Glaucoma

Why pressure matters

The front of the eye is filled with a clear fluid that is constantly made and drained. If the drain does not work well, pressure inside the eye can rise and, over time, damage the optic nerve.

Glaucoma can also occur with normal eye pressure, which is why the optic nerve itself is examined closely.

Cross-section of the front of the eye with arrows showing fluid flowing from behind the iris, through the pupil and out through the drainage angle — Fluid is made behind the iris, flows through the pupil, and drains out where the iris meets the cornea.

Two main types

Open-angle glaucoma

The most common type. The drain is open but works poorly, and pressure rises slowly. There is usually no pain, and side vision fades so gradually that it often goes unnoticed.

Angle-closure glaucoma

The iris blocks the drain. It can develop slowly, or suddenly as an emergency with eye pain, headache, blurred vision, halos, and nausea.

How glaucoma is found

Because early glaucoma has no symptoms, regular eye exams are essential. Testing usually includes measuring eye pressure, examining the optic nerve, checking side vision with a visual field test, imaging the nerve fiber layer, and looking at the drainage angle.

A quiet street with a small girl in a pink jacket stepping off the curb on the right — Vision loss from glaucoma does not cause black spots. Instead, it leaves gaps you are completely unaware of, because your brain “fills in” what it assumes is there. Important things can hide in the blind spots. Simulation for illustration only.

The same street seen with glaucoma: the girl has faded to a faint shadow, nearly filled in by the street and curb around her — Vision loss from glaucoma does not cause black spots. Instead, it leaves gaps you are completely unaware of, because your brain “fills in” what it assumes is there. Important things can hide in the blind spots. Simulation for illustration only.

Treatment

Any vision lost to glaucoma cannot be restored. Treatment is about protecting what you have left. Lowering eye pressure can slow or stop further damage.

Many people start with drops or an in-office laser (like SLT), and some need surgery to protect their sight. Minimally invasive glaucoma surgeries (“MIGS”) help the natural drain work somewhat better. More invasive surgeries (“fistulizing” surgeries) create a new drainage path.

Eye drops

Daily drops that reduce how much fluid the eye makes or help it drain.

Laser (SLT)

Selective laser trabeculoplasty, or SLT, is a quick in-office laser that helps the eye’s natural drain work better. It can be a first treatment instead of drops, or added to them, and can be repeated if needed. A different laser can make a small opening in the iris to relieve or prevent angle closure.

Glaucoma Surgery

Surgical options, from gentle to advanced

When drops and laser aren’t enough, surgery can create a better way for fluid to leave the eye. The right choice depends on how advanced the glaucoma is, your eye pressure goal, and any previous surgery.

01

MIGS

Minimally invasive glaucoma surgery

Tiny devices or micro-procedures that improve the eye’s natural drainage system. MIGS is often performed at the same time as cataract surgery and usually means a quicker recovery. It is generally used for glaucoma with only mildly elevated eye pressure, and does not lower pressure enough for eyes with moderate or severe elevation.

02

XEN Gel Stent

A small new drainage channel

A soft, tiny tube about 6 mm long, placed through a small opening. It creates a new path for fluid to drain from inside the eye to a space beneath the eye’s thin outer covering. Because it is a fistulizing surgery, it can bring pressure down to normal no matter how high it starts. See how XEN works

03

Drainage Tubes & Trabeculectomy

A larger new drainage channel

Small, flexible tubes, such as an Ahmed or Baerveldt, carry fluid from inside the eye to a plate placed on the eye’s outer wall, hidden under the eyelid. A trabeculectomy is a precision-made trap door that works in a similar way. These surgeries are more invasive and are reserved for special situations, or for hard-to-control glaucoma that other surgeries have not controlled.

Every surgery has benefits and risks. Your surgeon will explain which option fits your eyes and why.

Lifelong follow-up

Glaucoma cannot be cured. A new drain can silently fail, just like the original one. If your body proves to be “good at scarring things shut,” your surgeon may recommend a more invasive technique. Most new drains last many years, but everyone’s biology is different.

Featured Procedure

The XEN Gel Stent

The XEN Gel Stent is a tiny, soft, flexible tube about 6 mm long, roughly a quarter of an inch, and only about 0.15 mm wide.

Through a tiny opening, the stent is passed from inside the eye, through the drainage angle and the wall of the eye, so its far end rests beneath the conjunctiva, the thin clear covering over the white of the eye. Fluid then flows through the stent and collects in a small, shallow pocket called a bleb, where it is gently absorbed. This lowers eye pressure with a smaller incision and usually a quicker recovery than traditional filtering surgery.

Dr. Tenkman lectures on techniques his team developed to make XEN surgery last longer (“Ninja-XEN”), which have allowed many patients to avoid more invasive surgery.

XEN can be done on its own or together with cataract surgery.

Cross-section of the front of the eye showing a small yellow XEN gel stent running from the anterior chamber through the drainage angle to a fluid pocket under the conjunctiva, with arrows showing fluid flow — The stent carries fluid from inside the eye to a small pocket under the conjunctiva, lowering eye pressure.