Week 2.05 OrthoK Flashcards
Compare corneal topography to keratometry
Topography measures all over cornea whereas keratometry only central 3mm of cornea
With topography can monitor progression of corneal disease more easily over time
Keratometry less expensive and more durable
How does post refractive surgery benefit from the use of topography
- Identify the changes to the cornea
- corneas treated for myopia change from prolate to oblate eclipse
- for hyperopia from oblate to prolate
What is ortho-K
Non surgical method of vision correction using rigid gas permeable lenses to temporarily reshape the cornea
Lenswhat happens to the central and mid peripheral epithelium
Central epithelium thins slightly
Mid peripheral epithelium thickens
Ortho k can correct myopia up to
-7.00DS
Up to -14.00DS reportedly but more costly
Ortho k treats hyperopia up to
+4.00 rarely fitted
Who’s suitable for Ortho K lenses
Any rx within fitting parameters and cyl isn’t below -1.50
No age restrictions - possible benefits from fitting at young age
Px ineligible for LASIK
Why do we book 2 appointments 30 mins apart for Ortho k appts
First one to insert the lens, px to rest lying back once lens inserted
Second one to check the changes you made
Remove lenses and check RX and VA
No fluorescein assessment in Ortho k
Topography will show large changes
Ortho-k care
RGPs so same care regimen
Cermellose sodium for insertion
Plunger/sucker can also be used for removal
What are the disadvantages of Ortho-K lenses
- Px must cease current lens wear for trial
- many initial visits for fitting
- expensive?
- higher infection rate
- topographer required
What are advantages of Ortho k lens
- changes reversible if desired
- great for px who want to swim without specs, dry eye, sports
- less risk and less evasive surgery
- Myopia control
