Angle Recession Glaucoma (cont.)
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Angle Recession Glaucoma 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. An eye doctor will discuss the risks and benefits of each procedure with the patient.
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, lowering IOP.
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) between the sclera and 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.
Brian R. Sullivan, MD
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Traumatic glaucoma refers to a heterogeneous group of posttraumatic ocular disorders with different underlying mechanisms that lead to the common pathway of abnormal elevation of intraocular pressure (IOP) and increased risk of optic neuropathy.