Glaucoma is a group of eye conditions that can damage the optic nerve, leading to vision loss or blindness if left untreated. There are two main types of glaucoma: open-angle glaucoma and angle-closure glaucoma, also known as narrow-angle glaucoma.
Open-angle glaucoma: This is the most common type of glaucoma. It occurs when the drainage angle of the eye is open but becomes less efficient over time. The drainage angle is the space between the cornea and the iris, through which the fluid in the eye (aqueous humor) normally flows out. In open-angle glaucoma, the drainage angle becomes clogged or blocked, causing a gradual increase in eye pressure (intraocular pressure). The increased pressure can damage the optic nerve, resulting in vision loss. Open-angle glaucoma usually progresses slowly and may not cause noticeable symptoms until later stages.
Angle-closure glaucoma (narrow-angle glaucoma): This type of glaucoma occurs when the drainage angle of the eye becomes blocked or completely closed, preventing the aqueous humor from draining out of the eye. This leads to a sudden and significant increase in intraocular pressure. Angle-closure glaucoma can be categorized into two forms: acute and chronic.
Acute angle-closure glaucoma: This is a medical emergency. It occurs when the drainage angle suddenly becomes blocked, causing a rapid increase in intraocular pressure. Symptoms may include severe eye pain, headache, blurred vision, halos around lights, redness of the eye, and nausea/vomiting. It requires immediate medical attention to relieve the pressure and prevent permanent vision loss.
Chronic angle-closure glaucoma: In this form, the drainage angle gradually becomes narrower over time, causing a gradual increase in intraocular pressure. This type of glaucoma may not produce any noticeable symptoms or may cause intermittent symptoms such as mild eye discomfort or blurred vision. Chronic angle-closure glaucoma can lead to progressive vision loss if not treated.
It's important to note that both open-angle and angle-closure glaucoma can occur in one or both eyes, and regular eye examinations are crucial for early detection and treatment. Treatment options for glaucoma may include eye drops, oral medications, laser therapy, or surgery, depending on the severity and type of glaucoma.