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 Anterior eye Posterior 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 Direct illumination 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 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!

Example of lens recording Mittendorf dot Ant Post Side view Front 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