General Information about Glaucoma
Who can get “Glaucoma“?
Glaucoma can occur in all age groups right from infancy to adulthood, but the most common type of glaucoma, occurs in adults above the age of 40 yrs.
It is not proven that Hypertension or Diabetes have a direct relation to glaucoma.
How common is glaucoma?
Glaucoma is the second most common cause of preventable blindness, after cataract. It roughly affects 1-2 per 100 people above the age of 40 yrs.
Those who are at more risk of developing glaucoma are:
- Those with raised intraocular pressure ( > 24 mmhg)
- Those who have a parent or a sibling affected with glaucoma.
- High degrees of hypermetropia.
- Those with previous injury to the eye.
- Those with other eye problems like uveitis, retinal
- detachment, etc.
- Those who are using steroids for a long period in any forms.
e.g, eye drops, inhalers, tablets, etc
What are the symptoms of Glaucoma?
Glaucoma in its typical form, called primary open angle glaucoma, occurs silently, without any symptoms. By the time, the patient experiences a decrease in vision, it is very late in the course of the disease.
Some patients may experience vague symptoms such as pain in and around the eye, a sensation of heaviness, headache, fluctuating vision etc.
In the second type of glaucoma called angle closure glaucoma., the patient can experience periodic blurring of vision accompanied by pain, headache, nausea, and a perception of coloured haloes around lights. It can also result in a sudden pronounced raise in the eye pressure and manifest as an acute angle closure glaucoma., with severe pain, headache, vomiting, and blurring of vision.
How do I know whether I have Glaucoma or not?
Only a thorough examination by a qualified ophthalmologist will detect glaucoma in its early stages. Therefore, regular yearly eye checkups are recommended for all persons above the age of 40 yrs, and those with the other risk factors mentioned above.
What are the examinations done to detect or confirm Glaucoma?
- Measurement of eye pressure by a tonometer.Your eye pressure must be routinely checked in every eye examination by an instrument called a tonometer. There are
various types of tonometers available, but the most accurate is the applanation tonometer.
- Examination of the front of the eye with the slit lamp, and by a gonioscope to study the angle of the anterior chamber
- Examination of the optic nerve head in the retina, by a lens,along with the slit lamp. If any of these examinations are positive, your doctor may suggest further investigations to help confirm whether you have glaucoma or not.
Visual fields test:
Optic nerve head/ nerve fiber layer analysis techniques:
This is a computerized testing of the peripheral vision. The instrument flashes small spots of light which vary in intensity, and records the patient's responses.
The results are compared to a normal database that is inbuilt in the machine and results are printed. This test can help detect early changes that can occur in the field of vision in glaucoma.
These are newer ways to assess damage to the optic nerve head, and have the ability to pick up glaucoma very early, much before, the changes occur in the visual fields. HRT-2: this instrument maps the optic nerve head contours accurately, and compares the nerve with its normal database, and gives the results. Can be used excellently for following up patients to detect change in the nerve over time. GDx VCC: this instrument measures the thickness of the nerve fiber layer, in various quadrants and gives a comaparision with the normal database, and estimates the amount of damage. This can be used in early detection and in the follow up of patients with glaucoma
What is the role of eye pressure in glaucoma, and what is the normal eye pressure?
Raised intraocular pressure is not a absolute criterion to diagnose glaucoma. Glaucoma can occur at any eye pressure from 10- 30mmhg. However, patients with raised pressures ( > 25mmhg), are more likely to develop glaucoma.
The statistical range of normal eye pressure ranges from 10- 20 mmhg. However, whether the pressure produces damage from glaucoma, varies from individual to individual. Measuring the corneal thickness by a procedure called “pachymetry”, can help predict the susceptibility to the pressure related damage. Generally the optic nerve damage in glaucoma results from two factors:
- Eye pressure related
- Pressure independent factors e.g.: blood supply of the optic nerve, inherent weakness etc..
Once a diagnosis of glaucoma is made, when we consider treatment, it is only the eye pressure which we can manipulate or alter. The non pressure related factors cannot be altered in a significant manner. Therefore, the mainstay of glaucoma treatment is reduction of eye pressure. Depending on the initial pressures, the amount of damage and the age of the patient, your doctor will set a Target eye pressure, to be attained with
How is glaucoma treated?
Glaucoma is treated as mentioned above, mainly by reduction of eye pressure. This can be by
- Medications in the form of eye drops., tablets.
Once detected , and treatment started, it must be continued for life. Medical treatment can be stopped only if other means of reduction of eye pressure e.g., laser, or surgeries have been performed.
Since the patient will have no symptoms related to the eye pressure, periodic (3Monthly, or more frequent as advised by your doctor) eye check ups need to be done to ensure good control of glaucoma.
Glaucoma cannot be cured, it can only be controlled.
It is not necessary that every patient with glaucoma will go blind, or suffer from vision loss. When detected and treated early, vision damage can be minimized, and the patient can have absolutely normal and adequate vision, through out his/her lifetime.
It only requires care and regular medications, and eye check ups to ensure that the damage is prevented.
Tell your family members (siblings & children) to get checked for Glaucoma
Treatment of Glaucoma
Tips on Instilling Your Eyedrops Properly
If you have glaucoma, you most likely use 1 or more kinds of eye drops, possibly 2, 3, or more times during the day. These eye drops are critical in protecting and preserving your vision. By lowering the pressure inside your eye, the eye drops help prevent further optic nerve damage and vision loss.
If you are unable to properly instill the eye drops as prescribed by your ophthalmologist you may ultimately end up losing your vision permanently. The following tips may be helpful to you if you have glaucoma or another condition that requires the use of eye drops.
- Wash your hands before putting in your eyedrops. This will help reduce the chance that you will get an infection or that your eyedrops will become contaminated.
- You may find it easier to tell that the eyedrop has gone in your eye if you keep your eyedrops in the refrigerator because the eyedrop will feel cold when it goes in your eye.
- If you have to put in more than 1 kind of eyedrop at a time, it usually does not matter which eyedrop goes in first. However, allow 3-5 minutes between putting in different eyedrops so that the first eyedrop can “soak in” and is not “washed out” by the second eyedrop.