Ophthalmoscopy Flashcards
What are the different stages involved?
- Introduction
- Observation/General Inspection
- Assess fundal reflex
- Examine fundus – optic disc, 4 major arcade vessels, macula and fovea
- Repeat on fellow eye
- Conclusion
What is involved in the introduction?
- Introduction
A. Wash hands and don PPE if needed
B. Introduce yourself and confirm patient’s name and date of birth
D. Explain examination and gain consent
E. Position patient sitting on a chair or the edge of a bed
Ask the patient if they have ever had the procedure done before.
Explain that you are going to look at the back of the eyes with a light. Also explain that you are going to come very close and that you may have to put your hand on the patient’s head to steady yourself and avoid your heads touching.
The patient should sit on a chair, or the edge of the couch, with the knees together.
The patient and the examiner can leave their usual distance glasses or contact lenses on. Particularly in patients with very high refractive error it can be better to examine them through their glasses. Explain to the patient that the room will be darkened. The patient should be asked to fix on a distant target at eye level that you have identified for them and also reminded not to look at the examiner or the ophthalmoscope. The fixation target should compel the patient to keep their eyes in the ‘primary’ position (not looking to either side or up or down). They should also be reminded to keep their head still, but carry on blinking and breathing as normal.
What is involved in the Observation?
- Observation
A. Relative position (ptosis/retraction) and appearance (redness/swelling) of eye lids
B. Position of eyes looking for evidence of a squint (inward, outward or vertical displacement)
C. Relative size of pupils and regularity of shape
D. Conjunctiva and sclera for any redness, discharge or lesions
Inspect both eyes for any obvious abnormalities. Comment on any positive findings first then any relevant negative findings.
What is involved in Assessing the fundal reflex?
- Assess fundal reflex
A. Ideally perform in a dimly lit room
B. Prepare device with brightest light setting and lens power zero
C. Ask the patient to look straight at the light.
D. If a baby make sure they are secure and comfortable on a parent’s lap
E. Hold ophthalmoscope in your dominant hand and at arms length look at both eyes at the same time and compare appearances
Hold the sight hole very close to your own eye and look at both of the patient’s eyes at the
same time
You should see the normally central round dark pupil space light up brightly with shimmering
red, yellow and orange colours. This is known as the retinal reflection or ‘red reflex’
What is involved in Examining the fundus?
- Examine fundus – optic disc, 4 major arcade vessels, macula and fovea
A. Hold the device in your right hand: use your right eye to examine the patient’s right eye and vice versa
B. Start 15 ̊ temporal on the horizontal - not from low or high and not looking ‘straight in’
C. Use the zero power lens with the light on a low to medium level of brightness
D. Gradually move in maintaining the red reflex
E. Retinal detail should appear and ideally the disc if you are on the right ‘flight path’
F. Alter the lenses if fundal detail is out of focus
G. ‘Arrows’ created by branches of vessels point toward the optic nerve – follow them
H. Observe the optic nerve head commenting on the margin, colour and cup
I. Follow the four major arcade vessels examining the adjacent retinal quadrants
J. Finish by asking the patient to look at the light source to see the centre of the macula (fovea)
Use the correct eye; right-to-right and left-to-left. This allows you to get very close to the patient and therefore obtain a clear view, whilst also maximising the field of view. Place feet close to the patient where you will be comfortable when examining the eye close up. Then, lean back and start at arms-length from the patient and 15 ̊ temporal to the eye. Observe the red reflex in the pupil space and gradually move in closer towards the patient’s eye keeping the red reflex in your view. Retinal and optic nerve detail will appear.
To see the fundus in detail you’ll need to move very close to the patient. Just like peeping through a keyhole; the closer you are, the more you will see. If you begin with a zero lens in most patients you will see the fundal detail clearly. If the fundal detail is blurry then you may have to select lenses to see vessels more sharply. If you change lenses too quickly you will miss the one that gives you the sharpest view.
If you can’t focus on the retina go back to zero. If you know that you are long- sighted, try the ‘plus’ lenses first or if you are short-sighted try the minus lenses first. This can also be mitigated by wearing your glasses or contact lenses throughout the examination. If the patient has a high refractive error, it may also be easier to examine the patient whilst they are wearing their spectacles or contact lenses. However, you may find this more cumbersome and practice will highlight which technique you prefer.
Your initial ‘flight path’ using the technique above will hopefully take you to the optic nerve head. If you are ‘off target’ then you should see blood vessels on a random patch of retina. The wider, darker vessels are the veins while the narrower brighter red ones the arteries. To find the optic nerve head, follow the vessels, remembering that the V created by the branching always points to the disc like an arrow telling you
the way.
The optic nerve head lies on the horizontal meridian 15 degrees nasal to the centre of the retina. This is why it is important to begin your ‘flight path’ of the examination from the temporal side at roughly 15 degrees and to keep on the horizontal meridian. It is equally important that the patient keeps their head still and that they fix on an object that maintains their eyes in the ‘primary’ position. When you find the optic nerve head comment on the margin, colour and cup.
Comment on how distinct the margin of the nerve from the surrounding retina, the colour of the neuro-retinal rim and the size of the cup. The nerve often has a pigmented temporal margin-this is normal. At the centre of the disc there can be a pale area called the optic cup.
Next follow the 4 major arcade vessels and note the adjacent retina in these four quadrants in turn (superotemporal, inferotemporal, superonasal and inferonasal), going back to the optic disc between each inspection.
Finally, ask the patient to look directly into the light source. This brings the centre of the macula (the fovea) directly into view. This is the area of the retina shown in the black circle in the image above.
What is involved in Repeat on fellow eye?
- Repeat on fellow eye
A. Approach from left hand side of patient
B. Use left hand to hold ophthalmoscope to view patient’s left eye with your left eye
C. Repeat the steps as described above
What is involved in the Conclusion?
- Conclusion
A. Thank patient and wash hands
B. Summarise and present findings to the patient and examiner
How should you adjust the rack lenses in the arc light?
For most examinations the lens rack is best pushed to the top with no lens being used
In the Arclight there is a rack of lenses that moves up and down over the sight hole. If you are struggling to see the back of the eye clearly make sure you are wearing your normal distance glasses and the patient is doing the same. If this does not help then select different lenses but for the vast majority of situations it is best to have the lens rack at the top so there are no lenses just a hole.
What might cause the loss of the red reflex?
Cataracts, corneal scars, or vitreous hemorrhage
Describe some of the signs of diabetic retinopathy?
- gradually worsening vision.
- sudden vision loss.
- shapes floating in your field of vision (floaters)
- blurred or patchy vision.
- eye pain or redness
Describe some of the ways that patients can lose vision from diabetic retinopathy?
Diabetic retinopathy
Reduced vision due to:
* Growth of new vessels; vitreous haemorrhage, tractional retinal
detachment and rubeotic glaucoma
* Leakage of fluid from damaged vessels; macular oedema with loss of central visual acuity
The abnormal blood vessels (leaky vessels) associated with diabetic retinopathy stimulate the growth of scar tissue, which can pull the retina away from the back of the eye. This can cause spots floating in your vision, flashes of light or severe vision loss.
What might a swollen optic nerve head indicate?
- Pseudo swelling: Small Discs; Drusen
- Genuine swelling: Raised ICP; SOL; IIH; Hydrocephalus
- Symptoms of raised ICP: Headaches, especially when bending
forwards (frontal); vomiting/nausea; visual disturbance; tinnitus;
confusion; pupillary abnormalities; diplopia
Papilledema is swelling of your optic nerve, which connects the eye and brain. This swelling is a reaction to a buildup of pressure in or around your brain that may have many causes. Often, it’s a warning sign of a serious medical condition that needs attention, such as a brain tumor or hemorrhage
