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