Dry eye preparations

Question 1

what is the most general way to improve dry eyes

Answer 1

using ocular lubricants

Question 2

how many % of the total ophthalmic drugs do artificial tears contribute to in the UK

Answer 2

33%

Question 3

why are artificial tears not exactly the same as natural tears

Answer 3

because lots of glands contribute to natural tears which artificial tears can’t mimic

Question 4

other than functioning as lubricants, what do some more recent formulations mimic

Answer 4

the electrolyte composition of human tears (e.g.TheraTears®)

Question 5

what are the 3 forms that ocular lubricants are available as and what are they used to treat

Answer 5

• eyedrops
• gels
• ointments

used to treat the discomfort associated with conditions in which the tear film is reduced or unstable

Question 6

what are lubricant eye ointments also used in the treatment of as well as the discomfort associated with conditions in which the tear film is reduced or unstable

Answer 6

the treatment of recurrent corneal erosions

Question 7

what are the majority of dry eye preparations available as and who can they be sold and supplied by

Answer 7

over the counter (P medicines, GSL or CE marked products) and can be sold and supplied by optometrists

Question 8

what are the most commonly used drugs in optometric practice

Answer 8

ocular lubricants

Question 9

what are the 2 foremost objectives in caring for patients with dry eye disease

Answer 9

• to improve the patient’s ocular comfort and quality of life and
• to return the ocular surface and tear film to the normal homeostatic state

Question 10

symptoms can rarely be ____________, they can often be __________ with ocular lubricants

Answer 10

symptoms can rarely be eliminated, they can often be improved with ocular lubricant

Question 11

what did a systematic review conclude about artificial tears

Answer 11

that they improved the condition of the exposed ocular surface in patients with dry eye, based on Rose Bengal staining as the primary outcome measure.
However, there was no statistical difference in the efficacy of the various formulations

Question 12

list 4 limitations that the treatment of dry eye with ocular lubricants has

Answer 12

• Formulation cannot replace complexity of natural tears
• Administered intermittently rather than continuously as with natural tears. Therefore formulated to increase their contact time e.g. mucoadhesive polymers
• Choice of therapy is determined by the severity of the condition (taking into account the lifestyle and dexterity of the patient)
• The presence of preservatives in artificial tears can compromise the ocular surface following prolonged use

Question 13

what is the recommended treatment of ocular lubricants for mild dry eye disease

Answer 13

Artificial tears up to 4x per day

Question 14

what are the recommended treatments of ocular lubricants for moderate dry eye disease

Answer 14

• Unpreserved artificial tears up to 12x per day with lubricating ointment at night
• Tear conservation

Question 15

what are the recommended treatments of ocular lubricants for severe dry eye disease (name 3)

Answer 15

• Immunotherapy e.g. cyclosporin
• Autologous therapy (serum)
• Tear conservation

Question 16

what is the name of the recommended immunotherapy treatment for severe dry eye disease

Answer 16

cyclosporin

Question 17

list the 7 types of formulations that ocular lubricants are available in

Answer 17

• Cellulose esters
• Carbomers
• Polyvinyl alcohol
• Sodium hyaluronate
• Lubricating ointments
• Acetyl cysteine
• Liposomes (liposomal spray)

Question 18

what type of products are ocular lubricants increasingly available stand what does this stand for

Answer 18

• available as CE–marked products

- These are ‘medical devices’ (similar to contact lens solutions) and therefore not regulated by the Medicines Act

Question 19

if a product is a medical device which is CE marked, what are they not regulated by

Answer 19

the medicines act

Question 20

because ocular lubricants are increasingly available as medical devices, what is a limit as a consequence

Answer 20

their availability on NHS prescriptions

Question 21

what advantage do mucoadhesive properties in ocular lubricants have, and what are they available as

Answer 21

• Increased contact time with the ocular surface
  as they are more sticky
• available as mucoadhesive viscous gels
• most are polymers (artificial molecules)

Question 22

what are the side affects associated with mucoadhesive viscous gels

Answer 22

• blurring

- sticky lids

Question 23

what is the most commonly prescribed formulation of ocular lubricants and name 4 examples

Answer 23

Cellulose esters

e. g.
- hypromellose
- hydroxyethylcellulose
- methylcellulose
- carboxymethylcellulose

Question 24

which formulation of drugs are viscoelastic polysaccharides

Answer 24

Cellulose esters

Question 25

what is an advantage of the Cellulose ester formulation of ocular lubricants

Answer 25

Good retention time on ocular surface

Question 26

what is a disadvantage of the Cellulose ester formulation of ocular lubricants

Answer 26

Can cause crusting of eyelids mimicking blepharitis

Question 27

what two forms of packaging are the Cellulose ester formulations of ocular lubricants available as

Answer 27

- unit dose preservative free or - multi dose

Question 28

which type of ocular lubricant formulation is the cheapest and thus available on the NHS

Answer 28

Cellulose ester

Question 29

which type of molecule are the ocular lubricant formulation, carbomers

Answer 29

Synthetic polymers

Question 30

name 2 advantages of the carbomer formulation of ocular lubricants

Answer 30

- Good retention time on ocular surface | - Good viscosity when eyes open shear thin during blinking

Question 31

what is a disadvantage of the carbomer formulation of ocular lubricants

Answer 31

- Tends to blur vision

Question 32

what causes the viscosity of tears to be decreased

Answer 32

if applying a force when blinking

Question 33

what behaviour does the tear fluid display

Answer 33

non-Newtonian behaviour

Question 34

what are the majority of solutions unaffected by

Answer 34

the shear rate

Question 35

which type of molecule are the ocular lubricant formulation, Polyvinyl alcohol

Answer 35

Synthetic polymers

Question 36

Polyvinyl alcohol formulations have low....

Answer 36

viscosity

Question 37

which type of dry eye is Polyvinyl alcohol ocular lubricant formulations beneficial in

Answer 37

mucin and lipid deficiency dry eye

Question 38

what is a disadvantage of Polyvinyl alcohol ocular lubricant formulations

Answer 38

Short retention time | therefore need to put in more times

Question 39

which formulation of drugs are Mucopolysaccharides

Answer 39

Sodium hyaluronate

Question 40

Sodium hyaluronate is a __________ formulation

Answer 40

Sodium hyaluronate is a vicious formulation

Question 41

what is the advantage of Sodium hyaluronate ocular lubricant formulations

Answer 41

Good retention time on ocular surface (superior to cellulose esters and PVA)

Question 42

what 2 other formulations is the retention time of Sodium hyaluronat superior to

Answer 42

- cellulose esters and - Polyvinyl alcohol

Question 43

which ocular lubricant formulation is a natural product, which makes it work well as a ocular lubricant

Answer 43

Sodium hyaluronate

Question 44

what is the disadvantage of the ocular lubricant formulation, Sodium hyaluronate

Answer 44

Tends to blur vision

Question 45

which ocular lubricant formulation blurs vision less than the Cellulose ester formulation

Answer 45

Sodium hyaluronate

Question 46

what form do ophthalmic lubricating ointments come as

Answer 46

Liquid paraffin

Question 47

ophthalmic lubricating ointments have high....

Answer 47

viscosity

Question 48

what does ophthalmic lubricating ointments contribute to

Answer 48

rebuilding the lipid layer

Question 49

what does ophthalmic lubricating ointments melt at

Answer 49

the temperature of ocular tissues

Question 50

what is the advantage of ophthalmic lubricating ointments

Answer 50

long retention time

Question 51

when is ophthalmic lubricating ointments used at its best

Answer 51

when other artificial tears are used during the day and ophthalmic lubricating ointments used at night

Question 52

what is a disadvantage of ophthalmic lubricating ointments

Answer 52

Blurred vision

Question 53

what can be a result of tear modification as a result of dry eye

Answer 53

Mucolytic in filamentary keratitis

Question 54

which formulation of ocular lubricant needs to be used to treat Mucolytic in filamentary keratitis and at what dose

Answer 54

Acetylcysteine 5-10%

Question 55

name an example of Acetylcysteine 5-10% used to treat Mucolytic in filamentary keratitis and which type of medicine is it available as

Answer 55

- Ilube | - available as POM

Question 56

how does the Acetylcysteine 5-10% formulation of ocular lubricant treat Mucolytic in filamentary keratitis

Answer 56

it dissolves mucous filaments by breaking disulphide bonds

Question 57

what sensation is felt when instilling Acetylcysteine 5-10% into the eye

Answer 57

stinging sensation | the cornea feels rough

Question 58

what is the purpose of preservatives in ocular lubricants

Answer 58

to prevent bacterial contamination

Question 59

what is the drawback of preservatives in ocular lubricants

Answer 59

they are toxic to the ocular surface

Question 60

when do preservatives cause more harm/toxicity to the ocular surface

Answer 60

when they are put into the eye lots of times a day to treat a chronic condition

Question 61

what is the most common type of ocular preservative found in ocular lubricants and solutions

Answer 61

Benzylkonium chloride BAK

Question 62

what affect on the eye can 1 drop of Benzylkonium chloride have after 10 minutes

Answer 62

an effect/morphology on the microvilli of the corneal epithelium and on the corneal stroma

Question 63

what affect on the eye can 1 drop of Benzylkonium chloride have after 6 hours

Answer 63

it strips off microvilli of the corneal epithelium and on the corneal stroma

Question 64

how are preservative free ocular lubricants generally packaged as and what implications does this have

Answer 64

- as single dose minims | - this is more expensive

Question 65

what is Benzylkonium chloride BAK taken up by and what consequences does this have

Answer 65

- by soft contact lenses - and then is released slowly - exceeding upper safety limits (increases toxicity)

Question 66

what type of contact lenses absorbs greater quantities of Benzylkonium chloride BAK

Answer 66

High-water content lenses | greater than low water content lenses

Question 67

which lenses take up a very small amount of Benzylkonium chloride BAK and what implications do they have

Answer 67

- hard contact lenses - and then is released slowly - approaching upper safety limits (increases toxicity)

Question 68

what can tear film concentrations of benzalkonium, such as after eye drop use in the presence of soft contact lenses could result in

Answer 68

adverse effects on the ocular surface

Question 69

what have newer generation ophthalmic preservatives been developed with

Answer 69

reduced ocular toxicity

Question 70

name 4 newer generation ophthalmic preservatives

Answer 70

- Purite - Sodium perborate - SofZia - Polyquaternium

Question 71

what can newer generation preservatives be used with and why

Answer 71

contact lenses | as they're less toxic

Question 72

what happens to the newer generation preservative purite after going into the eye

Answer 72

dissociates into water, oxygen, sodium, and chlorine free radicals

Question 73

what happens to the newer generation preservative Sodium perborate after going into the eye

Answer 73

converts into water and oxygen on instillation

Question 74

what happens to the newer generation preservative SofZia after going into the eye

Answer 74

it is modified into harmless elements on instillation

Question 75

which newer generation preservative is more common in multi dose contact lens care products, and is less toxic than BAK

Answer 75

Polyquaternium

Question 76

name a brand of ocular lubricant that is a multi dose preservative free system and how does it achieve this

Answer 76

Hycosan | by having a valve system in the neck of its bottle

Question 77

what is the advantage to having a multi dose packaging preservative system

Answer 77

it is more cos effective than single use minims

Question 78

other than Hycosan, name 3 other multi dose preservative free systems with its available dose

Answer 78

- Hylotear 0.1% hyaluronate - Hyloforte 0.2% hyaluronate - Hyabak 0.15% hyaluronate

Question 79

what impact does a more concentrated dose (%) preservative free multi dose ocular lubricant have

Answer 79

it sticks more to the ocular surface | but then can affect vision

Question 80

what ingredient does the ocular lubricant Systane contain which causes it to increase its viscosity on contact with the ocular surface

Answer 80

hydroxypropyl (HP) guar

Question 81

what is the mechanism of the ocular lubricant Systane to increase its viscosity on contact with the ocular surface based on

Answer 81

the change in pH Systane is a liquid in the bottle at a pH of 7.0, but when placed in the eye (which has a pH of ~7.4), a chemical reaction occurs

Question 82

how does the ingredient hydroxypropyl (HP) guar in Systane cause it to increase its viscosity on contact with the ocular surface

Answer 82

the HP guar binds to the ocular surface and simultaneously crosslinks with borate ions in the solution, forming a network with a gel-like consistency

Question 83

what is the ocular lubricant liposomal spray and what does it contain

Answer 83

An aqueous suspension of phospholipid-containing liposomes containing hydrogenated phosphatidylcholine i.e. a lipid in an emulsion

Question 84

what type of dry eye has liposomal sprays been beneficial in

Answer 84

evaporative dry eye

Question 85

how is the liposomal spray formulation used

Answer 85

it is sprayed onto the closed eyelids

Question 86

what is recognised as a key pathogenetic mechanism of dry eye

Answer 86

inflammation

Question 87

which anti inflammatory drug was the first commercially available pharmaceutical therapeutic agent for the treatment of dry eye/keratoconjunctivitis sicca

Answer 87

Restasis - 0.05% cyclosporine ophthalmic emulsion available in US but not UK

Question 88

how does autologous serum work as a treatment for dry eye

Answer 88

it uses the patients own blood plasma, this is because it is a neutral substance and is very good for the ocular surface

Question 89

why is autologous serum a good dry eye treatment for the ocular surface

Answer 89

it contains serum and anti-bodies

Question 90

what other alternative dry eye treatments are there from ocular lubricants

Answer 90

ingestion Omega-3 and Omega-6 fatty acids

Question 91

where can Omega-6 fatty acids be found

Answer 91

evening primrose oil

Question 92

which fish contains lots of Omega-3 fatty acids

Answer 92

- mackerel - tuna - cod liver