Which type of glaucoma is characterized by a gradual increase in intraocular pressure?

Open-angle glaucoma is a type characterized by a gradual increase in intraocular pressure. This condition occurs when the drainage canals of the eye become partially blocked, leading to a slow buildup of pressure over time. It often progresses without noticeable symptoms in the early stages, which is why it is sometimes referred to as the "sneak thief of sight." The gradual nature of the pressure increase allows for damage to the optic nerve, ultimately affecting vision if not treated.

In contrast, other types of glaucoma, such as closed-angle glaucoma, present more suddenly with a rapid increase in intraocular pressure. Normal-tension glaucoma, while it does involve damage to the optic nerve, occurs despite normal levels of intraocular pressure, making the management and understanding of the condition different. Secondary glaucoma is a result of other medical conditions, and its pressure changes can vary based on the underlying cause. Thus, open-angle glaucoma stands out due to its progressive and insidious nature of pressure increase.