Dry Eye - Lubricants and Management

Question 1

What are the basic ingredients in Ocular Lubricants?

Answer 1

• Water - to replace water loss
• Buffer - for pH maintenance, contains electrolytes
• Active Ingredient - lubricant to reduce friction and sooth membrane irritation. increase ocular surface retention
• Preservative - lengthen shelf life however toxic and no longer used

Question 2

What is the impact of Osmolarity on the Tear Film?

Answer 2

increased osmolarity causes biochemical and morphological changes to the corneal-conjunctival epitheliums
reduced osmolarity induces stress on tear film

Question 3

Why are Viscous lubricants important?

Answer 3

for patient compliance, comfort, convenience

Question 4

why are preservatives not recommended?

Answer 4

toxic to the corneal epithelium and cause erosion that can be seen via punctate staining

dissolve the lipid layer, this destabilises the tear film

increase evaporation leads to dryness and ocular surface inflammation

Question 5

what are the preservative doses?

Answer 5

minims for single dose
multidose
smart preservatives - break down into natural tear components when exposed to light, oxidative

Question 6

what is normal osmolarity?

Answer 6

302.2 osmoles

Question 7

what reduces tear osmolarity? how long does it last?

Answer 7

hypertonic products by reducing salt levels and repairing conjunctival goblet cells

maintained for 2 hours, return to starting point after 3

Question 8

what is Viscosity?

Answer 8

measurement of a fluid’s internal resistance to flow.
measured vis centipoise scale

Question 9

what are the benefits of more viscous products?

Answer 9

reduce friction
increase retention time
sooth irritated membranes

Question 10

list the lubricants and their viscocity

Answer 10

blink contacts - 5.5
theratears - 40
lubristil gel - 25
blink intensive tear - 12.2
Intensive Tears Plus - 50