrument used
for assessment of
ocular health
 Posterior eye
 Can also be used for
the anterior eye
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)
Basic ocular anatomy
Posterior eye
Anterior eye
Anterior eye anatomy
Pupillary margin
Eyelashes
Lateral canthus
Medial canthus
Cornea
Conjunctiva
Episclera
Lid margin
Lens
Procedure
When?
How?
A few examples
Recording results
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
How to do ophthalmoscopy
 Set up
 Remove spectacles (yours and the patient’s)
 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 patient’s 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 patient’s nose
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
How to do ophthalmoscopy
 Systematic examination of
 Eyelids and eyelashes
 Conjunctiva
 Cornea
 Iris
 Pupil
 Lens
Eyelids
 Set the ophthalmoscope lens to +10D
 The patient’s 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 patient’s 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
Stye (external hordeolum)
Basal cell carcinoma
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
Allergic conjunctivitis
Subconjunctival haemorrhage
Pinguecula
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
Corneal arcus
Corneal ulcer
Iris nevus
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
How to view the lens
Retro-illumination
Cataract
Lens - retroillumination
This technique is also good for observing corneal lesions and iris transillumination
Iris transillumination
Recording your findings
Draw abnormalities
Never
EVER
write
NAD
or
WNL
Written description here
Written description here
or
BeLegally
descriptive, = Not Actually Done
Be descriptive,
even when normal
even when normal
We
Never
Looked!
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!
Example of lens recording
Mittendorf dot
Post
Ant
Front view
Side view
This diagram shows the position and the depth
Example
What to write
Limitations
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
Further reading
Elliott, Sections 6.4 to 6.5, 6.20
Become familiar with the procedural steps
Memorise anatomical structures