Glaucoma is an eye disorder in which the optic nerve suffers damage, permanently damaging vision in the affected eye(s) and progressing to complete blindness if untreated. It is often, but not always, associated with increased pressure of the fluid in the eye (aqueous humour). The term 'ocular hypertension' is used for cases having constantly raised intraocular pressure (IOP) without any associated optic nerve damage.

Glaucoma can be divided roughly into two main categories, "open angle" and "closed angle" glaucoma. Closed angle glaucoma can appear suddenly and is often painful; visual loss can progress quickly, but the discomfort often leads patients to seek medical attention before permanent damage occurs. Open angle, chronic glaucoma tends to progress at a slower rate and patients may not notice they have lost vision until the disease has progressed significantly.

Glaucoma has been nicknamed the "silent thief of sight" because the loss of vision normally occurs gradually over a long period of time, and is often only recognized when the disease is quite advanced

At Aster Eye Care following investigations are carried out to determine glaucoma:

Tonometry

measures pressure in the eye. Medicine drops are used to numb the eye. An instrument gently presses on the outside of your eye. Pressure is shown as a number followed by the abbreviation "mm Hg." This stands for "millimeters of mercury," a standard measure for pressure. An average pressure is about 16 mm Hg. Still, a higher than average number doesn't always mean you have glaucoma.

Ophthalmoscopy

Thickness of the cornea) may affect the pressure reading and the risk of glaucoma progression, pachymetry is done to measure the same.

Gonioscopy

After numbing the eye, the doctor gently places a special lens on the surface to examine the area in the front of the eye that drains fluid. Gonioscopy allows a more accurate diagnosis of the type of glaucoma.

Perimetry

evaluates your visual field. This tests your vision all around your field of viewing (360 degrees) to see if any areas are missing. It usually involves staring straight ahead at a light and trying to see lights that appear around the sides of your view. This is generally done with a computerized system.

Photography

Photography: or laser scanning may be used to show the appearance of the optic nerve inside your eye. This will also involve dilating your eye.

Glaucoma can usually be treated and controlled using medicine(s), laser surgery, glaucoma surgery or a combination of these treatments. Medicines (eye drops) are typically the first step in treatment, but laser surgery may be just as effective as a first choice. Your treatment is up to you and your doctor.

Treating Glaucoma with Medicines: Doctors prescribe many types of medication to treat glaucoma. These drugs lower pressure inside the eye. Often, people with glaucoma have to take these medicines for life to control the pressure and limit

Glaucoma Surgery

Filtering surgery creates a new path through the eye's tissues to let fluid drain from the eye. In the most common filtering surgery, called a trabeculectomy, the surgeon makes a small opening in the white part of the eye (the sclera) to create a new outflow path. The fluid then flows through the new opening and creates a bleb, which is like a small bubble or reservoir on the surface of the eye. The bleb holds the fluid while it is slowly absorbed into the surrounding tissue. The upper eyelid usually hides the bleb, so it's not noticeable to you or others.

Drainage implant surgery is sometimes performed when a person is not suited for filtering surgery or when filtering surgery has failed. Depending on the kind of implant used, the surgery is called valve, shunt or seton surgery.

Treating Glaucoma with Laser Surgery: Some people may need eye surgery to control their glaucoma. Lasers are very useful for treating glaucoma because they avoid cutting and have a lower chance of complications (compared to glaucoma surgery).

Laser procedures

• Laser trabeculoplasty
• Peripheral iridotomy
• Laser cyclophotocoagulation