Treatment of glaucoma :

Glaucoma is a group of eye diseases which result in damage to the optic nerve and vision loss. The most common type is open-angle glaucoma with less common types including closed-angle glaucoma and normal-tension glaucoma. Open-angle glaucoma develops slowly over time and there is no pain. Side vision may begin to decrease followed by central vision resulting in blindness if not treated. Closed-angle glaucoma can present gradually or suddenly. The sudden presentation may involve severe eye pain, blurred vision, mid-dilated pupil, redness of the eye, and nausea. Vision loss from glaucoma, once it has occurred, is permanent.

Risk factors for glaucoma include increased pressure in the eye, a family history of the condition, migraines, high blood pressure, and obesity. For eye pressures a value of greater than 21 mmHg or 2.8 kPa is often used with higher pressures leading to a greater risk. However, some may have high eye pressure for years and never develop damage. Conversely, optic nerve damage may occur with normal pressure, known as normal-tension glaucoma. The mechanism of open-angle glaucoma is believed to be slow exit of aqueous humor through the trabecular meshwork while in closed-angle glaucoma the iris blocks the trabecular meshwork. Diagnosis is by a dilated eye examination. Often the optic nerve shows an abnormal amount of cupping.

If treated early it is possible to slow or stop the progression of disease with medication, laser treatment, or surgery. The goal of these treatments is to decrease eye pressure. A number of different classes of glaucoma medication are available. Laser treatments may be effective in both open-angle and closed-angle glaucoma. A number of types of glaucoma surgeries may be used in people who do not respond sufficiently to other measures.Treatment of closed-angle glaucoma is a medical emergency.

About 6 to 67 million people have glaucoma globally. The disease affects about 2 million people in the United States. It occurs more commonly among older people. Closed-angle glaucoma is more common in women. Glaucoma has been called the “silent thief of sight” because the loss of vision usually occurs slowly over a long period of time. Worldwide, glaucoma is the second-leading cause of blindness after cataracts. The word “glaucoma” is from ancient Greek glaukos which means blue, green, or gray. In English, the word was used as early as 1587 but did not become commonly used until after 1850, when the development of the ophthalmoscope allowed people to see the optic nerve damage.

Surgical treatment forreducing intraocular pressure (IOP):

Combined cataract and glaucoma surgery


Non Penetrating Glaucoma Surgery: This includesprocedures such as Deep Sclerectomyorviscocanalostomy. Both of these methods are less invasive than filtration surgery and the anterior chamber remains intact.Both involve removal of a deep scleral flap, the external wall of Schlemm’s canal and corneal stroma behind the anterior trabeculum and Descemet’s membrane, thus creating an intrascleral space.In viscocanalostomy, viscoelastic is injected into Schlemm’s canal to make it wider.

Trabeculectomy: This method is somewhat similar to trabeculectomy. It involves removing part of the trabecular meshwork to allow fluid to flow through the eye’s drainage system.This method is usually used to treat congenital glaucoma when the cornea (the transparent part of the iris) is opaque. SinceTrabeculectomy andGoniotomyare less invasive, they are commonly used to treat children.
Goniotomy: a surgical procedure in which the doctor uses special lensescalled goniolens to viewangles of the eye. This technique is applicable for the treatment of congenital glaucoma if the cornea is not opaque. In this method, a hole is created in trabecular meshwork (a collection of tiny channels located in the drainage angle of the eye) to enhance aqueous outflow.
Ophthalmicshunt implant:Aqueous shuntssuch as Ahmed Valve and Moltenare small plastic tubes or valves connected from one side to a reservoir which isa round or ovalplate.Shunts are devices that are implantedthrough a small incision in the eye to provide an artificial alternative drainage site for fluid to exit the eye. This tiny tube extends from the body of the device into the anterior chamber, which is the front part of the eye that usually drains fluid from the eye. The excess fluid is absorbed in surrounding tissues by blood vessels.