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Qs & As about Medications Reprinted from Our Newsletters

Can I miss the occasional eye drop?

No. Your eye needs consistent medication to control the pressure and prevent blindness. Every time you miss an eye drop, eye pressure may increase, causing further damage to your sight.


How can I avoid side effects?

Two things will help. Keep your eyes closed for 3 minutes after putting in your drops. Apply pressure to the side of your nose (where your upper and lower eyelids meet) to prevent the drops from entering the nose from your tear ducts.


What if I forget to take my eye drops?

Take them as soon as you remember. Every time you forget to put an eye drop into your eye, your eye will have no medication to control the pressure. The pressure may increase, causing more damage to your sight. To control your glaucoma, you must apply drops regularly according to your doctor’s instructions.


Should I apply eye drops at the same time every day or immediately after I wake up and before I go to sleep, regardless of time?

It is best to be consistent with taking your drops at the same time each day. This helps minimize eye pressure variation. Most eye drops have a peak and trough effect. Once they’re administered it takes some time for the drops to work and their effect will last a certain number of hours before the next dose is needed. That’s why drops are used once, twice or three times a day.


I use 3 eye drops. Can I put them in all at once?

You should wait at least 3 to 5 minutes between drops. This prevents them from being diluted and lost in teardrops.


What is the consequence if I mistakenly instilled two drops of the same type in an eye at five minutes apart?

If two drops go into the eye at the same time – either extra from squeezing the bottle or if you felt the first drop didn’t get in – the eye will naturally get rid of any excess drops. Normal absorption of drops is during the next five to fifteen minutes.

The minimum five minute window is recommended for eye closure to minimize systemic absorption of drops and to prevent one drug from washing out the second drug if two different medications are required at the same time.

Adding a second eye drop of the same type five minutes later may not further lower eye pressure but can increase systemic absorption through the nasal lacrimal duct increasing the drug’s side effects.

The big issue will be toxicity from the second eye drop – either allergy to the preservative or the medication, or eye surface irritation. There is also a greater chance of systemic side effects such as low blood pressure, low heart rate, and tiredness.


Does the order of the drops matter?

If you are taking TIMOPTIC-XE®, it should go in last.


I was given a generic medication. Is it the same as I was taking before?

Few studies compare a generic medication with its branded counterpart. Generic medications must contain the same quantity of active ingredient (drug amount) as brand name medications. Fillers however, do not have to be the same. This means generics may have different side effects including burning and allergic reactions. The bottles can also be different. This may cause confusion with each use. If you switch to a generic medication, I suggest you bring the bottle to your doctor on your next visit.


Which eye drops for glaucoma are gluten free?

All brand name glaucoma eye drops are gluten free. One caution would be the fillers used in generic meds which may not be gluten free.


I have normal tension glaucoma with vascular-caused optic nerve changes, are eye drops still required to lower eye pressure?

The Normal Tension Treatment trial showed that despite treatment some patients’ glaucoma worsened and that without treatment some patients’ glaucoma did not worsen. It concluded that eye pressure reduction is generally beneficial. Regrettably, only lowering pressure has been shown to help with the disease. We have no way to treat the presumed vascular component involved in some patients with glaucoma.


I have glaucoma in my left eye and a severe allergy against preservatives in eye medications. What preservative-free glaucoma medications are available?

Preservative-free glaucoma eye drops available in Canada are: Cosopt – timolol and dorzolamide; Trusopt – dorzolamide only, and the newly released Monopost – latonoprost (Xalatan).

Some medications are not preservative-free, but BAK-free. BAK (benzalkonium chloride), the main component of glaucoma eye drops is associated with ocular allergy or dry eyes. BAK-free eye drops available in Canada are: IZBA (Travoprost) and DuoTrav.


I have been using LUMIGAN® at night and sometimes in the morning. Is this okay?

No, it is best to use LUMIGAN® in the evening. If you miss a dose, use it the next evening. Using the medication twice per day can affect its potency and increase side effects.


I have glaucoma and since my optic nerve’s condition is worsening, I’ve been prescribed one eyedrop of Ganfort* per day to be administered at night. I’ve read articles online about my type of glaucoma and the majority recommend taking Ganfort in the morning. When is the best time for me to use the drug?

Initial studies compared morning vs evening dosing and found that the prostaglandins (PG) – Xalatan, Travatan and Lumigan – all work better when dosed at night.
Ganfort, DuoTrav and Xalacom are combination medications. In addition to PG, they contain Timolol, a beta blocker. Recent studies, as well as clinical experience, have shown that dosing these combo meds in the morning may give a stronger beta blocker effect and thus better eye pressure lowering. So I suggest using Ganfort in the morning.
* please note Ganfort is not available in North America, only in Europe


I have glaucoma in both my eyes and use Ganfort for the right eye and Monoprost for the left eye. Last week I mistakenly put Monoprost in the right eye. What should I do if this happens again?

If it happens again, don’t add extra eye drops for that day, just resume the regular schedule the next day.

Having different drops for each eye can be confusing but try to keep mistakes to a minimum. Using a visual chart may help. The most important thing is to continue using the eye drops.


My husband has been diagnosed with incipient glaucoma with pressures of 21-28, but no medication was prescribed. When is medication normally prescribed?

While lowering eye pressure in certain individuals is beneficial, other ocular risk factors also contribute to glaucoma development. There is no such thing as a critical eye pressure. IOP in the twenties raises a flag for glaucoma, but does not indicate glaucoma disease.

Because the higher the eye pressure the greater the risk, most doctors start considering treatment when the eye pressure is in the mid to high twenties. This is based on individual cases and is not for everyone.

I suspect that your husband has a healthy optic nerve and normal visual field and that is why his ophthalmologist has elected to hold off treatment. The most critical thing is for your husband to maintain his regular follow-up appointment schedule, so if any changes are found in the future, treatment can be started promptly.


Using Lumigan and Travatan eye drops to treat my glaucoma has caused me to have red eyes and using over the counter drops for dry eyes worsens the redness. My doctor inserted plugs into my eyes which also worsened the redness. Any advice?

Redness with eye drop use for glaucoma is common and usually unavoidable. Try instilling the eye drops one hour prior to bedtime and wipe away any excess drop from around the eyes.

You may experience the same level of redness with different drops, but you could try Xalatan. You may also want to consider alternate therapy such as laser treatment if you are intolerant of eye drops. To lessen dry eyes, I suggest you clean your eye lashes with baby shampoo and apply a hot compress. Try preservative free artificial tears as preservatives in eye drops can contribute to redness.


Is Dorzolamide and Timolol taken separately but concurrently more effective in reducing eye pressure than taking the combined version of Cosopt?

There are fewer side effects and better compliance when taking the combo med, Cosopt, rather than the two separately.


I have normal tension glaucoma and the optic nerve in one eye is damaged. Three months of treatment with Travatan drops has not reduced the eye pressure. I have asthma, so I don’t want to have surgery. Should I continue to use Travatan or switch to other drops?

If you were consistent with your use of Travatan and it hasn’t lowered your pressure in three months then it likely won’t work. I would suggest trying one of the other drops in the same class of prostaglandins such as Lumigan or Xalatan. You might also like to consider Trusopt or Alphagan which won’t affect your asthma. You may want to try laser trabeculoplasty before going on to surgery.


My sister has been told that her “temporal angles are narrow which could increase the risk for pupillary block”. Because her pressures have been low and stable for many years, she wants to stop her Timolol drops. Is this a good idea?

To manage the narrow temporal angle, she may benefit from either a laser iridotomy or else cataract extraction. This will open the angle and lower the risk for pupillary block. Cataract surgery is the more definitive treatment.

If she has definite glaucoma then she should not discontinue timolol. If she has mild elevated eye pressure (ocular hypertension) but no glaucoma damage, then she may be able to discontinue the drops once she has had the laser iridotomy or cataract surgery.


My night-time eye drops cause significant eye redness, skin discoloration and long eyelashes. How can I avoid the first two problems?

These are common side effects of prostaglandins (Xalatan, Travatan, Lumigan) which are used to control eye pressure. To avoid these effects, take the medicine shortly before you go to bed and use a damp tissue to remove the eye drop residue that can form on your eyes after you use drops. Removing this residue will minimize eye redness and skin discoloration.


I’ve been taking various drugs including Travatan, Lumigan and Xalatan for 15 years to maintain the pressure in my eyes. They all give me headaches. Can you suggest alternatives without that side effect?

The prostaglandin medications you listed can have headaches as a side effect. You might want to try Timolol (beta blocker), Alphagan or Trusopt/Azopt (Carbonic Anhydrase inhibitor). You may also want to consider laser treatment or surgery.


I have been using Lumigan and Azarga eye drops for many years. Recently, I have been getting blurry vision and am seeing halos at night.

Ocular surface disease or long-standing glaucoma eye drop use can cause blurry vision. Most glaucoma drops contain preservatives, so that the medication is good for 30 days. These preservatives can irritate the surface of the eye and cause dry eyes which can cause your symptoms.

You might want to try preservative-free medications (Cosopt, Trusopt, Monopost) to help reduce ocular surface disease.

Cataract formation can also cause blurred vision. Even mild cataracts can give symptoms of glare at night. Speak to your ophthalmologist about these symptoms.


I take numerous drugs to control my asthma and various allergies. Are there specific eye drops I should avoid?

Avoid Beta Blocker eye drops such as Timolol, Cosopt, Azarga, Combigan, DuoTrav or Xalacom as they can make your asthma caused breathing issues worse.


A routine lab test indicated that my potassium level is high. Could this be caused by Cosopt® eye drops which I have been using for five years?

Many different things can cause high potassium blood levels including food such as bananas. You could try a different eye drop medication and see if that changes your potassium level. High levels of potassium can cause heart problems. I suggest you consult your family doctor.


My doctor has prescribed three eye pressure medications. I am worried about side effects and would like to use only one to keep my glaucoma in check.

Your doctor is trying to keep your eye pressure low. If you are experiencing side effects from the eye drops, you may want to consider laser treatment. But laser treatment is not a cure for glaucoma and follow-up appointments are essential.


I have been using Travatan, the kind with preservatives, for many years. I now have light sensitivity and see halos and star effects on car headlights and street lights. I also have migraines every day. Could this be from the eye drops?

Long-standing glaucoma eye drop use can lead to ocular surface disease with dry eyes and inflammation of the eyelids. This can result in visual symptoms such as glare, blurred vision and halos. The preservatives in eye drops are a major factor.

Some ways to reduce ocular surface disease include using preservative-free glaucoma drops, cleaning the eye lid margins, applying warm compresses on the eyes, and having sufficient Omega-3 fatty acid. Restasis eye drops also help.

Glaucoma can also lead to earlier onset cataract formation with similar visual symptoms. You may want to have the cataract removed if it is becoming visually significant.

Usually migraines are not directly related to ocular surface disease but chronic eye discomfort can be difficult for some people, precipitating the onset of migraines.


I have noticed darkening of my eyelashes. Is this a side effect of my glaucoma medications?

Darker, thicker eyelashes are a common side effect of all Prostaglandin medications – Lumigan, Xalatan and Travatan. There is no way to avoid this. It does reverse itself once you stop the medication but it can take a few months to return to normal.

Some people also notice some darkening of the skin around their eyes. You can minimize this by avoiding skin contact. Put the drop in about an hour before you go to bed, gently wipe around the eye with a damp tissue and rinse your eyes just before bedtime.


Does Xalatan cause high blood pressure?

No clinical evidence indicates that Xalatan raises systemic blood pressure. It has been shown to have no effect on blood pressure control and is overall safe to use.


Can using eye drops for an extended period result in loss of effectiveness and allergic reactions?

Most of the newer drugs do not wear off or lose their effect over time. Many studies with Prostaglandin meds, such as Xalatan, have shown long term effectiveness in stable patients. Beta blocker meds however, such as Timolol, do lose their effect over time.

Some drugs, such as Trusopt or Alphagan, have shown allergic effects of about 20-30% over time. We see less when the drug is used in combination with a beta blocker (Cosopt, Combigan).

With long term use, some preservatives in eye drops may cause red eyes with burning and irritation. Rather than an allergy, this has more to do with tolerability.

In spite of these issues, patients should continue to use eye drops as recommended by their doctors. Medications control glaucoma in more than 90% of patients.


Do eye drops cause cataracts?

Today’s eye drops probably don’t cause cataracts. Some of the older drops such as Phospholine Iodide may predispose patients to cataracts. Doctors tend not to use these very strong drops in patients with a normal lens.


How many times a day are Timolol eye drops recommended?

Generally, regular Timolol 0.5 % drops are recommended for twice daily use. The gel forming type is once daily, but because the drop is thicker in consistency, this may cause visual blur.

Over time research has shown that once daily T1/2 (non gel forming) can last up to 24 hours. Some ophthalmologists have therefore advocated using the drops once daily. If this is something you want to try, I recommend rechecking the eye pressure in the late evening after morning administration to ensure a prolonged effect of the drug.