Traumatic glaucoma refers to a group of ocular disorders that occur after the eye undergoes trauma. Following this trauma, different mechanisms can cause an abnormal elevation of pressure inside the eye, called intraocular pressure (IOP), and increase the risk of damage to the optic nerve.
Eye pressure is measured in millimeters of mercury (mm Hg). Normal eye pressure typically ranges from 10-20 mm Hg. When your pressure is higher than 20 mm Hg, you may be at an increased risk for developing glaucoma.
High pressure inside the eye is caused by an imbalance in the production and drainage of fluid in the eye (aqueous humor). The channels that normally drain the fluid from inside the eye do not function properly or are blocked. More fluid is continually being produced, but cannot be drained because of the improperly functioning or blocked drainage channels. This results in an increased amount of fluid inside the eye, thus raising the pressure.
Another way to think of high pressure inside the eye is to imagine a water balloon. The more water that is put into the balloon, the higher the pressure inside the balloon. The same situation exists with too much fluid inside the eye. The more fluid, the higher the pressure. Also, just like a water balloon can burst if too much water is put into it, the optic nerve in the eye can be damaged by too high of a pressure.
Glaucoma is an eye condition in which there is progressive permanent deterioration of the optic nerve and visual loss usually associated with increased eye pressure. Not all 3 criteria (that is, high pressure inside the eye, optic nerve damage, and vision loss) are required to diagnose glaucoma; however, a diagnosis of glaucoma is often determined when all 3 criteria are present.
Angle recession glaucoma is a type of traumatic glaucoma. It is classified as a traumatic, secondary open-angle glaucoma. This means that the open-angle glaucoma occurs due to a specific cause, in this case a traumatic event. Angle recession, with or without a diagnosis of glaucoma, commonly results after the eye experiences blunt trauma.
Although angle recession glaucoma is uncommon, it may not be readily diagnosed because the onset of symptoms is often delayed. The eye injury might have occurred a long time ago and, perhaps, has even been forgotten by the person.
Of those eyes with angle recession, very few (reportedly 0%-20%) develop glaucoma. In those that do develop glaucoma, the onset is extremely variable, ranging from immediately following the trauma to months or even many years later.
The risk of eventual progression to glaucoma is generally accepted to be proportionate to the extent of the angle recession, although the presence of angle recession alone is not a good predictor for the occurrence of glaucoma.
Glaucoma following an angle recession that involves less than 180° of the iris is very unusual.
Recessions involving more than 180° of the iris are associated with a 4-9% incidence of glaucoma.
Eyes with an angle recession involving more than 240° of the iris appear to be at the highest risk for glaucoma.