Glaucoma is a severe disease characterized by slow loss of optical nerve, threatening the vision. If glaucoma is left untreated, it van lead to loss of vision. The most common cause of glaucoma is high eye pressure.
Symptoms of Glaucoma
- A headache aggravating in the morning,
- Cloudy vision from time to time,
- Seeing halos around the lights in the evening,
- Pain around the eye,
Diagnosis of Glaucoma
The disease is asymptomatic if intraocular pressure is not really higher. Thus, diagnosis of this disease is made when it has progressed, i.e. in an advanced stage.
Glaucoma is mostly diagnosed incidentally in patients who are having an eye examination for other reasons.
However, a number of patients may experience an acute glaucoma in which intraocular pressure suddenly and highly increases, resulting in severe ocular pain, headache, and red eye. In this case, urgent medical treatment is required.
In diagnosis of glaucoma
Very high intraocular pressure: Normally intraocular pressure is around 10-20 mmHg. An intraocular pressure being higher than 20 mmHg is mostly in favor of glaucoma; however only a very high intraocular pressure is not enough to diagnose glaucoma because the eyes can be normal despite an intraocular pressure being higher than 20 mmHg, or the eyes may have glaucoma despite an intraocular pressure being lower than 20 mmHg.
Destruction of optic nerves at examination of optic fundus
The patients with glaucoma will be monitored by evaluating together the level of intraocular pressure, and state of optic nerve and visual field. A decision for pharmacotherapy or surgery is taken based on these symptoms.
Factors Increasing The Risk of Glaucoma
⦁ Family history of glaucoma
⦁ A long-term cortisone therapy
⦁ Advanced age
⦁ Diabetes mellitus
⦁ High or low body tension
⦁ High myopia or hypermetropia
⦁ Eye injuries
Types of Glaucoma
Open-Angle Glaucoma: The most common type of glaucoma. Intraocular pressure is increased when optic fluid is obstructed from flowing to escape. There is an obstruction (which should not be present normally) of canals that carry the optic fluid to blood vessels, and accumulated optic fluid causes intraocular pressure to increase. Higher intraocular pressure damages the optic nerve and results in loss of vision leading to blindness if left untreated.
Closed-Angle Glaucoma: Accounts for 5-10% of patients with glaucoma. This type of glaucoma presents with acute angle closure crises. This manifestation is called the closed-angle glaucoma or acute glaucoma crisis, and the symptoms include sudden ocular pain, redness, cloudy vision, a decrease in vision, sensitivity to light, nausea, and vomit. The eye pressure of a patient presenting with these symptoms is usually 40-50 mmHg or higher. This very high intraocular pressure must be immediately reduced by medication to take the patient under operation. The problem must be resolved as soon as possible otherwise if the patient is late to see a doctor, they might experience a total loss of vision in couple of days because of this higher eye pressure. A patient presenting with these symptoms must not attempt to relieve the pain with analgesics but see a doctor immediately.
Secondary glaucoma: There is a disease in the eye causing the intraocular pressure to increase in secondary glaucoma. This might be an intraocular hemorrhage for various causes, uveitis, diabetes mellitus, trauma, cataract in an advanced stage.
Treatment of Glaucoma
Initially, eye pressure of the patient is lowered by either limiting production of optic fluid or increasing its outflow. There are drugs used for these two methods. These drugs need to be taken at regular intervals a day and are used for a life time. If the patient’s eye pressure is unable to lower and visual field becomes narrowed despite medication, the method of treatment is surgery.
A hole is surgically made in the white section of the eye. This hole is too little to be seen outside and intended to discharge the excessive fluid in the eye. The glaucoma disease mostly disappears after the surgery; however this is not possible to achieve in all patients.
In treatment of eye pressure, laser beams are primarily used to treat acute glaucoma crisis and prevent the other eye from having a glaucoma crisis. Secondly, laser is applied to stimulate opening of the mesh to allow more outflow of aqueous fluid in chronic glaucoma cases. Another use area of laser in treatment of high eye pressure is delivering the laser beams on the white area around the color section (iris). The intention here is to destroy the area responsible for secreting the aqueous humor in order to reduce production of this fluid.