Glaucoma is a term describing a group of ocular (eye) disorders that result in optic nerve damage, often associated with increased fluid pressure in the eye (intraocular pressure)(IOP). The disorders can be roughly divided into two main categories, “open-angle” and “closed-angle” (or “angle closure”) glaucoma. Open-angle chronic glaucoma is painless, tends to develop slowly over time and often has no symptoms until the disease has progressed significantly. It is treated with either glaucoma medication to lower the pressure, or with various pressure-reducing glaucoma surgeries. Closed-angle glaucoma, however, is characterized by sudden ocular pain, redness, nausea and vomiting, and other symptoms resulting from a sudden spike in intraocular pressure, and is treated as an ocular emergency.