Shared article

Using an Ophthalmoscope

Introduction

 

Examining the fundus is different from other clinical examinations because there is no palpation, percussion or auscultation involved. However, the appropriate communication skills for the procedure remain the same. An ophthalmoscope is used routinely in clinical settings. It is not difficult to use, just requires some practice using the correct technique. Here is a quick insight into the equipment itself and the examination sequence of ophthalmoscopy in an OSCE setting. We will also discuss normal and abnormal findings, as well as investigations to differentiate common eye conditions.

 

Components and settings of the Ophthalmoscope

Figure 1. Components of an Ophthalmoscope

 

Adjusting the ophthalmoscope to your own and the patients’ eyesight

If you are wearing glasses or contact lenses, keep them on, you now only need to adjust to the patient’s prescription. Set everything to 0. If the patient is wearing glasses, you can get a rough idea what their prescription is by looking at what kind of glasses they are wearing. Adjust to their eyesight using the refraction adjustment wheel.

− Lenses (usually red numbers) corrects for myopia

+ Lenses (usually black numbers) corrects for hypermetropia

 

Ophthalmoscope settings for OSCE

  • How bright? Turn to maximum
  • Which beam? Large white beam

 

    Examination of the Fundus

     

    To begin: Wash, Introduce, Position, Expose

    • Wash your hands with soap and water/alcohol gel.
    • Introduce yourself, stating your full name and your role.
    • Check patient’s details – full name and DOB
    • Explain the procedure (avoid any jargon) and gain consent – before, during and after.
    • Position the patient sitting up and ask them to remove any glasses or contact lenses. Warn the patient that you will need to come quite close and will also need to dim the lights.
    • 1% tropicamide is sometimes used to dilate the pupils after examining the pupils and iris. Remember to check for a history of glaucoma!
    • Check patient comfort.

     

    Technique

    1. Select the correct brightness and beam. This is usually the large round white beam at maximum brightness.
    2. To examine the right eye: hold the ophthalmoscope in your right hand, look through it with your right eye to examine the patient’s right eye. Instruct the patient to look to a distant object on their left.
    3. Check for the red reflex by shining the light on the patient’s eyes about 30cm away. The red reflex is the red reflection of the retina, it looks like people’s red eyes you sometimes see in pictures.
    4. Place your hand on the patient’s forehead. Hold the patient’s upper eyelid open with your thumb. Warn the patient what you are going to do.
    5. Slowly move towards the patient until you are touching the hand which you rest on the patient’s forehead.
    6. When the retina comes into view, rotate the refraction adjustment wheel in an anti-clockwise direction to bring the blood vessels into focus.
    7. Identify a vessel and follow its course towards the optic disc.
    8. Identify the macula which is temporal to the optic disc. To do this, ask the patient to look directly into the light of the ophthalmoscope.
    9. Repeat the process to examine the patient’s left eye. Hold the ophthalmoscope in your left hand, look through it with your left eye to examine the patient’s left eye. Instruct the patient to look to a distant object on their right.

     

    What are you looking for?

    • Red reflex – present/obscured
    • Optic disc – atrophy, swelling, cupping, angiogenesis
    • Blood vessels – haemorrhages, artery or vein occlusion
    • Macula

     

    To finish:

    • Ask for questions and concerns.
    • Thank the patient.
    • If patient’s pupils are dilated, they should not drive for at least two hours. If they do not have a relative with them, they should rest until they feel their vision is back to normal. 
    • Wash your hands with soap and water/alcohol gel.

     

    You then turn to the examiner and say: I would also like to: 

    • Take a full history
    • Assess visual acuity and colour vision, visual fields, pupillary reflexes and extraocular movements
    • Do a full neurological examination

     

    Presentation to Examiner: A Normal Ophthalmoscopy. Say what you saw in an organised manner.

    • Thank you for letting me examine (name), a (age) year-old male/ female.
    • On general inspection, there were no abnormalities.
    • The red reflex was present in both eyes.
    • The optic disc was of normal colour and its margins were clearly visible.
    • The disc/cup ratio was not increased.
    • On inspection of the fundus, I cannot detect any abnormalities of the colour and the blood vessels.
    • In summary, this is a (age) year-old male/ female with a normal fundoscopy examination.

     

    Include any abnormalities in your presentation in the same order. Offer at least 2 differential diagnoses and investigations.

     

    Normal Fundus

     

    Optic Disc

    • Location: Nasally
    • Colour: Pale pink, yellow
    • Shape: Circular, Oval
    • Margin should be clearly demarcated
    • The physiological cup is in the centre of the optic disc.

     

    Macular

    • Location: Temporally
    • Colour: Dark red
    • The fovea is in the centre of the macular, where there is a concentration of cone photoreceptors responsible for sharp central vision.

     

    Retinal vessels

    • Veins appear larger and darker in colour compared to arteries.

     

    Figure 2: Normal Fundus

    Optic Disc Swelling

     

    Appearance:

    • Optic disc is swollen and enlarged.
    • Colour: Darker compared to normal
    • Margin is poorly demarcated.

     

    Causes of Unilateral Optic Disc Swelling:

    • Space occupying lesions
    • Ischaemic optic neuropathy
    • Cavernous sinus lesion

     

    Causes of Bilateral Optic Disc Swelling:

      • Subarachnoid haemorrhage
      • Malignant hypertension
      • Cavernous sinus lesion
        Figure 3: Optic disc swelling

        Optic Disc Cupping

         

        Appearance:

        • The overall appearance looks like a cup seen from below - Retinal vessels seem to appear from the optic disc at a sharp angle. 

         

        Causes:

        • Glaucoma (Most common)
        Figure 4: Optic Disc Cupping

        Optic Atrophy

         

        Appearance:

        • Pale optic disc

         

        Causes:

        • Giant cell arteritis
        • Optic Neuritis
        • Foster-Kennedy syndrome
        Figure 5: Optic Atrophy

        Retinal Artery Occlusion

         

        Appearance:

        • 'Cherry-red spot' appearance

         

        Causes:

        • Glaucoma
        • Ischaemic optic neuropathy
        • Giant cell arteritis
        Figure 6: Retinal Artery Occlusion

        Retinal Vein Occlusion

         

        Appearance:

        • 'Thunder storm' appearance

         

        Causes:

        • Glaucoma
        • Diabetes Mellitus
        • Hypertension

         

         

          Figure 7: Retinal Vein Occlusion

          Investigations – B.O.X.E.S

           

          Bloods

          Full Blood Count (FBC)

          CRP, ESR

          Blood glucose and lipids

          Liver Function Tests (LFTs) and clotting

          Blood cultures

           

          Observations and Bedside tests

          Blood pressure

          Visual acuity, visual field, colour vision

           

          X-ray and Imaging

          Optical coherence tomography (OCT)

           

          Magnetic Resonance Imaging (MRI)

          Intravenous Fluorescein angiography (IVFA)

           

          Electrograms

          Electrocardiogram (ECG)

          Echocardiogram (EEG)

           

          Special Tests

          Applanation Tonometry

          Lumber Puncher (LP)

          Indications/ Comments

           

          Anaemia

          Giant cell arteritis

          Atherosclerotic status, Diabetic control

          Blood viscosity, Clotting disorder

          Causes of infective emboli

           

           

          Hypertension, Malignant hypertension

          Optic atrophy

           

           

          Age-related macular degeneration (AMD), Macular oedema

          Causes of optic disc swelling

          Extend of vessel damage in retinal vein occlusion, retinal artery occlusion

           

           

          Heart arrhythmias

          Heart valvular diseases

           

           

          Raised intraocular pressure

          Papilledema

           

          Finally...Some tips for OSCEs

             

            • Do not be afraid to get close to the patient. In fact, you should almost be touching their cheek. Just tell the patient what you are going to do and gain consent.
            • This examination is unlikely to be performed alone in a station. It is normally combined with a cranial nerve examination station.

             

              References

              1. Thomas, J., Monagham, T. (2007) Oxford Handbook of Clinical Examination and Practical Skills. Oxford, Oxford University Press.
              2. Macleod, J., Douglas, Graham., Nicol, F., Robertson. (2009) Macleod’s Clinical Examination 12th Edition. Edinburgh, Churchhill Livingstone Elsevier.
              3. Cozma, I., Fraser, S., Nambiar, A. K., Peter, N., Spokes, D. (2004) How to use an Ophthalmoscope. BMJ. Career Focus. [Online] 329 (7461), 55-56. Available from: http://careers.bmj.com/careers/advice/view-article.html?id=354 [Accessed 30 December 2011]

               

                Images

                Figure 2 - Picture taken from: http://www.kellogg.umich.edu/theeyeshaveit/index.html

                Figure 3 - Picture taken from: http://www.cybersight.org

                Figure 4 - Picture taken from: http://www.kellogg.umich.edu/theeyeshaveit/index.html

                Figure 5 - Picture taken from: http://www.pediatrics.uci.edu/drhuang/research.asp

                Figure 6 - Picture taken from: http://emedicine.medscape.com/article/799119-overview#a0104

                Figure 7 - Picture taken from: http://www.avclinic.com/retinal_vein_occlusion.htm

                  Advertisement

                  Fastbleep © 2019.