About
Glaucoma
What is glaucoma?
Glaucoma is an eye disease caused by abnormally increased in intraocular pressure, which damages the optic nerve and narrows the visual field. Most of the early glaucoma have no obvious symptoms, the patient’s field of vision will be narrowed gradually. So, glaucoma is also called “A thief of vision”. In worse case, it can cause complete blindness.
Incidence rate
The incidence of chronic glaucoma increase with age. About 1%-2% of those over 40-years-old have chronic glaucoma.
Why does intraocular pressure
increase?
There is a liquid in the eyeball called aqueous humor. Aqueous humor is produced by the ciliary body in the eye and is discharged through the anterior chamber angle to provide nutrients and oxygen to the cornea and crystalline lens. If there is too much aqueous humor production or too little drainage, it will accumulate in the eyes, causing the intraocular pressure to increase. Gradually, it will compress and damage the optic nerve.
High-risk
groups
Any gender, any age, can suffer from glaucoma.
People with the following genetic or health factors are more likely to get glaucoma:
- Have a family history of glaucoma
- Over forty
- Diabetics
- High myopia (higher than -6.00 DS)
- Long-term use of steroid drugs
- Got eye trauma before
Types of glaucoma
Acute
glaucoma
Acute glaucoma often presents as sudden blurring of vision, accompanied by halo, red-eye, hazy cornea, severe eye pain, headache, nausea and vomiting. In case of acute glaucoma in one eye, the chance of the other eye being affected is more than 50% within 5 years. Thus, when one eye is diagnosed having acute glaucoma, the other eye should be examined and prophylactic treatment may be indicated.
Chronic
glaucoma
The majority of patients with chronic glaucoma are initially symptom free. Therefore, it is difficult to detect at early stage. Some patients may have gradual deterioration of vision. At the late stage, the visual field becomes constricted due to the damage of optic nerve. Eventually, only the central vision remains (i.e. the tunnel vision), patients will have difficulty in seeing the surrounding objects while walking. Further deterioration of visual acuity will result in total blindness.
Secondary
glaucoma
Secondary glaucoma is an increase in eye pressure as a result of other illness. These include hypermature cataract, uveitis, bleeding inside the eye, tumor, trauma, post-operative complications or improper use of steroid eye drop.
Normal-tension
glaucoma
Under normal intraocular pressure, the optic nerve is damaged, causing visual field defects.
Congenital
glaucoma
Congenital glaucoma is results from abnormal development in the baby’s aqueous drainage system. Majority of the cases present in the first year of life. The symptoms include enlargement of eyeball, cloudiness of cornea, increase tearing and photophobia.
How to prevent
glaucoma?
Most of the early glaucoma cases have no obvious symptoms, so the patient is not easy to notice. The best way to protect yourself from vision loss and even blindness from glaucoma is to have regular comprehensive eye exams.
Diagnosis
1. Intraocular pressure
measurement
2. Eye health and anterior
chamber angle examination
3. Fundus examination
4. Visual field test