Eye Drops - All You Need To Know
Eye drops can be very confusing, as there are around a dozen different categories. They can be either preserved or unpreserved. As a general rule of thumb at The Eye Practice, we prefer to prescribe unpreserved eye drops, as preservatives can further irritate the eyes, which often defeats the purpose of using them.
A trip to the pharmacy will reveal virtually an infinite number of options to choose from, and these are just the ones that are available over the counter!
So where do we start?
Main Uses of Eye Drops
- Infection - this includes bacterial, viral and fungal
- Dry Eyes
- Inflammation - this can be caused by a whole host of different conditions. Anything that causes red eyes is inflammation.
If you do not like a technical explanation read on. Wikipedia has a more technical explanation on its Eye Drop page.
Antibiotic Eye Drops and conjunctivitis
- These are used if a bacterial infection is suspected or confirmed with laboratory testing. In Australia the most common eye drop antibiotic is one that contains chloramphenicol.
- It is mainly marketed under the name of Chlorsig and recently was made available over the counter, without a prescription, as Chlorsig Eye Drops as well as an Chlorsig Ointment.
- Unfortunately it is used excessively and indiscriminately. Because the vast majority of eye irritations are not bacterial infections, Chlorsig does little to help these eyes and in some cases makes the irritation worse due to the preservatives.
- Other examples of antibiotic eye drops are Ciloxan and Ocuflox. These are particularly useful when a bacterial infection is suspected in the presence of contact lens wear. They are also commonly used for a week or two after eye surgery, to protect against possible infection. While these drops are excellent at protecting the eye and fighting infection, they can be quite toxic to the delicate surface of your eye and cause irritation. Always use them according to your eye doctor’s instructions.
Dry Eye Drops
Many eye drops are available for the symptomatic relief of dry eye symptoms. They act to hydrate and lubricate the surface of the eye to improve comfort. It is important to understand that most dry eye drops do not treat the underlying cause of dry eye and bring relief of symptoms only. They can sometimes do more harm than good, especially if overused or in prolonged use, as they can flush the essential oil layer out of your eye.
Anti-Inflammatories (Steroids and NSAIDs)
- These fall into two categories – steroids (also called corticosteroids) and non-steroidal anti-inflammatory drugs (or NSAIDs).
- Steroid eye drops are very potent anti-inflammatories.
- They come in different strengths from mild to very strong and, in Australia, can only be prescribed by a medical practitioner or a therapeutically trained optometrist. They include FML, Maxidex, FLAREX and Pred Forte.
- It is imperative that the pressure inside the eye is measured before beginning a treatment of topical steroids as they can significant increase the eye pressure in predisposed individuals and in turn can cause an eye condition called glaucoma.
- Steroids are used to control eye inflammation. This may be chronic or acute. Acute inflammation comes on quickly and includes serious conditions such as iritis (or uveitis) as well as less serious conditions such as conjunctivitis.
- Chronic inflammation occurs in many eye conditions including seasonal allergies and dry eye. In the case of dry eye sufferers, often a strong steroid eye drop is an effective way to kick-start successful treatment.
- Steroids are also used to control inflammation in the weeks following eye surgery such as a cataract procedure. It is important to use them as instructed as they perform a vital role in switching off the body’s immune response and facilitating healing.
- Non-steroidal anti-inflammatory drugs (also called NSAIDs) work in a similar way to steroids, calming down inflammation in the eye. They include Voltaren and Acular and are often routinely used after eye surgery (such as cataract or laser eye surgery) to relieve pain and inflammation.
- Often, both steroids and NSAIDs are prescribed, as they work in different ways and have different effects.
- NSAIDs have an important role in controlling allergy and inflammation from dry eye.
Eye Drops for Allergies (antihistamines and mast cell stabilisers)
- Eye drops for allergy fall into two categories – antihistamines and mast cell stabilisers.
- They work in different a ways to block the inflammation cycle caused by exposure to an allergen such as pollen or dust. They are a godsend for anyone suffering from hay fever or seasonal allergies.
- The latest generation antihistamines such as Patanol and Zaditen are highly effective at controlling ocular allergies and usually only need to be used twice a day.
- Antihistamines can cause side effects such as dehydration, which can be an issue if there is a tendency towards dry eye.
- Mast cell stabilisers can be used for longer periods and work in a different way to anti-histamines. They are often used to control contact-lens related allergies.
- It is very important to realise that preservative in eye drops can cause inflammation and allergy and always, where possible use an unpreserved formula. Preservative-free formulas are available for most eye drops on prescription from compounding pharmacies.
Glaucoma Eye Drops
Occasionally you might have no symptoms yet your optometrist or ophthalmologist will recommend that you use eye drops for an eye disease called glaucoma. Eye drops are one of the mainstays of glaucoma treatment. There are several categories of these, including prostaglandin analogs, beta blockers, alpha agonists, carbonic anhydrase inhibitors (CAIs) and combined medications. They work in different ways to lower the pressure within the eye.
• Prostaglandin analogs include Xalatan, Lumigan and Travatan Z. They work by allowing fluid to drain more easily from the eye. They have few side effects but can cause thickening of eyelashes and changes to iris colour.
• Beta blockers include Timoptol, and decrease the secretion of fluid in the eye. They have numerous systemic side effects (which can be reduced by closing the eyes tightly or punctal occlusion after application – see below under TIPS).
• Alpha agonists include Alphagan P, and work to both increase drainage and decrease secretion. Alphagan P has a preservative that breaks down on exposure to air, so it useful for those with sensitivities to preservatives.
• CAIs include Trusopt, and work to decrease fluid production. They are also available as pills (Diamox) which are used to control acute spikes in eye pressure, e.g. after surgery or in response to steroids.
• Combined drops include Combigan and Cosopt, and are used to improve compliance when more than one type of glaucoma drug is required.
With all glaucoma drops, compliance is key, and many patients unfortunately lose vision permanently on account of not complying with their instructions.
Other Eye Drops include:
- Vasoconstrictors: (e.g. Murine, Visine) constrict the blood vessels in the white of the eye as a treatment for redness.
- Mydiatics (also called parasympatholytics): (e.g. tropicamide) dilate the pupil, either to allow a view of the retina or for myopia control
- Cycloplegics: temporarily paralyse the accommodating muscle in the eye to allow accurate measurement of refractive error
- Topical Anaesthetics: numb the eye for procedures. These MUST NEVER be used on a long term basis, as they are very toxic.
- Miotics (also called parasympathomimetics): (e.g. pilocarpine) constrict the pupil as therapy for some eye conditions such as glaucoma
- Antifungals /Antivirals: for the treatment of fungal or viral eye infections.
Tips For Administering Eye Drops
With any eye drop, getting it into the eye is essential for it to work. Many patients struggle with administering their eye drops, but the consequences of not getting the drug into your eye can be very serious. Here are some tips:
- Wash your hands before using eye drops
- Shake the bottle thoroughly – some eye drops are formulated as suspensions, which means you need to shake thoroughly to distribute the active part of the drug throughout the bottle
- Use a mirror to align the bottle above your eye
- Avoid touching the bottle or dropper off your eyelids or eyelashes, as this can introduce bacteria to your eye
- Look away from the bottle to avoid the drop falling on your cornea – the most sensitive part of your eye
- Aim for the corner of your eye or into the pocket created when you pull down your lower eyelid.
- Once in, close your eyes tightly or press firmly on the inner corners of your closed eyes with your fingertips. This closes off the puncta, or ducts that lead to the back of your throat, where the eye drops can be absorbed into your system.
If you are really struggling to get your drops in, here are some further tips:
Get someone to put the drops in for you
Use a drop dispenser (available from pharmacies)
Apply the drop to softly closed eyes, but be careful of touching the tip of the bottle on your skin, as it can infect the drops for future use.
Confused about the best eye drops for dry eyes or conjunctivitis? Talk to the experts. Call The Eye Practice or make an appointment online today.