Week 1.06 Contamination Flashcards
What are the 3 main categories of deposits
- protein
- lipids
- calculi/jelly spots
What do protein deposits look like
Semi opaque, grey sheet like
Appears as small blobs, then progresses to a full film
High water content regular replacement lens
What are px sxs with protein deposits
Reduced VA and CS
Increased discomfort due to more lens movement and irritation on lid blinking, dry eye sensation
Causes of protein deposits
Denatured protein from tear film
Contact lens material/regimen
High water content, surface change of lens, lens age and use, contact lens polymer size
Tear film quality and quantity, hygiene and care regimen, reduced replacement frequency, systemic illness
Management of protein removal deposits
Adding protein removal to care regimen - protein removal tablets contains enzymes,es to remove protein or extra surfactant. If tears potential issue add comfort drops
Change px care regimen completely- solution to hydrogen peroxide, increase px lens replacement
What do lipid deposits look like
Blob like appearance or coating that appears to wet poorly
Which lenses do lipid deposits usually be on
High water non ionic lenses
Silicone hydrogel lenses
What are px symptoms for lipid deposits
None, reduced VA, CS, foreign body sensation
What are the caucuses of lipid deposits
Excessive lipids in tears and oil layer
High water content lens
Tear film quality and quantity
Hygiene and care regimen
Chronic MGD
Blepharitis
How to manage lipid deposits
Recheck how pox replaces lenses solutions etc
Check tear quality, MGD treatment
Change px care regimen - less water content
What do calcium deposits look like
White crystalline or granular film initially
Also appear as white sheet with small distinct boundaries
Px sxs with calcium deposits
Irritation, reduced lens wear, drop out, reduce CS
Causes of calcium deposits
- Multifactoral and unexplained due to poor reporting and differentiation from other deposit types
- Dietary intake of fat, protein or alcohol?
- Raised blood Ca2+ or lowered k+?
- Basically, not sure what causes
Management for calcium deposits
Difficult or impossible to remove no tx advised
Replacing lens easiest
