Angle Recession Glaucoma
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.
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 can be performed as an alternative to trabeculectomy filtration surgery or after 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.
Next Steps - 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.