7.1.7-special needs of severe vf defects

Question 1

What types of severe visual field defects are there?

Answer 1

• Quadrantanopia
• Hemianopia
• Heteronymous
• Homonymous
• Superior, Inferior, Nasal, Temporal

Question 2

How would you adapt routine for severe vf defects

Answer 2

-Use a trial frame to give greater field of view
Use LogMAR chart (Bailey Lovie/ETDRS/Thomson) as there are more letters compared to Snellen chart so more precise VA scoring
-Use single lines instead of displaying the whole chart, maybe even highlight single letters on the side that the px can see
-Measure contrast sensitivity, especially those where reported visual function is less than what VA shows (e.g.Pelli-Robson)
-Subjective should be big jumps and not spend too long
-Note near working distance and NVA actual and comfortable, along with NVA with +4.00DS ADDNas it corresponds to unit magnification and will be useful when calculating mag- also with and without reading lamp
- Use confrontation/peripheral field testing or increase spot size in vf machine. Check macular function with amsler or central vf
-Perform opthalmoscopy at the end of the routine so that any disability glare does not effect refraction

Question 3

How would you adapt a routine to take a px mobility into consideration?

Answer 3

• Guide px to the test room
• Describe the room or setting to them beforehand
• Put the chair footrest up