Problems Flashcards
Giant Papillary Conjunctivitis (GPC)
Signs/Symptoms:
- large papillae under superior lid
- itch upon lens removal
- mucous discharge
- CL intolerance
- lens movement
- lens need replacement quickly
Treatment:
- temporarily discontinue/consider daily
- Pataday/Zaditor for mild
- topical steroid for severe
Contact Lens Overwear or CLARE (Contact lens acute red eye)
Signs/Symptoms:
- severe injection
- sterile subepithelial infiltrates (peripheral)
- pain
- photophobia (often upon awakening after wearing overnight)
- corneal edema (microcystic)
Treatment:
- discontinue
- use antibiotic (fluoroquinolone) or steroid combo
- cycloplegic/oral analgesic as needed
- Fit in SiHy
Infectious corneal ulcer
Signs/Symptoms:
- acute red
- painful
- photophobia
- corneal infiltrate with overlying epithelial defect
- corneal edema
- tearing
Treatment:
- aggressive fluoroquinolone (loading dose)
- close follow-up
- culture as needed
Tight-fitting Lens
Signs/Symptoms:
- lens becomes less comfortable after several hours
- redness
- long-term may cause signs of corneal hypoxia
Treatment:
- refit with a flatter lens
- add artificial tears and consider temporary break
Soft lens dryness/dessication
Signs/Symptoms:
- decreased comfort with extended wear time
- sandy feeling
- SPK usually in interpalpebral area
- protein coated lenses
Treatment:
- rewetting drops
- better fit
- refit with low water content lens (draws less water)
- thicker lens
- humidifier
Oxygen transmissibility
Dk/t
- lens thickness affects transmissibility
- thicker lens, lower transmission
Oxygen permeability
Dk
- increased water, decreases SiHy Dk, increases hydrogel
True or False:
PMMA has good oxygen permeability
FALSE.
No oxygen permeability.
Characteristics of a tight soft lens?
Mucin balls, central bubbles, poor comfort on insertion but improved comfort after wearing, improved vision after a blink, perilimbal injection after hours.
Characterstics of a loose soft lens?
Drops inferiorly, poor comfort especially with blink, blurred vision after blink which improves between blinks.
What is the classification system for all hydrogel materials by FDA?
Group 1: <50% water, nonionic
Group 2: >50% water, nonionic
Group 3: <50% water, ionic
Group 4: >50% water, ionic
Group 2 and 4 with high water content is good for extended wear.
Mucin balls, GPC and edge fluting are characteristic of..?
High modulus of elasticity!
Signs of solution sensitivity?
- GRADUAL onset of redness and iriritation
- may be stinging after lens insertion, faint/diffuse infiltrates may be present
What kind of fit?
Central touch with no fluorescein centrally, a broad green ring underneath the peripheral region of the lens.
Flatter than K.
What kind of fit?
Bull’s eye pattern, pooling in the apical region.
Steeper than K.
