Competency 3.1.3

Question 1

Direct Ophthalmoscope Filters

Answer 1

• Large Aperture Circular Beam
• Medium Aperture Circular Beam
• Small Aperture Circular Beam
• Red-Free Filter (with graticule)
• Slit Beam
• Cobalt Blue

Question 2

Large Aperture Circular Beam

Answer 2

• Used to assess the anterior eye (remember +10DS lens to focus)
• Has good illumination over large areas of the external eye

Question 3

Medium Aperture Circular Beam

Answer 3

• Used in fundus assessment
• Covers larger areas of the fundus (FoV)
• Small enough to get through most pupils without resulting in excessive glare

Question 4

Small Aperture Circular Beam

Answer 4

• Known as macular stop
• Used to assess macular area and foveal reflex

Question 5

Red-Free Filter (with graticule)

Answer 5

• Used to examine blood vessels and haemorrhages
• Graticule can be used to assess eccentric fixation in e.g. microtropia

Question 6

Slit Beam

Answer 6

• Used to assess depth
• Makes up for some of the loss in stereo as direct is a monocular technique

Question 7

Advantages of Direct Ophthalmoscopy

Answer 7

• Erect image of fundus
• Portable
• Suitable for all patients

Question 8

Disadvantages of Direct Ophthalmoscopy

Answer 8

• Non-stereoscopic view
• Poorer FoV when compared to volk
• Cannot view beyond the equator
• Image can be harder to obtain in dense cataract and high ametropia (think astigmatism)
• Breaches personal space a little more