Glaucoma is one of the most common eye diseases, and our risk of developing this serious condition increases as we age. Glaucoma has earned the nickname “the silent thief of vision” because it can develop slowly over time without showing any symptoms.
Glaucoma usually develops when blockages form in the drainage canals of your eyes. When this happens, the intraocular pressure of your eyes (IOP) builds up slowly over time, gradually damaging your optic nerve and causing permanent vision loss.
The two most common forms of glaucoma are:
Open-angle glaucoma. Open-angle glaucoma is the most common form of glaucoma and can take years to exhibit symptoms. It occurs when the drainage canal of your eye, known as the trabecular meshwork, becomes blocked. This prevents fluids from exiting your eyes. Over time, the fluid builds up and raises IOP levels, putting pressure on your optic disc, causing damage and vision loss. An optometrist can detect open-angle glaucoma using a comprehensive eye exam.
Closed-angle glaucoma. Closed-angle glaucoma, sometimes known as angle-closure glaucoma, is less common than its open-angle counterpart but is much more severe. This condition forms when the drainage angle between the iris and cornea closes off completely, causing the IOP levels to rise rapidly. This often leads to permanent vision damage. You can tell if this is happening if you are starting to feel sudden eye pain, headaches, flashes and floaters, or even loss of vision. Closed-angle glaucoma is considered to be a medical emergency and needs immediate treatment.
Another form of glaucoma, known as normal-tension glaucoma, can develop without raising IOP levels. Doctors aren’t sure how this occurs, but they can still detect it using a comprehensive eye exam.