RGPs - troubleshooting Flashcards
What are the probable causes for an RGP lens when SUBJECTIVE:
- Fogging (late) (2)
Tight/dirty lens
What are the probable causes for an RGP lens when SUBJECTIVE:
- Photophobia (3)
Tight lens
Lens too flat
FB stain
What are the probable causes for an RGP lens when SUBJECTIVE:
- Difficulty looking up (2)
Improper edge (too steep)
Lens too small
What are the probable causes for an RGP lens when SUBJECTIVE:
- Hazing, haloes or fogging (2)
Inadequate tear exchange
dirty lenses
What are the probable causes for an RGP lens when SUBJECTIVE:
- Flare (2)
Optic zone in pupil area
Decentred lens
What are the probable causes for an RGP lens when SUBJECTIVE:
- General lens discomfort initial (2)
Spherical lens on toric cornea
Pt inability to adapt to lens wear
What are the probable causes for an RGP lens when SUBJECTIVE:
- General lens discomfort late (3)
Damaged/warped lens
Lenses in wrong eyes
Lens Deposits
What are the probable causes for an RGP lens when:
- Excessive movement/too loose (3)
BC too flat or steep
Edge lift too flat
Lens too small
What are the probable causes for an RGP lens when:
- No movement (3)
BC too steep
Edge lift too steep
Lens too large
What are the probable causes for an RGP lens when:
- Displaced by lids (2)
Thick edge profile (high minus)
Lens too flat
What are the probable causes for an RGP lens when:
- Bubbles under standard lens (4)
Excessive clearance under lens
BC too steep
Steep fit (central bubbles)
OZ too large (mid periph bubbles)
What are the probable causes for an RGP lens when:
- Bubbles under KCN lens (3)
Excessive clearance
Steep fit (central bubbles)
OZ too large (mid periph bubbles)
NB: If bubbles w central touch - steepen BC, if bubbles without central touch, flatten BC
What are the probable causes for an RGP lens when:
- Central pooling (1)
Excessive clearance (so flatten BC in response)
What are the probable causes for an RGP lens when:
- Excessive Edge Standoff (1)
Peripheral curve too flat or wide
What are the probable causes for an RGP lens when:
- Fine stippling/spk (3)
Normal in adaptation
Poor tear circulation
BC or periph curves too tight
What are the probable causes for an RGP lens when:
- Zig-zag corneal staining
FB under lens
What are the probable causes for an RGP lens when:
- 3 and 9 o’clock staining (under lens) (3)
Periph too flat or steep
Inappropriate size
Decentred inferiorly
What are the probable causes for an RGP lens when:
- 3 and 9 o’clock staining past lens edge (1)
Front surface profile abrupt - mostly high minus rx (should reduce front optic size and incr lens diameter)
What are the probable causes for an RGP lens when:
- Deep corneal stain w pain (1)
Corneal ulcer or uveitis
What are the probable causes for an RGP lens when:
- Sudden unusual change in refraction (2)
Lenses in wrong eyes
Lenses damaged/warped
What are the probable causes for an RGP lens when:
- gradual change in refraction (2)
Lenses slowly distorting
Pt Rx changing
What are the probable causes for an RGP lens when:
- mucus on lens (3)
Poor hygiene
scratches on surface
deposits on lens
What are the probable causes for an RGP lens when:
- lens falls out in fitting (3)
Lens too small
Lens too flat
Lens too steep
What are the probable causes for an RGP lens when:
- lens falls out after continued wear (2)
Lens damaged
Wrong lens in wrong eye
What are the probable causes for an RGP lens when:
- Lens rides to side (2)
against the rule astig
lens too small
What are the probable causes for an RGP lens when:
- Lens rides under top lid (2)
Lens is too flat
Lens too small
