Ask an Expert about 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.

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.

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.

Glaucoma is actually a group of eye diseases that lead to damage of the optic nerve (the bundle of nerve fibers that carries information from the eye to the brain), which can then lead to vision loss and possibly blindness. Optic nerve damage usually occurs in the presence of high eye (intraocular) pressure; however, it can occur with normal or even less than normal eye pressure. Glaucoma is estimated to affect approximately three million Americans, but up to half of these individuals may be unaware that they have the disease. Worldwide, an estimated 66.8 million people are visually impaired due to glaucoma, and an estimated 6.7 million are blind.

Thank you for your question. Glaucoma is classically defined as a stereotypical pattern of damage to the optic nerve and certain layers of the retina. In addition, in patients with glaucoma, there are also corresponding visual field defects that are consistent with the damage to the optic nerve. Often patients may have an eye exam and all of the classic findings associated with glaucoma may not be present, but something on the exam may cause the eye doctor to become concerned that there are signs that the eye could develop glaucoma in the future. This may be a family history of glaucoma, an early defect in the visual field, something curious that they see on the optic nerve during the exam, or other findings. If this is the case, the doctor may tell you that you are a “glaucoma suspect” or that you have “pre-glaucoma.” This means that they do not yet believe you have glaucoma, but that you should be watched closely for the development of glaucoma in the future. Our goal as eye doctors is to identify glaucoma before you, as a patient, ever notice any changes. Your eye doctor will likely follow the intraocular pressure, vision, visual fields, OCT, and the appearance of the optic nerves to see if there is any evidence of glaucoma that presents in the future.

As for preventing you from progressing to glaucoma, that is a more difficult question to answer. In a patient that will eventually go from being a glaucoma suspect to having clinically diagnosed glaucoma, it is possible, but not absolutely proven, that lowering the intraocular pressure may slow that progression. This can be achieved by starting a pressure lowering drop in a patient labeled as a “glaucoma suspect.” However, there are some patients that may remain glaucoma suspects for their entire life and never progress to clinically defined glaucoma. Knowing which patients will progress and which patients will not progress is impossible. The problem is that some of our glaucoma drops have side effects, and starting drops without clinically defined glaucoma puts a patient at risk for experiencing those side effects when it may not be necessary. You would need to discuss the risks, benefits and alternatives of choosing this course with your doctor and then determine whether or not you are willing to risk the side effects of the medicine even though you may not need them.

Thank you for your question. The answer to both questions is absolutely. First, most drugs that we use have a relatively short half life, meaning that they only work for a short amount of time (usually several hours to one day). This is the reason that you have to put drops like Travatan in each day, and the reason we have to put drops like timolol and brimonidine in multiple times during the day. If you skip using the drop one night, your pressure absolutely can, and likely will, be increased the next day. The second part of your question relates to the long-term effectiveness of drops. In many of our patients, a drop will continue to work for their entire life; however, we also have many patients that have used a drop for years and have done well, but suddenly the eye drop no longer maintains their intraocular pressure at our target. The exact reason for this is not always clear, and people are doing research to look into this. Glaucoma is a progressive disease, and it may just be that the resistance to the flow of aqueous through the trabecular meshwork continues to get worse over time. It is possible that one drop may be adequate initially, but as the glaucoma progresses, it eventually becomes insufficient. It is also possible that the body may begin to respond less well to the same medication over time. More research needs to be done to find the exact mechanism, but the simple answer to your question is that it is not unusual for an eye drop that has worked for some time in a patient to become insufficient at maintaining our goal intraocular pressure later in life.

Thank you for your question. Without having examined your mother or having seen the results of her previous exam tests, it is nearly impossible for me to predict what course her disease or vision will take. To my knowledge, there are no approved intraocular injections for the treatment of open-angle glaucoma. Occasionally, we will inject medications around the eye after a trabeculectomy to help the trabeculectomy function, but the injection does not go into the eye. The medications that we typically inject into the eye are anti-VEGF agents (Lucentis or Avastin, for example) for the treatment of neovascularization, which may be caused from diabetes, macular degeneration, or after a vessel occlusion in the eye. The second medication that can be injected into the eye is steroid, and this is to treat inflammation. With pressures of 40-50 I would suggest asking her doctor if she has neovascular glaucoma. If this is the case, my question would then be why is the neovascularization present? For example, does your mother have diabetes or has there been a vascular occlusion of the eye. Without knowing more and examining her myself, I could not give you an accurate recommendation. What I can tell you is that if your mother has advanced glaucoma that has progressed to the stage that she is only seeing some light and images with difficulty, a pressure of 30 is still too high and at that pressure, she will likely continue to lose vision. Unfortunately, if the vision loss is caused by glaucoma it is most likely permanent. I suggest you speak with your eye doctor to understand why the course of treatment has been taken and what the goal pressure is for your mother. You can also ask for a second opinion from an ophthalmologist that has completed a glaucoma fellowship and is comfortable treating advanced complicated problems.

The second part of the question is again difficult to answer without having actually seen the “blood mark” myself. It is very possible that this is simply a subconjunctival hemorrhage. The eye is similar to a baseball wrapped in plastic wrap. The leather of the baseball is similar to the sclera. The plastic wrap is similar to the conjunctiva. A subconjunctival hemorrhage is simply a small blood vessel that has broken between the conjunctiva and the sclera that has allowed the blood to collect. It is almost always completely benign and will likely resolve over several weeks (longer if your mother takes blood thinners). To be safe, I suggest you have the spot examined by an eye doctor for confirmation.

Thank you for your question. Let’s take the last part of your question and answer it first. Cat Scratch Disease is caused by getting scratched by a cat and that scratch then allows the penetration of bacteria known as Bartonella henselae into the body. This infection can involve the eyes and result in what we call neuroretinitis. This is a swelling and inflammation of the optic nerve and the retina. However, this swelling is different from the enlarged optic nerve cup that is a sign of glaucoma. An eye doctor should not be confused by the appearance of these two very different presentations, so I would say that this is not likely related to your kittens.

As for the asymmetric cupping between the right and left eyes, this is another matter. I think you should be followed closely by a glaucoma specialist to watch for the development of glaucoma. It sounds as though your doctors have done a good job by completing a visual field exam, taking the intraocular pressure, and looking at the optic nerves. I would suggest making sure that you have baseline stereo optic nerve photos completed as well. It may be possible that the enlarged cupping may be related to the previous retinal detachment. In the area of the detachment, there may be some old scaring and thinning of the retina. Because one of the layers of the retina, the retinal nerve fiber layer, comes together to create the optic nerve and optic cup, a thinning of the retina related to your old retinal detachment may be the cause of the enlarged cupping. If this is the case, it will likely remain stable. However, in some patients, previous eye surgery can put you at a slightly increased risk of developing glaucoma in the future, so I think that you should be watched closely. Your eye doctor should continue to monitor your visual fields and intraocular pressure, and continue to do dilated exams to look for changes in your optic nerve.