What do these eyedrops do?
Lowering eye pressure is a proven method of slowing down the progression of glaucoma. Eye pressure is the balance between the production of fluid, and the drainage of fluid within the eye.
Glaucoma eye drops work by either:
– Increasing the outflow of fluid in the eye
– Reducing the production of fluid in the eye
Examples of eyedrops that increase outflow of fluid:
– Prostaglandin analogues: Latanoprost, Travaprost, Brimatoprost, Tafluprost
– Pilocarpine
Examples of eyedrops that reduce fluid production in the eye:
– Beta blocker: Timolol
– Alpha agonist: Brimonidine
– Carbonic anhydrase inhibitors: Brinzolamide, Dorzolamide
Fixed combination glaucoma medications combine 2 glaucoma medications into 1 bottle:
– XalacomTM : Latanoprost + Timolol
– GanfortTM : Brimatoprost + Timolol
– CosoptTM : Dorzolamide + Timolol
– CombiganTM : Brimonidine + Timolol
– SimbrinzaTM : Brimonidine + Dorzolamide
Some eyedrops are believed to have additional ‘neuroprotective’ effect by increasing blood flow to the optic nerve head. Examples are: Brimonidine and Dorzolamide.
What are the side effects of eyedrops ?
The common side effects of eyedrops include a transient “stinging” sensation when the eyedrops are instilled. This typically lasts for a few seconds or a few minutes and the eye quickly returns to normal afterwards. However, if the eye is persistently red, itchy, swollen or produces discharge, then you could be allergic to the eyedrop or the preservatives in them. Please seek advice from your ophthalmologists as soon as possible.
There are other common side effects with prostaglandin analogues such as longer eyelashes, increased pigmentation of the iris and/or skin around the eye and loss of fat around the eyeball. Stopping the eyedrops usually reverse these side effects, although it can take months to get back to normal.
Timolol eye drops belong to the class of beta-blockers and can result in wheeziness or slowing down of the heart rate. If you have asthma or take inhalers, or if you have any heart problem, please inform your doctor as these drops may not be suitable for you. They may also cause depression in some people and in men they may cause impotence. If you notice any of these problems, again, please inform your doctor.
Sometimes your doctor may prescribe oral medications (tablets) to reduce your eye pressure quickly over a short period of time. The most common is oral acetazolamide (commonly known as Diamox). If you have kidney or liver conditions, are pregnant or are allergic to sulphur drugs, please let your doctor know because you might not be suitable to consume acetazolamide. Adverse reactions, occurring most often early in therapy, include numbness or a “tingling” feeling in the hands and feet, hearing problems or tinnitus, loss of appetite, taste alteration and gastrointestinal disturbances such as nausea, vomiting and diarrhoea, the need to urinate frequently and occasional instances of drowsiness and confusion.
How do I use my eyedrops?
Using eyedrops may be tricky for some especially if their vision is reduced, they have poor hand-eye coordination or have difficulty squeezing the eyedrop bottles. In these situations, a care giver may be required to help instil the eyedrops.
Several tips include:
• Check that the eyedrops have not expired
• Check the patient’s name and eye drops label against the prescription
• Sit the patient down or lie down on the bed comfortably
• Remove the cap from the bottle (or the pipette from the bottle)
• If you are instilling the eyedrops yourself, look upwards. If you are the care-giver, ask the patient to look upwards
• With the index finger of one hand take a folded swab or paper tissue to gently pull down the lower eyelid. Do not make the eyelid turn out too much as instilled drops may fall out on to the cheek
• With the dropper about five centimetres above the eye, squeeze the bottle or pipette rubber and allow one or two drops to fall inside the central part of the lower eyelid
• Do not allow the bottle or pipette to touch the eyelid skin or eye lashes as it will cease to be sterile and needs to be thrown away
• Ask the patient to close the eye and rotate the eyeball by keeping the eyelid closed, but pretending to look left, right, up and down
• Finally, being careful not to touch the tip of the bottle to anything, replace and secure the bottle top
If you are comfortable taking eyedrops, try also placing a finger at the edge of the eye nearest to the nose and pressing in gently. This will stop the medication being flushed down the ducts and into the back of the throat. This very simple technique is called ‘punctal occlusion’ and you can ask your ophthalmologist to demonstrate how to do it.