Glaucoma is a very common disease of the eye and anyone can suffer from it without even showing any symptoms at all before turning to blindness. That’s why it’s necessary for all of us to have some knowledge about keeping our eyes healthy in order to save our vision.
Glaucoma is a disease caused by the damage of the optic nerve leading to blindness if undetected and left untreated. It can remain undetected until the optic nerves are significantly damaged by the fluid pressure in the eye. The damage of the optic nerve by the excessive fluid pressure creates “blind spots” in the eye which may go undetected in many patients. Usually a little clear fluid circulates in the front portion of the eye and this fluid is termed as “aqueous humor”. To maintain healthy eyes, a little pressure in the form of aqueous humor is circulated continuously within the eye and the same amount of fluid flows out of the eye using a minute microscopic drainage system called “trabecular meshwork”. In case of someone suffering from glaucoma, the aqueous humor does not flow through the trabecular meshwork and thus creates excessive pressure in the eye and in the long run this excessive pressure may damage the optic nerves, which develops into glaucoma.
There are many subtypes of glaucoma that can affect the patients due to various reasons. But no reason clearly states the causative agents of glaucoma. Following are its main types:
Open Angle Glaucoma
In this case, the trabecular meshwork becomes less efficient in draining the aqueous humor in the eye. As a result, the intraocular pressure develops within the eye thereby damaging the optic nerves. The development of intraocular pressure could be different in patients and the amount of damage caused by this pressure may also be different in individuals. However, this type of development of glaucoma has no significant symptoms at an early stage rather than developing blindness slowly and thus remains undetected in most of the cases and as a result the patient may turn completely blind by the time it is detected by doctors.
This type of glaucoma may often occur in patients with:
- High eye pressure.
- Elderly people over 55 years of age.
- Eye injury or surgery.
- Highly myopic patients.
- Family history.
- Diabetes.
- Hypertension and High Blood pressure.
- Longer use of corticosteroids in the form of eye drops, creams, pills.
Closed or Narrow Angle Glaucoma
In this case, the drainage from trabecular meshwork gets blocked by the iris. As a result, the intraocular pressure develops very fast and thus causes severe damage to the optic nerves. However, this particular type of glaucoma has some symptoms like pain in the brow or in the eye, redness in the eye, development of blurred vision or vision is reduced day by day including nausea and vomiting. Closed angle glaucoma could be acute or chronic depending upon development of the intraocular pressure in the eye. In case of acute closed angle glaucoma, the flow of aqueous humor is blocked suddenly thereby causing severe pain in the eye or brow. This type should be treated immediately; otherwise the patient may turn completely blind within one or two days. Chronic closed angle glaucoma generally affects the patients very slowly like the open angle types without showing any significant symptoms leading to complete blindness.
Closed angle type of glaucoma may often occur in patients with:
- Age.
- Family History.
- Farsightedness.
- Result of eye injury or eye surgery.
Congenital Glaucoma
This type of glaucoma is usually detected in children and they are born with this defect which prevents the normal drainage of the aqueous humor in their eyes.
Juvenile Glaucoma
This is a type of open angle glaucoma which may affect infants, adolescents and young adults.
Secondary Glaucoma
This could either be open or closed angle and may affect the patients with a particular medical condition of the eye or the body.
Normal Tension Glaucoma
This may develop in patients even having the normal intraocular pressure in the eye. The optic nerve may tend to get damaged due to several factors like suffering from cardiovascular disease, or patients with family history or even with low intraocular pressure of the eye. This can be treated with medication by lowering the intraocular pressure and is similar to the one that is applied for open angle glaucoma.
Diagnosis
Glaucoma can be detected by regular eye exams by an ophthalmologist with routine eye tests as follows:
Tonometry: This test measures the intraocular pressure (IOP) of the eye. This is carried out with the help of a sophisticated instrument called a tonometer. There are again various types of tonometry that can be done with different types of tonometers. They are:
- Applanation Tonometry (Goldmann Tonometry): This measures intraocular pressure by using a Goldmann tonometer.
- Non-Contact Tonometry: This type of tonometer measures the IOP by using a rapid air pulse.
- Diatone Tonometry: This is one of the latest technologies which uses a diatone tonometer to measure the intraocular pressure through the eyelid without adding any drops or coming in contact with the cornea, thereby preventing the chance of infections. This type of tonometry can be safely used on both adults and children as it is comparatively quick, safe, painless and very efficient.
Opthalmoscopy: This is done with an instrument called ophthalmoscope. In this test, the back side of the eye is examined with the help of an opthalmoscope and a light source. This can give a clear picture of the different structure of the inside of the eye.
Gonioscopy: This is done to check whether the angle between the iris and the cornea is open or closed in order to detect the type of glaucoma the person is suffering from.
Perimetry: This is a painless test and is also called the visual field test.
Medication
Glaucoma can be treated with various eye drops to reduce the intraocular pressure of the eye. However, some of these eye drops may have side effects which should be immediately relayed to the concerned doctor treating the patient in order to prevent vision loss in the long run.
Treatment
Besides medication, glaucoma can also be treated by advanced technology using various methods like surgery, canaloplasty, laser surgery, trabeculectomy, glaucoma drainage implants and veterinary implants.
