Contact Lens: Lecture 8. Solutions

Front 1

Hypertonic Solution

Back 1

Solution with GREATER concentration of solutes.

Causes water to move toward the solution to dilute it.

Front 2

Hypotonic Solution

Back 2

Solution with LESS concentration of solutes.

Causes water to move away from the solution.

Front 3

Borate Buffer: drawback of use.

Back 3

Causes MORE corneal Problems

Front 4

Phosphate Buffer: benefit of use.

Back 4

Causes FEWER corneal problems.

Front 5

Definition: Wetting Angle and acceptable range.

Back 5

Measures the area between the non-adhering part of a droplet and the surface on which it sits.

Range: 0 (complete wetting) to 180 (non-wetting).

0 to 90: good wetting

Front 6

Examples of Wetting Agents

Back 6

Povidone: a synthetic polymer used as a dispersing and suspending agent.

Hydroxy -methylcellulose

Polyvinyl alcohol

Poloxomer 407

Hyaluronan (Hyaluronic Acid)

PHPHP

Front 7

CL: Cleaning Agents

Back 7

Purpose: Remove the contaminants from the CL surface.

MOA:
1. Friction/rubbing: lowers surface tension to easy removal.

2. Emulsify: one liquid distributed in small globules throughout a second liquid. Part SURFACTANT and part CHELATING agent in a multipurpose solution.

Front 8

What are emulsifying agents good for cleaning?

Back 8

Used for removing debris.

Good: LIPIDS, DIRT, cosmetics
Not good: PROTEINS!

Front 9

Cleaner Detergents

Back 9

Ionic and Non-Ionic.

1. Pluonic F 127 (surfactant)
2. Polaxomer 257 (surfactant)
3. Tyloxapol (surfactant)
4. Toxoplomer
5. Citrate (enhances cleaning efficiency)

Remember: PPTTC

Front 10

Cleaner: Chelating Agents

Back 10

Sequesters metal ions by disrupting intermolecular bridges.

1. Edetate (EDTA) Disodium - used synergistically with other agents.

Remember: ED disrupts bridges

Front 11

Buffer pH Range for solutions

Back 11

pH of 6.6 to 7.8

Front 12

Preservatives in Cleaners

Back 12

Uses to prevent contamination and decomposition from micro organism AFTER contact with the air.

Front 13

Rinsing Salines/Solutions

Back 13

Non-preserved or Preservative Free. Used to wash away cleaners.

SORBIC ACID is a common preservative in rinsing salines.

Front 14

Thimerosol

Back 14

Early sCL preservative that contained Mercury (good anti-microbial/fungal effect.

20-70% of population reacted to it. Caused CLARE, red eye, discomfort, dryness.

Front 15

Polyquad

Back 15

Modern solution sCL preservative.

Alcon.

1. Doesn't enter lens matrix
2. Low toxicity.

Front 16

Dymed

Back 16

Modern solution sCL preservative.

B&L

1. Low toxicity.
2. Some matric absorption.

Front 17

Sorbic Acid

Back 17

Modern solution sCL preservative.

Used in SENSITIVE EYE products, but can YELLOW the lens.

BacterioSTATIC.

Front 18

Polyhexamide (PHMB)

Back 18

Modern solution sCL preservative.

Found in:
1. Ciba - Aquify
2. AMO - Complete MPS

Front 19

Four Modern Day sCL solution preservatives

Back 19

1. Polyquad
2. Dymed
3. Polyhexamide (PHMB)
4. Sorbic Acid

Remember: PDPS as "Police Department of Public Safety.

Front 20

Lubricating Drops for CLs

Back 20

1. Blink Contacts
2. ReNu
3. Refresh Contacts
4. Clerz Plus
5. Aquify
6. Complete

Front 21

Artificial Tears for Eyes

Back 21

1. Blink
2. Genteal
3. Soothe XP
4. Soothe Ultra
5. Systane
6. Thera Tears
7. Refresh

Front 22

Protein Deposits

Back 22

Source: Tears

Proteins become denatures and cause CL to lose their clarity, reducing vision and comfort.

Front 23

Lipid Deposits

Back 23

Jelly bumps that affects vision and comfort.

More common in EW.

Exacerbated by: Make-up, meibomian gland dysfunction, dry eye

Front 24

Rust Deposits

Back 24

Source: tap water.

Harmless, but psychologically a problem to patients.

Front 25

Most common deposit for
1. Soft CL (non-Silicon Hydrogel)
2. Silicon Hydrogel

Back 25

1. sCL- PROTEINS
2. SH- LIPIDS

Front 26

Lobob

Back 26

RPG Daily Cleaner.

Contains 3 surfactants and 1 antifungal.

NO: thimerosol, chlorhexidine, BAK, polyamino-propyl biguanide.

Front 27

Boston Advanced Cleaner

Back 27

RPG Daily Cleaner.

Milky white.

Front 28

Miraflow

Back 28

Ciba (discontinued)

Available through CVS.

Extra strength soft lens cleaner.

Front 29

Wishlist for perfect CL Solution

Back 29

1. Effective
2. Safe
3. Simple Instructions
4. Fast
5. Inexpensive

Front 30

Enzymatic Cleaners

Back 30

Hydrolyzes the protein left on the lens. Good for conventional CL wears.

Enzymatic Cleaning Tablets for sCL and RGPs.

Front 31

Hydrogen Peroxide Systems

Back 31

Contain 3% micro-filtered H202 for rapid disinfection.

1. Platinum Disc (AOSept) first system.
2. Clear Care
3. Ultracare

Good for killing HIV, NOT FUNGUS.

Front 32

AOSept

Back 32

Ciba

Hydrogen peroxide cleaner. First system. Uses a platinum disc to neutralize peroxide. Usually lens is cleaned with Miraflow first, then placed in solution.

Front 33

Clear Care

Back 33

Ciba

Hydrogen peroxide cleaner with cleaning agent in solution (Pluronic 17R4).

Lens must be rinsed for 5 seconds before 6 hour soak.

Platinum disc.

Front 34

Oxysept/Ultracare

Back 34

AMO

Hydrogen peroxide cleaner.

Pink colored catalase tablet to neutralize H2O2.

Front 35

Hydrogen Peroxide Solutions and Acanthamoeba.

Back 35

Kill the trophozoites at 1 hour, but kills the CYSTS at 4-6 hours.