Glaucoma is a serious eye disease caused by increased fluid pressure within the eye, which can damage the optic nerve that transmits images to the brain. One of the leading causes of irreversible blindness, the estimated number of cases of glaucoma in India is 12 million. This is around one fifth of global burden of glaucoma.
Glaucoma is known as the “silent thief of sight” as it is a symptomless disease, and people usually do not realize that they are suffering from glaucoma unless they visit the ophthalmologist or have reached an advanced stage of disease. If undiagnosed and untreated, glaucoma can lead to irreversible loss of vision and even cause blindness. Though the disease is not curable, the progress of glaucoma can be halted and total blindness can be prevented if it is detected early.
HOW GLAUCOMA AFFECTS VISION
In glaucoma the fluid pressure inside the eye increases, and this leads to progressive damage of the optic nerve, resulting in a gradual loss of vision. Initially, the loss of vision starts from periphery and progressively affects the central vision. The central visual acuity is affected only in the advanced stage.
The front half of the eye is filled with a clear fluid known as the “aqueous humor”. This fluid is continuously produced and constantly flows in and out of the eye, maintaining a steady pressure inside the eye. If there is either reduced drainage or excessive production of this fluid, the pressure in the eye will increase. This increased eye pressure, if left untreated, can damage the eye (optic) nerve and cause permanent vision loss. Not everyone with high eye pressure will develop glaucoma, and some people with normal eye pressures may also develop glaucoma.
The disease usually affects both eyes, though one may be more severely affected than the other. Unfortunately, the damage to the eye nerve due to glaucoma is irreversible and the loss of vision cannot be reversed. However, this condition can be halted and the remaining vision can be retained if glaucoma is diagnosed on time and appropriate treatment is started.
Primary open angle glaucoma – is the most common type of glaucoma. In this type of glaucoma, the part of the eye through which the fluid of the eye flows out is open, permitting the outflow of fluid, but the patient still has high pressure. This type of glaucoma develops slowly without any symptoms. Initially it affects the peripheral or side vision and very gradually progresses to the centre. This is the reason why many people are not aware that they have the condition until they have significant vision loss affecting central vision.
Risk factors for primary open angle glaucoma are:
Age more than 40 years
Race – African Americans
Family history of glaucoma
Systemic diseases such as diabetes mellitus, hypertension, heart disease
Injuries to the eye
Angle closure glaucoma or closed angle glaucoma –is a less common type of glaucoma which occurs due to narrow drainage channels in the eye. Gradual closing of the angle is called chronic angle closure and if the drainage angle closes suddenly, it causes an acute angle closure attack. Acute angle closure glaucoma usually presents as an emergency. A patient who is in an acute angle closure attack will have symptoms of eye pain, nausea, vomiting, redness and blurred vision due to a rapid increase in the eye pressure. In such cases the patient needs immediate treatment by an eye specialist.
Risk factors for angle closure glaucoma:
Age more than 40 years
Race – East Asians
Family history of glaucoma
High hypermetropia or those with a high plus power
Normal tension glaucoma /Low tension glaucoma –In this type of glaucoma the optic nerve can get affected even though the pressure in the eye is normal. Although its cause is not entirely known or understood, normal tension glaucoma is believed to occur either because of an extremely fragile optic nerve that can get damaged even though the pressure in the eye is normal, or because of reduced blood flow to the optic nerve. Because of its silent nature, people usually do not have any visual complaints until a very advanced stage of the disease.
Risk factors for normal tension glaucoma are:
Family history of normal tension glaucoma
Race – Japanese ancestry
Migraine and peripheral vascular disease
Secondary glaucoma –There are certain other types of glaucoma where there is an identifiable cause for increased eye pressure resulting in optic nerve damage and vision loss. These are called secondary glaucoma. It may be caused by prolonged, indiscriminate use of steroids, severe diabetic retinopathy, injuries to the eye, inflammation of the eye (uveitis) or advanced cases of cataract.
If you believe you have any of these risk factors get an eye examination done. Always remember to inform your eye doctor about the risk factors that you have. This will help your doctor decide how often you need to get your eyes examined.
GLAUCOMA IS HEREDITARY – Family history increases the risk of Glaucoma
Primary open-angle glaucoma, which is the most common type of glaucoma, is hereditary. If members of your immediate family such as a parent or sibling have glaucoma, you are four to nine times more likely to develop this disease than the rest of the general population.
Know your risks! Save your vision! Be informed about your family’s medical history and understand the hereditary risks of glaucoma. Speak to your doctor if you have a family member with glaucoma, it may save your sight. Be vigilant about eye check-ups and alert to possible glaucoma symptoms.
Since early symptoms or pain may not show up in people with glaucoma, this disease is often diagnosed at a later stage when visual loss has already happened. If you’re over the age of 40 and have a family history of glaucoma, you should get a comprehensive eye exam, which includes dilated eye exams and eye pressure checks every year, even if your vision is healthy.
Without treatment, glaucoma can cause total permanent blindness within a few years. As this damage is irreversible, loss of vision due to glaucoma cannot be regained. However, if detected early, vision loss can be avoided, or delayed with the use of eye drops, laser treatment or surgery. Even a small reduction in pressure can make a big difference in slowing vision loss.
WHAT ARE THE TESTS I NEED TO UNDERGO?
The following tests help in finding out the presence of glaucoma and also its progression in the subsequent follow-ups.
Tonometry is a diagnostic test that measures the fluid pressure, known as intraocular pressure (IOP), inside your eye. The tonometry test is important as it can help your doctor evaluate whether or not you may be at risk of glaucoma.
Gonioscopy is a painless eye examination of the front portion of your eye (anterior chamber), to examine whether the area where fluid drains out of your eye (drainage angle) is open or closed. This test is important as it helps your doctor to diagnose and monitor various eye conditions associated with glaucoma.
The Visual Field test is a method of measuring your peripheral or side vision (which is affected first by glaucoma), through which your doctor can diagnose and monitor glaucoma. The data from the test is used to determine the severity of your glaucoma, level of vision loss, damage to the visual pathways of the brain, and other optic nerve diseases.
In today’s world, people are quite aware about how lifestyle choices affect our overall health, and the same goes for glaucoma. Lifestyle choices can, to some extent, influence eye pressure and affect the risk of developing glaucoma, but there aren’t enough proven studies about the same in glaucoma patients. However, a shift towards a healthier lifestyle makes for an overall positive change.
Exercise – Research indicates that regular exercise and an active lifestyle can help reduce their risk of glaucoma. Activities which raise your pulse by 20 to 25, like walking briskly, can help reduce IOP. The more number of steps a person walks throughout the day, less likelihood of an increase in IOP. Aerobics is known to cause a temporary decrease in the intraocular pressure but it has not been tested in glaucoma patients. Swimming reduces vulnerability of the optic nerve to an increase in the intraocular pressure.
Diet – Various studies have been undertaken to study the role of diet in glaucoma. A diet rich in green leafy vegetables is supposed to lower the eye pressure. Dietary nitrates in green leafy vegetables lowers risk of developing open angle glaucoma. DHA (docosahexanoeic acid) is an omega- 3 fatty acid and it is helpful in preserving a healthy retina and lowering the IOP. Rich sources of DHA such as salmon, shellfish, tuna should be consumed twice or thrice a week. If its natural addition to the diet is not possible, DHA supplements in the form of fish oil supplements can be taken. A diet rich in lutein and zeaxanthin helps in lowering intraocular pressure. It avoids oxidative damage to the optic nerve. Spinach, broccoli and sprouts are rich sources of lutein and zeaxanthin. Antioxidants provide nutrients and strengthen the muscles and nerves in the eye. Rich sources of antioxidants are blueberries, grapeseed extract, goji berries, pecan nuts and cranberries.
What to avoid
Exercise – Lifting of heavy weights is known to cause a temporary increase in the intraocular pressure. Hence, patients who already suffer from glaucoma are advised to avoid lifting very heavy weights. Yoga, which is a very popular form of exercise includes various ‘asanas’ or positions. Some of these asanas, particularly those with the head – down position (sheershasana) have been proven to cause an increase in the eye pressure. Therefore, patients with glaucoma are advised to avoid such positions.
Diet – Foods which are rich in trans-fats, the kind found in deep fried food, prevent the optimal functioning of omega 3- fatty acids and increases eye pressure. Such food should be avoided.
Habit forming substances – such as caffeine, alcohol, tobacco and marijuana are known to have a negative effect on eye pressure. Caffeine, which is consumed widely, is known to cause a temporary increase in the eye pressure. Consumption of caffeine in small quantities is alright, but an excessive intake of caffeine is has been proven to increase the risk of glaucoma. Alcohol is known to decrease the eye pressure for a short duration but a daily consumption of alcohol is supposed to increase the risk of glaucoma. Smoking cigarettes is known to increase the risk of glaucoma. Though marijuana is known to lower eye pressure, it is not recommended for treatment due to its side effects.
Musical instruments – such as the trumpet and the saxophone are known to cause an increase in the eye pressure. Glaucoma patients are advised to avoid playing such high resistance wind instruments which can increase the intraocular pressure.
Glaucoma affects the quality of life of millions of people. In the early stage of glaucoma, patients experience compromised vision which affects their quality of life. This worsens as the disease progresses. Ocular discomfort, psychological factors, economic factors, and social constraints contribute to the burden of the disease.
TIPS to make the life of a glaucoma patient easier
A better understanding of your treatment and medications can make it easier to live with glaucoma and easier for your doctor to control your disease. Early diagnosis, and therefore early intervention, is crucial in delaying the progression of the disease process.
Before the disease is detected:
Prevention is better than cure
Ophthalmic consultation is a must for everyone over the age of 40, in an eye hospital rather than getting tested for near vision at an optical shop.
Get glaucoma screening done if you have a family history of glaucoma, diabetes, hypertension, heart disease, asthma, arthritis, migraine, thyroid disease, using minus or plus powered glasses, any history of trauma to eye. If detected in the early stage, the disease can be arrested and existing vision can be retained.
Babies born with whitish coloured eyes or bigger than normal eyes, or babies with severe watering and difficulty in opening their eyes at birth, should be screened for congenital glaucoma.
After the disease is detected:
If you have undergone any surgery or laser treatment for glaucoma, it is important to understand that these procedures are performed to reduce the intra-ocular pressure and are an attempt to restore the remaining vision.
Follow the instructions of your doctor and attend follow up examinations as advised
Follow the technique properly while instilling the medication into the eye so that the desired effect of medication is attained.
Regular usage of medications
– keeping alarms on your mobile phones will remind you to instil your medications on time
– making a simple drug chart in a pocket diary as shown in the figure so that it can be noted and showed to your doctor as well.
Morning 8 am
If you have any difficulty in instilling the medication or if you have any discomfort with the medication, let your doctor know about it rather than stopping the medication.
Never stop the medications without consulting your doctor – people usually think that there is no change in vision and stop the medication. This can compromise your vision further.
How do my glaucoma eye drops work and help save my vision?
The goal of glaucoma treatment is to lower the pressure in your eye. It often starts with the prescription of eye drops. These can help decrease your eye pressure by improving how fluid drains out of your eye or by decreasing the amount of fluid your eye produces.
What precautions should I take while putting my eye drops?
Wash your hands before instilling your drops. While opening the cap of your eye drop, be careful not to touch the nozzle of the bottle. Gently pull your lower eyelid and put one drop into the eye. Gently close your eye for a few seconds. Do not squeeze the eye forcefully after putting the drop, as it may cause the medication to come out of your eye and get wasted.
My doctor has prescribed more than one eye drop for glaucoma. Can I put them into the eye one after the other?
No, usually you should leave a gap of 5-10 minutes between the two eye drops as it helps in better absorption of the drop and helps in better eye pressure control.
Is it safe to put in an extra drop just to make sure?
Yes, if you are not certain that the first drop went in, it is safe to put in another drop. In general, it is best to avoid putting in more than one drop.
I miss instilling my eye drops often. Will it affect my vision?
Missing your eye drops often leads to inadequate control of eye pressure. In order for them to help your eyes, you will need to use your drops every day. Make it a part of your daily routine, like brushing your teeth. Follow your doctor’s instructions properly.
How important is it to put the drops at exactly the time stated?
It is important to get into a routine and to instil the eye drops at around the same time each day, but the exact time is less important.
There are several ways to help yourself remember when to put your drops in:
A chart with tick boxes,
A box with compartments for the drop bottles,
A special timer can be set to ring several times each day as required
Where should I keep the drops and for how long?
Read the storage instructions mentioned on the cover of your eye drops. Keep your drops in a cool place or in the door of the refrigerator. Do not place them in the freezer section. Check the expiry date on unopened bottles before using them.
What happens if I forget to take my drops when I go out?
Do not worry unduly if you forget on the odd occasion, but try to get into the habit of taking your drops with you wherever you go. If you have forgotten a drop, just put it as soon as possible after the time it was due.
Can I take other medicines at the same time as my glaucoma treatment?
Patients with angle closure or narrow angle types of glaucoma should seek advice before taking some types of tranquillizer or certain asthma and indigestion medicines. However, glaucoma eye drops are usually safe if you have had laser treatment (laser iridotomy) or glaucoma surgery.
Steroid (cortisone-type) drops and tablets should be used with caution because they can increase the pressure in the eye.
Always mention that you are on glaucoma medication when you visit a doctor for any other treatment.
Do I need to put the drops in before I come to the clinic?
Yes, always continue as usual unless requested otherwise. It helps the doctor to judge the effect of the treatment.