Ask an Expert about Glaucoma

Thank you for submitting your question. Normal tension glaucoma is a difficult type of glaucoma to treat. There are some studies that do show an association between hypotension (low blood pressure) and normal tension glaucoma. Raising the blood pressure to a normal level may be of some benefit; however, you should talk with your primary care doctor regarding ways to safely increase the blood pressure. As eye doctors, we are not specialists in monitoring and regulating blood pressure. Your primary care doctor will work with your eye doctor to monitor your blood pressure to ensure that you do not end up getting hypertension (high blood pressure) as this can be detrimental to your health. Eating more salt may be helpful, but your doctor may ask that you keep track of your salt intake and blood pressure to determine how your body responds. In addition, even though your eye pressure is normal, you may want to also try using intraocular pressure lowering drops. In normal tension glaucoma patients, lowering the eye pressure can also prevent progression of glaucoma.

In glaucoma, it is optic nerve damage that can lead to vision loss and possibly blindness. In many people, fluid pressure increases inside the eye and damages the optic nerve (the bundle of nerve fibers that carries information from the eye to the brain). Elevated eye pressure increases the risk of developing glaucoma; however, the disease can occur in people with normal or even lower than normal eye pressure. In addition, individuals with higher than normal eye pressure do not always develop the symptoms of glaucoma. Since normal-tension glaucoma does not involve high eye pressure, it is diagnosed by observing the optic nerve for any signs of damage. The eye doctor will use an ophthalmoscope to look through the pupil at the shape and color of the optic nerve. In addition, a visual field test can help determine if there is any loss of peripheral vision.

The risk factors for developing normal-tension glaucoma include a family history of glaucoma, low eye pressure, and cardiovascular disease. Ongoing research is aimed at determining all of the factors that contribute to the optic nerve damage. For example, scientists believe the optic nerve may be affected by blood flow in the eye. They are also investigating susceptibility and genetic factors.

There are very few precautions that will cause you to change your activities of daily living after glaucoma laser surgery. Your eye doctor should discuss the risks, benefits, and alternatives of any procedure before you agree to have any procedure performed in the office or in the operating room. For any glaucoma laser surgery, you will have a few drops of medication put into your eye prior to the procedure to help with your comfort level during the procedure. In addition, a few drops may be put in after the procedure to decrease the amount of inflammation that is created during the laser procedure. After the procedure has been completed, you will likely be asked to wait approximately 20-30 minutes to have the intraocular pressure checked again.

There is a small risk that the laser procedure can cause an increase in the eye pressure. This can often be reversed in the office with a couple of additional pressure lowering drops and in most people it does not last long. It is very common to have a slight headache after the laser procedure, so you may not feel like doing much that evening. Other than that, there are no real restrictions to your activities. There is often a small amount of inflammation that occurs in the eye after the procedure, so you will likely be given an anti-inflammatory eye drop for approximately 1 week. I often see my patients back one week after the procedure to make sure that the eye is no longer inflamed and the patient is comfortable. We would not expect the pressure to be reduced at one week because the full effect of the laser is often not complete until at least 4-6 weeks after the laser procedure. You will likely be seen again 1-2 months after the laser procedure to see if your eye pressure is reduced to the target that was set by your eye doctor.

Thank you for this excellent question. The simplest answer I can give you is ABSOLUTELY. The intraocular pressure fluctuates throughout the day even in patients without glaucoma. This is called a diurnal rhythm or circadian rhythm. We do not yet know the exact mechanism that controls this diurnal fluctuation, but some people are studying it to determine why this occurs. In most people, but not all, intraocular pressure is highest in the morning. The peak is often shortly after someone wakes up.

We also know that even in patients without glaucoma the intraocular pressure can vary approximately 4 to 6 millimeters of mercury (mmHg) throughout the day. In patients with glaucoma or glaucoma suspects, this amount of variation can increase (similar to what you are describing). In these cases, it is not uncommon to see variations over 6 mmHg throughout the day and the highest pressure may occur at a time other than the morning. If we believe someone may have glaucoma, but has always had normal pressure readings in the office, we will look to see what time they have had appointments. Often we will schedule them for a day long appointment and get a "diurnal pressure reading." This means that the patient will come in as early in the morning as possible to have the intraocular pressure checked. They will then stay in the office or return to the office every hour or two throughout the day to have the pressure checked to determine how much the intraocular pressure is fluctuating and how high it gets. It sounds as though your eye doctor may have suspected this, and that is why you have had appointments scheduled in both the morning and afternoon.

That is an excellent question, thank you for submitting it. Glaucoma itself is not usually a cause of dry eyes; however some of the drops that doctors use can be irritating to the eyes. In particular, one of the medications in Cosopt, the carbonic anhydrase inhibitor, often causes a stinging sensation when it is put in. In addition, some patients will notice some redness after using prostaglandin analogs like Xalatan. While these may cause some minor irritation, they do not necessarily cause dryness. Alternatively, if the bleb from the trabeculectomy is large and hangs over the cornea, it may cause an uneven tear film distribution over the cornea when you blink. I suggest that you have your eye doctor check to make sure that the shape of the bleb is not causing any problems with the tear film distribution. Finally, your doctor should be able to do a Schirmer's test to determine if you have a baseline deficiency of tears being produced or if there are other problems. If the artificial tears and the Restasis are not helping, your doctor may suggest that you use an ointment at bedtime to help hydrate the eye throughout the night, and this may improve your symptoms during the day.

The second part of your question is a bit difficult to answer in light of your dry eyes. The dryness of the eyes can cause extreme blurring of your vision by itself. Secondly, the trabeculectomy can cause some changes in your vision and even the refraction depending on how the surgery was performed. Over time, the sutures will often relax and you will return to a stable refraction and can get new glasses if needed. Finally, your doctor should be following your visual fields to make sure that your glaucoma is not progressing and causing a change in your vision (although this is less likely if your pressures are stable between 6-8 millimeters of mercury).

Thank you for the question. According to all of the sources currently available, your eye doctor is correct. It is not likely that this medication is going to make your glaucoma worse, and it is not contraindicated in patients with documented open-angle glaucoma. Imipramine is a tricyclic antidepressant. The insert states that the medication should not be used in patients with glaucoma; however, studies have not shown a contraindiaction to using this medication in patients with open-angle glaucoma. All of the literature and studies show that imipramine is associated with angle-closure glaucoma and therefore should not be used by individuals that have narrow angles or episodes of angle closure. It is important that you make sure that your eye doctor has completed a gonioscopy to ensure that the drainage angle is open, and then I would feel comfortable recommending that you can continue using imipramine.

Thank you for submitting your question. Unfortunately the symptoms that you are noticing are very non-specific and are not predictive of having or not having glaucoma. In fact, a lot of patients that do end up having glaucoma have never noticed any symptoms and it is simply recognized on a regular ophthalmic examination. In your case, a difference in the size of your two eyes can be an indication of glaucoma because when infants or young children have glaucoma it can cause the eyes to become enlarged.

You can think of this as being similar to a balloon. When we increase the pressure inside of a balloon it will become larger. Your doctor has done the right thing by doing a baseline examination and then plan on re-examining your eyes after a short interval. Your eye doctor will follow the intraocular pressure, vision, visual fields and the appearance of the optic nerves to see if there are any changes. If your eye doctor sees any progression, they will discuss your treatment options. Your case is not typical, so if you have any concerns, I would not hesitate to request a second opinion from an ophthalmologist that has completed a glaucoma fellowship.

Thank you for the question. Travatan Z is a type of medication called a prostaglandin analog. It lowers the intraocular pressure by increasing the outflow of aqueous humor (fluid) from inside the eye back to the body. There is no evidence that this medication has any effect on blood sugar levels. In addition, there have been no studies indicating that prostaglandin analogs are contraindicated in patients with diabetes or elevated blood sugars.