What is the composition and function of tear film?
Two layers: lipid and combo of aqueous and mucous layer
fxn: hydration, lubrication, oxygen + nutrition for cornea, removal of debris
Antimicrobial, Smooth surface
What does the ocular surface consist of?
cornea and conjunctiva
Cornea
Transparent dome-shaped tissue that has no blood vessels and allows light to enter the eyeball to stimulate rods and cones in retina -> able to see
Conjunctiva
Thin transparent membrane covering the inside of eyelids and top of sclera
Lipid layer secreted by?
Meibomian glands (inside eyelid)
Gland of Zeiss and Moll (base of each eyelash)
Aqueous layer secreted by…
Lacrimal glands (above each eyeball)
Glands of Krause and Wolfring (under the eyelids)
Mucous layer secreted by….
Goblet cells (conjunctiva)
Corneal and conjunctival epithelial cells (outermost layer of cells on cornea and conjunctiva)
Label the glands/structures
Lacrimal gland
Meibomian gland
N/A
Corneal and conjunctival epithelial cells
Label the glands/structures
Meibomian gland
Glands of Moll
Glands of Zeis
What are the non-modifiable risk factors for dry eyes?
Age : incr w/ age (> 65 yo, 15%)
Female Sex (> 50 postmenopausal women)
What are the modifiable risk factors for dry eyes?
Systemic dz
Autoimmune disorders: Sjorgen’s syndrome, RA, Lupus, Rosacea
Endocrine disorders: DM, Grave’s Dz
Local eye conditions
Blepharitis, Multiple Sclerosis, Eye, Lid defects
Medications
Diuretics, B blockers, Antihistamines, Anticholinergics (scopolamine, some meds for psych), Antipsychotics, Benzodiazepines, some analgesics, Vit A
Environment
Dry, Dusty
Lifestyle
Excessive use of computer or other screens, Smoking, alcohol
What characteristics with the eye are considered referrals?
Red eye w/ pain, blurred vision, acutely inflamed eyelids
angle closure glaucoma
keratitis
uveitis (inflammation inside eye)
Discharge and matty lids (crusty, sticky layer of mucus)
conjunctivitis (viral/mucopurulent or bacterial/less mucopurulent)
Regarding timing of sx, what would constitute a referral?
Sudden onset of sx w/in past few hours/days
What is the active ingredient class called in artificial tears?
demulcent (water-soluble polymer)
What are the 4 types of demulcents?
cellulose derivatives
polyols
alcohols
dextran 70 (used in combo)
What are the different types of cellulose derivatives?
Carboxymethylcellulose (CMC)
Hydroxypropyl methylcellulose (HPMC, Hypromellose)
What are the different type of polyols?
Propylene glycol
polyethylene glycol
glycerin
polysorbate 80
What are the different types of alcohols?
Polyvinyl alcohol
Povidone
What are the inactive (universal) ingredients?
NaCl, KCl, MgCl2, Phosphate/Bicarbonate based sulfur
Osmoprotectants
Humectants
Hydroxypropyl guar gum
Ingredients that prevent of water evaporation
MOA and types of osmoprotectants
Protect cells against hyperosmolarity-med injury
Trehalose, Carnitine, Erythritol
MOA and types of humectants
Absorb and retain water
Sodium hyaluronate
MOA of Hydroxypropyl guar gum
Mucin mimetic action
What are the ingredients that prevent water evaporation?
Oils (castor oil, flaxseed oil, mineral oil)
What are the types of vanishing preservatives?
Purite: oxychloro complex containing 99.5% chlorite, 0.5% chlorate
Upon instillation, light breaks it into sodium chloride, O2, H2O
Sodium perborate (Dequest)
Upon instillation, light breaks it down to low levels of H2O2
What are the types of Quaternary ammonium compounds?
Polyquaternium-1
high molecular weight quaternary ammonium compound w/ microbicidal activity but has very low toxicity to corneal/conjunctival epi cells
Benzalkonium Chloride (BAK)
High molecular weight quaternary ammonium compound
Toxic to corneal/conjunctival epithelial cells
AVOID eye drops in pts of dry eye
What is a similarity with all preservatives? (and which eye drops contradict this similarity?)
pH neutral (except Thera tears which is hypotonic)
What are counseling points regarding Preservative-Free Single Dose Unit eyes drops?
can use multiple times in a SINGLE DAY, discard at the end
pt advised to keep in a cool place (refrig) and not touch the tip by hand or other object
How often should preservative-containing articifical tears be used?
4-6 times/day
If the patient needs to use eye drops 6 or more times a day, what should they use?
unit dose single use eye drops
When should a pt discard a multidose vial after opening?
after 30 days
Is dry eye disease chronic or acute?
chronic (should use artificial tears as sx improve and to sustain improvement)
For Mild cases of dry eyes, what should be recommended?
CMC or HPMC-based tears with lifestyle changes
If you have already recommended a CMC or HPMC-based tears and lifestyles changes, what is the next step if the pt still complains of dry eyes?
increase freq (4-6 for preservative-based, ≥ 6 for preservative free)
If already increased frequency, what is the next step if the pt still complains of dry eyes?
tears w/ multiple active ingredients (esp lipid component)
CMC + (Trehalose, hyaluronic acids, oils, glycerin, polysorbate)
switch to polyols-containing tears (guar gum, mineral oil)
If already recommend tears w/ multiple active ingredients (esp lipid component), what is the next step if the pt still complains of dry eyes?
consider referral (if sx do not improve/worsen)
add gel-based tears
supplement w/ nighttime ointments
What is not recommended for dry eyes?
Vascoconstrictors
tetrahydrozoline, nephazoline, phenylephrine
Visine, Clear Eye
Why are vasoconstrictors not recommended?
rebound increase in redness
tolerance + pt ends up using more freq
ocular surface damage (preservatives)
vascular fragility
Artificial Tear Inserts are prescription only, what is the product and its limitations?
Lacrisert
water soluble rod + hypromellose
swells up and dissolves
Limits:
expulsions, vision blurring
does not work in pts w/ low tear secretion
Why are ointments recommended?
NIGHT-time use only since they interfere w/ vision (mineral oil, white petrolatum)
tak contact lenses OFF
close eyes for 2 min
MOA of punctal plugs
Prevent the tear outflow, thus retaining the tear film
Inserted under topical anesthesia using jeweler's forceps either into punctum or canaliculus
What are the two types of materials punctal plug?
silicone and collagen
What are the limitations to punctal plugs?
spontaneous extrusion
replacement has higher rate of expulsion
What products inhibit ocular surface inflammation?
cyclosporine (Restasis)
liftergrast (Xiidra)
How is cyclosporine (Restasis) provided?
ophthalmic emulsion in a single unit vial
What is the response of the guy by ophthalmic response to cyclosporine?
decreases ocular surface inflammation and increases tear production
Instill one drop twice daily in the affected eye
Indicated for moderate to severe dry eye
What are the side effects of cyclosporine (Restasis)?
burning sensation upon instillation (most common)
conjunctival hyperemia, discharge, eye pain, foreign body sensation, pruritus, stinging, blurring (in 1-5% pt)
Counseling points regarding cyclosporine (Restasis)
invert bottle few times b4 admin
allow min of 15 min interval between instillation of cyclosporine and artificial tears or other eye drops
not to use while wearing contact lenses; REMOVE PRIOR
re-insert 15 min after instillation of drops
How is Lifitegrast (Xiidra) provided?
5% opthalmic solution in a single unit vial
MOA of Xiidra
lymphocyte fxn-associated antigen-1 (LFA-1) antagonist
decr ocular surface inflammation
Instill 1 drop BID
What are the side effects of Xiidra?
blurred vision, conjunctival hyperemia, eye irritation, headache, incr lacrimation, eye discomfort, eye pruritus
Counseling points for Xiidra
allow min of 15 min interval btwn instillation and artifical tears or other eye drops
not to use while wearing contact lenses
remove PRIOR to admin → re-inserted 15 min after instillation of drops
What are the products that stimulate tear secretion?
pilocarpine
diquafosol (Diquas)
What is the difference in MOA between pilocarpine and diquafosol?
Pilocarpine stimulates lacrimal, krause, and wolfring glands whereas Diquas stimulates goblet cells and accessory glands