Questions & Answers

Thank you for your question. I will look at each medication individually. First, taking diltiazem is not contraindicated in patients with glaucoma. In fact, quite the opposite may be true. Currently there are studies being completed looking at a topical drop form of diltiazem to see if it may actually assist in lowering intraocular pressure for the treatment of glaucoma. Studies at this timeCurrently, studies are not conclusive, but we are continuing to do research in this area. At. I have multiple glaucoma patients that take diltiazem, and at this time, there is no evidence to suggest stopping this medication. Triamterene/Hydrochlorothiazide (HCTZ) is a combination of two different medications. The first, triamterene, is a diuretic that works in the kidneys primarily. It is what we call a potassium sparing diuretic. Again, there are no contraindications to using this medication if you have been diagnosed with glaucoma. This medication is also being studied to determine if it actually lowers intraocular pressure. The studies were not conclusive, but it is being examined further.

Finally, we should discuss hydrochlorothiazide. Of the medications that you have asked about, this medication can have adverse side effects in patients with glaucoma. HCTZ is a sulfonamide (in the same family as sulfa drugs). While it is relatively rare, sulfonamides have been known to cause attacks of angle closure in some patients. Your eye doctor has likely already done a procedure called gonioscopy to determine if you have open- angle glaucoma, narrow- angle glaucoma, or angle- closure glaucoma. This will help your eye doctor determine how much of a risk using HCTZ is for you. The risk of angle closure is very small and the majority of glaucoma patients can still use HCTZ. I have multiple patients on HCTZ and Mmost glaucoma patients that use this medication never have problems; however, a small number of patients can have further narrowing of their angle or closure of the drainage system when using this medication, so I encourage you to discuss this with your doctor further.

That is an excellent question, thank you for submitting it. Glaucoma is classically defined as a stereotypical pattern of damage to the optic nerve and certain layers of the retina. This is likely what your eye doctor has seen on your examination. Elevated intraocular pressure is a risk factor for glaucoma, but just because the pressure is elevated this does not mean you have glaucoma (similarly, people with "normal" pressures can have glaucoma). In someone with glaucoma, the damage to the optic nerve and the retina usually causes a loss of peripheral vision first and only as the glaucoma advances does central vision become affected. Because of this, very few isglaucoma patients ever notice any changes in vision until they have more advanced disease. Our goal as eye doctors is to identify glaucoma before you, as a patient, ever notice any changes. The vision changes that you describe as "looking through dirty glasses" are not typical of glaucoma. While patients with glaucoma do have some reduction in contrast sensitivity (i.e. the ability to distinguish similar shades of grey), the changes you describe sound more consistent with changes at the cornea, the development of cataracts in the natural lens of the eye, or other changes in the retina. I encourage you to discuss these symptoms with your eye doctor.

There are a lot of different types of glaucoma, and they can progress at different rates. It is difficult to predict what course your glaucoma will take. The only variable that we can change to slow or stop the progression of glaucoma is the intraocular pressure. Once a thorough eye exam has been completed, as eye doctors we often set a target or goal intraocular pressure. To achieve this goal, there are essentially three different tools that we can use to treat your glaucoma. We use eye medicated eye drops, laser treatments, and surgical methods to lower the intraocular pressure. Your doctor has started you on a prostaglandin analog eye drop and will follow the intraocular pressure, vision, visual fields, and the appearance of the optic nerves to see how your eyes respond. If the pressure is not reduced enough or your doctor ever notices advancement in your glaucoma, they will add more medications or use laser surgery or conventional surgery to help lower the intraocular pressure further. If you have questions or concerns, do not hesitate to start an open dialog with your eye doctor and ask them to explain why they have chosen the particular treatment plan that they have prescribed for you.

Individuals at high risk for glaucoma should have a dilated pupil eye examination at least every two years. Eye doctors use several tests to detect glaucoma; these tests include:

• Tonometry measures the pressure inside the eye. Examples of tonometers include: 1) The air puff or noncontact tonometer emits a puff of air. Eye pressure is measured by the eye’s resistance to the air. 2) The applanation tonometer touches the eye’s surface after the eye has been numbed, and measures the amount of pressure necessary to flatten the cornea. This is the most sensitive tonometer, but a clear, regularly-shaped cornea is needed for it to function properly. 3) The electronic indentation method measures pressure by directly contacting anesthetized eyes with a digital pen-like instrument.
  
  
• In pupil dilation, special drops temporarily enlarge the pupil so that the doctor can better view the inside of the eye.
  
  
• Visual field testing measures the entire area seen by the forward-looking eye to document straight-ahead (central) and/or side (peripheral) vision. It measures the dimmest light seen at each spot tested. Each time a flash of light is perceived, the patient responds by pressing a button.
  
  
• A visual acuity test measures sight at various distances. While seated 20 feet from an eye chart, the patient is asked to read standardized visual charts with each eye, with and without corrective lenses.
  
  
• Pachymetry uses an ultrasonic wave instrument to help determine the thickness of the cornea and better evaluate eye pressure.
  
  
• Ophthalmoscopy allows the doctor to examine the interior of the eye by looking through the pupil with a special instrument. This can help detect damage to the optic nerve caused by glaucoma.
  
  
• Gonioscopy allows the doctor to view the front part of the eye (anterior chamber) to determine if the iris is closer than normal to the back of the cornea. This test can help diagnose closed-angle glaucoma.
  
  
• Optic nerve imaging helps document optic nerve changes over time. An eye doctor may choose to use one or more of the four available scanning techniques, all of which are painless and non-invasive.

New research is focused on lowering pressure inside the eye, and finding medications to protect and preserve the optic nerve from the damage that causes vision loss. Scientists are also investigating the role of genetics in glaucoma, and over the last few years their understanding of this factor has progressed. Researchers have discovered genes associated with congenital glaucoma, juvenile glaucoma, normal-tension glaucoma, adult-onset open-angle glaucoma, pigmentary glaucoma and other conditions related to secondary glaucoma.

Treatments vary depending on the type of glaucoma:

• Open-angle glaucoma treatment normally begins with medications, usually eye drops or rarely, pills that either help eye fluid drain more effectively or cause the eye to produce less fluid. Several forms of laser surgery can also help fluid drain from the eye; these include trabeculoplasty and cyclophotocoagulation. Conventional filtration surgery (trabeculectomy, glaucoma drainage implant, peripheral iridectomy or Trabectome procedure), are sometimes used to create a new opening for fluid drainage.
  
  
• Acute closed-angle glaucoma (a medical emergency) is treated with medications, laser peripheral iridotomy or peripheral iridectomy.
  
  
• Chronic closed-angle glaucoma is treated with laser peripheral iridotomy and medications.
  
  
• Normal-tension glaucoma is currently treated in the same ways as open-angle glaucoma. When this form of the disease is better understood, treatment strategies may be modified.
  
  
• Congenital glaucoma is usually treated with medications and either goniotomy or trabeculotomy, two forms of eye surgery.
  
  
• Juvenile glaucoma is treated using medications, laser surgery and conventional filtration surgery.
  
  
• Secondary glaucoma can be open-angle or closed-angle, and acute or chronic. Treatment depends on these factors and whether the underlying condition causing increased eye pressure needs to be addressed. Treatments for secondary glaucoma include:
  
  
• Pigmentary glaucoma is treated using medications, laser surgery and filtration surgery.
  
  
• Pseudoexfoliation Syndrome is treated with medications, laser surgery and filtration surgery. Surgery may be performed earlier than in open-angle secondary glaucoma.
  
  
• Neovascular glaucoma may be managed with medications, and if abnormal blood vessel growth is occurring in the back of the eye (for example, in diabetic retinopathy), with a laser procedure called scatter panretinal photocoagulation. Treating abnormal growth of blood vessels in the retina may improve abnormal blood vessel growth blocking fluid drainage near the front of the eye. Trabeculectomy and cyclophotocoagulation (aimed at the eye-fluid producing ciliary body) may also be used to try to decrease eye pressure.
  
  
• Iridocorneal Endothelial (ICE) Syndrome is extremely rare and not well understood, and it is not known how to halt its progression. Medications are often used to help manage the glaucoma, and corneal transplants are sometimes needed to treat swelling of the cornea.

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 two main forms of glaucoma: open-angle (the most common form affecting approximately 95% of individuals) and closed-angle. There are also several other forms of glaucoma, including normal-tension, congenital, juvenile and secondary.

• Open-angle glaucoma, the most common form of the disease, is progressive and characterized by optic nerve damage. The most significant risk factor for the development and advancement of this form is high eye pressure. Initially, there are usually no symptoms, but as eye pressure gradually builds, at some point the optic nerve is impaired, and peripheral vision is lost. Without treatment, an individual can become totally blind.
  
  
• Normal-tension glaucoma occurs when eye pressure is normal, yet the optic nerve is damaged and peripheral vision is lost. Lowering eye pressure through medication sometimes slows the progress of the disease, but this type of glaucoma may worsen despite low pressure. The treatment is generally the same as for open-angle glaucoma.
  
  
• Closed-angle glaucoma may be acute or chronic. In acute closed-angle glaucoma the normal flow of eye fluid (aqueous humor) between the iris and the lens is suddenly blocked. Symptoms may include severe pain, nausea, vomiting, blurred vision and seeing a rainbow halo around lights. Acute closed-angle glaucoma is a medical emergency and must be treated immediately or blindness could result in one or two days. Chronic closed-angle glaucoma progresses more slowly and can damage the eye without symptoms, similar to open-angle glaucoma.
  
  
• Congenital glaucoma affects infants born with defects that prevent the normal drainage of fluid from the eye.
  
  
• Juvenile glaucoma is open-angle glaucoma that affects children, adolescents and young adults.
  
  
• Secondary glaucoma can be open-angle or closed-angle, and is the result of some other medical condition in the eye or the body. Examples of secondary glaucoma include:
  
  
  • Pigmentary glaucoma in which pigment granules from the iris flake off into the eye fluid (aqueous humor) and clog the eye’s drainage system (trabecular meshwork).
    
    
  • Pseudoexfoliation Syndrome occurs when white material flakes off the lens of the eye and blocks normal flow of the aqueous humor.
    
    
  • Neovascular glaucoma occurs when abnormal blood vessel growth blocks the eye’s fluid drainage channels and leads to increased eye pressure. This abnormal growth can be caused by low blood supply to the eye due to diabetes, insufficient blood flow to the head because of blocked neck arteries, or blood vessel blockage in the back of the eye.
    
    
  • Iridocorneal Endothelial Syndrome (ICE) is extremely rare, and has a number of features, including the breaking off of cells from the cornea, which blocks the drainage channels in the eye and leads to increased eye pressure. Scars may also connect the iris to the cornea.
    

When a patient has glaucoma or is at high risk for developing the disease, physicians may document changes over time in the optic nerve through imaging techniques including stereo optic nerve photographs, scanning laser polarimetry (GDx), confocal scanning laser ophthalmoscopy (Heidelberg Retinal Tomograph or HRT II) and optical coherence tomography (OCT). An eye care professional will determine which method(s) to use.