Angle Recession Glaucoma

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 usually high pressure inside the eye that damages the optic nerve and can result in permanent vision loss. 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.

In the United States, over 1 million Americans experience eye injuries each year. Blunt eye injuries are estimated to account for over 60% of all episodes of eye trauma. Although injuries often occur to only one eye, the incidence rate of trauma to both eyes is as high as 27%.

• In 1988, a study of adults in New England yielded an annual rate of 9.75 eye injuries per 1000 people, based on a self-reported history.
  
  
• In 1990, an estimated hospitalization rate for children with eye trauma was reportedly 15.2 eye injuries per 100,000 children per year.
  
  
• Work-related injuries have been reported as 13-18% of total eye trauma cases.
  
  
• Injuries at home account for 27-31% of eye trauma cases, followed by assault (11-37%), recreation (approximately 25%), travel (approximately 5%), and miscellaneous (eg, school, unknown; <5%).

Angle recession is one of the most common complications after eye trauma. The exact incidence of angle recession in the United States has not been reported, but it has been described in 20-94% of eyes that have experienced blunt trauma. 

• Angle recession following traumatic hyphema (bleeding into the anterior chamber of the eye) occurs in 71-100% of cases.
  
  
• A 1987 study involving routine examination of asymptomatic (that is, no symptoms) boxers found angle recession in 19%, with 8% having angle recession in both eyes.

Worldwide, the incidence of eye trauma is similar to that found in the United States.

• A study of Australian adults older than 40 years yielded a lifetime cumulative rate of eye injury of 21.1%. Among men, those in rural areas had higher rates than those in urban areas (42.1% vs 30.5%). In contrast to US data, workplace injuries predominated at 60%, with home injuries closer to agreement with US figures at 24%.
  
  
• The Israeli Ocular Injuries Study reported in 1988 that injuries occurring at home were the most frequent type of eye trauma in Israel.
  
  
• A 1995 study of eye trauma among Nigerians reported the rate of home injuries at 26.4%. This study identified women and children at the greatest risk of sustaining eye trauma during domestic activities.
  
  
• A 1996 report described a predominance of home injuries in Scotland.

As in the United States, the exact incidence of angle recession in other countries is unclear. Most reports verify that contusional injuries (direct blows to the eye) represent most eye trauma cases, but rates of angle recession and/or traumatic glaucoma are not well documented.

• One survey published in 1994 based on the results from gonioscopic examinations (see Exams and Tests) of individuals older than 40 years in a community in South Africa reported a cumulative prevalence of angle recession of 14.6%.
  
  
• In this study, it was found that of eyes with angle recession involving all 360° of the iris, only 8% had glaucoma, and the overall prevalence of glaucoma of eyes with any degree of angle recession was 5.5%.

Eye injury is a relatively common occurrence in people who are admitted to the hospital or present to the emergency department with major head trauma.

• In 1996, a study found that an annual cumulative incidence of serious eye trauma necessitating hospital admission was approximately 8 per 100,000 cases. Of those cases, approximately 13% had a poor visual outcome; 10.7% had a blinding outcome.
  
  
• In 1999, a study reported eye injuries in 55% of all facial injuries and in 16% of all major trauma cases.

Because angle recession glaucoma can have its onset years after the traumatic episode, estimating the resultant visual disability is difficult. Published data of visual outcomes following eye trauma usually only describe short-term results. The long-term incidence of significant vision loss or blindness from posttraumatic glaucoma has not been reported.

Angle recession glaucoma appears to affect all races equally. In general, African Americans may be at an increased risk for all types of glaucoma, particularly primary open-angle glaucoma (POAG).  

• Because of the possible relationship of POAG with angle recession glaucoma, African Americans theoretically may be at an increased risk of glaucoma following eye trauma.
  
  
• One urban study published in 1991 found that, at a Los Angeles inner city hospital, African Americans experienced eye injuries more than twice as frequently as Hispanics. However, a comparison of rates of progression to angle recession glaucoma among different races has not yet been reported.

Among men and women, eye trauma occurs more often to men, outnumbering women by a ratio of 4 to 1. Therefore, presumably, angle recession and angle recession glaucoma develop most frequently in men.  

• Women appear to be at a greater risk of sustaining eye injuries at home.
  
  
• Among children, eye injuries occur more frequently in boys than in girls.

The risk of angle recession as a person gets older has not been formally described.

• Because the onset of symptoms is often delayed following a blunt eye injury, angle recession glaucoma is not usually diagnosed until middle to late adulthood. It may even be misidentified as POAG, since angle abnormalities may not be readily evident on examination and often appear late in the disease course. A distant or even forgotten history of eye trauma, particularly common among elderly persons, may result in the condition being overlooked.
  
  
• Among adults, the risk of injury appears to decline steeply with advancing age. Studies of urban populations have indicated that elderly persons sustained only 1.6% of eye trauma, and, for persons older than 65 years, eye injuries were most often due to a fall.
  
  
• Angle recession glaucoma has been described in childhood, but eye trauma generally occurs during young adulthood. The annual incidence of pediatric eye injuries has been reported at 15 per 100,000 children.

Any cause of eye trauma that does not penetrate the eye can result in angle recession glaucoma.  

The episode may be seemingly trivial and forgotten. The circumstances of the injury can be quite variable but are often due to trauma from high-speed or fast-moving blunt objects or projectiles, such as the following: 

• Airbags
  
  
• Fists
  
  
• Stones
  
  
• Balls
  
  
• Champagne stoppers
  
  
• Bungee cords
  
  
• Tree branches

The most common types of blunt trauma occur as a result of the following:  

• Sports injuries (eg, boxing, paintball)
  
  
• Motor vehicle accidents (eg, airbag deployment)
  
  
• Assaults
  
  
• Falls
  
  
• Military combat injuries
  
  
• Accidents (eg, industrial, farm, home)
  
  
• Other (eg, school accidents, natural disasters)

Like most people with other forms of glaucoma, if you have angle recession glaucoma, you may not have any specific eye or visual complaints.  

Although eye trauma invariably occurs before angle recession, it is common to have forgotten details of the injury or even the entire episode after a number of years have passed. During regular eye examinations, an ophthalmologist (a medical doctor who specializes in eye care and surgery) may be helpful in eliciting otherwise forgotten information that could point to the cause of the angle recession.

Regular eye examinations with an ophthalmologist are important to screen for angle recession, especially since it is often caused by eye trauma and details of such an injury or even the entire episode may have been forgotten after a number of years. Regular eye examinations are particularly critical for people who are at a higher risk for glaucoma in general, such as African Americans and elderly individuals. 

Your initial visit to an ophthalmologist is extremely important in the evaluation for angle recession glaucoma or other possible eye diseases that could cause increased IOP. During this visit, the ophthalmologist will ask you about your past ocular history, including any previous eye/head trauma, eye surgeries, or eye diseases.

|Questions to Ask the Doctor|

• Is my eye pressure elevated?
  
  
• Are there any signs of internal eye damage due to an injury?
  
  
• Are there any optic nerve abnormalities on my examination?
  
  
• Is my peripheral vision normal?
  
  
• Is treatment necessary?
  
  
• How often should I undergo follow-up examinations?

Ideally, angle recession should be discovered before glaucoma develops, so that the actual risk of glaucoma can be assessed and appropriate care can be arranged. In determining whether or not you have angle recession, your ophthalmologist performs different tests during an office examination. Each test is described below. 

• Angle recession is always diagnosed by a test called gonioscopy.
  
  
  • During gonioscopy, the drainage angle of your eye is checked. The angle of the eye is formed where the iris and the cornea come together inside your eye. This test is important to determine if the angles are open, narrowed, or closed and to rule out any other conditions that could cause elevated IOP. To view the angle, a special contact lens is placed on the eye.
    
    
  • During this test, your ophthalmologist examines the angle for characteristic features of angle recession. Your eye doctor also compares the affected angle with the angle of the fellow eye. When many years have passed following the injury, recognizing angle recession may be difficult.
    
    
  • If the eye is severely traumatized and gonioscopy cannot be performed, then a high-frequency ultrasound biomicroscopy may be used to examine the angles for any abnormalities.

• Visual field testing is very important in detecting and monitoring angle recession. Visual field testing checks your peripheral (or side) vision, usually with an automated visual field machine. This test is done to rule out any visual field defects due to glaucoma.
  
  
  • Visual field defects may not become apparent until over 40% of the optic nerve fiber layer has been lost.
    
    
  • Visual field testing may need to be repeated. If there is a low risk of glaucomatous damage, then the test may be performed only once a year. If there is a high risk of glaucomatous damage, then the test may be performed as frequently as every 2 months.
    
    
  • If your visual field defects seem to appear or change in a manner that is uncharacteristic of glaucoma, then your ophthalmologist performs additional tests to look for other causes of vision loss.
    
    
• Tonometry is a method used to measure the pressure inside the eye. 
  
  
  • Elevated IOP in one eye is a hallmark finding in angle recession glaucoma, but it may not be noted early on. High IOP that occurs soon after the injury (within the first few months) may indicate more extensive damage and, thus, a poorer prognosis.
    
    
  • Measurements are taken for both eyes on at least 2-3 occasions. Because IOP varies from hour to hour in any individual, measurements may be taken at different times of day (eg, morning and night). A difference in pressure between the 2 eyes of 3 mm Hg or more may suggest glaucoma.
    
    
  • As in other forms of glaucoma, uncontrolled and sustained IOP elevation in angle recession glaucoma ultimately leads to optic nerve damage and vision loss.
    
    
• Each optic nerve is examined for any damage or abnormalities; this may require dilation of the pupils to ensure an adequate examination of the optic nerves.
  
  
  • Different imaging studies may be conducted to document the status of your optic nerve and to detect changes over time.
    
    
  • Fundus photographs, which are pictures of your optic disc (the front surface of your optic nerve), are sometimes taken for future reference and comparison.
    
    
• The front of your eyes (or anterior segment), which includes your cornea, anterior chamber, iris, and lens, are examined using a slit lamp. A number of abnormalities in the anterior segment often accompany angle recession.
  
  
• Abnormalities in the posterior segment may signify prior episodes of trauma, which might have caused the angle recession. The posterior segment is considered to include the choroid, the retina, the optic nerve, and the vitreous humor (a gel-like substance in the eye that, along with aqueous humor, helps to retain eye pressure).
  
  
• Your visual acuity, which refers to how well you can see an object, is also evaluated. Your ophthalmologist determines your visual acuity by having you read letters from across a room using an eye chart. Any changes in visual acuity are not typically seen until the late stages of glaucoma.

|Self-Care at Home|

If your ophthalmologist prescribes medicines to help lower the pressure inside your eye, properly applying the medication and complying with your eye doctor’s instructions are very important (see How to Instill Your Eyedrops). Not doing so could result in an additional increase in IOP that can further affect the optic nerve and cause permanent vision loss.

|Medical Treatment|

The treatment of angle recession glaucoma depends on how severe your eye is injured and how well your eye heals following this injury. If you are diagnosed with angle recession, then your treatment will be similar to that of POAG. (For a complete discussion of the treatment of POAG, see Primary Open-Angle Glaucoma.) 

The treatment of angle recession glaucoma includes monitoring your IOP as well as reducing it through the use of medicated eyedrops (see Medications).

• Eyes with normal IOP and with angle recession involving more than 180° of the iris are routinely examined for an indefinite time period to monitor for the development of late glaucoma.
  
  
• If the IOP in your eye is abnormally elevated, your ophthalmologist will decide whether or not to begin medical treatment based on your overall risk of vision loss.
  
  
  • To assess this risk, your eye doctor takes into account how high your IOP is elevated, the appearance of your optic nerve, and the findings of your visual field tests.
    
    
  • Treatment is most often indicated when your IOP is greater than 25-28 mm Hg and/or when changes in your optic nerve or your visual field are documented over time.

• Each person’s response to medical treatment is different.
  
  
  • Treatment with medicated eyedrops may be effective in cases of mild-to-moderate angle recession, while elevated IOP in eyes with extensive injury to the angle may eventually no longer respond to medications.
    
    
  • Severe cases of angle recession may not respond to even aggressive medical treatment and typically have a poorer overall prognosis. 

|Medications|

The goal of therapy is to reduce IOP, typically by using medicated eyedrops. These medications must often be used for a long time. Each person’s response to medication varies and changes with time, and IOP control may deteriorate despite the use of multiple medications. Therefore, your IOP is continually monitored, especially whenever medications are changed or discontinued.

• The preferred drugs for lowering IOP include beta-antagonists, alpha-agonists, and carbonic anhydrase inhibitors, all of which reduce the amount of fluid (aqueous humor) in the eye. Beta-antagonists are typically the first choice, and alpha-agonists and/or carbonic anhydrase inhibitors are added later.
  
  
• Prostaglandin analogs and miotics increase the outflow of fluid (aqueous humor) from the eye. Prostaglandin analogs may be useful, but miotics are not routinely recommended.

|Surgery|

In angle recession glaucoma, surgery is recommended when the maximum amount of medicine has been tried and failed to reduce IOP and when the risk of vision loss outweighs the risk of surgery. Either laser surgery or conventional incisional surgery in an operating room may be needed.
 
Although favorable results have been reported for surgical intervention of angle recession glaucoma, success rates are lower when compared to other forms of glaucoma. Your eye doctor will discuss the risks and benefits of each procedure with you.

Laser surgery

Argon laser trabeculoplasty

During a trabeculoplasty, the ophthalmologist uses an argon laser beam to place small spots (burns) on the trabecular meshwork, which further open the spaces in the trabecular meshwork, allowing the fluid (aqueous humor) to flow better out of the eye. In effect, this should lower IOP.

• Argon laser trabeculoplasty is successful in the short term, but the procedure is not as effective for the long term, particularly in eyes with angle recession involving more than 180° of the iris.
  
  
• In eyes with angle recession involving less than 180° of the iris, argon laser trabeculoplasty is useful if applied only to the part of the angle not involved in angle recession.

Other laser procedures

Laser procedures other than an argon laser trabeculoplasty may be performed. Some recent procedures that have shown promise (but are not discussed herein) include transscleral krypton laser cyclophotocoagulation, transpupillary argon laser cyclophotocoagulation, and endoscopic cyclophotocoagulation.

Conventional incisional surgery

If medicine and laser surgery have failed to adequately control IOP, then conventional incisional surgery (also known as filtering surgery) may be performed. The most common filtering surgery is trabeculectomy.

Trabeculectomy

During trabeculectomy, the ophthalmologist creates an alternate pathway (or drainage channel) in the eye to increase the passage of fluid (aqueous humor) from the eye. By constructing a new drainage channel, aqueous humor is able to flow better from the anterior chamber into a bleb (a space created for drainage of aqueous humor) below the conjunctiva. As a result, IOP is lowered.

Medicines, called antimetabolites, are sometimes used in conjunction with trabeculectomy. They help reduce scarring and increase the chance of IOP being lowered.

Although effective, trabeculectomy for angle recession glaucoma has a lower success rate when compared to POAG. Trabeculectomy in eyes with angle recession is associated with less IOP reduction after surgery, greater bleb fibrosis (scarring), higher rate of bleb failure, and greater dependence on glaucoma medications after surgery.

Drainage implant surgery

Drainage implant surgery is generally performed after one or more attempts at trabeculectomy have failed.

In drainage implant surgery, the ophthalmologist places a tube in the anterior chamber to shunt the aqueous humor. Different types of implants can be used, but most function by allowing better drainage of the aqueous humor from the anterior chamber, thereby lowering IOP.

Although beneficial, drainage implant surgery may be less successful in angle recession glaucoma than in other types of glaucoma. In angle recession glaucoma caused by a traumatic event, one study reported better results using trabeculectomy with antimetabolites over drainage implant surgery.

|Follow-up|

As with other types of glaucoma, the frequency of follow-up care depends on the level of IOP control and the risk of vision loss.

• If your IOP is elevated soon after a blunt trauma, you may be reexamined every 4-6 weeks during the first year to monitor your condition. Although most cases do not progress to angle recession glaucoma, you should continue to be checked even after the condition has appeared to resolve. Sometimes, the early elevation of IOP represents a severe form of the disease that may not respond to standard medical treatment. Severe forms require more frequent follow-up care.
  
  
• In eyes with angle recession involving more than 180° of the iris but without any signs of glaucoma, the potential for late-onset glaucoma is still a reasonable concern, even many years after the injury. If you fall into this category, annual eye examinations will be performed for an indefinite period of time.

|Prevention|

The incidence of angle recession glaucoma could be reduced by prevention of underlying trauma. Data indicate that most eye injuries (eg, sports-related accidents) in both adults and children are preventable.

• Public education on the use of eye, face, and/or head protection during high-risk activities may lower the incidence of eye injuries.
  
  
• Public safety standards to reduce the rates of eye injuries can be achieved by enacting legislative policies, such as seatbelt laws and helmet laws.

|Outlook|

As with most types of glaucoma, angle recession glaucoma can cause progressive vision loss and eventually blindness. The risk of vision loss depends on many factors, particularly the timeliness of the initial diagnosis and the treatment of the disorder.

The long-term visual outcome of eyes with chronic (long-standing) angle recession glaucoma is not known.

• Eyes that develop early-onset angle recession glaucoma are thought to have more extensive injury to the angle; however, the degree of angle recession does not always correlate with the severity of glaucoma in these eyes.
  
  
• Late-onset angle recession glaucoma almost always occurs in eyes with angle recession involving more than 180° of the iris. Eyes with angle recession involving all 360° of the iris are at the greatest risk. Hence, the greater amount of angle recession, the higher the risk.

|Support Groups and Counseling|

Educating people with angle recession glaucoma is important for medical treatment to be successful. The person who understands the long-term, potentially progressive nature of glaucoma is more likely to comply with medical treatment.

American Academy of Ophthalmology
655 Beach Street
Box 7424
San Francisco, CA 94120
(415) 561-8500
 
Glaucoma Research Foundation
490 Post Street, Suite 1427
San Francisco, CA 94102
(800) 826-6693
 
Prevent Blindness America
500 East Remington Road
Schaumburg, IL 60173
(800) 331-2020
 
The Glaucoma Foundation
116 John Street, Suite 1605
New York, NY 10038
(212) 285-0080
 
Lighthouse International
111 East 59^th Street
New York, NY 10022-1202
(212) 821-9200
(800) 829-0500

|Web Links|

American Academy of Ophthalmology

Glaucoma Research Foundation

Prevent Blindness American

The Glaucoma Foundation

Lighthouse International

traumatic glaucoma, traumatic angle recession glaucoma, posttraumatic angle recession glaucoma, contusion angle recession glaucoma, contusion angle deformity, contusional injury, contusional injuries, direct blows to the eye, blunt trauma, ocular trauma, eye trauma, head trauma, eye injury, eye injuries, ocular injury, ocular injuries, POAG, primary open-angle glaucoma, high pressure inside the eye, intraocular pressure, IOP, increased IOP, elevated IOP, high IOP, increased intraocular pressure, elevated intraocular pressure, high intraocular pressure, high eye pressure, elevated eye pressure, increased eye pressure, optic nerve, optic nerve damage, visual field defect, vision loss, blindness, angle recession glaucoma

Author: Brian R Sullivan, MD, Assistant Professor, Department of Ophthalmology, University of Texas Southwestern Medical Center.

Coauthor(s): Lauri Graham, Medical Writer, .com, Inc.

Editors: Richard W Allinson, MD, Associate Professor, Division of Ophthalmology, Texas A&M University Health Science Center, Associate Professor, Department of Surgery, Scott and White Clinic; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, ; Robert H Graham, MD, Ophthalmologist, Robert H Graham, MD, PC; Affiliated With Department of Ophthalmology, Mayo Clinic, Scottsdale, Arizona and Carl T Hayden VA Medical Center, Phoenix, Arizona.