Primary Open Angle Glaucoma

Primary Open Angle Glaucoma (POAG) accounts for the majority of glaucoma cases in the United States. This is characterized by elevated IOP and damage to the optic nerve head (often described as ‘cupping’). Most people do not experience symptoms or early warning signs until their vision is compromised and extensive damage to the optic nerve has been done. This type of glaucoma develops slowly and sometimes without noticeable sight loss for many years. Eye drops are generally prescribed to lower the eye pressure. In some cases, surgery is performed if the IOP cannot be adequately controlled with medical therapy.

Normal Tension Glaucoma

Normal tension glaucoma is also known as low-tension glaucoma (LTG) and is characteristically similar to POAG, although the IOP is not elevated. Doctors do not know why some people’s optic nerves suffer damage even though pressure levels are in the “normal” range. Treatment of patients with NTG/LTG is the same as for all types of glaucoma, lowering the intraocular pressure. Studies have demonstrated that although the eye pressure is not elevated by the normal definition, further lowering of the pressure (or stabilizing the IOP so there are not intermittent spikes in IOP) does decrease the risk of optic nerve damage and visual field loss.

Angle Closure Glaucoma

Angle Closure Glaucoma, also known as acute glaucoma or narrow-angle glaucoma accounts for fewer than 10% of cases. This type of glaucoma is much more rare and is very different from open angle glaucoma in that the pressure usually rises very quickly and is considered an ophthalmic emergency. If the drainage channel is completely blocked, IOP rises suddenly, causing acute angle-closure glaucoma. If not properly diagnosed and treated, progressive and permanent ocular damage occurs within days. Symptoms may be severe and include extreme eye pain, headache, nausea/vomiting, blurred vision, and halos around lights.

It is important to monitor the angle with gonioscopy. If there is a risk of narrow angle noted on exam the doctor will likely recommend laser peripheral iridotomy as treatment to prevent an acute angle closure attack. If left untreated and an angle closure attack occurs, treatment typically includes eye drops, oral medications, and laser iridotomy ASAP to avoid permanent vision loss.

Pigmentary Glaucoma

This is an inherited type of open angle glaucoma that most commonly affects myopic men in their 20’s or 30’s. Myopia (nearsightedness) causes the eyes to have a concave iris, creating a wide angle. This causes the color (pigment) layer of the eye, the iris, to rub off onto the lens where it can shed into the aqueous humor and the trabecular meshwork. The pigment can clog the pores of the trabecular meshwork, which prevents adequate aqueous humor drainage and increases IOP.

Pediatric/Congenital Glaucoma

The Pediatric glaucoma’s consist of congenital glaucoma (present at birth), infantile glaucoma (appears during the first three years), and juvenile glaucoma (age 3 to young adult years). Congenital glaucoma is present at birth and most cases are diagnosed during the first year of life. Sometimes symptoms are not recognized until later in infancy or early childhood.

When glaucoma is diagnosed before a child’s third birthday, it is considered congenital (present since birth). In approximately 1/3 of children, it is inherited through an autosomal recessive gene. Autosomal means that boys and girls are affected equally, and recessively indicates that both parents have the gene. The risk is 25% with each pregnancy that the infant will have congenital glaucoma when both parents are carriers (ie: they don’t have the condition, but they can pass it on to their child).

Secondary Glaucoma

Glaucoma can occur as the result of an eye injury, inflammation, tumor, or advanced cases of cataract or diabetes. Certain drugs such as steroids can also cause secondary glaucoma. This form of glaucoma may be mild or severe. The type of treatment will depend on whether it is open-angle or angle-closure glaucoma.

• Pseudoexfoliative Glaucoma
  A form of secondary open angle glaucoma, this occurs when the pigment granules in the back of the iris (the colored part of the eye) break into the clear fluid produced inside the eye. These tiny pigment granules flow toward the drainage canals in the eye and slowly clog them, causing eye pressure to rise. Treatment usually includes medication or surgery.

• Traumatic Glaucoma
  Injury to the eye may cause secondary open angle glaucoma. This type of glaucoma can occur immediately after the injury or years later.

It can be caused by blunt injuries that “bruise” the eye (called blunt trauma) or by injuries that penetrate the eye.

In addition, conditions such as severe nearsightedness, previous injury, infection, or prior surgery may make the eye more vulnerable to a serious eye injury.

• Neovascular Glaucoma
  The abnormal formation of new blood vessels on the iris and over the eye’s drainage channels can cause a form of secondary open angle glaucoma.

Neovascular glaucoma is always associated with other abnormalities, most often diabetes. It never occurs on its own. The new blood vessels block the eye’s fluid from exiting through the trabecular meshwork (the eye’s drainage canals), causing an increase in eye pressure. This type of glaucoma is very difficult to treat.

• Irido Corneal Endothelial Syndrome (ICE)
  This rare form of glaucoma usually appears in only one eye, rather than both. Cells on the back surface of the cornea spread over the eye’s drainage tissue and across the surface of the iris, increasing eye pressure and damaging the optic nerve. These corneal cells also form adhesions that bind the iris to the cornea, further blocking the drainage channels.

This syndrome occurs more frequently in light-skinned females. Symptoms can include hazy vision upon wakening and appearance of halos around lights. Treatment can include medications and/or surgery. Laser therapy is not effective in these cases.

• Steroid Induced Glaucoma
  Steroidal medication can be associated with elevated intraocular pressure, this can include all types of steroidal treatment whether prescribed or over the counter including topical eye drops, injections, cream, oral steroid, etc. Steroidal treatment can be the initial cause of glaucoma or cause in increase in IOP in those that already have a diagnosis of glaucoma. Treatment usually includes medications or surgery.