As with open angle glaucoma, older persons are more likely to have angle closure. We have seen people in their twenties with the disease, but that is very rare. The rate peaks around age 60 or so, at least in part because the natural tendency is for eyes to get shorter (slightly smaller) with time. By contrast with open angle glaucoma, angle closure affects women probably 50% more often than men. The reasons for this aren’t completely settled, but we do know that women have smaller eyes and that is one of the contributors.

For reasons that aren’t yet fully understood, East Asian persons have a lot more angle closure than everyone else in the world, though it may be that persons whose families come from Eastern India also have a greater risk. Asians don’t have more of the other risk factors; at least present research says that their eyes don’t have more of the other contributing factors, such as more persons with smaller eyes. Asian eyes look a little different from Europeans because they have different eyelid structure, not because their eyes themselves are a different size. The contribution of family history (genetics) to angle closure is real, but not as well studied as for open angle glaucoma. Some DNA code differences (polymorphisms) are known that are associated with angle closure, but no clear test can detect these in a practical way now. Without question, however, if your mom (or another close blood relative) had it, you are at least somewhat more likely to have angle closure as well.

Angle closure glaucoma is more a disease of higher than normal eye pressure than is open angle glaucoma. As discussed in a previous section, the process of angle closure means that the iris moves to block the trabecular meshwork, raising eye pressure and causing damage. This can happen either suddenly (an acute angle closure crisis) or more commonly as a silent but off-and-on process that gradually plugs up the meshwork with iris stuck to it, leading to a chronic disorder. The dominant reason for the iris to block the meshwork is that it starts out close to the outflow area in the first place in smaller eyes. Smaller eyes are often “far-sighted” (hyperopic). Persons with hyperopia develop the need for eyeglasses in mid-life and become unable to read print without glasses earlier than everyone else. When we measure the length of their eyes, they are shorter than average, with crowding of the structures together. This slows the movement of aqueous humor from where it is produced behind the iris (at the ciliary body) through the pupil (between the iris and lens) and into the front chamber (anterior chamber) of the eye. Because the block of aqueous movement is at the pupil, doctors call it pupil block. If there were an opening in the iris, the fluid could not be blocked—so the first treatment for angle closure is to make a hole where there isn’t one naturally. This is done in the office with a laser that is pretty painless, with only eyedrop anesthesia (see section Laser glaucoma surgery: iridotomy and angle treatment).

More detail about the risk of developing angle closure glaucoma and treatment or no treatment for suspects for angle closure is included in the section Why isn’t glaucoma either there or not there? - What makes you an angle closure suspect?