DEFINITION

Glaucoma is a group of diseases of the eye that can damage the optic nerve when the white and thick fluid (responsible for healthy eye) gets stuck during draining, clogs up and causes pressure, leading to vision loss and blindness. Early treatment is very important for eye and vision protection.

TYPES

1. Primary Open-Angle Glaucoma
2. Normal Tension Glaucoma (NTG) or Low Tension Glaucoma
3. Angle-Closure Glaucoma
4. Acute Glaucoma
5. Pigmentary Glaucoma
6. Exfoliation Syndrome
7. Secondary Glaucoma
8. Pediatric Glaucoma
9. Congenital Glaucoma
10. Neovascular Glaucoma
11. Trauma-Related Glaucoma

CAUSES

1. Hereditary factors
2. Steroids of eye drops
3. Diabetes
4. Previous eye injury or surgery
5. Improper imbalanced diet
6. Wearing contact lenses
7. Too much reading or reading in low light

It is common in African Americans than it is in Whites, and affects people of all ages.

SYMPTOMS

1. Blurred and diffused vision
2. Eye pain
3. Red eye
4. Dilated pupils
5. Severe pain in the head
6. Seeing halos around lights
7. Decreased straight-ahead vision

DIAGNOSIS

1. Tonometer - to measure the pressure of the eye.
   Using some drops (as anesthesia), slit lamp and a plastic prism, IOP (Intra Ocular Pressure) is measured.
2. Visual Field Test [Perimetry]
   This includes testing of the patient's visual field so as to determine the extent of damage to the optic nerve from increased IOP.
   
   In this, flash of light are incident on the patient's eye and his field of vision is noted through computer on paper.
   One more similar test - the Goldmann perimeter which does not require computer but the patient's reaction is noted.
3. Ophthalmoscopy
   An ophthalmoscope which enables the doctor to look directly through the pupil at the optic nerve. Its color and appearance can indicate the existence and extent of glaucoma.
4. Gonioscopy
   It is a painless eye test that checks the angle of meeting of iris and cornea. Glaucoma exists in case of open as well as closed angles.

TREATMENT
There is no cure for Glaucoma. It leads to irreversible loss of vision, so the main purpose is to prevent further loss of vision which can be done by keeping IOP under control. Ways for the same are:

1. Eyedrops
2. Pills
3. Laser treatment or cutting surgery
4. Eye operations
5. Exercise and good nutrition