Artificial Tears/Oc. Lubricants

UK OPTOMS MAY SELL & SUPPLY. USE OF ART. TEARS SHOULD BE SUPERVISED

• Art. tears is name for various avail preparations for tear film deficiencies thru stuff like ocular surface disease or use of systemic medications. These are medicinal products
• SIMPLE art. tears re-wet the eye but don't really act as a quality lubricant. They usually contain some salts and one or two polymers and have a viscosity that is similar to/slightly increased from human tears that's acheived w/low concs of various polymers.
  
• Artificial tears are generally iso or slightly hypotonic to the tear film and have a pH that is slightly acid to normal tears ie 6.5-7.5. pH is geared towards stability, comfort not so much.
  
• COMPLEX art. tears have a slightly different set of polymers (2 or more)
• Cellulose polymers such as hypromellose, carmellose and hydroxyethylcellulose are often used
• P-Polymers like PVA, PEG, Povidone and 'Tween' (which also has surfactant properties) are used also
• New prods could include sodium hyaluronate which is in 'rewetting drops' and not officially desig. art. tears. Also guar gum is found in ce marked rewetting drops and does provide a bit more lubrication than the trad polymers.

ASSESSMENT PRE RECOMMENDING ART. TEARS

1. Objectively evaluate the tear film/oc surface using flu/rose b and measuring the tear prism/tear break up time. Important to get some sort of quantitative assessment that you can compare w/after using the art tears for some time.
2. Establish a true baseline condition - good to get px to stop using the ophthalmic prods they're using for a day before a detailed ee. Knowing the true nature of the px's condition can be helpful when selecting a prod to use.
3. Consider px preferences - important for compliancy. Some artificial tears sting and some don't, some smell/'taste' funny, some people won't like initial blurring of vision, be good w/multidose bottles etc etc etc
4. Preserved or non-preserved? The vast maj of px will be fine with multidose art. tear w/preservative but some will develop allergy. Unit dose & preserv. free are available if the patient might experience adverse reactions or feels that 6x a day use is needed
5. General allergy to eyedrops. need to work out if px is sensitive to a specific ingredient w/questioning before beginning NB no art tear/oc lub can be expected to compete w/an ongoing disease process or display satisfactory efficacy if there's poor ocular/peri-ocular hygiene.
6. Cost. Simpler products = cheaper. Unit dose forms = expensive. Larger bottles = cheaper.
7. Choose regimen. For the most part simple art tears are designed for use prn for the relief of mild & uncomplicated symptoms arising from stuff like
   

• working for extended periods in environment which may irritate eyes
• from inadequate blinking due to over-tiredness
• A dry atmosphere
• -----One or two drops can be expected to simply wash out tear film debris and irritants

8. Px Education & Communication: Give correct instructions, don't assume intelligence, get them to come back

FOR UNCOMPLICATED DRY EYE SYMPTOMS

All multi use bottles contain preservatives (usually BkCl) and include (ALL P MEDICINES)

• Saline eyedrops w/out polymers P NaCl Eyedrops. Minim version is 0.9%
• Hypromellose/hydroxypropylmethylcellulose 0.3% P Brolene Cool Eyes
• Hypromellose 0.32% P Artelac 10ml bottle
• Hypromellose 0.5% P Isopto Plain 10ml bottle
• w/PVA 1.4% P Liquifilm Tears 15ml bottle
• w/PVA 1.8%, Povidone 2%, NaCl, KCl & Amisol, Preserved w/EDTA & Polyquarternium-42: Clinitas Ultra 3 3ml bottle

Single dose options

• NaCl P Minims 0.9%
• Hypromellose 0.32% P Artelac SDU 0.5mlx30 or 60
• Hypromellose 0.3% w/dextran 0.01% SL Tears Naturale 0.5mlx28
• Hydroxyethylcellulose 0.44% as P Minims Artificial Tears
• Carboxymethylcellulose 0.25% in hypotonic mixed salts vehicle buffered w/borate & phosphate. foil sachets as 'Theratears'
• PVA 1.4% w/povidine 0.6% P Liquifilm Tears Preservative free

OCULAR LUBRICANTS & OTHER PREPS aka A STRONGER ARTIFICIAL TEAR W/MORE LUBRICATION

This sort of stuff is for a patient who actually has a dry eye ie Keratoconjunctivitis Sicca and needs something stronger than an artificial tear. They are indicated for use when there is a non-infective or non-toxic chronic irritation and inflammation of the conj w/poor traction of the lids across the ocular surface eg a px w/Sjorgens.

A lubricant does not replace the tear film with a simple aqueous fluid but w/a lubricating film with long residence time at the ocular surface. As such it doesn't improve the hydration of the ocular surface, merely reduces friction and the patient's symptoms which can usually be summed up w/BURNING! PAIN! SOMETHING IN IT! Actually supplementing the lubrication with artificial tears can be useful.

Selection of a lubricant depends on how much friction needs to be reduced and for how long. For example if you step up w/ nightly use of a lubricating gel or ointment then the px might change regimen from simple artificial tears every hour to lubricating tears every 3 or a liquid gel every 4 or 6 hours. NB Ointment during the day = matted lashes and smeary vision so not v popular for that.

As well as allergy to ingredients

• not to be used as primary therapy in follicular conjuntivitis
• use w/caution in toxic keratitis from excessive use of ophthalmic pharmaceuticals or systemic medications
  
• use w/caution in cases of vernal keratoconjunctivitis or atopic conjunctivitis. Other anti-inflamm drug therapy needed in that case

Examples of oc lubs

• Cellulose Polymer prods at 1% level eg Hypromellose P Isopto-alkaline (more comfort for px) Eye-Drops
• Sodium Hyaluronate is widely used in CL rewetting soln and 0.2% in Ocusan 20, 20x0.5ml or at 0.4% in SL Clinitas Soothe
• Carbomer Gels SL Optrex Dry Eye Liquid Gel for use 3 or 4 times a day and before bed. Also P Geltears and P Liquivisc. These contain a special polyacrylic acid gel that forms a coat on the eye's surface that thins rapidly with each eyeblink.
• Lubricating ointments (use 0.5-1cm long ribbon) w/low quantities of liquid paraffin or mineral oil, white paraffin & lanolin eg P Lacrilube 3.5g tube, P Lubritears 5g tube
  
• Bland ointments w/higher concs of yellow soft paraffin and lanolin eg P Simple Eye Ointment generic 3.5g or 4g tubes. Yellow Paraffin is older & a bit more lubricating than white
• ADDNL SUPPLY ONLY Acetylcysteine eye-drops
• Glycerol/Castor oil: glycerin can be formulated from hosp. pharmacy by diluting w/water. Castor oil was once widely used and avail in minims.