The pathophysiology of glaucoma lies on the overproduction of the aqueous humor, the clear fluid that fills the anterior chamber (the space between the cornea and iris) or a drainage problem. Any imbalance between the production and drainage of the aqueous will lead to an increase in intraocular pressure. Normal IOPs of most people falls between 8 and 21 mmHg. Some eyes can tolerate higher pressures than others.
The following are the common types of glaucoma:
1. Open angle - also known as the chronic open angle or primary open angle glaucoma (POAG)
2. Acute angle-closure
3. Secondary glaucoma
4. Congenital
The most common type of glaucoma is the primary open angle. With this type even though the complex drainage system and the space between the iris and the cornea appear normal, the aqueous fluid continue to accumulate within the anterior chamber causing the IOP to become elevated. Patients with the open angle type often don’t have symptoms at all. The visual loss is subtle and first affects the peripheral vision and may be left unnoticed by the patient. Eventually, the patient experiences “tunnel vision” and finally progressing to blindness because of optic nerve and retinal damage. On the other hand, although the acute angle closure type affects only about 10% of cases with glaucoma, these patients need emergency treatment by an ophthalmologist. The problem here is the aqueous outflow because of the narrow than normal angle between the iris and the cornea. If the outflow of the aqueous humor becomes completely blocked then the IOP rises abruptly causing sudden angle closure attack. Therefore, patients with this angle closure type typically experience symptoms like extreme eye pain accompanied by nausea, vomiting, headache, sudden blurring of vision, and rainbows around lights and eye redness which prompted them to seek emergency consult. Secondary glaucoma usually has an underlying disease or problem within the eye such as the following: inflammation, trauma, previous surgery, diabetes, tumor and certain medications. Hence, treatment approach should be both the glaucoma and the underlying problem. Congenital glaucoma is generally seen in infants; most of these cases require surgical treatment.
In general, glaucoma does not cause symptoms in most cases because it is an insidious disease. Risk factors include: family history, diabetics, black, Asians and hypertension. Ideally, at the age of thirty-five and above, screening for glaucoma should be performed by ophthalmologists. The following are components of a complete glaucoma evaluation: tonometry (measure the IOP); opththalmoscopy (evaluate the optic nerve); visual field test or perimetry (test the peripheral vision) and gonioscopy (examine the structures in front of the eye.
The following are the common types of glaucoma:
1. Open angle - also known as the chronic open angle or primary open angle glaucoma (POAG)
2. Acute angle-closure
3. Secondary glaucoma
4. Congenital
The most common type of glaucoma is the primary open angle. With this type even though the complex drainage system and the space between the iris and the cornea appear normal, the aqueous fluid continue to accumulate within the anterior chamber causing the IOP to become elevated. Patients with the open angle type often don’t have symptoms at all. The visual loss is subtle and first affects the peripheral vision and may be left unnoticed by the patient. Eventually, the patient experiences “tunnel vision” and finally progressing to blindness because of optic nerve and retinal damage. On the other hand, although the acute angle closure type affects only about 10% of cases with glaucoma, these patients need emergency treatment by an ophthalmologist. The problem here is the aqueous outflow because of the narrow than normal angle between the iris and the cornea. If the outflow of the aqueous humor becomes completely blocked then the IOP rises abruptly causing sudden angle closure attack. Therefore, patients with this angle closure type typically experience symptoms like extreme eye pain accompanied by nausea, vomiting, headache, sudden blurring of vision, and rainbows around lights and eye redness which prompted them to seek emergency consult. Secondary glaucoma usually has an underlying disease or problem within the eye such as the following: inflammation, trauma, previous surgery, diabetes, tumor and certain medications. Hence, treatment approach should be both the glaucoma and the underlying problem. Congenital glaucoma is generally seen in infants; most of these cases require surgical treatment.
In general, glaucoma does not cause symptoms in most cases because it is an insidious disease. Risk factors include: family history, diabetics, black, Asians and hypertension. Ideally, at the age of thirty-five and above, screening for glaucoma should be performed by ophthalmologists. The following are components of a complete glaucoma evaluation: tonometry (measure the IOP); opththalmoscopy (evaluate the optic nerve); visual field test or perimetry (test the peripheral vision) and gonioscopy (examine the structures in front of the eye.
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