CL rules and solutions

Question 1

10 rules to comply as a CL wearer

Answer 1

1. novice - build up wearing time 2-4 and increase by 4 hours each day
2. wash hand and dry thoroughly before handling CL
3. rub and rinse lens after use, use fresh solution to disinfect
4. do not sleep with lens unless instructed
5. no tap water . do no swim or shower with lenses on
6. rub lens case and rinse with disinfecting solution before air dry. replacing lens case according to manufacturer recommendation
7. look, feel, see good (stop len wear if red eye, vision blur, discomfort/ pain)
8. replace lenses according to schedule
9. only use cl rewetting solution to relieve dryness when lens are worn
10. regular check up every 6 month

Question 2

effect of denatured protein build up on cl

Answer 2

• opaque deposit can affect vision
• deposit can rub against the palpebral conjunctiva to induce GPC
• lens deposit can take up chemicals in CL solution during soaking and release it into the eye later on. resulting in toxicity / hypersensitivity or allergic response
• lens deposit also can increase microbial adhesion to cl an hence increase the risk of infection

Question 3

what is the gold standard disinfecting system?

Answer 3

3% H2O2

- kills most microbes within minutes and neutralized to water and oxygen and considered preservative free

Question 4

what does the CL care system consist of ?

Answer 4

• daily cleaner
• saline
• multipurpose solution
• hydrogen peroxide system
• enzymatic cleaners
• in eye cleaner & rewetting agent

Question 5

what does CL care system contains

Answer 5

• buffer and salt
• cleaning agent
• disinfectant / preservative
• wetting agent/ lubricants/ demulcents

Question 6

advantages of MPS

Answer 6

• convenient
• effective
• safe
• largely without the toxicity and hypersensitivity adverse effect

Question 7

disadvantage of MPS

Answer 7

• more ingredient = higher chance of toxicity reaction
• group 4 ionic polymers may react negatively with potassium sorbate or sorbic acid preserved solution
• SiHy do not seem to show an affinity for preservative build up in lens

Question 8

Advantages of H2O2

Answer 8

• provides excellent antimicrobial efficacy by oxidizing microbes
• pH 4.00 it is able to break proteins and lipids bond and remove trapped debris
• ideal for patient who have hypersensitivities / dry eyes
• neutralization is easily accomplish with the use of a platinum disc / catalase tablet

Question 9

disadvantage of H2O2

Answer 9

• neutralisation happens too fast = unable to kill acanthamoeba cyst
• solution after neutralisation does not protect lens against microbes
• 3 percent H2O2 is toxic to the eye
• not as convenient as MPS (neutralisation must be completed before lens wear )