Glaucoma is the result of damage to the optic nerve fibers, which transmit visual signals to the brain. The optic nerve may be damaged due to a buildup of pressure within the eye, called ocular hypertension.
Recent evidence has shown that about half of all patients with glaucoma have normal or low pressures. This is contrary to the widely held belief that if a person's eye pressure is normal, then they are not at risk for losing their vision from glaucoma.
There are several types of glaucoma, but most cases are categorized as open-angle glaucoma or closed-angle glaucoma. Primary open-angle glaucoma (POAG) is the most common type of glaucoma. Part of the problem is inadequate drainage of intraocular fluid.
Many current treatments for POAG are aimed at enhancing the drainage of intraocular fluid from the front or the back of the eye. New evidence is pointing towards the exit of the optic nerve from the eye as the crowded area that may be part of the problem in POAG.
Open-angle glaucoma is painless and usually does not cause symptoms at first. Vision loss typically occur over many years.
In acute closed-angle glaucoma, also known as narrow-angle glaucoma or angle-closure glaucoma, the iris blocks the drainage canal and the fluid cannot drain at all, causing a sudden dramatic rise in eye pressure.
Acute closed-angle glaucoma quickly causes serious symptoms such as severe eye pain, headache, nausea, and vomiting. Vision may become blurry or cloudy, or you may see halos around lights.
Acute angle-closure glaucoma is a medical emergency. If it is not treated rapidly, it can lead to permanent loss of vision within hours of the onset of symptoms.
Vision loss from glaucoma is irreversible. Early diagnosis and treatment is vital to delaying visual loss associated with glaucoma.
Symptoms of glaucoma can take years to appear, and many patients find that their glaucoma is advanced by the time they seek medical care. The most common early symptom is loss of side vision, or peripheral vision.
With open-angle glaucoma there are generally no early symptoms; however, acute angle-closure glaucoma causes sudden symptoms such as hazy or blurred vision, the appearance of rainbow-colored circles around bright lights, severe eye and head pain, nausea or vomiting, and slight vision loss.
Since most patients are unaware they have glaucoma, screening is the best way to find the disease early and manage symptoms so you can see for years to come. Optic nerve and visual field testing are key components of screening for the disease. They are relatively rapid. The testing is performed in our office.
Many patients start glaucoma treatment with eye drops to help lower pressure inside the eye. For some, these drops are highly effective but other patients forget to take them or only take them when they know they have a doctor’s visit coming up. Some are unable to squeeze the eyedrop bottles. Other patients struggle to pay for the prescriptions.
Thanks to advancements in office-based laser treatments, the doctors at Jaffe Eye Institute can provide office-based care, which may be ideal for your glaucoma needs. Laser treatments for open-angle glaucoma such as selective laser trabeculoplasty (SLT) can be used as an alternative to drops early in the disease. It is a low-risk procedure that can last for years and has the effect of replacing one eyedrop for glaucoma.
Transcleral laser cyclophotocoagulation (TSCPC) is typically offered to patients with more advanced glaucoma. It is a treatment aimed at lowering eye pressure by 30 to 40 percent after patients have reached their maximally tolerated medicine level. It is offered as an alternative to trabeculectomy or tube shunt procedures. It is not offered early in the treatment plan
The goal of glaucoma surgery is to reduce intraocular pressure (IOP) and slow the progression of the condition. When it comes to surgery for open-angle glaucoma, the gold standard has been trabeculectomy and various tube shunts, both of which involve extensive cutting of the sclera and conjunctiva and the potential for numerous complications.
In recent years, however, a group of procedures known as minimally invasive glaucoma surgeries, or MIGS, has been gaining in popularity. They are safer than traditional glaucoma surgeries, with quicker recovery times and few complications.
According to the American Glaucoma Society, a glaucoma procedure meets the definition of MIGS if it:
- Lowers IOP by improving the outflow of eye fluid
- Can be performed from outside or inside the eye (traditional surgeries are performed from outside the eye only)
- Involves limited cutting of the sclera and conjunctiva
MIGS procedures are performed using microscopic-sized equipment and tiny incisions. Many of them involve implanting small devices and may be combined with cataract surgery.
MIGS procedures are typically shorter in duration and safer than trabeculectomy and tube shunt surgeries.Most MIGS are not as effective in lowering eye pressure as traditional procedures. They were initially designed and may be appropriate only for those with mild to moderate glaucoma.
Newer MIGS keep getting approved. There are currently 3 categories of MIGS procedures. The procedures that increase the drainage of fluid through the drainage angle include the iStent and the goniotomy procedure using the Kahook Dual Blade.
The second category is currently occupied by the recently approved CyPass® implant. It drains intraocular fluid from the front of the eye to the uveoscleral outflow, which is located further back in eyes.
The third category of MIGS is for devices that drain fluid to the subconjunctival space. There is one newly approved device for this route as well: the XEN® gel stent.
As more devices with a wide range of actions are approved, it is conceivable that much lower pressures may be achieved by combining MIGS procedures in one eye.
Some of the MIGS procedures are approved to be performed along with cataract surgery. Others can be performed before or after cataract surgery. Recent studies also have shown that cataract surgery itself is a pressure-lowering procedure.
With a number of MIGS procedures approved and on the horizon, it is indeed an exciting time for glaucoma surgery.
To find out if you’re a candidate for minimally invasive glaucoma surgery, visit Jaffe Eye Institute, South Florida’s leader in advanced eye surgeries.