Glaucoma : Types, Causes, Symptoms, Diagnosis,Treatment & Prevention.

 

What is Glaucoma

Glaucoma is an eye condition that results in damaging of the optic nerve. It is basically caused due to increase in intraocular pressure (pressure inside our eyes) as you can see above in the image. We will talk about its causes in detail in the further article. Since the optic nerve is damaged, this can lead to permanent loss of one's eyesight. Generally, people suffering from glaucoma don't have early symptoms or any kind of pain therefore one should have regular eye checkups from their doctors so that problem could be early diagnosed because glaucoma worsens with time which may lead to total blindness.

 
Causes Of Glaucoma

Basically as discussed above glaucoma is caused due to increase in intraocular pressure (pressure inside eyes). Fluid, aqueous humor is continuously made in the back of the eyes and gets filled in the front part of the eyes and leaves the eyes through channels of cornea and iris. These humors are basically secreted to maintain the pressure inside the eyes but in glaucoma condition, these channels somehow get blocked or obstructed which results in increasing of intraocular pressure (IOP) and  which further results in damaging of the optic nerve.

This can happen because of many factors, few are listed below.

•           Blocked drainage in eyes

•          One may have poor blood flow in the optic-nerve of their eyes.

•          High blood pressure is also one of the factors.

•          Medicinal side effects.

•          Genetically inherited

•          Medical history: Diabetic patients, people having high blood pressure or any heart disease may also develop glaucoma condition.

•          Age: Chances of developing glaucoma increase with the increase in age. People over 60 years are at greater risk of developing glaucoma.

•          Any other eye infection

Types Of Glaucoma and their Symptoms

 

Symptoms of glaucoma vary depending on the type of condition. Let's  discuss different types of glaucoma and their symptoms.

 

1.   Open - Angle Glaucoma : This is the most common and primary type of glaucoma. This generally has no symptoms or signs and is usually painless in the early stage. With time one may observe patchy blind spots in their vision and gradual visual loss. Since no symptoms, one remains unaware whether he/she is suffering from the disease or not, therefore, everyone should get regular eye exams if not in months at least every year so that if one is having this hidden disease, it could be diagnosed and treated on time preventing any permanent damage to eyes.

2.   Acute Angle - closure Glaucoma: In this type, rapid buildup of aqueous humor due to sudden blockage resulting in a quick, severe, and painful increase in pressure happen. In this, one should contact their doctor immediately.

·       Symptoms :

                                                                            i.            Severe Pain in eyes.

                                                                         ii.            Headache

                                                                       iii.            Vomiting & Nausea

                                                                       iv.            Redness in Eyes

                                                                         v.            Blurred Vision

3.      Normal-Tension Glaucoma: In this condition although IOP(intraocular pressure) is in normal range still optic nerve is damaged which is responsible for glaucoma. Reasons for the damage are unknown.

4.      Secondary Glaucoma: In this type, the optic nerve is damaged due to another disease, trauma, drug, injury, etc causing increased IOP(intraocular pressure).

5.      Pseudoexfoliation Glaucoma: In this type, the pressure inside the eyes is increased due to the accumulation of microscopic granular proteins which results in blocking of drainage of aqueous humor.

6.      Pigmentary Glaucoma: It is a rare condition often known as pigmentary dispersion syndrome, in this, pigmentary cells from the iris are responsible for the blockage.

7.      Primary Juvenile Glaucoma: In this, people have glaucoma like conditions either at the time they were born or may develop it shortly after birth. They may have abnormalities in the anterior chamber angle responsible again for blockage of the drainage of aqueous humor.

8.      Uveitic Glaucoma: This glaucoma condition is caused due to swelling of uvea i.e. middle layer (also called uveal layer) of the eye. Most of the blood is supplied to the retina through the retina, therefore, damage or increased pressure in this due to swelling also causes glaucoma.

Above mentioned symptoms are common to all.

 

Visual Defects:

Some visual defects experienced in glaucoma are listed below:

·         Baring of blindspot.

·         Small wing- shaped scotoma.

·         Siedel's sickle-shaped scotoma.

·        Ring Scotoma.

·        Peripheral field defects.

Diagnosis:

1.    Tonometry Test: This test is done to measure the inner eye pressure using a tonometer.

2.    Ophthalmoscopy Test: This test examines magnified optic nerve using a small magnification device by observing the shape and color of the optic nerve. 

3.    Perimetry Test: In this test, the examiner maps the patient's complete field of vision.

4. Gonioscopy Test: In this test, the examiner sees the angle between the cornea and the iris, and glaucoma is diagnosed accordingly.

5. Pachymetry Test: In this, the thickness of the cornea is examined as corneas thinner than average have an increased risk of developing glaucoma.

6. Nerve - Fibre Test: This test is done to examine the thickness of the nerve fibre layer.

Treatment For Glaucoma:

Remember that there is no cure for glaucoma, we can't stop glaucoma to happen but yes we have various methods available to treat glaucoma . The main aim is to reduce increased pressure in the eyes. some of the treatments are listed below:

1.      Medications :

Generally, everyone's first priority to treat any kind of disease is  by medicines instead of any surgery  or operation. Fortunately, Glaucoma can be treated with the help of medicines. Various eye drops and pills are available in the market for this purpose however drops are more common. These medicines may cause side effects, so on observing something like this, one should immediately approach to their doctor so that situation could be controlled otherwise, that would again give rise to another problem along with glaucoma and one should not take any chance because our eyes are really precious and delicate.
 
2.      Laser :

Argon laser trabeculoplasty, also known as ALT can be used to treat open-angle glaucoma. This helps in opening up of the mesh hence allowing more outflow of aqueous humor.
 
Patients susceptible to or affected by the angle closure glaucoma can be treated by laser peripheral iridotomy (LPI). In this, laser energy is used to make a small, full-thickness opening in the iris in order to equalize the pressure in the iris, thus correcting any abnormal bulging in the iris.
 
Diode laser cycloablation can be used to  lower intraocular pressure by reducing aqueous secretion by destroying secretory cells.
 
3.    Surgery :

·         Canaloplasty :  Microcatheter technology is used in this procedure. Schlemm's canal is opened by making an incision in the eyes, pressure can be reduced by this.

·         Trabeculectomy: This one is the most common conventional surgery in order to treat glaucoma. In this, in the scleral wall of the eye, a partial-thickness flap is made, and a window opening is made under the flap to remove the trabecular meshwork. The scleral flap allows fluid to flow out of the eye through this opening, resulting in lowered intraocular pressure.

·       Glaucoma drainage implants: Glaucoma can also be treated by several types of implants. These are for glaucoma patients who are not getting relief from medical therapy or any of the surgeries.

Prevention :

Unfortunately, there are no measures that could be taken to prevent glaucoma. All we can do is, getting it treated as soon as possible so that it doesn't get worse. You might be having this disease and you are unaware of it, what will you do then? That is why regular eye checkups are important so that any kind of problem can be caught and treated accordingly as early as possible.