What is Glaucoma?
Many people have heard of glaucoma, but few know how common it is or the damage it can cause. At SightMD, we believe knowledge is the first step to preventing glaucoma-related vision loss. What should you know about one of the leading causes of blindness in the world?
Glaucoma refers to a group of related conditions that cause damage to the optic nerve. If that damage becomes severe enough, it can have a significant impact on vision, and in some cases, cause irreversible blindness. While glaucoma is typically associated with high intraocular pressure (IOP) or the pressure of the eye, many patients can develop glaucoma with normal IOP. According to the National Eye Institute, about 3 million Americans suffer from glaucoma. The condition is a leading cause of blindness in older adults.
Types of Glaucoma
Glaucoma is divided into two broad categories: open-angle and closed-angle. Primary open angle glaucoma (POAG) is the most common form, and the damage tends to occur over several years. This is caused by the slow clogging of the drainage canals, resulting in increased eye pressure. There are many other forms of secondary open angle glaucoma, typically associated with other conditions of the eye, such as inflammation, pseudoexfoliation syndrome, pigment dispersion and trauma.
Angle-closure glaucoma can develop suddenly or over a period of time. In acute angle closure glaucoma, eye pressure increases rapidly due to the sudden blockage of the internal drain of the eye. This is an emergency, requiring immediate attention. Chronic angle closure glaucoma, on the other hand, develops more gradually, similar to primary open angle glaucoma. In this form, the drain slowly becomes blocked, resulting in gradual elevation of eye pressure over time.
Symptoms of Glaucoma
POAG does not cause any significant symptoms. Many people do not realize they have glaucoma until they start noticing vision loss at a later stage. At that point, any vision loss cannot be recovered. Therefore, we encourage routine eye examinations. Yearly glaucoma tests can help prevent glaucoma-related vision loss.
Closed-angle glaucoma is different. Because of the sudden increase in IOP, closed-angle glaucoma can cause significant symptoms as described below. Closed-angle glaucoma is considered a medical emergency. If you experience any of the following symptoms, be sure to contact emergency services:
- Severe eye pain
- Blurry vision
- Profuse tearing
During a comprehensive eye exam, your doctor will use several methods to detect glaucoma. A visual acuity test can screen for any changes in your central vision. Applanation tonometry is often used to measure eye pressure. After numbing the surface of your eye with an eyedrop, a small blue light probe will press against your cornea, and the resistance of the cornea will indicate your IOP. Gonioscopy is a painless test where the angle of the eye can directly be examined, determining whether the angle is open, narrow, or closed. For patients who may be at risk, a number of diagnostic tests may be performed. Visual Field testing is used to determine if there is any loss of peripheral vision. Several different tests can be used to evaluate the health of the optic nerves. Ultrasound testing can help quantify if one is at higher risk for angle closure. Early diagnosis and intervention are the best way to ensure the success of your treatment.
What causes Glaucoma?
In a healthy, functioning eye, the drainage system called, the trabecular meshwork, drains a fluid called aqueous humor from inside the anterior chamber of the eye, allowing eye pressure to remain normal. Glaucoma develops when the trabecular meshwork does not drain properly, resulting in an increase in pressure inside the eye. Although ocular hypertension does not necessarily cause optic nerve damage and vision loss, it is a risk factor for glaucoma and should be monitored closely.
Glaucoma Risk Factors
Glaucoma can happen to anyone, but there are some risk factors that can make glaucoma more likely to occur. Common glaucoma risk factors include:
- Age: Older people are more likely to develop glaucoma. However, it is still possible for young people to get glaucoma, and it can even be present at birth.
- Ocular Hypertension: Ocular hypertension (high eye pressure) is a common cause of glaucoma and should be monitored closely.
- African American Ethnicity: People of African American descent are more likely to develop glaucoma. In fact, they are at an increased risk after age 40. The risk of developing glaucoma increases slightly with each year of age.
- Latino Ethnicity: The incidence of glaucoma in Latinos is estimated to be to be approximately five time higher
- Diabetes: Diabetic patients are more susceptible to developing glaucoma, especially those with uncontrolled blood sugar levels.
- Family history: Having a family history of glaucoma increases the risk of developing glaucoma. If your family has a history of glaucoma, you should come in for yearly eye exams.
- Chronic steroid medication use: Some patients who suffer from asthma, COPD, certain skin disorders and have had organ transplants are frequently required to use steroid medications to keep these conditions controlled. The chronic use of steroids can frequently lead to glaucoma due to elevation of IOP. Steroid medication can be in the form of inhalers, sprays, creams, injections, and/or pills.
- Normal Pressure Glaucoma, which presents with IOP that is not elevated, is often associated with low blood pressure, dizziness, migraines, Raynaud’s phenomenon, and sleep apnea.
Treatment for Glaucoma
The goal of glaucoma treatment is to lower and stabilize IOP to prevent vision loss. Regardless of the treatment needed, catching glaucoma early is the best way to prevent glaucoma-related vision loss. Glaucoma treatment is recommended based on the type of glaucoma the patient is experiencing, and its severity. Common glaucoma treatment methods include:
- Eye drops: Medicated eye drops are commonly used to keep eye pressure stable. Eye drops are typically used on patients with all types of glaucoma. Once started, eye drops are typically lifelong.
- Oral medications: Oral medication is another method of lowering and stabilizing IOP; however, these medications are typically associated with significant side effects, limiting their usefulness as a long-term treatment.
- Durysta: Durysta is a new, injectable form of bimatoprost, one of the most effective glaucoma medications available. It is implanted into the anterior chamber of the eye during a simple office procedure, is painless and quite effective. It is ideal for those patients who do not adhere to eye drop medications. Durysta will help to reduce and maintain healthy pressure levels in the eye and will slowly release for a minimum of 4 months.
Types of Surgery for Glaucoma
Due to ongoing research in the field of glaucoma, there are more surgical options than ever. The decision as to which procedure is appropriate for a particular patient is based on the severity of the condition, the current level of the IOP and the number of medications required to treat the disease. Glaucoma procedures are often combined with cataract surgery, affording the patient the opportunity to have both conditions treated at once.
- Trabeculectomy: This procedure involves using the patient’s own eye tissues to create a new filter or drainage system by removing part of the eye’s drainage system., creating a fistula where aqueous humor can drain to a space outside the wall of the eye.
- Tube shunt: Tube-shunt surgery involves inserting a new artificial drainage system by placing a plastic tube with an attached silicone drainage pouch in the eye to help drain fluid. Typically, doctors will suggest this procedure after a trabeculectomy fails or in certain types of glaucoma where the likelihood of a trabeculectomy success is limited.
- MIGs: MIGS has become a commonly used abbreviation in the glaucoma world. It stands for Minimally Invasive Glaucoma Surgery. These procedures are an ideal adjunct for those patients with glaucoma who require cataract surgery. The MIGS group of operations are divided into several categories:
- Trabecular meshwork stenting (Istent or Hydrus microstents)
- Hydrus: The Hydrus Microstent is an implantable, flexible, metal (nitinol) tube with windows preloaded onto a hand-held delivery system
- Trabecular meshwork augmentation operations (Goniotomy, Trabeculotomy, Canaloplasty)
- Canaloplasty: Canaloplasty utilizes a microcatheter or tube placed in the Canal of Schlemm to enlarge the drainage canal, relieving pressure inside the eye.
- Micro shunting procedures (Xen stent, Express shunt)
- Milder, gentler versions of laser photocoagulation (Micropulse cyclophotocoagulation)
- Laser trabeculoplasty: Laser trabeculoplasty is a frequently used, and effective treatment for open angle glaucoma. During this procedure, gentle laser energy is applied to the trabecular meshwork, or drain of the eye. The laser energy stimulates a reaction that allows better fluid flow through the drain. This type of laser is not intended to alter your vision in any manner.
- Laser Iridotomy and Iridectomy: This laser is used to treat patients with angle closure glaucoma or those whose angles are narrowed to the point where angle closure glaucoma becomes a significant risk. With laser iridotomy, a small opening is made in the iris, the colored part of your eye, which allows escape of aqueous humor (eye fluid) through the opening. It is the fluid, trapped behind the iris, that pushes the iris forward, closing the drain. Laser iridotomy frequently corrects this condition. This type of laser is not intended to alter your vision in any manner.
It is not uncommon for your doctor to devise a treatment plan that includes more than one treatment method. You may receive surgery as your primary treatment method, and then use eye drops or medications to supplement the results.
Vision loss resulting from glaucoma cannot be reversed, but treatment can slow the effects of the disease and help protect your remaining eyesight. The results of your treatment will depend on how early intervention was initiated, as well as the progression of the disease. Our goal is to protect and preserve your eyesight and choosing an experienced eye doctor is the most important decision you can make to ensure the success of your treatment.
Cost of Glaucoma Surgery
Total treatment cost varies from patient to patient. The cost of your glaucoma surgery will depend on a variety of factors, including which surgical method your doctor recommends, the type of anesthesia used, and any medications you receive before or after your procedure. Your doctor will discuss the cost of your procedure in detail during a consultation. Typically, most glaucoma procedures are covered under insurance.
Contact SightMD to schedule a comprehensive eye examination with one of our experienced doctors.