Glaucoma affects approximately 3 million Americans and over 120,000 will go blind from this disease. Glaucoma ranks as a leading cause of blindness worldwide. And when it does not cause blindness, it can severely impair vision.
There are two major types of glaucoma:
- Acute closed-angle glaucoma.
- Chronic or primary open-angle glaucoma.
Other variations include congenital glaucoma, pigmentary glaucoma and secondary glaucoma.
There are no warning signs of Chronic glaucoma. About half of Americans with chronic glaucoma don’t even know they have it. Glaucoma gradually reduces your peripheral vision. By the time you notice it, permanent damage has already occurred. If your intraocular pressure remains high, you can develop tunnel vision. You will only be able to see objects straight ahead.
Other signs to watch for include headaches, blurred vision, difficulty adapting to darkness or halos around lights. Chronic glaucoma normally develops after age 35.
The great news is that our doctors have introduced a safe, effective, laser treatment called SLT, or selective laser trabeculoplasty.
Medical therapy to treat glaucoma works to relieve eye pressure, which is a primary cause of pain associated with this disease. Eye pressure is also a leading factor in glaucoma-related vision loss due to its contribution to nerve damage within the eye.
Drs. Alvi or Quraishi administers two main categories of drugs that alleviate pain and prevent further degeneration of vision. Because pain and disease progression is caused by increased intraocular pressure (IOP), treatment works to balance IOP by creating equilibrium of the in and outflow of aqueous humor, a clear fluid that fills the anterior and interior chambers, plus the pupil, of the eye. Therefore, these medications seek to either decrease aqueous humor production, or increase the outflow of aqueous.
Drugs aimed at reducing aqueous humor production:
Carbonic anhydrase inhibitors – Carbonic anhydrase inhibitors are generally used for closed-angle glaucoma, and may be administered in emergencies to rapidly reduce pressure inside the eye. When eye drops have failed to release pressure, the oral form of carbonic inhibitors is often used.
Beta-blockers – Beta-blockers have remained the most popular anti-glaucoma agents for the past 20 years due to their safe nature and very high effectiveness. Beta-blockers are most often used to treat open-angle glaucoma. They can be used in combination with other glaucoma drugs, and usually must be taken twice per day.
Drugs aimed at increasing aqueous humor drainage:
Parasympathomimetic (cholinergic) agents –
Parasympathomimetics are used to control IOP in closed-angle glaucoma. These eye drops constrict the pupil, which allows for opening the narrowed or blocked angle where drainage occurs.
Prostaglandin analogies –
Prostaglandins used in eye drops work by relaxing muscles within the eye, which serves to better allow the outflow of fluids. Prostaglandins are very effective, and have been proven to lower IOP by up to 50% on average. These eye drops are also popular among users because they only need to be administered once daily.
Adrenergic agonists –
Adrenergic agonists work both by reducing aqueous humor production and increasing drainage. Some forms of the drug can reduce eye pressure by about 20-27%, and may contain neuroprotective properties to aid in possible prevention of retinal nerve cell degeneration.
As with all medications, some side effects may occur. If you experience any irritation, it is important to contact our practice. Remaining consistent with follow-up visits and medication-use will help reduce preventable vision loss. If medical therapy fails or side effects become unbearable, surgical options such as Selective Laser Therapy (SLT), and trabeculectomy are also available to treat glaucoma.
Other therapy for glaucoma treatment includes aerobic exercise, which has been proven to lower IOP and some studies show it may improve blood flow to the retina and optic nerve as well. As little as a brisk twenty-minute walk four times per week can significantly lower eye pressure.
Overview of Trabeculectomy:
Trabeculectomy-sometimes referred to as filtration surgery-is the most commonly used glaucoma surgical procedure, usually performed when medical therapy does not succeed in controlling the intraocular pressure (IOP). It can be performed on patients with most types of glaucoma, but not all. In order for Drs. Alvi or Quraishi to proceed with this procedure, you must have an intact, non-scarred conjunctiva, or a thin tissue that coats the surface of the eye wall. Trabeculectomy is also difficult to perform on eyes with any scarred tissue from previous surgeries. Trabeculectomy does not reverse any existing vision damage caused by glaucoma, but it can be very successful in preventing further vision loss.
How Trabeculectomy is Performed:
The main goal of trabeculectomy is for Drs. Alvi or Quraishi to create a small hole by removing a piece of tissue in the drainage angle of the eye. The opening this creates is then covered with a flap of tissue from the sclera, or the “white part” of the eye, and the conjunctiva. This new opening allows clear fluid, or aqueous humor, to drain out of the eye, and thereby relieves the high IOP, the cause of nerve damage and vision loss. As fluid flows through the new drainage passage, it forms into a blister called a bleb, located where the sclera and iris meet, and which is then absorbed into the bloodstream.
What to Expect After Surgery:
Patients are not usually admitted to the hospital following the procedure, but are generally expected to have a checkup the next day with their eye specialist. Antibiotics will be applied to the eye or injected under the conjunctiva. The eyelid will be taped shut, and a hard eye shield will be placed over the eye to facilitate healing and protection. Patients will be instructed to avoid activity that may strain the eye following surgery, including bending, and lifting.
The recovery period for trabeculectomy is generally between six to eight weeks. The postoperative follow-up is especially important with this procedure, as the effectiveness depends greatly on the ability of the conjunctiva to heal. Mild discomfort following surgery is common, but severe pain ay be a sign of complications. If you experience such pain, contact our practice immediately.
Risks and Side Effects:
As with all surgeries, some side effect may occur. Likewise, it is important to understand the risks of trabeculectomy, and to determine your suitability for the procedure. Drs. Alvi or Quraishi can help you decide when trabeculectomy is right for you.
A main risk of trabeculectomy is postoperative scarring of the new opening. Scarring in this area prevents fluid drainage, and interferes with the functioning of the bleb. Other possible side effects include bleeding in the eye, infection in the eye, and extremely low eye pressure causing blurred vision.
Trabeculectomy has about a 65-70% success rate in reducing visual field loss and lowering eye pressure, with an additional 20% success rate at achieving the goal IOP when combined with postoperative anti-glaucoma medications. Trabeculectomy is considered successful if it controls the IOP for a period of 7 to 8 years. If the first procedure fails, an additional trabeculectomy (or two) can be performed. Subsequent surgeries however, have a higher chance of failure than the original trabeculectomy.
Selective laser trabeculoplasty (SLT) is one of the greatest advances in the surgical treatment of intraocular pressure (IOP) in patients with open-angle glaucoma. SLT is a safe and simple 5 minute in-office laser treatment that effectively reduces the pressure in the eye for most patients with glaucoma. SLT can reduce or eliminate the need to use daily glaucoma medications. Studies have shown that less than 50% of glaucoma patients actually take their medications as prescribed and many stop taking them due to the numerous side effects experienced, cost, busy lifestyle and all other daily variables and challenges we all experience. Compliance is now controlled by your physician. The low percentage of non-responders to SLT therapy can simply begin traditional medications.
Benefits of SLT
- Safe: SLT is not associated with systemic side effects or the compliance and cost issues of medications.
- Selective: SLT utilizes selective photothermolysis to target only specific cells, leaving the surrounding tissue intact.
- Smart: SLT stimulates the body’s natural mechanisms to enhance outflow of the fluid in your eye.
- Sensible: SLT therapy is reimbursed by Medicare and many other insurance providers, which minimizes your out-of-pocket expenses.
How SLT works
Selective Laser Therapy (SLT) is an advancement over other lasers that have been used safely and effectively in the treatment of open-angle glaucoma for more than two decades. SLT works by using laser light to stimulate the body’s own healing response to lower your eye pressure. Using a special wavelength and energy, the laser affects only pigmented (melanin containing) cells of your eye unlike ALT which permanently damages and scars the eye. SLT improves the flow of fluid in the eye, which in turn lowers your eye pressure.
How SLT is performed
SLT is usually performed in the physician’s office and only takes a few minutes. Prior to the procedure, eye drops will be given to prepare the eye for treatment. The laser applications are applied through a regular physician microscope (slit lamp), similar to the one used for eye examinations.
What to expect after SLT treatment
Your eye pressure may drop as quickly as in a day after having SLT performed. The doctor may treat the eye with anti-inflammatory eye drops that will be continued for a few days after the procedure. Patients have no limitations after their procedure and are able to drive home. Patients will be scheduled for a follow up appointment to allow the physician to evaluate the results.
FAQ about SLT
What are the side effects of SLT?
Unlike with glaucoma medications, there is no risk of allergy or systemic side-effects with SLT. Complications are rare, but may include inflammation, temporary increase in eye pressure, conjunctivitis, or eye pain. Unlike older laser procedures (such as ALT), SLT does not permanently damage or scar the eye.
Will I feel anything with the laser treatment?
The laser treatment does not cause a sensation. You may see a green flash of light, and feel nothing from the laser. The lens used on your eye may cause some temporary redness or irritation.
Will I still need to continue using my eyedrops following the SLT procedure?
It is well documented that Selective Laser Therapy (SLT) can reduce or eliminate your need for glaucoma medications. Results will vary depending upon the severity of the disease.
Most patients when given the option prefer to be treated with SLT Laser therapy than be prescribed the immediate use of medications. Many individuals today are also concerned of the long term side effects of medications or the effects of multiple medications being prescribed. Due to the abundance of medications being prescribed today, patients are challenged to properly take their medications. When discussing glaucoma therapies with your eye care professional, ask if you are a candidate for SLT Therapy.