Description
Angle recession is usually due to nonpenetrating blunt trauma to the eye. Blunt trauma is thought to compress the globe, leading to an equatorial expansion and aqueous being forced laterally. This may tear the ciliary longitudinal and circular muscles apart, the resultant damage to the trabecular meshwork embarrassing aqueous outflow and causing raised intraocular pressure (IOP), perhaps years hence. Such traumas include sporting injuries from, for example, squash and the various forms of pugilism, motor vehicle accidents, falls, especially in the elderly, and criminal assaults. The trauma can
also be surgical, as in cataract extraction. Angle recession can lead to a form of secondary open-angle glaucoma, which may arise within days or years of the injury. There is a higher incidence of primary open-angle glaucoma and steroid responsiveness in both the injured and the uninjured eye.
Symptoms
As with primary open-angle glaucoma, the glaucoma associated with angle recession is usually asymptomatic until the late stages of the disease when the patient may notice blurred vision and visual field loss.
Signs
Angle recession is diagnosed by means of gonioscopy. An increase in the width of the ciliary body band is seen, together with an increase in the depth of the anterior chamber corresponding to those areas. The scleral spur may appear whiter than normally anticipated. It is important to compare the angle structures with the appearance of those in the uninjured eye. Evidence of other signs of trauma such as iridodialysis, iris sphincter tears and unilateral cataract should initiate a careful history into the possibility of previous
ocular trauma and a gonioscopic search for angle recession. With the passage of time, the healing process may make the recognition of angle recession more difficult.
Angle recession is typically unilateral. A unilateral increase in IOP is an important finding, and if this occurs soon after the injury the prognosis is guarded, as a significant degree of damage may have been sustained by the trabecular meshwork.
Prevalence
Angle recession is a frequent complication of blunt trauma to the eye, with reported estimates varying between 20 and 100 per cent, especially if traumatic hyphemia is an added complication. Up to 20 per cent of these eyes will develop glaucoma. The risk of glaucoma is higher if the extent of the angle recession is greater than 180 degrees and especially in cases where therecession is greater than 240 degrees.
Differential diagnosis
Other causes of secondary open-angle glaucoma.
Management
Advice and review Patient education is vital in this condition as glaucoma may present many years after the initial injury. If glaucoma is not present, patients should be reviewed on an annual basis, especially when the angle recession is greater than 180°. The fellow eye is always examined with great care in view of the potential for delayed primary open-angle glaucoma. In addition, it should be remembered that these patients often show a steroid responsiveness in both eyes.
Topical medication If glaucoma is present, the condition is managed as for primary open-angle glaucoma, with the initial use of topical aqueous suppressants. Miotics, however, may lead to a paradoxical
Fig. 11.1
Gonioscopy photograph of anglerecession glaucoma.
increase in IOP owing, it is thought, to a reduction in uveoscleral outflow. Cycloplegic agents have been reported to reduce IOP and their trial could be considered when a conventional approach has failed.
Surgery Where medical treatment has failed, surgery may be considered. Generally speaking, argon laser trabeculo
plasy is not particularly effective in anglerecesskin glaucoma, especially where the recession is greater than 180°. Filtration procedures such as trabeculectomy have had some success, but less than that in primary open-angle glaucoma. The use of antimetabolites may improve the outcome after trabeculectomy.