What is the purpose of an iridotomy in glaucoma treatment?

The purpose of an iridotomy in the treatment of glaucoma is to facilitate aqueous humor drainage. In conditions such as narrow-angle glaucoma, the angle between the iris and the cornea becomes obstructed, which can prevent proper drainage of the aqueous humor—the fluid produced inside the eye. This obstruction can lead to increased intraocular pressure, which can be harmful and result in vision loss.

By creating a small opening in the peripheral iris through an iridotomy, the pathway for aqueous humor to flow out of the posterior chamber of the eye into the anterior chamber is improved. This allows for better drainage and helps to reduce the intraocular pressure, preventing the complications associated with glaucoma. While reducing intraocular pressure is a key outcome, the mechanism by which this is achieved through iridotomy specifically targets the drainage function of the aqueous humor.

The other purposes listed—repairing a ruptured iris, removing cataracts, and directly reducing intraocular pressure—do not accurately describe the role of an iridotomy in glaucoma management.