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OP1201 – Basic Clinical Techniques
Anterior eyeDr Kirsten Hamilton-Maxwell
Today’s goalsBy the end of today’s lecture, you should be able to
explainWhy examining the anterior eye is importantBasic construction and optical principles of the direct
ophthalmoscopeHow to use it to examine the anterior eye and how to record
resultsHave some awareness of normal and abnormal anterior eye
conditionsLimitations of direct ophthalmoscopy for the anterior eye
By the end of the related practical, you should be able toAssess and record the health of the anterior eye using direct
ophthalmoscopy efficiently and accurately
Why ocular health assessment is important
What is a direct ophthalmoscope?
Basic ocular anatomy
Ocular healthGood ocular health is vital to good visionOptometrists are primary care practitioners
Required to identify ocular health problemsManage 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!
OphthalmoscopyAn instrument used
for assessment of ocular health
Posterior eyeCan also be used for
the anterior eye
The direct ophthalmoscope
Most contain…Light sourceEyepieceLens rack and power dial
Usually between -15D and +15D in 1D steps Jump change of ±10/15D Total range of -30D to +30D
Aperture selectorFilter selectorOn/off and brightness controlPower handle
(We will talk more about how it all goes together in the next lecture)
Basic ocular anatomyAnterior eyePosterior eye
Anterior eye anatomy
Eyelashes
ConjunctivaEpisclera
Lens
Medial canthusLateral canthus
Pupillary margin
Lid margin
Cornea
When?How?
A few examplesRecording results
When should I do direct ophthalmoscopy?This is probably the most important test that you will
doEvery patientLegal 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 contraindicationsi.e. No reason that you should not attempt it on every
patient
How to do ophthalmoscopySet up
Remove spectacles (yours and the patient’s)Explain what you are doingRaise the examination chair so you are bending
slightlyDim 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 LEHold as close to your eye as possibleTilt ophthalmoscope to about 20deg to avoid bumping
into the patient’s nose
How to do ophthalmoscopyAsk the patient to look at a spot about 15deg
temporal, and up slightlyKeep BOTH eyes open (you and the patient) and
look through the eyepieceUsing both eyes will help control your accommodation
and it will be more comfortableThis will take practice
How to do ophthalmoscopySystematic examination of
Eyelids and eyelashesConjunctivaCorneaIrisPupilLens
EyelidsSet 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 2.5xAdjust 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 beamLook for changes in colour (especially red or brown),
lumps, rough areas, ulcerations, loss or irregularity of eyelashes
Stye (external hordeolum)
Basal cell carcinoma
ConjunctivaAs for eyelids, but ask patient to look in 9 cardinal
directions of gazeUp, up-left, left, down-left, down, down-right, right, up-
rightLift eyelid to see upper conjunctiva when eye looks
downLook for changes in colour (especially redness),
raised/rough areas, irregularity of blood vessels
Allergic conjunctivitis
Subconjunctival haemorrhage
Pinguecula
Cornea, iris and pupilAs for the conjunctiva and lids, but ask the
patient to look straight aheadThe cornea
Look for a loss of transparency, ulceration, presence of blood vessels
IrisLook for irregularities in colour, texture, raised areas,
blood vessels, transilluminationPupil
Look for shape, size and at the pupil margin
Corneal arcus
Corneal ulcer
Iris nevus
The lensIs located immediately behind the iris
When looking at the pupil, you are actually looking at the lens
Direct illuminationShine the light onto the lensLook for changes in colour (especially white or yellow)
Indirect illuminationRelies 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
Be descriptive, even when normal
Draw abnormalities
Record cards always show the RE on the left side of the page– the way you see the patient!
Colour, size, shape
Written description here
Be descriptive, even when normalColour, size, shape
Written description hereNever EVER write NAD or WNLLegally = Not Actually Done or
We Never Looked!
Example of lens recording
Front view Side view
Ant Post
This diagram shows the position and the depth
Mittendorf dot
Example
What to write
Limitations of direct ophthalmoscopyDirect ophthalmoscopy of the anterior eye is a
screening techniqueInstrument of choice is the slit lampWe will cover this later in the year
Low magnification (2.5x for the anterior eye)No stereopsis (3D vision)Minimal lighting variability
Elliott, Sections 6.4 to 6.5, 6.20Become familiar with the procedural steps
Memorise anatomical structures