Conventional contact lenses and its common problems How to manage contact lens in covid 19 situation Basic care & maintenance In which aspect conventional Cl are using Hydrogel contact lens

1. Conventional CL & its problems
Session by : - Nehal lilawala
3rd year student
Hari jyot college of optometry

2. Overview
• Definition
• FDA classification
• Indications and Contra-indications of conventional lenses
• Case study
• Slit lamp examination and investigations
• Comparison between RGP and soft cl based on conventional
lenses
• Care and maintenance
• Precaution for CL wearer in Covid-19 situation

3. Definition
• Conventional/traditional contact lens is also referred as "Vial"
contact lens.
• This lenses does not replace until their expected longer
lifespan has been reached or their adequacy is terminated
permanently by damage or deposits.
• Conventional contact lenses usable for a long term and proper
care, cleaning and disinfection can be done on a regular basis
before wearing.
• In RGP lenses maximum life span getting up to 1-2 years and
in soft lenses up to 1 year.

4. FDA classification for hydrogel
Low water
ionic
High water
Non ionic
High water
ionic
Group I
Low water
Non ionic
Group II Group III Group IV

5. FDA category available for
conventional lenses
Group I: Low water Non-ionic
 Low water content: it’s percentage volume of the H2O in lens
material by weight
 Low H2O means <50%
 Material which are electrically neutral are non-ionic
• All conventional lenses comes under group I

6. Group-I Materials and products
Material
• Tefilcon(38%)
• Tetrafilcon A(43%)
• Helfilcon A&B(45%)
• Mafilcon(33%)
• Polymacon(38%)
• HioxifilconA&B(49%)
• Isofilcon(36%)
• Crofilcon(38%)
Product
• Acme42 Aspheric/ toric
• Acme: Comfort+ prosthetic
• B+L Optima38
• Silklens conventional color
lens
• Purecon: prolong wear
• Acme: Comfort+ Xcrome

7. Group-I
Advantages
• Due to neutral charge and
low H2O content they are
least deposit to prone
• Can use acidic solution for
cleaning
• Indicate for dry eye patients
• Rigid and required less care
and maintenance
• Durable & corrects some
amount of astigmatism as
they are rigid
• Thermal disinfection can be
done
Disadvantage
• Low DK
• Less wettable
• Not comfortable as H2O
content is low
• Can’t be worn for longer
period of time

8. Indication
Conventional Soft CL
• Myopia
• Hypermetropia
• Astigmatism
• Anisometropia
Therapeutic purpose
Prosthetic lens
Color deficiency

9. Contra
Indication
Ptosis
Non-compliance and
unmotivated patient
Occupational/environment
incompatibility
Poor patient hygiene
Chronic Dry eye
Certain systemic disease
Inflammatory and
ocular infection
Inadequate tear film

10. Why we need to prescribe soft
conventional lenses!?

11. Contd..
2. Prosthetic & tint lens: These are prescribed to mask flaws
and improve the appearance of an eye disfigured from a
birth defect, trauma, or eye disease.
• If certain structures of the injured or disfigured eye also fail
to function properly, special prosthetic lenses can be
designed to block excess light from reaching the back of the
eye to reduce glare and increase comfort.
• A frequently treated to patient like aniridia, albinism,
Amblyopia.

12. Contd...
Before
After

13. Contd..
3. Therapeutic & bandages:
• Promote corneal healing
• Treat corneal/ocular disease
• Collagen lenses offer good results
• They are also therapeutically used to deliver drugs to the eye
over several days damaged cornea.

14. Contd..
4. Filtered lenses/X-chrome lenses: color blindness or color vision
deficiency is the inability or decreased ability to see color or
perceive color differences under normal lighting condition

15. Some case we can prescribe only
conventional lenses
• CASE1:
• Demographic data:
– Patient name- sohel memon
– Age:38
– Occupation-farmer
• Chief complain- DOV in left eye
– watering, redness and pain
 Aided: previous glasses since 3years (pg)
• Family history: -
• Systemic illness: hypertension & diabetes (on Rx)

16. Contd..
• Pupil: PRRRL
• SLE: normal
• Fundus: retinitis pigmentosa
• Refraction: RE: +15dsph VA: 6/12
LE: +15dsph VA: 6/60
• Retinoscopy: +15.50dsph
• Diagnosis: LE low vision
• Treatment: conventional lenses for distance (BE)

17. • CASE2:
• Demographic data:
Patients name- paras tanna
– Age:35
– Occupation- Food stall
• Chief complain- DOV, glare, photophobia
Trauma: Right eye had an accident with metal rod before
6month
Glasses: (previous glasses since 3years)
Pg Rx: BE +2.25sph / -0.75cyl @ 180
• Family history: -

18. Contd..
• Consulted by: xyz hospital
• Needs: patient having an issue of cosmetic look in RE
• Systemic illness: cardiac problem On Rx
• Pupil: RE corneal opacity and LE: PRRRL
• SLE: RE Corneal opacity ; LE: normal
• Fundus: LE Normal
• Refraction: RE; PL+ve
LE +2.25sph / -0.75cyl @ 180 VA: 6/9
• Retinoscopy: LE +2.25sph / -0.75cyl @ 180
• Diagnosis: RE: corneal opacity LE: Refractive error
• Treatment: RE Prosthetic conventional lens
LE conventional soft lens

19. What investigations should be done to
cl wearer?
• Eye Lids
• Eye lashes
• Conjunctiva
• Cornea

20. Eyelids & lashes
• Points to be noted:
– Assess lid tension
– Blink rate
– Check if there is any lid abnormalities

21. Conjunctiva
• Bulbur conjunctiva is examined by retracting the upperlid &
lower lid by index finger & thumb respectively
• Lower palpebral conjunctiva is seen by asking the patient to
look up & then pulling the lower lid down
• Upper palpebral conjunctiva & fornix is seen by asking the
patient to look down & then grasping the lid margin by thumb
& index finger, the lid everted using index finger as fulcrum

22. Points to be noted while examining
• Redness or congestion
• Discharge
• Discolorations
• Chemosis
Changes on surface
• Formations: papillae, follicles, pterygium, tumors, cysts etc
• Ulcer and granulomas
• Scar
• Foreign bodies

23. Examination of cornea
• It should done under slit lamp examination
• Points to be noted are:
– Curvature of cornea
– Surface is also assessed under placido’s disc and other test
for topography are photokeratoscopes
– Transparency
– Opacity
– Foreign bodies
– Abrasion
– ulceration

24. Contd..
• Vascularization
• Corneal sensation
• Corneal endothelium examination using specular microscopy
• Corneal thickness using pachymetry
• Corneal staining is performed when epithelial defect is
suspected
• In this fluorescent strip is placed in the inferior fornix, patient
is asked to blink and then cornea is inspected under cobalt
blue light

25. Tear film assessment
• Invasive
– TBUT(tear break up time)
– Schirmer test
– Phenol-red thread
– Rose bengal test
• Non Invasive
—NIBUT(Non invasive tear breakup time)
—Lipid prism height
—Lipid layer evaluation

26. What basic requirement keep in mind
before prescribe soft conventional lens
• Occasional wearer: Many patient only require social or part-
time wear
• Occupational condition: compatibility with environment,
should not be exposed to dust, hazardous, humidity(in such
condition wear cl with sunglasses)
• Contact lens wearer should sit in normal temperature but not
directly faced towards the air flow(AC)
 Hobbies should be asked and according to that contact lenses
are prescribed

27. Why do we need to prescribe RGP
lens?
• Critical vision demands when as it corrects unusual
astigmatism like corneal astigmatism
• Demand more oxygen supply unlike soft CL
• RGP lens provides better crisp, clear vision and more deposit
resistance than soft CL
• RGP retains its position more faster than soft CL which gives
more sharper vision

28. Contd..
• RGP material doesn’t contain water so protein and lipid from
tear do not adhere lens
• If patient is already an RGP wearer so they cannot adapt soft
CL easily
• More convenient in RGP multifocal lenses as soft multifocal cl
are getting in disposable
• Irregular cornea- keratoconus trauma, corneal warpage
• When Soft lens failure occurs like poor vision, eye health
compromise RGP are prescribed

29. Disadvantages of RGP
• Less initial comfort.
• Longer adaptation period
• More easily dislodged.
• More susceptible to the intrusion of foreign objects under the
lens, such as dust.
• Can scratch and break.
• Intermittent wear is less feasible because adaptation is
required if a person takes an extended break from use.

30. • Soft contact lens
• This lenses are flexible
• Short adaption period
• Stay in place, rarely fall off
• Greater initial comfort
• Low oxygen supply to cornea
• Cosmetic/color lens
available
• May dry out & susceptible to
more protein deposits
• RGP contact lens
• This lenses are durable
• Longer adaption period
• Slip off/dislodge more easily
• Less initial comfort
• Allow more oxygen to the
cornea
• Clear lens optimal vision
• More susceptible to
intrusion of foreign object
under the lens
• Easily scratch and break, if
improper handling
Comparison

31. Problem faced due to conventional lens
• Irritation and reduce comfort
• Reduce visual acuity
• Shorten lens life
• Increased potential for infection
• Increased potential for giant papillary conjunctivitis
• Reduced oxygen transmissibility
• End of the day eye tiredness
• If patient wears more than 8-10 hrs results in redness,
discomfort and dryness

32. Contd..
• Some of the complications are corneal ulcer, CLARE, keratitis,
corneal hypoxia, neovascularization, corneal edema, CLPC etc.
• Contact lens related complication: physical damage to cl, cl
discoloration, deposits.
• NON-COMPLIANCE ISSUES
* 40% to 90% of contact lens wearers are non compliant in
some aspect1
• Solution-related compliance issues
– 62% “Top off” solution
– Re-use of contact lens solution
– Under-filled lens case wells
– 40% never clean contact lens case

33. Care & maintenance
•Most of the crucial aspect of contact lens wear
•Influence the success of contact lens wear and
patient’s satisfaction with their lives.

34. Contd..
• Purpose:
 Clean lenses
 Good comfort
 Good vision
 Safe lens wear
 Increase life span of contact lenses
 Minimize deposit accumulation
 Reduce microbial contamination
 Increase lens wettability

35. Contact lens care
• Daily cleaner.
• Rinsing solution.
• Disinfections.(H2O2 system is preferred)
• Weekly protein cleaner if required
• Lubricating / rewetting solution
or
Multi-purpose solution can be used

36. Multipurpose solution
• A multipurpose solution contains all the components or
ingredients which serve the purpose of cleaning, disinfecting,
rinsing, storing, removes protein daily for soft contact lenses.
It fights contact lens dryness and delivers sustained comfort.
• Its also called as One Bottle System.

37. Daily cleaner
• Daily cleaner is for cleaning your contact lenses. You
place a few drops in the palm of your hand and carefully
rub the lens for as long as directed (usually about 20
seconds, making sure to clean both sides of your lenses.
Use other products for rinsing and disinfection.
• Components.
– Surfactants
– Osmolality adjusting agent.
– Viscosity enhancing agent.
– Hyper tonic and abrasives.
– Buffer agent system.
– Chelating agent.
– Water.

38. RINSING SOLUTION
• Contains isotonic saline which
maintains the contact lens
parameters on eye.
• Rehydrate the contact lenses.
• Removes the daily cleaner
remnants, loosened deposits and
micro-organisms.
• Saline may be included with
preservative or preservative free.
• Done after and before disinfection.

39. What is a Preservative…?
• A chemical added to a water or saline to keep it stable and
prevent compounds in it from changing to other forms or to
prevent microorganism densities from changing prior to
analysis or use.
• Types of perservatives:
– Benzalkonium Chloride (BAK).
– Thimerosal.
– Ethylene Diamine Tetracetic Acid (EDTA).
– Ethanol and Isopropyl Alcohol.

40. DIS-INFECTING SYSTEM
• Maintains the lens pathogenic-free stage.
• Maintains the normal ocular flora at a safer levels.
• Maintains the hydration of the lens so maintains stability or
parameters of the contact lens.
• Attains contact lens to “ready-to-wear” state.

41. Types of Disinfection systems
Heat Disinfection
Wet
Chemical Disinfection
oxidative Cold chemicals
One-step Two-step
Dry

42. Heat Disinfection
• At 70-80oC most of the micro organisms are killed.
• Contact lens material remain stable up to 85oC.
Heat Disinfection
WetDry

43. Dry heat disinfection
• Done at 70-800C.
• Contact lenses are placed in lens case containing saline.
• The lens case is placed in electric plugs or electrically heat
controlled device or ultrasonic device.

44. Wet heat disinfection
• The lens case is immersed in water at or near to its boiling
point.
• Chances of lens case crack.

45. HEAT DISINFECTION
• Advantages:
– Short duration(10-30 min)
– Highly anti microbial
disinfection system
– No hyper sensitivity
reactions
– Large number of lenses
can disinfect at a time
• Disadvantages:
– Protein denature(increased
protein deposition)
– Incompatible with high water
content lenses
– Discoloration and decreased
life span of CL if its held more
than 850C

46. Chemical Disinfection
• If disinfection is done in chemicals then the contact lenses has
to undergo neutralization to avoid hypersensitivity reaction in
on eye condition.

47. Chemical Disinfection
Oxidative:It is done by H2O2 3%
• One step method:
– Disinfection and neutralization is done simultaneously.
– Contact lens is placed in lens baskets containing the
platinum disc and H2O2.
– Platinum disc is used as a catalyst which decomposes the
H2O2 in towater and O2.
2H2O2 2H2O+O2
Disinfection - First10 to 15min
Neutralization - 4 to 6 hours

48. Chemical Disinfection
• Two step method:
– Disinfection and neutralization is done separately.
– Disinfection- H2O2 for overnight.
– Neutralization-Chemicals (sodium pyruvate, sodium
sulphite) for 4-6 hours.

49. Cold chemicals
• Chemical disinfection is done by conventional
chemicals(disinfectants or preservatives) which are used
as soft lens storage solutions.(disinfection during storage
period).
• Thimerosal.
• Chlorohexidine.
• Sorbic acid.
• Ethanol, Alcohol, Isopropyl alcohol.
Chances of hypersensitivity reaction….

51. AOSEPT
AOSEPT Travel Pack with disposable cup &
disc. A sterile ophthalmic solution containing
microfiltered hydrogen peroxide 3%, sodium
chloride 0.5% .
Use AOSEPT disposable Cup & Disc for
disinfection and neutralization

52. PROTEIN REMOVERS
• Enzymatic cleaners (tablets or solutions).
• Done weekly or frequency depends up on the rate of patient
protein deposition.
• Lenses are Cleaned and Rinsed before and after enzymatic
cleaning.
• Enzymatic Protein Removers Contain one of the following:
•Papain.
•Pancreatin.
•Subtilisin A or B.

53. Components of Enzymatic Cleaners
• Bulking agent.
• Buffer agent.
• Effervescent system.
• Lubricating agent.
• Liquid vehicle.

54. Protein remover tablets
• Sensitive Eyes® Protein Tabs have a
fast-acting and odorless formula that
removes stubborn deposits in as little
as 15 minutes. These protein tablets
contain an enzyme that breaks up
cloudy, irritating film on soft contact
lenses caused by protein build-up and
tear deposits.
• Provides excellent wearing comfort
Odorless formula works in about 15
minutes.

55. Intensive cleaner
• Menicon Progent - is a weekly protein
remover, disinfectant and intensive
cleaner compatible with all RGP
contact lenses. To ensure excellent
comfort and prolong the life of your
RGP lenses. The efficacy of Menicon
Progent lies in its strong, rapid action
against all the organisms likely to
contaminate lenses, including
bacteria, moulds, yeasts, viruses and
Ancanthamoeba trophozoites and
cysts.

56. Rewetting or Lubricating drops
• Alleviating symptoms of dryness / discomfort.
• Flushing the irritating particles.
• Rehydrating the lenses.
• Mainly useful for
– Marginal dry eyes CL patients
– Dry environment
– Tired eyes.
Ex: Methyl Cellulose Acetates and
Polyvinyl Alcohol.

57. How to manage conventional cl in this
pandemic covid-19 situation?
• There is currently no evidence to suggest that there is any
increased risk of infection or contracting coronavirus through
contact lens wear.
• Remember to follow strict hygiene measures, such as
thorough handwashing, along with optimal wear and care
procedures.
• These include replacing your lenses as prescribed, case
hygiene for reusable lenses and avoiding lens wear if you are
unwell (in particular with any cold or flu-like symptoms).
• Avoid touching your eyes, especially in high risk environments

58. Troubleshooting CL wearer in
lockdown?
• In this current pandemic situation those who are already a
contact lens wearer can use the saline bottle for cleaning and
storing contact lens in replacement of multi-purpose solution.
• Due to lockdown situation people might face a condition
where solution is not available at that time they can buy
normal saline from pharmacy.

59. What to Do If You Contract COVID-19
• If you become ill or suspect you have COVID-19, you should
cease contact lens wear and switch to eyeglasses instead.
• Contact lens wearers should always practice good hygiene when
handling lenses.
• But It has been noted that contact lens wearers touch their
faces and eyes when inserting and removing lenses. Touching
your face can spread germs/ virus.
• So as an optometrist we should not prescribe contact lenses
• Though Glasses are not proven to offer protection. There is no
scientific evidence that wearing spectacles or glasses provides
protection against COVID-19 or other viral transmissions.

60. Expert advice*
 You can keep wearing
contact lenses.
 Good hygiene habits are
critical.
 Regular eyeglasses do
not provide protection.
 Keep unwashed hands
away from your face.
 If you are ill, temporarily
stop wearing your
contacts and use your
glasses instead.

61. FAQ
• There is lot of misinformation around contact lens and coronavirus.
• I would like to reassure you that wearing contact lenses is safe.
How ever before inserting your lens in/removing your lens out, its
very important that you wash you hands thoroughly with soap and
water and ideally you would them with a clean paper towel

62. •We would always advise you to wash your wash with soap and water,
however if that option is not available then you could use but the
concerns with a hand sanitiser is that most of them contain alcohol
and if you get that alcohol onto your CL and put it into your eye it's
going to sting, so you need to make sure either that all of the hand
sanitiser is rubbed in thoroughly or you might even need to clean your
finger with a clean dry cloth before putting the lens in.

63. • We advice to replace your replace your CL case atleast every
month and in the morning when you put in, what you should do is
first of all discard any solution in the case make sure it's
completely empty, rinse with some fresh solution and then just
turn it over and leave it upside down to dry or use piece of clean
tissue paper

64. • As long as you're washing your hand thoroughly, there's no
need to wear gloves when you putting in your CL

65. Reference
• https://coopervision.com/blog/contact-lens-wear-care-
amidst-covid-19
• https://www.aoa.org/covid-19-patient-resources/contact-
lens-wear-during-covid-19
• Understanding about Contact Lenses by Darshan Kulkarni
• Introduction to Contact Lenses Published by Georgia Skinner
• Contact faq by specsaver https://youtu.be/IkW5TdxQP0k

66. STAY SAFE & HEALTHY

67. Guided