Glaucoma is a group of diseases that can damage the eye’s optic nerve and may result in vision loss and blindness. Multiple factors are often important in causing glaucoma, but it is most commonly related to in an increase in pressure in the eye. Symptoms are generally absent until the condition has progressed to an advanced stage. Very occasionally, a rarer form of glaucoma can develop suddenly and symptoms may then include: headaches and aches around the affected eye, seeing halos around lights, sensitivity to light, blurred vision, nausea and vomiting.
You may be more likely to develop glaucoma if you:
- have someone else in your family with glaucoma
- already have high pressure in your eye
- have experienced injury to your eye
- have or have had certain other eye problems
- have migraine or circulation problems.
Glaucoma is more common in people over 50 years of age and more common in women than men. Diagnosis usually comes after consultation with an eye doctor. Signs of glaucoma may also be picked up at an optometrist’s eye examination.
The following tests are used to diagnose and monitor glaucoma:
- Tonometry – measures eye pressure. It is often the first screening test for glaucoma. The eyes are numbed with eye drops and then examined.
- Dilated eye exam - this is done with an ophthalmoscope (which is a medical instrument that allows the doctor to look through the pupil to the back of the eye).The retina and optic nerve are then examined for any sign of damage.
- Visual acuity test – test to check distance vision using an eye chart.
- Visual field test – test to measure side (peripheral) vision.
- Pachymetry – test to measure the thickness of the cornea.
- OCT scanning of the retinal nerve fibre layer is a new technique that is useful in both diagnosing glaucoma and following someone with established glaucoma.
Many other new techniques are emerging to help identify the likelihood of glaucoma and help determine its rate of worsening. Although glaucoma cannot be cured, early treatment can prevent further worsening of the condition and vision loss. Regular eye examinations will need to be continued life-long.
Eye drops to decrease eye pressure are the most common early treatment. Surgery may be required, especially if medications are not taking adequate effect.
Laser trabeculoplasty, in which a surgeon uses a laser to help the fluid drain from the eye, may be considered in some cases, but has limited effectiveness.
More commonly, a trabeculectomy may be performed when other methods have failed to adequately control pressure. This is a medium length operation that makes a new opening for fluid to drain from the eye.