Eye injury may lead to a condition known as angle recession, and later, traumatic glaucoma.
More than 1 million eye injuries occur in the United States each year, most often to men and boys at work or playing sports. Sometime after trauma to the eye or a head injury, the angle – the area where the iris and the cornea come together – begins to narrow or close. This condition is called angle recession.
Since the angle allows fluids in the eye to drain, a narrow or closed angle causes pressure to build inside the eye. Traumatic glaucoma eventually develops in up to 20 percent of cases of angle recession. Left unchecked, high pressure in the eye damages the optic nerve and causes vision loss or blindness.
Angle recession glaucoma is relatively rare and is often hard to diagnose because the symptoms may appear long after the eye injury occurred. Symptoms are sometimes so delayed that it is not unusual for the patient to have forgotten about the injury. This also explains why angle recession glaucoma is usually not diagnosed until middle to late adulthood.
After an eye injury has occurred, regular eye examinations with an ophthalmologist are important to screen for angle recession and to monitor the eye for any developing glaucoma. Most people don’t experience any vision loss until glaucoma is fairly advanced. Regular eye exams are particularly critical for people who are at a higher risk for glaucoma in general, such as African-Americans and the elderly.
If your ophthalmologist doesn’t ask, be sure to mention any previous eye or head trauma, eye surgeries, or a family history of eye disease.
Exams and Tests
Angle recession should ideally be discovered before glaucoma develops, so an appropriate schedule for follow-up exams can be arranged. Different tests show whether you have angle recession.
These tests include:
- Used to check the drainage angle of the eye. The angle of the eye is formed where the iris and the cornea come together inside the eye. This test shows if the angles are open, narrowed, or closed, and rules out any other conditions that might cause elevated eye pressure. To view the angle, a special contact lens is placed on the eye. Your eye doctor also compares the affected angle with the angle of the fellow eye. A high-frequency ultrasound biomicroscopy may be used if the eye is severely traumatized and gonioscopy cannot be performed.
- Visual field tests
- Used to check your peripheral (or side) vision, usually with an automated visual field machine. This test rules out any visual field defects due to glaucoma. Since visual field defects may not be noticeable to a patient until more than 40 percent of the optic nerve is lost, your ophthalmologist will judge how often you need to repeat visual field tests. If you are at low risk to develop glaucoma, the test may be repeated once a year. If you are at high risk to develop glaucoma, the test may be performed up to every 2 months.
If you are experiencing vision loss and traumatic glaucoma doesn’t seem to be the cause, these additional tests may be performed:
- Lets the ophthalmologist see the optic nerve and examine it for any damage or abnormalities.
- Fundus photographs
- May be taken to document the status of your optic nerve and help detect changes over time. Fundus photographs are pictures of your optic disc, the front surface of your optic nerve.
- Slit lamp photographs
- Record the front of your eyes (or anterior segment), which includes your cornea, anterior chamber, iris, and lens. A number of abnormalities in the anterior segment often accompany angle recession.
- Measures the pressure inside the eye. Pressure inside the eye is called intraocular pressure (IOP). Measurements are taken for both eyes on at least two to three occasions. Because IOP varies from hour to hour, measurements may be taken at different times of the day.
- Visual acuity tests
- When you read an eye chart from across the room. Changes in visual acuity are not typically seen until the late stages of glaucoma.
Treatment for angle recession glaucoma varies according to the severity of the eye injury. Generally, if your eye pressure (IOP) is elevated soon after the trauma, your doctor may recommend exams every 4 to 6 weeks during the first year after the injury to monitor your eye pressure. Early elevation of IOP sometimes represents a severe form of the disease that may not respond to standard medical treatment. Severe forms require more frequent follow-up care.
Treatment includes medicated eyedrops to reduce pressure inside the eye and frequent follow-up appointments to monitor the pressure in the eye. Sometimes it is necessary to try different medications to find one that works, or one medicine will work for some time and quit working. Surgery may be necessary in more advanced stages.
Surgery is generally recommended when the maximum amount of medicine has been tried and failed to reduce eye pressure, and when the risk of vision loss outweighs the risk of surgery.
Either laser surgery or conventional eye surgery may be needed to improve drainage in the eye. Although favorable results have been reported for surgical intervention of angle recession glaucoma, success rates are lower when compared to other forms of glaucoma. The most typical types of surgery include argon laser trabeculoplasty, trabeculectomy, or drainage implant surgery.
If your eyes show no early signs of elevated pressure, the potential for late-onset glaucoma is still a reasonable concern, even many years after the injury. Therefore, an annual eye exam is recommended.