Because early detection is of utmost importance in limiting the vision loss caused by glaucoma, regular eye examinations are recommended. Certain characteristics on an eye exam are clues for glaucoma: high eye pressure, optic nerve changes, thin corneas (the front window or layer of the eye), and closed angles (access to the drainage system of the eye is not open). Gonioscopy is when a mirrored contact lens is used to look at the drainage system of the eye and distinguish between open and closed angle glaucomas. Doctors commonly use diagnostic testing to help in establishing the diagnosis of glaucoma. Not only has Dr. Rhodes completed specialized training in glaucoma, our clinic also has the most advanced equipment for early detection of this disease.
Optic Nerve Photography
Digital photos are taken of your optic nerves periodically and included in your medical record. The photos can be analyzed and compared to evaluate for changes in appearance that are characteristic of glaucoma. Learn more about our Optos retinal imaging technology.
Optical Coherence Tomography
This test, commonly referred to as OCT, measures the thickness of the nerve layer in the back part of the eye. This nerve layer is thinned when glaucoma damage occurs. Repeat testing can be performed to evaluate the thickness of this layer over time. Our ophthalmologists use a state-of-the art OCT machine, which performs the scan in the shortest amount of time and uses computer analysis to compare results to all previous exams. This technology can greatly increase the ability to detect and follow glaucoma. Our newest glaucoma test is OCT Angiography. This technology allows quantification of the density and blood flow in the microvasculature around the optic nerve.
Visual Field Testing
This test evaluates the entire visual field, both central and peripheral. Glaucoma results in typical changes to the visual field, such as peripheral loss of vision. This test has been shown to increase glaucoma detection early in the disease. Usually, this test is performed yearly in glaucoma patients. Dr. Rhodes and Dr. Dang use the most advanced visual field testing available: the equipment actually has a computer program which can evaluate every new test scientifically for changes from previous examinations.
Normal Visual Field
Glaucomatous Visual Field Changes
Anterior Segment Optical Coherence Tomography
This technology is similar to the previously mentioned OCT, but is used to image the front part of the eye. The anterior segment OCT is commonly performed in angle closure glaucoma patients to evaluate and quantify the opening between the iris and the trabecular meshwork (drainage system).
Currently, there is no cure for glaucoma. All treatments are undertaken to reduce the risk of progressing visual loss. Usually, if treatment is begun early, the disease can be controlled and vision can be saved.
Systemic health issues can also affect glaucoma. Even a regular exercise program and weight loss have been shown to decrease eye pressure! The 3 general categories of glaucoma therapy are medicines, in-office laser procedures and operating-room surgery.
Medicines are the most common first-line treatment for glaucoma. These eye drops and/or pills work by slowing the production of fluid inside the eye or by improving the flow of fluid through the drainage meshwork. There are five main groups of eye drops: prostaglandins, beta-blockers, carbonic anhydrase inhibitors, adrenergic agonists and miotics. These medications may be taken between one and four times daily. The most common side effect is that the drops can cause burning and stinging. Some drops can cause allergies, which lead to red, itchy eyes. Even though the medicines do not instantaneously make you see better, they should not be stopped without speaking to the doctor. The goal of these eye drops/pills is to decrease your eye pressure and reduce the risk of further vision loss. Our Austin area ophthalmologists will discuss with you what medications are recommended specifically for you.
There are several different types of glaucoma laser procedures. The most common are: argon laser trabeculoplasty (ALT), selective laser trabeculoplasty (SLT), micropulse laser trabeculoplasty (MLT), and cyclophotocoagulation. Each of the first three lasers are applied to the trabecular meshwork, the drainage system of the eye. They can help to increase the amount of fluid drained out of the eye, which can lead to a lower eye pressure. These procedures can be done in the office, usually take less than five minutes, and cause only temporary mild discomfort.
Of these, SLT is the most common due to its remarkable combination of ease of treatment and repeatability. After instilling a topical anesthetic eyedrop, the laser treatment is applied through a focusing contact lens. The laser is effective in about 80 percent of patients and lowers IOP by 20 to 25 percent. The effect usually lasts 5-10 years and can be repeated if necessary.
Endocyclophotocoagulation (ECP), is applied to the ciliary body in an operating-room procedure through a small corneal incision in order to decrease the production of intraocular fluid. A newer, and less invasive, operating room laser is called transscleral cyclophotocoagulation. With this procedure, the laser is actually applied to the ciliary body without an incision. The laser treatment is applied topically in less than 5 minutes and only causes mild swelling and discomfort. Our Lakeway eye doctors have access to all types of lasers and will discuss with you which type is best for your eyes.
Laser Peripheral Iridotom
This treatment is performed in patients with angle closure glaucoma. The laser is used to create a small hole in the iris (colored part of the eye). This hole acts as a channel for fluid and helps to provide access for the fluid to reach the drainage flow. The laser usually causes temporary blurred vision and mild discomfort.
Trabectome, Canaloplasty, and Stent Surgery
These are new and exciting procedures due to their increased safety over older/traditional glaucoma surgeries.
Trabectome and Goniotomy
In these procedures, the inner portion of the drainage system (which is usually the portion of the system that is not working properly in glaucoma) is removed with a microscopic instrument- either a Trabectome or a Kahook dual blade. The fluid inside the eye then has a more direct path into the drainage canals, and ultimately results in a lower eye pressure.
This procedure can be performed via a small corneal incision (ABiC or ab-interno canaloplasty) or an external incision through the sclera (white part of the eye). A small lighted catheter is inserted through the drainage system of the eye. As the catheter is removed, a gel substance is injected in order to dilate the drainage system. This dilation helps to restore the normal fluid flow out of the eye by reducing outflow resistance. Canaloplasty can be combined with cataract surgery or performed as a stand-alone procedure.
Stent Surgery currently is always combined with cataract surgery in the United States. The tiny stent is inserted into or near the trabecular meshwork in order to provide easier outflow access for the intraocular fluid. There are newer similar stents that have recently become FDA approved, and are becoming the treatment of choice for mild to moderate glaucoma because of their combination of efficacy and safety. A few examples of these stents are the Cypass (drains to the supraciliary space), the istent, and the Xen (drains to the subconjunctival space).
This type of surgery is performed in the operating room and is usually only undertaken if the above medications and lasers have failed to lower the eye pressure appropriately. In this surgery, a small silicone tube is inserted into the eye. The tube, which drains fluid from the eye, leads to a small drainage “lake” that usually is hidden under the upper eyelid. The tube is microscopic and is usually not noticeable by others.
This type of surgery is performed in the operating room and is usually only undertaken if the above medicines and lasers have failed to lower the eye pressure appropriately. In this surgery, an alternate route for fluid to flow out of the eye is created. The fluid drains into a lake or “blister” that is normally hidden under the upper eyelid.
Our ophthalmologists have experience with all of the above surgical treatments and will discuss with you which are appropriate for your eye(s).