It’s estimated that about 3 million Americans have glaucoma, but about half of them don’t even know it. One of the scariest things about glaucoma is that usually there are no symptoms in the early stages. The first notable symptom may be a loss of peripheral vision, but this is actually a late-stage, irreversible result of the disease. This is why glaucoma is called the “silent thief of sight.” Anyone can be at risk. The only way to detect this disease is to have regular, thorough eye examinations.
What is Glaucoma?
Glaucoma is defined as a disorder of the optic nerve (the bundle of fibers connecting the eyeball and the brain). Gradual damage and loss of the fibers composing the nerve leading to vision loss in a specific pattern, initially in the periphery, and if advanced, affecting the central vision. The disease is typically but not always associated with elevated intraocular pressure. Glaucoma is one of the leading causes of blindness in America, but can often go unnoticed in its earliest stages because there may be no noticeable symptoms.
Because of this, regular eye exams are the best way to detect signs of the disease before serious irreversible damage has been done to your eyesight. While there is no cure for glaucoma, if detected early, your vision can often be preserved, and further damage can be prevented.
There are several types of glaucoma: they can be divided into “open-angle” and “narrow-angle,” depending on the anatomy of the area in the front of the eye where intraocular fluid movement happens (the anterior chamber). About 30% of glaucoma patients never have above-normal eye pressures; this is “normal-tension glaucoma”.
Another way to categorize the disease is “primary” (in absence of other eye conditions) and “secondary” (associated with other eye disorders, past traumas, or previous eye surgeries).
What Causes Glaucoma?
Glaucoma is typically caused by an imbalance between the eye’s fluid production and the outflow of that fluid. When your eyes experience high levels of pressure, the optic nerve, a delicate and vulnerable part of your eye, can become damaged. Regular eye exams to detect early stages of glaucoma should be a crucial part of your regular healthcare.
Those who may be at an increased risk of developing glaucoma include people with a family history of glaucoma, people over the age of 40, African-Americans age 35 and over, diabetics, people with extreme nearsightedness, and those with long-term steroid medication use.
When the process is gradual, patients may be completely unaware – there is no appreciable pain, no difference in how the eye looks and feels, and no perceptible changes in how you see. By the time pain or evidence of vision loss is obvious, it may be too late. The nerve damage caused by glaucoma is irreversible and the vision loss is permanent. Early detection and prevention of loss is critical.
This involves detailed evaluation in the office by one of our expert eye physicians. A complete eye exam, with measurements of the intraocular pressure (IOP), determinations of the thickness of the central cornea (pachymetry), evaluation of the anterior chamber angle anatomy (gonioscopy) occurs.
Drops are instilled for dilation of the pupil, which allows for careful visualization of optic nerve appearance. Imaging studies of the nerve (photographs and ocular coherence tomography) and assessment of its’ the functioning (visual field testing) are all required to correctly diagnose whether someone may have glaucoma, and if so, how severe, or if the individual is at risk for developing glaucoma in the future (glaucoma suspect).
How Can Glaucoma be Treated?
There is no cure for glaucoma, but it can be managed with a variety of treatment options aimed to lower and stabilize the eye pressure, reducing further damage to the optic nerve, and protecting you from vision loss. Eye drops of several classes can decrease eye fluid production or improve eye fluid outflow.
Laser procedures of two types (YAG or SLT) can serve to improve eye fluid circulation. More invasive procedures are at times performed by glaucoma surgical sub-specialists if other treatments are ineffective.
MIGS: a newer option for glaucoma management
Minimally invasive or micro incisional glaucoma surgery (MIGS) is a treatment option for patients who have glaucoma or glaucoma suspect diagnosis and are undergoing cataract surgery. These are procedures performed in the operating room, on the same session as cataract surgery.
After the cataract has been removed and the intraocular lens implant of your choice has been placed, the surgeon can insert a microscopic device into the eye to help with lowering eye pressure. Several devices are presently FDA-approved in the US, including the iStentInject.
Chicago Cornea Consultants specialists have been using the iStent (also known as the trabecular micro-bypass stent) for a number of years, and have found it a successful modality for lowering the pressure in our glaucoma patients. A good number of patients are able to achieve target pressures and discontinue or decrease the number of glaucoma drops they need to use to keep glaucoma under control.
Above is the surgeon’s view of the area where eye fluid movement and iStent placement occurs (the trabecular meshwork)
According to Glaukos, the makers of the iStent, it is also “the smallest medical device ever approved by the FDA” – 20,000 times smaller than the (already tiny) intra-ocular lens used in cataract surgery. You can read more details about this amazing micro-device on the Glaukos website.
Another MIGS procedure offered at Chicago Cornea Consultants is Kahook Dual Blade Goniotomy. This can be performed as a standalone intervention, or in combination with cataract surgery and IOL implantation.
A specially-designed microscopic tool, the Kahook blade is inserted into the eye via a tiny corneal incision and is used to remove a strip of tissue (trabecular meshwork) that creates resistance to intraocular fluid flow (goniotomy). The circulation and outflow of fluid are improved and the intraocular pressure lowered. For many patients, drops can be decreased or discontinued. Click Here to Learn More
Patients still need to keep their glaucoma under control by taking drops and seeing their doctor regularly, but this technology is an exciting advance we are glad to be offering our patients at Chicago Cornea Consultants.
For more information about glaucoma, or to schedule an exam, please contact us.