Glaucoma sneaks in

You don't know till vision is lost

The eyes are like a balloon filled with watery substance. This fluid is continuously secreted and drained out at the same time, maintaining a healthy state of eyes. 

In glaucoma the outflow of this fluid is stopped or reduced, thus leading to accumulation and increase in the pressure on eye. This is different from cataract where the lens of the eye gets opacified with age

Glaucoma is a disease that can lead to blindness or loss of vision. It is caused by damage to the eye's optic nerve. If detected and treated early, permanent damage can be minimized or even avoided. However, once damage occurs, it cannot be reversed. Normal pressure of the eye should never be over 20mm hg.

There are many types of glaucoma. The most common form is open angle glaucoma, also called chronic glaucoma.  Open angle glaucoma is caused by high pressure in the eye, which damages the optical nerve and impairs vision. Increased eye pressure does not always mean you will get glaucoma, but it does increase your risk.

Another type of glaucoma is low-tension or normal tension glaucoma, which occurs when the optic nerve is damaged despite seemingly normal pressure levels. Treatment is the same as open angle glaucoma. Closed-angle glaucoma is also commonly caused when the iris and lens essentially stick together, preventing fluid flow from the eye.   

Symptoms

Glaucoma initially can be absolutely symptom less thus most often missed by  patients. Sometimes glaucoma may cause decreased vision in night time or glare and haloes around bright light and frequent change of spectacles. If glaucoma is untreated, vision slowly worsens. Peripheral vision (to the sides) is usually the first to deteriorate thus slowly reducing the field of vision. Glaucoma can develop in one or both eyes. 

Detection

There are many tests that can be done to detect glaucoma. Usually intraocular pressure tests and visual field tests are performed in combination to determine the eye's pressure and the pressure's affect on the optic nerve. Photographs of the optic nerve may also be taken to determine the health of the optic nerve. 

Treatment Options

There is no cure for glaucoma. Damage done to the optic nerve is permanent. There are, however, many treatment options that can minimize the effect and prevent further damage. Treatments include eye drops, laser trabeculoplasty or conventional surgery. These treatments are often used together. 

Medication can be used to reduce eye pressure, preventing further damage to the optic nerve. Eye drops are the most common type of medicine.   

Anti-glaucoma medications

Laser trabeculoplasty is a treatment performed by a doctor or eye care professional. A laser machine is used to improve drainage in the eye. This is a long-term solution than medicine, but the effect will reduce over time.

Laser treatment of glaucoma includes

• Selective Laser Trabeculoplasty (SLT)

• Argon Laser Trabecul-oplasty (ALT)

• YAG Laser Iridoplasty

• Endoscopic Cyclophoto-coagulation (ECP)

• Argon Laser ciliary body ablation

• Diode Laser ciliary body ablation 

Surgical treatment of glaucoma including:

• Trabeculectomy with and without antimetabolites

• Non-penetrating glaucoma surgery: Aquaflow and Viscocanalostomy

• Glaucoma implant surgery Surgical treatment for Glaucoma In conventional surgery, a small piece of tissue is removed from the eye, which creates a new opening for the fluid to leave the eye.

 Age-Groups at risk

Glaucoma can affect anyone. The most common groups who are affected are as follows:

• b  Everyone over the age of 45

• People with a family history of glaucoma

• From 35 on, everyone should have regular check-up for early signs of glaucoma  

A case history

Mr. Jha was an active and healthy 52 year old man. He never had problems with his vision or eyes.  He went for a regular health check-up with his doctor, who recommended that he have eye tests done to see if he was affected by glaucoma.

The doctor explained that people are often not aware that they have glaucoma and remain symptomless until permanent damage has already occurred. Vision can slowly get worse, and people do not notice a sudden change until a lot of vision is lost.

Mr. Jha agreed to have the pressure of his eyes checked and to have a visual field test.

Once the tests were done, the doctor explained that it was coincidental that Mr. Jha had increased eye pressure and that some damage had been done to his optic nerve. Fortunately, his glaucoma was detected early so he only lost a small amount of his peripheral vision. 

The doctor recommended that he should use eye drops to control his eye pressure.   Jha now returns for regular check ups with the doctor. 

—Dr Kamal Kapoor,Sharp Eye Centre 

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