Glaucoma is a group of disorders in which the main risk factor is high fluid pressure within the eye. All glaucoma disorders are characterized by vision loss, caused by damage to the optic nerve. The optic nerve provides the pathway from the eyeball to the brain. If a doctor discovers it early and the patient follows directions carefully, the damaging effects of glaucoma can be addressed.
In a normally functioning eye, fluid is being formed and drained constantly. However, when an eye’s drainage canals do not work well, the fluid cannot get out. The extra fluid raises the pressure inside the eye. The increased pressure can destroy sensitive nerve fibers on the back wall of the eye. Each time a nerve fiber is lost, the eye loses some ability to see. Usually, the glaucoma patient loses peripheral (side) vision first; eventually central vision can be lost. When vision is lost from glaucoma, it is irreversible and cannot be restored.
If you have glaucoma, your doctor can keep the pressure within your eye to a normal level with careful treatment. It is important to have your eye doctor check your pressure regularly so that he or she can prescribe proper treatment. This way, you can prevent further loss of vision.
Although, glaucoma is far more common in older individuals, it can strike at any age and can even affect babies. It is a disease that is present worldwide and remains a leading cause of blindness.
In most instances, the cause of glaucoma is unknown. Although, the genetic inheritance of glaucoma is still unclear, a family history of glaucoma increases one’s risk for developing this condition. Patients who have a history of eye trauma or chronic steroid use are also at risk for developing glaucoma. Currently, there are multiple researchers actively trying to find the cause of visual loss in glaucoma.
Diagnosis and Evaluation
When physicians diagnose and monitor glaucoma disorders, they are primarily focused on the fluid pressure in the eye, the reasons for the increased pressure, and the extent of vision loss as the disease progresses.
Forms of Glaucoma
- Inherited forms of the disease: Rarely evident in the first two decades of life, a form of inherited glaucoma known as Primary Open-Angle Glaucoma (POAG) is the most common form of the disease, affecting 7 to 8 million Americans.
- Congenital glaucoma
- Pigmentary glaucoma
- Neovascular glaucoma
- Pseudoexfoliation syndrome
- Anterior segment dysgenesis syndromes
- Low or normal tension glaucoma
Clinical Evaluation During your Visit
Your visit to the Mass. Eye and Ear Glaucoma Service will include a very specialized exam as well as specific diagnostic tests, which aid the physician in providing a comprehensive evaluation of your condition and in answering any questions you may have. The initial evaluation will cover your medical history, ocular history and family history. Examinations and diagnostic tests can include slit-lamp biomicroscopy, gonioscopy, optic nerve head imaging, tonometry (pressure), threshold visual field (also known as perimetry.
As a result, please be prepared to be here for two to three hours on your first appointment. Almost every new patient will have his or her pupils dilated in order to do a complete ophthalmic evaluation. Dilation takes 30 to 45 minutes, but the effects can last an average of four to six hours. In some cases, effects persist up to 24 hours. Blurry vision is usually a side effect, and it is strongly suggested that patients have someone drive them home from their appointment.
The primary goal of glaucoma treatment is to prevent further loss of vision because any pre-existing vision loss is irreversible. Glaucoma treatment may be recommended in the form of medical therapy, laser surgical therapy or incisional surgical therapy. The appropriate treatment for each patient is different and depends on many factors, such as the overall health of the patient, the severity of the glaucoma, the age of the patient and the specific type of glaucoma. Although, glaucoma cannot be cured, treatment is aimed at slowing or stopping the progression of visual loss. The earlier glaucoma is detected, the more successful treatment is at preserving vision.
Most treatment for glaucoma is managed with medications, with the goal of managing the disorder well enough to prevent its progression and surgical treatments. There are several kinds of medication that may be prescribed.
- Prostaglandins: These eye drops work near the drainage area of the eye to improve the fluid outflow
- Beta blockers, carbonic anydrase inhibitors and miotics: Eye drops that lower the amount of fluid produced
- Alpha adrenergics: Drugs which reduce the eye’s resistance to fluid drainage
- Combination drops, which incorporate two medications into one application
Self-Care for Glaucoma Patients
Glaucoma is a disorder that requires significant attention and self-management by the patient. In addition to the medication schedule and need for return appointments to monitor the disease, patients also need to avoid medications and supplements that can worsen glaucoma. Close attention to the warnings on over-the-counter products and open discussion with the patient’s physicians about drug interactions are necessary.
Glaucoma Surgical Procedures Available
When a patient’s glaucoma progresses beyond the ability of the medications to control, surgical intervention may be necessary.
- Glaucoma Filtration Surgery (Trabeculectomy): This is a surgical procedure that creates a new drainage site in the eye to help the eye drain fluid more readily.
- Glaucoma Tube Shunt Procedures: In this surgical procedure, a device is implanted into the eye, permitting extra fluid to drain and reduce the interior pressure of the eye.
- Laser Peripheral Iridotomy (LPI): This laser procedure is a preventive measure for patients at risk of rapid, high pressure build-up, as it opens or widens the drainage structures in the eye.
What is Laser Peripheral Iridotomy?
Laser Peripheral Iridotomy (LPI) attempts to “open” alternative pathways for fluid to drain from the eye and prevent more serious glaucoma disease. The “angle” is the part of the eye that drains fluid from the eye, and narrowing in its structures can put the eye at risk for an acute attack of angle closure glaucoma. During the LPI, a laser is used to make a small opening in the peripheral iris (the colored part of the eye). This changes the fluid dynamics in the eye and “opens” the angle. If a patient already has acute angle closure glaucoma, the small opening that is made in the peripheral iris allows fluid to drain more normally and also lowers the eye pressure.
When is LPI indicated?
Laser peripheral iridotomy is generally recommended for patients with narrow angles, narrow angle glaucoma, or acute angle closure glaucoma. When LPI is used in patients with narrow angles, it is considered to be a prophylactic procedure that prevents these patients from developing acute angle closure glaucoma, which they are at higher risk of developing. This is significant in that an acute attack of angle closure glaucoma usually presents with high eye pressures, pain, and loss of vision. When LPI is used in the treatment of patients who already have acute angle closure glaucoma, it is used to help lower the pressure as well as to prevent another attack of angle closure glaucoma.
If I am having the LPI for preventing an acute attack of angle closure glaucoma, will this lower my eye pressure or improve my vision?
No, the LPI will not improve your vision or lower your eye pressure. It will only try to prevent your eye from developing an acute attack of angle closure glaucoma.
If I am having the LPI for treatment of an acute attack of angle closure glaucoma, will this lower my eye pressure and improve my vision?
In general, the LPI will help to lower your eye pressure, which may then lead to improvement of your vision. The amount of eye pressure lowering and the degree to which your vision will improve depends on the severity and duration of your acute attack of angle closure glaucoma. Sometimes, other medications or even glaucoma filtration surgery may be needed to ultimately control the eye pressure.
What should I expect if I have a laser iridotomy?
The procedure is an outpatient procedure that can usually be done in the eye doctor’s office. You are seated at a slit-lamp with your forehead resting against a headpiece and your chin resting in a chin rest. After some numbing eye drops are put in the eye, a lens will be placed on your eye. This will prevent you from blinking and will also minimize your eye movements. The lens also helps to direct the laser light into your eye. The laser, which is attached to the slit-lamp equipment, is then directed into the eye. The procedure usually takes a few minutes.
Most people experience minimal discomfort during the procedure. After the laser, you may experience some irritation in the eye and some blurry vision, but this is largely resolved after a day or two. Usually, you will have your eye pressure checked one hour after the laser procedure. Then, you are seen the day after the laser procedure and/or the following week. The number and frequency of visits after the laser may vary and depends on the condition of your eye. Most people will need to be on an eye drop four times a day for one week to help the eye heal from the laser. The main long-term symptom that you may notice after the laser is that some patients may experience a light reflex or linear light in their vision if they are in a bright room or if the upper eyelid transiently crosses a successfully-created laser iridotomy opening.
What are some risks of laser surgery?
All laser procedures have some risks. Laser treatment is not done unless the benefits outweigh the risks. Risks include, but are not limited to, bleeding, inflammation, eye pressure elevations, and vision loss. In general, serious risks are not common, however, you may want to discuss the benefits and risks with your doctor should you have any further questions.
Glaucoma Filtration Surgery (Trabeculectomy)
What is trabeculectomy surgery?
Trabeculectomy surgery creates a new drainage site to help filter internal fluid from the eye. Instead of going through the normal drainage site of the eye (the trabecular meshwork), the fluid is drained into a new “space” that is created underneath the outer covering (the conjunctiva) of the eye. This will lower the eye’s fluid pressure.
When is trabeculectomy surgery indicated?
Trabeculectomy is generally recommended for patients with glaucoma that continues to progress despite use of medications and/or laser treatments. In some cases, trabeculectomy surgery may be recommended prior to trying medical or laser treatment. These decisions vary depending on the type of glaucoma, the stage of glaucoma, as well as other factors. Sometimes, this surgery can be combined with cataract surgery.
Why do some trabeculectomy surgeries require use of special medications that prevent scarring?
The main reason trabeculectomy surgery can fail is that the new drainage site can scar and therefore close up. Medications that prevent scarring, known as antimetabolites, can be used to increase the success rate of trabeculectomy surgery in some patients. Since, an antimetabolite can increase the complication rate of surgery, it is generally reserved for patients that may be at increased risk for trabeculectomy failure. For example, patients who have failed previous trabeculectomy surgery, patients who are younger, patients who have had previous eye surgery in general, patients with uveitis etc. The decision to use antimetabolites is determined by the surgeon. Not all patients who have trabeculectomy surgery need antimetabolites.
What should I expect if I have trabeculectomy surgery?
The procedure is done under local anesthesia in the operating room. After some eye drops are put in the eye and after the eye is numbed, your eye will be cleaned. A sterile drape is put over your face and body, leaving only your eye uncovered, to keep the operation area clean and sterile. Your eye will be held open by a “lid speculum,” so you will not blink during the surgery. Some surgeons may also give you sedating medications through an IV (intravenous) line to keep you completely comfortable. After the surgery is over, a patch and shield will be placed over your eye. This will be removed the day after surgery on your first post-operative visit. You should expect to be seen quite frequently by your surgeon until the eye completely heals. For many people, this may take up to two or three months. During this time, you will be taking frequent and multiple eye drops. You may also need removal of sutures, a laser procedure to cut some sutures, injections of supplemental medications, or other procedures to guide the healing process toward the best result. You will also be restricted from strenuous activities during the healing process. In general, postoperative care will vary from patient to patient.
Will my glaucoma be cured with trabeculectomy surgery?
No. Any vision that is already lost prior to the surgery, in general, will not return. Trabeculectomy surgery only lowers your eye pressure. By lowering the eye pressure, the goal is to either stop or slow down your vision loss. Sometimes this goal is not possible.
Can I stop my eye drops after the surgery?
You will usually need eye drops for two or three months after the surgery. Some people do not have to take eye drops after that period. It is more likely that you will eventually need some glaucoma eye drops to keep your pressure under control. In some cases, people will be taking fewer eye drops than they were before the surgery. The need for eye drops long-term varies greatly and is determined by the type of glaucoma and the rate it is progressing.
What are some risks for trabeculectomy surgery?
All eye surgery has some risks. In general, operations are only done when the benefits outweigh the risks. Risks include, but are not limited to, bleeding, infection, swelling, scarring, retinal detachment, a droopy eyelid, double vision, loss of vision or loss of the eye. Many of these risks are uncommon, however, you may want to discuss the benefits and risks with your surgeon should you have any further questions. All surgery also has the possible need for another operation.
Glaucoma Tube Shunt Procedures
What is a tube shunt drainage device?
Glaucoma tube shunts are devices that are implanted in the eye to provide an artificial alternative drainage site for fluid to exit the eye. These devices lower the eye pressure in glaucoma. Most shunt devices look somewhat like a very small computer mouse, with the body of the device being about the size of an average person’s fingernail. A tiny tube extends from the body of the device into the anterior chamber, which is the front part of the eye that usually drains fluid from the eye. The device allows excess fluid to drain out through the tube and be absorbed in surrounding tissues. Glaucoma tubes come in many different varieties.
When is a tube shunt procedure indicated?
Glaucoma tube shunt surgery may be needed in patients with glaucoma that is not controlled by medications and/or laser treatment. It may be needed either after failure of previous trabeculectomy surgery (or surgeries) or in certain types of glaucoma where traditional trabeculectomy surgery would almost certainly fail. Examples of such patients are those with neovascular glaucoma, and patients who have corneal transplants.
What is done during the tube shunt procedure?
Usually, a small incision is made near the top of eye underneath the conjunctiva, the thin outer covering of the eye. The body of the device lies over the top of the eye but underneath the outer covering of the eye. After the body of the device is sutured in place, the tube, which extends from the body of the device, is inserted into the eye’s anterior chamber. Although the device is sutured onto the top of the eye, it is completely covered by the eye’s white outer covering, the conjunctiva. Most, if not all, of the device will not be visible behind the upper eyelid after the surgery.
What should I expect if I have a tube shunt procedure?
The procedure is done under local anesthesia in the operating room. First, eye drops are used to numb the eye. Then, your eye will be cleaned and a sterile drape will be put over your face and body, leaving only your eye uncovered. This keeps the area of the operation clean and sterile. Your eye will be held open by a “lid speculum,” so you will not blink during the surgery. Some surgeons may also give your sedating medications through an IV (intravenous) line to keep you completely comfortable. After the surgery is over, a patch and shield will be placed over your eye. This will be removed the day after surgery on your first post-operative visit. You should expect to be seen frequently by your surgeon until the eye completely heals. For many people, this may take six to eight weeks. During this time, you will be taking frequent and multiple eye drops. The postoperative care varies greatly and may include suture removal and/or other minor procedures to maximize the outcome of the surgery. During this time, you will need to restrict yourself from strenuous activities.
Will my glaucoma be cured with the glaucoma tube device?
No. Any vision that is already lost prior to the surgery, in general, will not return. Tube shunt surgery only lowers your eye pressure. By lowering the eye pressure, the goal is to either stop or slow down your loss of vision. Sometimes this goal is not possible.
Can I stop my eye drops after the surgery?
You will definitely need eye drops for two or more months after the surgery. Some people do not have to take eye drops after that period. Many people will eventually need some glaucoma eye drops to keep their pressure under control. In some cases, people will be taking fewer eye drops than they were before the surgery. The need for eye drops after tube shunt surgery varies greatly and is determined by your type of glaucoma and the rate it is progressing.
What are some risks for tube shunt surgery?
All eye surgery has some risks. Operations are not done unless the benefits outweigh the risks. Risks include, but are not limited to, bleeding, infection, hypotony (very low pressure), scarring, swelling, retinal detachment, droopy eyelid, double vision, loss of vision, or even loss of the eye. Sometimes the tube fails and needs to be replaced. In general, many of the risks are not common, however you may want to discuss the benefits and risks with your surgeon should you have any further questions..
What to Expect?
We ask that patients arrive 15 minutes in advance of their scheduled appointments to assure that all the necessary information is in place.Most appointments in the Glaucoma Service require quite a bit of testing to monitor the progression of the disease and the effectiveness of on-going treatments. As a result, a thorough examination and discussion with the physician may take up to two or three hours. Your care will also involve ophthalmic assistants and physicians in residency and fellowship training, as Mass. Eye and Ear is a teaching hospital for Harvard Medical School.
Dilation of pupils will be done on almost every new patient in order to do a complete ophthalmic evaluation. Dilation takes 30 to 45 minutes, but the effects can last an average of four to six hours. In some cases, the effects persist up to 24 hours. Blurry vision is usually a side effect so it is strongly suggested that patients have someone who can drive them home from their appointment.
What to Bring?
- Insurance card and/or Medicare cards and pharmacy cards
- Copy of the authorization notice from your insurance carrier, if appropriate
- Any records or test information you have from a previous ophthalmologist that may be helpful
- Contact information of referring physician
- Prescription eye glasses (even if they are old or you wear contact lenses)
- Sunglasses (for after dilation)
- List of medications (eye medications, supplements and over the counter medicine)
- If you are diabetic, bring snacks in anticipation of a long visit