Glaucoma Educational

At MarinEyes, our ophthalmologists have literally decades of experience diagnosing and treating glaucoma. We select from the most current proven equipment and methods. While the vast majority of our glaucoma patients do well with medical therapy alone, we have performed hundreds of glaucoma laser surgeries and incisional glaucoma surgeries as well. For those needing surgery, Marin Ophthalmic Surgery Center (across the hall from our medical suites) houses specialized lasers and a microsurgery suite where the doctors operate. The staff of the surgery center specializes in eye surgery. What is Glaucoma? Glaucoma is a progressive wasting away of the optic nerve, usually associated with higher than normal eye pressure but not always. The condition responds by stabilizing or progressing very slowly in most patients who receive treatment. Even patients with "normal" eye pressure can develop glaucoma. The most common type "chronic open angle," develops when pressure within the eye reaches a level too high for the health of the optic nerve. Over time, the optic nerve wastes away and may eventually cause blindness. The optic nerve is similar to a TV cable carrying images from the eye to the brain. High pressure presses on and damages the nerve fiber layer and blood vessels in the optic nerve. As the nerve wastes away vision is lost imperceptibly at first then more rapidly as time goes by. The other category, narrow angle glaucoma, may start suddenly or gradually and causes the same kind of vision damage. Usually the pressures go very high.

Healthy optic nerve above	Normal Visual Field


Damaged optic nerve above	Moderate Visual Field loss, no symptoms	More Advanced vision loss with symptoms beginning
Glaucoma can be separated into two broad categories, Open Angle and Angle Closure (narrow angle) Glaucoma. Open Angle Glaucoma, the more common condition, occurs when normal internal drain (trabecular meshwork) in the eye is impaired and pressure builds up. Open Angle Glaucoma usually develops slowly and usually has no symptoms until a substantial part of the vision has been permanently damaged. In Angle Closure or Narrow Angle Glaucoma, the iris physically obstructs the internal drain of the eye. The iris floats over the drainage area and clogs it. This type of glaucoma usually develops suddenly. Emergency treatment is required for this acute and often painful condition. Many cases are prevented when the narrow angle is detected during a "routine" eye exam, before there actually are symptoms. Laser treatment at this time prevents most cases of a glaucoma attack.
	[TOP]
How is Glaucoma Diagnosed? Routine Eye Examinations! Most cases of glaucoma are unsuspected! They are usually detected in the course of an eye examination for done for some other reason, such as "routine" exams, cataract evaluations, or even follow-up of a patient with macular degeneration (an unrelated condition). It is a fortunate discovery, because the worst cases of glaucoma are those that go undetected and untreated. This is one of the reasons we recommend a schedule of periodic eye exams even for individuals with presumably "healthy eyes." Glaucoma Testing There is no single test for glaucoma. The diagnosis is made by evaluating the patient from a number of perspectives, using specialized instruments. We use these instruments at MarinEyes: Tonometry measures eye pressure. At Marin Eyes, we use applanation tonometry, because it is the most accurate method available. Applanation tonometry is quick and painless. Pachymetry measures the corneal thickness ultrasound (sonar). Thin corneas may predispose a patient to glaucoma, whereas thick corneas may occasionally be considered somewhat protective. Here are other tools we use:
Gonioscopy This is what your physician sees when he performs gonioscopy. He is looking to see how much dark pigment is clogging the drainage meshwork, and whether the iris is floating up close enough to cause angle closure glaucoma. A special viewing lens is used and a drop of anesthetic makes the eye numb.
The cross-section at right shows a wide-open angle, where the iris is far away from the corneal dome.
Dilated Optic Nerve examination While special testing is extremely useful, it has not replaced a careful examination and assessment by your ophthalmologist. This is what he might see, a damaged optic nerve. This patient probably has NO SYMPTOMS!
Visual field tests The visual field gray-scale printout (right) corresponds to this kind of optic nerve damage. *Visual field tests* assess your peripheral vision. Early damage from glaucoma can often be detected by this test. At Marin Eyes, we uses the latest computerized technology to assess peripheral vision. Currently we are using the Humphrey SITA 24-2 test. Both eyes are tested in 10 to 20 minutes and the visual field examination is usually repeated annually to monitor for progression of glaucoma damage. Once we have several reliable studies on a given patient, the glaucoma progression analysis ("GPA") software analyzes your visual field tests to determine whether your disease is stable, possibly worsening or getting worse. This provides a very useful "second opinion" for your doctor in making this assessment.
Nerve fiber analysis Nerve fiber analysis A scanning low-energy light measures the optic nerve and the thickness of the nerve fiber layer (the nerve that carries the vision message from the eye to the brain). This is the nerve that is damaged in glaucoma. This testing is performed by our state of the art "OCT", a scanning instrument with computerized image processing and analysis. The test is usually repeated annually.

How is Glaucoma treated? Open Angle Glaucoma Medical Therapy controls most cases. Laser Therapy may be added relatively early, or later, depending on response to medical treatment. Surgery is usually reserved for particularly resistant cases.
Open Angle Glaucoma is usually first treated with eye drops. If eye drops are insufficient to achieve satisfactory control, laser therapy (trabeculoplasty) may be added. For patients requiring additional intervention, glaucoma surgery may be performed. Most patients these days are treated successfully with eye drops. Surgery is done less frequently than in the past. Blindness is VERY infrequent in an experienced glaucoma practice such as MarinEyes.

Angle Closure (narrow angle) Glaucoma Typical Sequence of Treatment: Laser Therapy is nearly always effective. Medical Therapy may be necessary after laser treatment. Surgery is relatively infrequent.
Fluid pressure builds behind the iris, causing it to billow forward and eventually, often suddenly, flop up against the drainage ("trabecular") meshwork. When this happens, the pressure rises quickly. Pain, haloes around lights, even nausea often result.
Angle Closure (narrow angle glaucoma) may be quickly and simply relieved, or even prevented, by making a small opening (iridotomy) in the iris to relieve the blockage of fluid behind the iris. This is best done before an attack when the risk is diagnosed (often during a routine eye examination). The procedure is performed painlessly with use of a laser. We treat our patients on our premises, in the Marin Ophthalmic Surgery Center.
Some patients will still have "open angle" glaucoma after the attack is relieved. Some others will have developed permanent scar tissue from the angle closure and they, too, may need medication (or in some cases surgery) to manage that problem. medicines and surgery are sometimes added to satisfactorily control intraocular pressure and preserve vision.

[TOP] Laser Surgery for Glaucoma Laser surgery Eye drops are administered prior to your laser treatment. The laser treatment is performed in the laser room at Marin Ophthalmic Surgery Center. For the treatment you sit in front of a microscope like the ones we use in the clinic for examination except that the laser is connected to the microscope. The procedure takes 5 to 15 minutes. Post-laser eye drop instructions and a follow-up pressure test scheduled for 2 hours later. Occasionally there is a high pressure that needs additional treatment.

Laser for Open Angle Glaucoma	Laser for Narrow Angle Glaucoma
After laser surgery: There are no limitations on activity. You can resume full activity. Eye drops are prescribed. Little if any discomfort is expected. Minor ache responds well to Tylenol. IF THE EYE HURTS, call the office (415) 454 - 5565. A post-operative examination is scheduled one to four weeks after your laser treatment. [TOP]
Incisional Glaucoma Surgery Incisional glaucoma surgery Your eye is prepared for surgery by surgical nurses. This takes 30-45 minutes. Our anesthesiologist will give you relaxing medicine, and your surgeon will anesthetize the eye. After the eye is anesthetized, it is cleansed with antiseptic and draped for surgery using sterile technique. This is microscopic surgery. It takes 30-60 minutes, depending on the complexity of the situation. After surgery, you will rest in the recovery area for approximately 30 minutes. Plan on spending a total of about 2.5 hours at the surgery center. After surgery, a friend or relative must drive and escort you to your home where you should relax quietly for the rest of the day. Most patients feel well but tired. You'll probably sleep very well that night.

Surgery to create new drainage area (hides under upper eyelid)	"Bleb," new drainage area, after surgery
After glaucoma surgery You will wear an eye patch overnight. A list of postoperative instructions will be given to you and reviewed with you before you leave the surgery center. Most patients experience little or no pain afterward, although some have low to moderate discomfort. You will come in for a postoperative exam the day after surgery. Expect your vision to be blurry at first. Best vision and intraocular pressure control take up to 2 months after surgery. A follow-up visit is scheduled and postoperative instructions reviewed. Eye drops are typically used on a tapering schedule for 8 weeks postoperatively. Permitted activities levels are reviewed with you at your first postoperative visit. Your initial restrictions will be at least as cautious as after cataract surgery. The limitations will be maintained for a longer period. [TOP]
Effectiveness of Glaucoma Surgery The success rate for glaucoma surgery varies with the nature and stage of your glaucoma. In best cases, the success rate for intraocular pressure control approaches 90%, but many cases eye drops will still be needed. Laser Trabeculoplasty for Open Angle Glaucoma Controls Pressure in about 75% of Patients. The success rate in terms of intraocular pressure control approaches 75% at one year and 50% at five years following laser treatment in the best cases. This is usually considered a temporary treatment about equivalent to the effectiveness of a single eye drop medication. Laser Iridotomy for Angle Closure Glaucoma 95% Cure. Laser iridectomy cures Angle Closure Glaucoma in 95% of patients. Further treatment depends on whether permanent closure has already developed, and upon the possible co-existence of a component of "open angle" glaucoma that will need to be treated with eye drops. Risks and Possible Side Effects of Glaucoma Surgery As with all types of surgery, complications are possible. Every effort is made to minimize risk, but serious or long-term complications including failure to achieve results, continued need for medication, permanent loss of vision and need for further surgery can occur. Discuss this with your surgeon before consenting to surgery. [TOP]