What is Glaucoma?
Glaucoma is a group of related diseases that damage the optic nerve, resulting in vision loss and possible blindness. Glaucoma, a leading cause of blindness and visual impairment in the United States, can affect patients of all ages. Many people affected with glaucoma do not experience any symptoms and may not be aware that they have the disease until they have lost a significant amount of vision.
With early detection and treatment by Dr. Aizuss in West Hills and Encino, CA, eyes can be protected against the serious loss of vision or blindness. Catching glaucoma at an early, treatable stage is one important reason to have thorough eye examinations regularly.
There are several factors that increase the risk of developing glaucoma, including:
- Age over 60
- Ethnic origin, genetic background or race such as African-American or Asian
- A family history of glaucoma
- History of elevated intraocular pressure
- History poor vision or other eye disorders or injuries
- Certain medical conditions such as diabetes
- Taking certain medications, such as corticosteroids for prolonged periods
Patients with risk factors for the disorder should be especially vigilant about having regular eye examinations.
Causes Of Glaucoma
Certain diseases or conditions can contribute to the development of glaucoma. These include:
- Increased pressure within the eye
- Severe eye infection
- Injury to the eye
- Blocked blood vessels
- Inflammatory conditions of the eye
Glaucoma is considered primary if its origin is unknown and secondary if it results from another medical condition.
Symptoms Of Glaucoma
It is important to remember that patients with early-stage glaucoma are most often asymptomatic. When symptoms occur, they vary depending on the type of glaucoma and can occur in one eye or both eyes. The symptoms of open-angle glaucoma include:
- Dim or blurred vision
- Gradual loss of peripheral vision
- Tunnel vision (at advanced stages)
The symptoms of angle-closure glaucoma encompass systemic, as well as eye symptoms, including:
- Severe eye pain
- Nausea and vomiting
- Sudden visual disturbance
- Blurred vision
- Halos around lights
- Red eyes
Either type of glaucoma may be a primary or secondary disorder.
Types Of Glaucoma
There are several types of glaucoma. The two major types are primary open-angle glaucoma, in which fluid drains too slowly from the drainage channels (trabecula) of the eye, and angle-closure (narrow-angle) glaucoma, which occurs when the trabecula become blocked. Approximately 95 percent of glaucoma patients suffer from primary open-angle glaucoma. Other types of glaucoma include:
- Low Tension Glaucoma
- Congenital Glaucoma
- Secondary Glaucoma
- Pigmentary Glaucoma
- Pseudoexfoliation Glaucoma
The diagnosis of glaucoma is made after a comprehensive medical examination of the eye and a review of the patient’s medical history. Tests are conducted to confirm the diagnosis. Testing may include some of the following:
- Dilated eye examination
- Visual field test (perimetry)
- Retinal evaluation
- Visual acuity test
- Ocular Coherence Tomography (OCT) of the optic nerve
Once glaucoma has been diagnosed, treatment should begin as soon as possible to help minimize the risk of permanent vision loss.
There is no cure for glaucoma, so treatment focuses on relieving symptoms and preventing further damage. Some of the treatment methods for glaucoma are as follows:
- Medication: Eye drops or oral medication may be used to either reduce fluid production in the front of the eye or to help drain excess fluid. Side effects of the medication may result in redness, stinging, irritation or blurred vision. Regular use of the medication is needed to keep the eye pressure under control.
- Laser Surgery: Trabeculoplasty, iridotomy or cyclophotocoagulation are laser procedures that aim to increase the outflow of fluid from the eye, eliminate fluid blockages or reduce fluid production.
- Other Surgery: A trabeculectomy may be used to create a new channel to drain fluid from the eye and reduce the pressure that causes glaucoma. Surgery is performed only after medication and laser procedures have been unsuccessful. Placement of a drainage valve or stent may also be performed.
What is iStent?
In combination with cataract surgery, an iStent may be used to reduce pressure. iStent is a tiny implanted device that improves the eye’s natural ability to direct fluid flow through the trabecular meshwork, which is the channel through which fluid normally exits the eye. In patients with mild to moderate open-angle glaucoma, this channel is often blocked to some degree. This allows fluid levels to build in the eye, increasing intraocular pressure. This pressure impacts the optic nerve, degrading eyesight over time — glaucoma.
iStent is the world’s tiniest medical device, 20,000 times smaller than the intraocular lenses that you will have placed with your cataract surgery. The iStent is placed through the trabecular network, opening the passage and allowing fluid to drain more effectively. These implants are placed during cataract surgery for patients who are also suffering from mild-to-moderate open-angle glaucoma.
How does iStent help with glaucoma?
Over time, your eye’s natural drainage system becomes clogged. Fluids that should be draining out of the eye now start to build. This increases intraocular pressure; this is glaucoma. If this pressure is allowed to stay elevated, it begins to permanently damage the person’s vision. This damage is not reparable.
When iStent is implanted during your cataract surgery, it acts like a pipeline that now creates a permanent opening through the blockage in your eye’s trabecular network. Now the eye can naturally drain again; this can lower the pressure in the eye, and it may allow the patient to reduce the glaucoma medications he or she is using to lower their eye pressure.
What are the risks factors with iStent?
The FDA has approved the iStent for treatment of open-angle glaucoma. The iStent implant is incredibly small, so it doesn’t interfere with MRIs and it won’t set off airport scanners. Its insertion is minimally invasive, and the risk of complications has been quite low. In some cases, there can be some bleeding in the eye, but that typically resolves within hours. In rare instances, the eye pressure can rise for a few days after the surgery, but this can be lowered with additional eye drops until this resolves.
There are newer procedures under development commonly referred to as MIGS, or microinvasive glaucoma surgery, that offers further advances for surgical intervention for glaucoma. While patients with early-stage glaucoma may not experience any symptoms, prompt treatment is required to preserve their vision.
XEN Gel Stent
What is the XEN Gel Stent?
The XEN Gel Stent is a tiny tube, about the length of an eyelash. It’s a surgical implant designed to lower eye pressure in open-angle glaucoma patients who have had unsuccessful trabecular surgery or for whom eye drops are not effective for lowering intraocular eye pressure.
How does the XEN Gel Stent work?
The XEN Gel Stent is placed just under the conjunctiva, the clear membrane that covers the white of your eye. Once in place, the XEN Stent creates a small channel in the eye to drain fluid and lower elevated eye pressure. The XEN Gel Stent creates a new pathway for necessary fluid to drain in eyes with open-angle glaucoma where normal drainage capacity has been blocked or seriously degraded. By returning normal drainage, the XEN Gel Stent may allow the patient to reduce or even stop using glaucoma eye drops.
How is the XEN Gel Stent different than traditional glaucoma surgery?
Before the evolution of these artificial stents, glaucoma surgery involved creating a drainage hole through the trabecular network to increase the flow of fluid out of the eye. This surgery is done either with lasers or with incisional surgery. Usually laser surgery is the first option, and if it is not successful incisional surgery may be attempted. The XEN Gel Stent is used when these surgeries do not have the intended result of lowering pressure in the eye.
Is XEN safe and what are the risks?
The FDA has approved the XEN Gel Stent for glaucoma patients with refractory glaucoma who failed previous surgical treatment or in patients with primary open-angle glaucoma. Risks include a buildup of fluid between the inner layer of blood vessels and the white outer layer of the eyeball, blood in the eye, very low eye pressure, implant exposure, development of scar tissue, and other eye surgery complications. But these risks have proven to be low, and the benefits to glaucoma patients faced with vision damage outweigh the risks.
What is the CyPass Micro-Stent?
The CyPass Micro-Stent was another stent inserted during cataract surgery. Like the iStent and the XEN, it created a new channel for fluids to exit the eye, reducing elevated intraocular pressure. The FDA approved the CyPass Micro-Stent in 2016 for glaucoma treatment. However, Alcon, the manufacturer recently made a voluntary recall of this product and has told surgeons to immediately stop implantation.
What happened to the CyPass Micro-Stent?
On August 29, 2018, Alcon, the maker of the CyPass Micro-Stent announced it was voluntarily withdrawing all versions of the CyPass Micro-Stent from the global market. The company based the decision on safety data from a study that found a statistically significant difference in endothelial cell loss at 5 years after surgery in patients who received the device in conjunction with cataract surgery compared to those who underwent cataract surgery alone.
The CyPass Micro-Stent is no longer available. Whether its flaws are addressed and the product returns in the future is unknown.
If you are interested in scheduling a consultation, call Dr. Aizuss at (818) 907-1038 or complete a Contact Form here! Dr. David Aizuss from Ophthalmology Associates of the Valley serves Encino, West Hills, Calabasas, Agoura Hills, Tarzana, Woodland Hills, Sherman Hills, and Reseda, CA with glaucoma treatments.