3.1.3 Examines the fundi using both direct and indirect techniques.

Question 1

HOW TO DO VOLK:

Answer 1

• 10X MAG (ALWAYS), 14mm height (ALWAYS). Align the microscope & illumination at 0 degrees exactly. Ensure eyepieces are completely focussed or your view will not be good & neither will your stereopsis be. Focus on the pupil with a parallelepiped around 50-60% the size of the pupil with 60-70% brightness. Move the slit lamp back a bit, THEN pop the Volk in front of the pupil. Ensure your index finger touches their eyebrow so that you get a good FOV and are stable. Other fingers should be against the forehead rest.
• Before putting in front of the pupil, let the patient know you are about to examine the back of their eye. “I’ll just be having a look at the back of your eye with a lens. It will be a bit bright, it may touch your eyelashes but just keep your eyes nice and wide looking at my ear. If you need me to stop, just let me know.”
• Must do all 8 directions! Start left, then up left, up, up right etc.

Question 2

With volk… all directions why?

Answer 2

• You may need to flip the record over 180 degrees for volk. E.g. if you see a superior disc haem on volk, it is actually inferior. Naevus superiorly to macula is actually inferior.
• If px looks toward their left i.e. toward their nose with their right eye, you are looking at NASAL retina. If they look right, i.e. towards outer canthus with their right eye, you are looking at TEMPORAL retina. If px looks towards their nose when examining left eye, then again, NASAL & outer canthus with temporal. This principle makes Volk MUCH EASIER to understand

Question 3

When would you want to do Volk?

Answer 3

• When you want a stereoscopic view of the fundus e.g. optic disc assessment
• When you want a larger field of view compared to direct Ophthalmoscopy
• When you want a better view of a myopic fundus
• When you want a superior view through media opacities
• When you want varied magnifications

Question 4

DIRECT OPHTHALMOSCOPY:

Answer 4

• Hyperopic patient will have greater FOV
• Myopic patients have increased magnification on examination so lower FOV, so high myopia is difficult to examine
• If degree of astigmatism high then difficult to examine as the correcting lenses are only spherical so one meridian corrected at a time. As a result, disparity in both images can cause distortion & even make the optic disc look like an oval.
• Remember: Appropriate lens power = sum of your own Rx & px’s Rx