Week 9 - Assessing Soft CL fits and problem saving

Question 1

What are the two main aspects of fitting design that can cause discomfort? (anything else?)

Answer 1

1. Total diameter
2. Inappropriate fit

But don’t forget non-fitting related possibilities
- Foreign body
- Lens inside out
- Lens damage
- Lens spoilation

Question 2

What happens when the total diameter is too large?

Answer 2

• Can lead to increased pressure and therefore conjunctival indentation
• If there is poor flexure it can lead to superior arcuate staining
• Limited options in the standard lenses, consider specialist lens
• Learn which standard lenses look smaller once they have settled on the eye. Efron advises Air Optix Night & Day and
  Soflens

Question 3

What happens when the total diameter is too small?

Answer 3

• Can lead to peripheral corneal staining
• Limited options in the standard lenses, consider specialist lens
• Learn which standard lenses look larger once they have settled on the eye. Efron advises Proclear, Air Optix Aqua and Acuvue Oasys 1-day

Question 4

What if the lens is not fitting well as in too loose and too tight?

Answer 4

• Too loose
- Steepen the base curve
- First thing to check is whether the lens is inside out.
- Changing to the same lens but in a steeper BC doesn’t always help as the lenses are so thin that it may not tighten much
- Consider changing to lenses that are known to have a tighter fit
- Increase TD
Too tight
- Discomfort tends to be towards the end of the day
- Flatten the base curve
- Decrease TD

Question 5

What might be reasons for poor visual acuity for lens? (even if comfort is fine?)

Answer 5

Possible causes
- Uncorrected astigmatism (found in over-refraction)
- Lens deposits
- Poor surface wetting
- Lens imperfections

Question 6

What might cause variable vision?

Answer 6

• Excessive lens movement
• Incorrect BVP
• Poor binocular balance
• Poor tear film