Glaucoma Risk Factors

The following are risk factors associated with glaucoma; 

Stages of Glaucoma 

Glaucoma usually develops gradually over a long period of time and initially, no symptoms are present. This is the reason why regular examination of the eyes should be done by an Ophthalmogist to be able to detect possible risk factors of glaucoma or to detect glaucoma at an early stage to avoid vision loss.  A comprehensive periodic eye examination is recommended for all adults starting at the age of 40 years and more often for high risk groups.

 

Glaucoma usually undergoes various stages before a vision loss can occur. These four stages of glaucoma are; 

 

The initiating Events - These are the risk factors or precipitating factors that lead to predispose someone to developing glaucoma. Such as illness, congenital abnormalities of the eyes, long term use of medications that dilates the eyes. 

 

The second stage involves the structural alteration of the fluid drainage system. For example, when the iris moves forward to block the angle between the cornea and iris, leading to blockage. 

 

The third stage is the functional alteration - The increased intraocular pressure inside the eye lead to compression of the small blood vessels, impairing the blood flow to optic nerve. This leads to the fourth stage which is the optic nerve damage. 

 

The Optic Nerve Damage - Results from the atrophy and death of the optic nerve, due to decreased blood flow to the eye. 

 

Visual Loss - This the final stage that is characterized by progression visual field defects and vision loss. 

 

Types of Glaucoma 

The four recognized types of glaucoma are: open-angle glaucoma, angle-closure glaucoma (also known as pupillary block), congenital glaucoma and glaucoma that develop from other conditions. The most common type of glaucoma in adults is the open-angle glaucoma and angle closure glaucoma.  

 

Open-Angle Glaucoma 

In open-angle glaucoma both eyes are affected but one eye may be severely affected than the other. The three different types of open-angle glaucoma are: chronic open-angle glaucoma (COAG), normal tension glaucoma and ocular hypertension. In all the three types of open-angle glaucoma, the anterior chamber (the space behind the cornea and in front of iris) appears normal and the angle is open but the drainage channel (trabecular meshwork) is the one that is blocked, restricting the fluid flow. This causes the fluid to remain inside the eye, hence increasing the pressure inside. 

 

Signs and Symptoms of Open-Angle Glaucoma 

Chronic Open -Angle Glaucoma - visual field defects (not able to see the immediate surroundings clearly), optic nerve damage, intraocular pressure higher than 21mm Hg, headache, ocular pain and seeing of stars. Sometimes, no symptoms are present. 

 

Normal Tension Glaucoma - intraocular pressure of less or equal to 21mm Hg, optic nerve damage and visual fields defects.

 

Elevated ocular hypertension - increased intraocular pressure, headache and ocular pain. 

 

Angle-Closure (Pupillary Block) Glaucoma 

Angle-Closure (Pupillary Block) Glaucoma occurs when there is an obstruction of the aqueous humor outflow. The iris moves forward and partially or completely closes the angle formed by the cornea and iris. As a result the aqueous humor (fluid) cannot flow outside, increasing the pressure inside the eye. The three different types of angle-closure glaucoma are: Acute-angle closure glaucoma, sub acute angle-closure glaucoma and chronic angle-closure glaucoma. 

 

Signs and Symptoms of Angle-Closure (Pupillary Block) Glaucoma  

Acute Angle-Closure Glaucoma - Usually develop suddenly and rapidly progresses to visual impairment. Signs and symptoms of acute angle-closure glaucoma include;  

Subacute Angle - Closure Glaucoma - Consistent blurring of vision, seeing of halos or stars around the lights, temporal headache, ocular pain and the pupil may be semi-dilated. 

 

Chronic Angle-Closure Glaucoma - Marked by a significant visual field loss, headache and ocular pain. The intraocular pressure may be increased or normal.

 

Complication of Glaucoma 

Possible complications associated with glaucoma, if left untreated are: 

Glaucoma Diagnosis Tests 

A comprehensive eye examination, together with your medical history to determine the risk factors.

 

Other diagnosis tests include;  

Glaucoma Treatment and Management 

Treatment of glaucoma is directed towards preventing the progression of glaucoma to optic nerve damage. Since glaucoma cannot be cured or reversed, a long time therapy is usually prescribed, in considering to your medical history, the stage of glaucoma, your preference and other factors. The main goal of any treatment is to maintain the intraocular pressure within an acceptable level, in order to prevent further damage. 

 

Medications used to treat glaucoma include both topical and systematic to lower the intraocular pressure. Initially, you may receive a lower dose and then it is adjusted to make sure the desired intraocular pressure is maintained. 

 

The following are different kind of medications that are used to decrease the intraocular pressure; 

 

Miotics (Cholinergic Agents) - Used to increase the outflow of the aqueous humor fluid. Examples include; pilocarpine and carbochol. Possible side effects are: pain around the eye, blurry vision and problem seeing in dark.

 

Adrenergics Agonists - Decreases the production of the fluid and increases the outflow. Examples include; dipivefrin and epinephrine. Possible side effects are; redness of the eye, feeling of a burning sensation inside the eye, feeling of the heart beating (palpitation), increased blood pressure, anxiety, headache and tremors. 

 

Carbonic Anhydrase Inhibitors -to decrease the production of the fluid. Examples are acetazolamide, dorvolamide and brinzolamide. Possible side effects include; Oral medications (acetazolamide and methazolamide) can leads to severe allergic reactions, depression, electrolytes loss, stomach upset, weight loss, impotence and increased frequency in urinations. Topical applications can lead to skin allergies. 

 

Alpha Adrenergic Agonists - to decrease the production of the aqueous fluid. Examples: apracloniddine and brimonidine. Possible side effects are: Eye redness, irregular heart rate, fatigue, dry mouth and nasal passage, swollen eyes. 

 

Prostaglandin Analogs - to increase the outflow. Example is the latanoprost. Possible complications: redness of the eye, burning sensation, feeling of the heart beating (palpitation) and increased blood pressure. 

 

Beta-blockers - to reduce the production of the aqueous fluid. Examples are: betaxodol and timol. Possible side effects are: decreasing heart rate, decreasing blood pressure, fatigue and impotence. Beta-blockers are not recommended for patients with history of lung diseases since they can exaggerates the symptoms. 

 

Surgical Management of Glaucoma 

If medications are not effective in treating glaucoma, surgery may be performed. The following are surgical procedures that can be performed;

 

Laser Trabeculoplasty - laser burns are applied inside the surface of the eye to widen the drainage system to increase the outflow of the fluid. Possible complication of this procedure is sudden rise in intraocular pressure usually 2 hours after the surgery that may continue for a longer period. 

 

Laser Iridotomy - Done to patients suffering for angle-closure glaucoma. A small opening is made in the iris to eliminate the blockage on the pupil and ease the fluid flow. Possible complication include: burning of the cornea, retina or lens, sudden increase in intraocular pressure, closure of the iris opening that was created and blurred vision.

 

Filtering Procedures - Used to treat chronic glaucoma. An opening is made inside the eye (in the trabecular meshwork) to drain the fluid by bypassing the usual drainage system. Possible complications include, hemorrhage, very low or high intraocular pressure and cataracts. 

 

Drainage Implants - An artificial tube is inserted inside the eye to help in draining the fluid away from the eye.

 

How to Prevent Glaucoma 

Have a regular eye checkup - This will help in detecting glaucoma and other eye problems early enough before a permanent damage occurs. 

 

Take your medications as prescribed - This is to make sure the intraocular pressure is maintained within the desired level and avoid further damage to the eye. 

 

Protect your eyes from injuries by wearing eye protection gears while working with equipment that can lead to eye injuries. 

 

Ask your doctor about possible side effects of glaucoma medications and what to expect when taking the medications. 

 

Keep all follow-up appointments with your doctor.