CLM - Specialty Contact Lens Fitting - Week 10 Flashcards
What percentage of keratoconic patients fail to adapt to RGP lenses?
10%
List three disadvantages of RGPs for keratoconus.
Initial adaptation and comfort
Lens ejection/stability
Unilateral fitting
List three types of specialty contact lenses.
Corneoscleral lenses
Hybrid lenses
Miniscleral lenses
What is the physically larger diameter RGP lenses of corneo-scleral designs to optimise? What is the comofrt like compared with corneal RGPs?
Optimises centration
Better comfort profile
How do corneo-scleral RGPs interact with the limbus?
They vault the limbus
How does tear exchange occur with corneo-scleral lens designs?
Pumping action
What are E series ACL limbal lift designs for (4)?
Normal eyes
Non-proud grafts
PMD
High ametropia
What are K series ACL limbal lift designs for?
Keratoconus
What are G series ACL limbal lift designs for?
Advanced/highly proud corneal grafts
Compare the cost of E series lenses to regular RGPs.
Marginally more expensive
Are E series lenses more prone to lens ejection? What about debris entrapment?
Very good resistance to both
Can E series lenses be fit unilaterally?
Yes
Can E series lenses be combined with SCLs or are they incompatible?
Can be combined
How do hybrid lenses deal with the main corneal irregularities of corneal ectasia?
Vault them
Are the fitting concepts of hybrid lenses the same as SCLs and RGPs?
No
What are hybrid lense ideal for?
Oval/central/dectentred cones
What three indications may hybrid lenses be suitable for?
Globus/pellucid degeneration
Other corneal irregularities (LASIK induced ectasia or trauma)
Post-INTACs, post-CXL
Are hybrid lenses also suitable for corneal grafts?
No