18 - Dry eye preparations

Question 1

ocular lubricants

Answer 1

• used in form of eye drops/gels/ointment to treat discomfort associated with conditions in which tear film is reduced or unstable

Question 2

management of dry eye

Answer 2

• depend on severity

spectrum of disease

• aqueous deficiency?tear instability
• evaporative dry eye

Question 3

mild dry eye - management

Answer 3

1. education
2. nutritional advice (fatty acid consumption)
3. modification or elimination of systemic and topical
   - ocular lubricants
   - lid hygiene
   - warm compress

Question 4

moderate dry eye - management

Answer 4

• non preserved lubricants - take more frequently
• non medicated ointment at night
• topical antibiotics for anterior bleph
• ## oral antibiotics e.g. tetracyclines

Question 5

what are the limitations of treating dry eye with artifical tears

Answer 5

• formulation cannot replace complexity of natural tears
• presence of preservatives can compromise ocular surface after prolonged use

Question 6

what are some tear replacement approaches

Answer 6

• aqueous substitutes e.g viscosity enhancers (increase contact time)
• bioloical tear substitues
• other agents

Question 7

examples of aqueous substituion

Answer 7

• cellulose esters
• carbomers
• polyvinyl alcohol
• sodium hyaluronate
• hydroxypropyl guar

Question 8

cellulose esters

Answer 8

• good retention time on ocular surface
• visco elastic polysaccharides
• can cause blurred vision and crusting eyelids due to increased contact time

e.g. methylcellulose

Question 9

carbomer - 980 and 940

Answer 9

• synthetic polymer
• good retention time
• good viscocity

tend to blur vision

e.g gel tears

Question 10

polyvinyl alcohol

Answer 10

• synthetic polymer
• low viscocity (no impact on vision)
• beneficial in mucin and lipid deficiency
• short retention time

e.g liquifilm tears

Question 11

sodium hyaluronate

Answer 11

• mucopolysaccharide
• viscous formation
• good retention time
• non newotnian shear thinning properties
• blur vision

Question 12

Preservatives: Contact lenses

Answer 12

• benzylkonium chloride is taken up by soft cl, released slowly
• artifically elevates preservative contact time

Question 13

newer ophtalmic preservatives - reduced ocular toxicity

Answer 13

• purite
• sodium perborate
• sofzia
• polyquaternium

Question 14

multi dose preservative free

Answer 14

-Hycosan 0.1% Hyaluronate
-Hycosan Extra 0.2% Hyaluronate
-Hylotear 0.1% hyaluraonate
-Hyloforte 0.2% hyaluronate
-Hyabak 0.15% hyaluronate

Question 15

lubricating eye ointments

Answer 15

for px with severe dry eye - in addition to other lubricants

• liquid parrafin/wool alcohol
• high viscocity
• help rebuild lipid layer
• long retention time
  -blurred vision

e.g lacrilube

Question 16

Tear modification

Answer 16

-mucolytic in filamentary keratitis

-Acetlcsteine 5-10%

-e.g. llube (POM)

-Stinging sensation on installation into eye

-Dissolves mucous filaments by breaking disulphide bonds

Question 17

Lipid supplementation: lipsomal spray

Answer 17

-An aqueous suspension of phospholipid-containing liposomes containing hydrogenated phospatidylcholine has been shown to be beneficial in evaporative dry eye

Question 18

prescribing guidance - mild dry eye

Answer 18

-hypermellose 0.3% eye drops
-carbomer 980 0.2% gel
-carmellose 0.5% eyedrops

Question 19

prescribing guidance - Moderate dry eye

Answer 19

-carbomer 980 0.2% gel
-carmellose 0.5% SDU
-Multidose preservative free e.g. 0.1% sodium hyaluronate eye drops

Question 20

prescribing guidance - severe dry eye

Answer 20

-ophthalmic lubricating ointments
-multidose preservative free e.g. 0.1% sodium hyaluronate eyedrops
-Multidose preservative free e.g. 0.2% sodium hyaluronate eyedrops