CONTACT LENSES: Lectures

Question 1

Fitting dilemmas in HAYFEVER.

when?
how?
which problems might occur with CL wear?

Answer 1

1) she is most affected during summer months (also called as seasonal allergic conjunctivitis which the allergen is the pollen):
Chief complaint:
-bilateral ocular itching
-assoc with burning
-watery or mild bilateral mucous discharge
-photophobia
-pain
-blurred vision
-sneezing and nasal congestion

2) how is she most affected)
ocular signs (bilateral):
-mild conjunctival injection
-papillary hypertrophy of tarsal conjunctiva
-increase mucous in the tear film and the inferior fornix
-periorbital oedema.

3) which problem might occur
- side effect of anti-histamine: dry eye

Question 2

compare and contrast seasonal allergic conjunctivitis vs dry eyes?

Answer 2

seasonal allergic conjunctivitis (SAC) and dry eye syndrome both associated with:

• mild conjunctival irritation
• burning sensation
• intermittent exacerbation
• patient suffering from dry eye more susceptible to SAC.

however px with SAC does not complain a foreign body sensation.
a complain of ocular itching that involves the lid margin may indicates a possible MGD.

Question 3

what could we fit in hayfever px?

Answer 3

1) daily disposable
- soft lenses claimed to be more comfortable with dry eyes are:
- -proclear (cooper vision)
- -dailies aqua comfort plus (ciba vision)
- -1 day acuvue moist (vistakon)

2) silicone hydrogel
3) orthokeratology

Question 4

how should routine differ in patient that suffered from hayfever?

Answer 4

• manage patient expectation
• time of year for CLs aftercare (once in a summer and once in a winter)
• act on signs and symptoms promptly
• pharmacological intervention

Question 5

list silicone hydrogel lenses:

Answer 5

1) Disposable lenses: one day
- 1-day acuvue true eye (johnson & johnson) | water content:46
- myday (cooper vision) | water content:54

2) Disposable lenses: one month
- ACUVUE ADVANCE with HYDRACLEAR (johnson & johnson) | water content:47
- ACUVUE OASYS with HYDRACLEAR PLUS (johnson & johnson) | water content:38
- AIR OPTIX AQUA ( Alcon/ CIBA VISION) | water content: 33
- AIR OPTIX NIGHT AND DAY AQUA (Alcon & CIBA VISION) | water content: 24
- AVAIRA ( Cooper Vision) | water content:46
- Biofinity ( Cooper Vision) | water content: 48
- Biofinity XR (cooper vision) | water content: 48
- Pure vision (Bausch&Lomb) | WC: 36
- Pure Vision 2 HD (Bausch & Lomb) | WC: 36

Question 6

why is it the water content of the contact lens so important?

Answer 6

• the WC in hydrogel CLs is an important factor in determining oxygen permeability
• this is because the oxygen is able to pass trough the water while unable to pass trough the material itself.
• oxygen permeability increases logarithmically with an increase in water content
• however, refractive index decreases with an increase in water content because the refractive index of water is normally lower than that of the material itself
• a lower refractive index means a thicker lens, which then offsets some of the gain in oxygen transmission.

Question 7

Ocular surface implications and risk factors for diabetic px?

Answer 7

• stability of refractive error
• eyelid
• cornea
• -mechanical trauma
• -recurrent epithelial defect
• -prolonged epithelial healing rates
• -reduced recovery from corneal oedema
• -reduced corneal sensitivity-corneal ulcers

should be concerned about:
-corneal sensitivity and healing response

Question 8

how should the routine differ in diabetic px?

Answer 8

• remind px to inspect CLs for damage prior to insertion
• fingernails short and smooth
• more frequent aftercare
• premium lens/solution

Question 9

What makes patient complaints “My eyes got red when i wear my lenses. Why do they do that?”
-usually occurs as the day goes on

Answer 9

Try to see them in the afternoon:

1) 3&9 with RGP
- drying of the peripheral cornea in association with unstable tear film; causes are multifactorial, including poor peripheral lens fit, inadequate blinking, poor lens wettability, and abnormal tear composition
- signs:
- -conjunctival hyperaemia along the horizontal meridian in conjunction with epithelial punctate
- -staining at the 4 and 8o’clock positions

2) infiltrate with lembal redness
3) dryness

4) CLIPC:
- common in extended wear soft lenses
- multifactorizl aetiology, probably due to mechanical trauma and immunologically mediated process. frequently associated with atopy.
- signs: tarsal hyperaemia, mucous discharge, excessive lens movement, poorly wetting lens surface.
- histologically the conunctiva thickens and the conjunctival epithelium demonstrates and increase in mast cells,eosinophils, basophils, neutrophils, and lymphocytes.

5) tight fitting lens
6) eye rubber

Question 10

what happened when there is acute redness in one segment of the sclera?

Answer 10

1) episcleritis
2) pointing at an infiltrate
3) traumatic
4) damaged lens edge

Question 11

what is PEDAL?

Answer 11

symptom of redness that hurting

Pain
Epithelial defect
Discharge
Anterior chamber reaction
Location