Glaucoma is a disease in which the pressure in the eye leads to optic nerve damage. The optic nerve is what carries light signals from the eye to the brain. Damage to the optic nerve can lead to blindness.
- 3 million Americans are estimated to have glaucoma
- Half of patients with glaucoma do not realize they have the disease
There are generally no symptoms in the early stages of glaucoma. The loss of vision can be gradual, thus glaucoma can be a silent disease. If left untreated, blindness can ensure. Fortunately there are treatments that can help prevent vision loss from glaucoma.
There are several types of glaucoma, most commonly:
- Open-angle glaucoma
- Closed-angle glaucoma (or Narrow-angle glaucoma or Angle-closure glaucoma)
- Secondary glaucoma
Primary open-angle glaucoma (POAG) is the most common form of glaucoma in the U.S. There is fluid in the eye called aqueous. The aqueous drains through the trabecular meshwork and out of the eye.
When the fluid drainage is less than fluid production, the intraocular pressure (IOP) increases and leads to glaucoma damage. Some people can have higher than average IOP and not have signs of vision loss or glaucoma. We call this ocular hypertension. Conversely, other patients may have low to normal IOP and yet still develop optic nerve damage called normal-tension glaucoma (NTG).
Risk factors for glaucoma include:
- Age over 60
- Family history
- African American
- Myopia (near-sightedness)
- High IOP
- Eye injury
- Steroid use (particularly eye drops)
Glaucoma is a treatable disease, and with early detection, blindness is preventable. Your vision is important- schedule an eye exam today!
Narrow-angle and angle-closure glaucoma
The fluid in the eye drains through the “angle” which is the space between the iris and the cornea [insert picture of angle]. If this angle is narrow or closed, the fluid drainage is obstructed and pressure can build up in the eye. This can happen quickly, as with acute angle-closure glaucoma, or over time with chronic angle closure. Patients with increased risk include hyperopes (farsightedness) and Asian ancestry. Signs of acute angle closure include: pain, redness, blurred vision, haloes around lights, headache, and nausea and vomiting. Over-the-counter decongestants and certain medications can increase risk of angle closure. Check with your eye doctor before taking such medications.
Fortunately angle-closure is preventable for those with narrow angles if detected early. Most commonly, a laser peripheral iridotomy (LPI) is performed to create a new drainage pathway by creating a small opening in the iris. If cataracts and visual symptoms are present, cataract surgery can also be a method for resolving the narrow angle. Both LPI and cataract surgery are outpatient procedures that are covered by Medicare and insurances.
Some patients have glaucoma as a result of external pressure on the eye (i.e. from a tumor), inflammation or diabetes, or due to a medications or eye drops. These forms of glaucoma are considered secondary glaucoma and may be treated differently from normal primary open angle glaucoma.
The most common treatment for glaucoma is medication drops. These medications help lower the IOP by decreasing aqueous production or increasing aqueous drainage. Eye drops will not affect or improve the vision, but are used to reduce progression of glaucoma and vision loss. Compliance and daily use of glaucoma drops is crucial.
It is important to discuss with your eye doctor what medical conditions you have as this may affect which eye drop is recommended for you. You should also inform your doctor of all oral or systemic medications you take as some may affect your eye pressure.
Laser and surgery are options for patients who have exhausted or failed glaucoma medical therapy. Some patients have difficulty taking or remembering to take their glaucoma drops. If eye pressure is uncontrolled despite maximal medical therapy, laser or surgery are the next lines of treatment. Laser can also be a first line option for patients with early or mild glaucoma who elect this therapy over using drops.
Selective Laser Trabeculoplasty, or SLT, is a laser procedure performed to lower the eye pressure. SLT works by targeting specific cells in the trabecular meshwork, which is the main drainage pathway for the aqueous. This outpatient procedure has been shown to be effective for lowering eye pressure without systemic side effects or ocular irritation that may be seen with glaucoma drops. SLT is covered by Medicare and other insurances.
Trabeculectomy is the traditional surgery performed for glaucoma in patient’s with progressive disease despite medical and or laser therapy. The procedure is performed by creating an ostomy or opening in the sclera (white layer of the eye) for the aqueous to “filter” through to a reservoir. The reservoir forms a bleb or bump on the conjunctiva (clear membrane overlying sclera). Additionally, an Ex-press shunt can be inserted at the time of trabeculectomy in order to facilitate flow and decrease complications such as low pressures following surgery. Many patients who undergo trabeculectomy can gain independence from glaucoma medications and drops.
Aqueous shunt surgery
Tube shunts are an alternative to traditional trabeculectomy. A tube shunt is a tube and plate device (typically made out of silicone) that directs aqueous from inside the eye through a tube to a reservoir underneath the conjunctiva (thin membrane covering white part of the eyes) and eyelid. This procedure has been shown to be as effective as trabeculectomy. Some patients with certain types of glaucoma may benefit from tube shunt surgery. For more information, click here.
Endocyclophotocoagulation (ECP) is a procedure typically done at the time of cataract surgery to lower eye pressure. Cataract surgery in itself can ofter lower IOP, especially in patients with narrow angles or advance cataracts. Combined ECP and cataract surgery can further lower the eye pressure. A video endoscope is used to guide a laser targeted at the ciliary processes. Shrinking the ciliary processes decreases the aqueous production and hence lowers eye pressure. If you have both glaucoma and cataracts, you may be a candidate for this procedure. Many of our patients are able to decrease or eliminate their glaucoma drops after combined cataract surgery and endocyclophotocoagulation.
Micro-incision glaucoma surgery (MIGS)
New treatment options for glaucoma continue to emerge. One of the latest advances in glaucoma management is micro-incision glaucoma surgery. The i-stent is the smallest FDA approved device. It is a small implant is inserted into the drainage channel improving aqueous outflow and lowering eye pressure. It is performed at the time of cataract surgery through the 2-3 millimeter incision. This surgery has the advantage of quicker visual recovery compared with traditional glaucoma surgeries.
At Premier Eye Care, we strive to give our patients the latest, most advanced treatments. Schedule an appointment today with one of our eye surgeons to discuss which glaucoma surgery or treatment is best for you.