Eyes: administration of drugs to eyes

Question 1

How are drugs administered for eye treatment?

Answer 1

1. Eye drops
   - Into the pocket of the eye, by pulling down the eyelid
   - Keep the eye closed as long as possible after administration
2. Eye ointment
   - Spread a line of the ointment into the pocket of the eye, by pulling down the eyelid
   - Blinking helps to spread the ointment
   - Most people experience blurred vision for the next 5 minutes1. Eye drops
3. Local injection
   - Usually used when higher drug concentrations are required
   - Subconjunctival injection
   - Intracameral route
   - Intravitreal route

Question 2

If two different eye drops are being used on the same day, can they be used at the same time?

Answer 2

• No since dilution and overflow may occur when one immediately follows the other
• The patient should wait atleast 5 minutes

Question 3

If an ointment and eye drop are being applied on the same day, what should be applied first?

Answer 3

• Eye drop FIRST
• 5 minutes after the ointment (depending on what the product says)

Question 4

What are something to consider with local eye treatments

Answer 4

1. Systemic side-effects
   - Varies from drug to drug
2. Nasal drainage
   - Much more common with eye drops than eye ointment
   - Pressure on the lacrimal punctum (corner of the eye adjacent to nose) for at least one minute after administration can reduce this
3. Blurred vision
   - Patients should be warned not to drive or perform other skilled tasks until vision is clear
4. Contact lenses wear
   - Some drugs and preservatives in eye drops can accumulate in hydrogel (soft) contact lenses and induce toxic and adverse drug
   reactions
   - Patients should remove soft gel contact lenses and avoid wearing them for the duration of treatment
   - Alternatively, unpreserved eye drops can be used whilst wearing soft contacts
   - Eye ointments should NEVER be used with contacts

Question 5

How long should eye drops be used until disposal?

Answer 5

• If multiple-application containers are for home use, then they should be discarded after 4 weeks of opening (unless stated otherwise)
• Multiple-application
  containers in the hospital are discarded after 1 week of opening

Question 6

What are eye lotions? What are the main uses?

Answer 6

• These are solutions for the irrigation of the conjunctival sac
• They act mechanically to flush out irritants or foreign bodies as a first-aid treatment
• Sterile sodium chloride 0.9% solution is normally used

Question 7

How many types of contact lenses are there?

Answer 7

• Rigid (hard or gas permeable)
• Soft (hydrogel or silicone hydrogel) - adults only, most popular type, more comfortable

Question 8

What infections are patients at risk of getting from poor use of contacts?

Answer 8

• Keratitis
• Conjunctivitis

Question 9

Which system drugs can have adversed effects on contact lenses?

Answer 9

1. Oral contraceptives
   - Particularly those with high estrogen content
2. Drugs which reduce blink rate
   - Anxiolytics
   - Hypnotics
   - Antihistamines
   - Muscle relaxants
3. Drugs which reduce the secretion of tears
   - Antihistamines
   - Antimuscarinics
   - Phenothiazines
   - Beta-blockers
   - Diuretics
   - TCAS
4. Drugs which increase tear secretion
   - Ephedrine
   - Hydralazine
5. Isotretinoin
   - Causes conjunctival inflammation
6. Aspirin
   - Salicylic is in tears and can be absorbed by contact lenses leading to irritation
7. Rifampicin and sulfasalazine discolour contacts

Question 10

Which drugs can discolour contacts

Answer 10

Rifampicin and sulfasalazine