SCL Solutions - Part 2

Question 1

What solution component assists in removal of lipid?

Answer 1

Surfactant

Question 2

What solution component assists in removal of protein?

Answer 2

Chelating agents (Hydranate, sodium citrate…)

Question 3

Deposition on SiHys

Answer 3

Small amount of protein (most denatured)
Increased lipid
(Reduced surface wettability)

Question 4

What materials showed most lipid deposition?

Answer 4

Senofilcon (OASYS)

Balafilcon (PureVision)

Question 5

What materials showed least lipid deposition?

Answer 5

Lotrafilcon A (Focus N&D)

Question 6

What percentage of bacteria will rinsing the lens remove?

Answer 6

90%

Question 7

What percentage of bacteria will rubbing and rinsing the lens remove?

Answer 7

99%

Question 8

Of SiHy lenses, which has most silicone exposed on lens surface?

Answer 8

PureVision

Question 9

How to fix problem of lipid deposits on SiHy lenses

Answer 9

1. Switch back to Hydrogel
2. Daily disposables
3. Solution w/ more surfactant (better wettability)

Question 10

How does contact angle relate to wettability?

Answer 10

Lower contact angle, better tear spreadability

More wettable lens

Question 11

What lenses have been found to interact w/ PHMB in solutions?

Answer 11

SiHys and FDA group II

more hydrophobic lenses

Question 12

When is corneal staining induced by solutions the WORST?

Answer 12

After 2 hours

Question 13

How does the “staining grid” work?

Answer 13

Each grid represents 30 px’s
Lens in solution overnight
Lens inserted, taken out after 2 hrs
Checked for staining

Question 14

What does a percentage on the staining grid mean?

Answer 14

Percentage of the cornea that shows staining

Question 15

What are the trends seen in the Staining Grid?

Answer 15

B&L (Renu) solutions show more corneal staining after 2 hrs. Worst w/ Softlens, Proclear, Purevision, O2 Optix.

Question 16

What did the IER Matrix Study do?

Answer 16

Looked at lenses randomly after min 3 mod wear (more true to life)

Question 17

What does a percentage in the IER study show?

Answer 17

Percentage of Px’s w/ abnormal corneal staining

Question 18

What are the trend of the IER study?

Answer 18

Greater corneal staining in patients using polyquad (opti-free) products over a long period of time.
**Renu wasn’t included in this study…

Question 19

What is PATH?

Answer 19

Preservative
Associated
Transient
Hyperfluorescence

Question 20

How does PATH work?

Answer 20

PHMB taken up in lens, and leaked onto the eye
NaFlu adheres to PHMB

Transient, irrelevant observation

Question 21

Is there a link between staining and MK?

Answer 21

NOPE.

Increased use of MPS and SiHy lenses, yet no increase in MK rate.

Question 22

How can you avoid the problem of corneal staining in SiHy’s?

Answer 22

Switch to peroxide soln (no preservatives!)

Daily disposables