ANGLE RECESSION GLAUCOMA

INTRODUCTION

• Secondary open-angle glaucoma• Presents with an elevated intraocular pressure up to

years after onset of blunt trauma• This condition may be underdiagnosed because

onset is often delayed and because a history of eye injury may be distant or forgotten

• Clinically, patients with angle recession glaucoma are usually detected during a routine eye examination later in life

ANATOMY

• Angle recession refers to a tear between the circular and longitudinal fibers of the ciliary body.

• Cyclodialysis is defined as a detachment of the ciliary body from its insertion at the scleral spur.

• Iridodialysis is separation of the iris root from its attachment to the anterior ciliary body.

• By comparison, iridoschisis refers to splitting of layers of iris stroma.

• All of these conditions are sequelae of blunt ocular trauma, and any of these conditions may coexist.

• Iridodialysis and cyclodialysis occur at higher blunt impact energies compared with the relatively lower thresholds resulting in angle recession.

HISTORY• Angle recession was first described by Collins in 1892

[1] • The association between trauma and unilateral

glaucoma was made by D'Ombrain in 1949 [2] • The pathological entity of angle recession and the

clinical phenomenon of unilateral chronic glaucoma were linked by Wolff and Zimmerman in 1962.[3]

1)Collins ET. On the pathological examination of three eyes lost from concussion. Trans Ophthalmol Soc UK. 1892;12:180–186. 2) D’Ombrain. Traumatic or concussion chronic glaucoma. Br J Ophthalmol. 1949;33:395–4003)Wolff SM, Zimmerman LE. Chronic secondary glaucoma. Association with retrodisplacement of iris root and deepening of the anterior chamber angle secondary to contusion. Am J Ophthalmol. 1962. 84:547-63.

ETIOLOGY• Any cause of nonpenetrating ocular trauma can result in

angle-recession glaucoma. • The most common types of blunt trauma are the following:• Sports injuries (eg, boxing, paintball, airsoft gun toys)• Motor vehicle accidents (eg, airbag deployment, other

facial trauma)• Assaults• Falls• Military combat injuries• Accidents (eg, industrial, farm, home, bungee cord injuries• Ocular surgery, such as penetrating keratoplasty or cataract

extraction, may also result in angle recession

EPIDEMIOLOGY

• The reported frequency of angle recession as a complication of blunt trauma is 20-94%.

• Angle recession after traumatic hyphema occurs in 71-100% of cases.

• Of eyes with identifiable angle recession, 1-20% develop glaucoma

• Interestingly, up to 50% of patients whose angle recession progresses to glaucomatous optic neuropathy will develop glaucoma in the fellow uninjured eye.** Tesluk GC, Spaeth GL. The occurrence of primary open-angle glaucoma in the fellow eye of patients with unilateral angle-cleavage glaucoma. Ophthalmology. 1985;92:904-911.

• Glaucoma after angle recession of less than 180° is unusual;

• Recessions greater than 180° are associated with a 4-9% incidence of glaucoma.

• Eyes with angle recession of greater than 240° appear to be at the highest risk of chronic glaucoma

• Other risk factors for progression to glaucoma after ocular contusion include chronic elevation of intraocular pressure, poor initial visual acuity, advancing age, lens injury, and hyphema.

• The elevation of intraocular pressure from angle recession demonstrates a bimodal pattern with glaucoma occurring either within the first year or after 10 years as described by Blanton

• No known racial predilection exists.• No gender predilection for angle-recession glaucoma

has been reported.• A strong predominance of eye trauma exists in men,

with a male-to-female ratio of 4:1. Therefore, it may be assumed that angle recession and angle-recession glaucoma occur most frequently in men.

PATHOGENESIS• The mechanism of glaucoma associated with angle

recession appears to involve 5 processes.• First, blunt force delivered to the globe initiates an

anterior to posterior axial compression with equatorial expansion.

• Sudden indentation of the cornea may be a key factor in angle trauma, creating a hydrodynamic effect by which aqueous is rapidly forced laterally, deepening the peripheral anterior chamber and increasing the diameter of the corneoscleral limbal ring

• Second, this transient anatomic deformity results in a shearing force applied to the angle structures, causing disruption at the weakest points if the force applied exceeds the elasticity of the tissues.

• Third, the ciliary body is torn in a manner such that the longitudinal muscle remains attached to its insertion at the scleral spur, while the circular muscle, with the pars plicata and the iris root, is displaced posteriorly.

• During this process, shearing of the anastomotic branches of the anterior ciliary arteries can occur, resulting in a hyphema.

• The anterior chamber typically becomes abnormally deep in the meridians of recessed angle due to posterior deviation of the relaxed iris-lens diaphragm.

• Fourth, in some cases, angle recession progresses to glaucoma.

• The contusional deformity, when extensive, may result in trabecular dysfunction, which may lead to early or delayed loss of outflow facility and elevation of IOP.

• Fifth, chronic elevation of IOP leads to optic neuropathy characterized by progressive optic cupping and visual field loss.

• Two other proposed mechanisms to explain the elevated pressures are

• Loss of tension of ciliary muscle on the scleral spur thus narrowing Schlemm’s canal [1]

• A hyaline membrane has been reported to grow across the trabecular meshwork which may be another mechanism to explain decreased aqueous outflow[2].

1)Herschler J. Trabecular damage due to blunt anterior segment injury and its relationship to traumatic glaucoma. Trans Am Acad Ophthalmol Otolaryngol .1977;83:2392)Jensen OA. Contusion angle recession, a histopathological study of a Danish material. Ophthalmol. 1968;46:1207–1212

CLINICAL FEATURES• Although nonpenetrating eye trauma invariably

precedes angle recession, the patient may forget details of the injury or the entire episode after a number of years have passed.

• A unilateral cataract in a young or middle-aged adult should raise the suspicion of remote trauma, even when the history is negative

• Like in patients with other forms of glaucoma, may present with no specific eye or visual complaints.

• Snellen visual acuity is typically uninvolved until the late stages of glaucoma.

• Angle recession is typically diagnosed by means of gonioscopy.

• Typically, an irregularly wide ciliary body band is visible with retroplacement of the iris root.

• More likely to occur in the superotemporal quadrant.• Comparison with the angles in the injured and

uninjured eyes is important, particularly in cases with subtle findings. Documented asymmetry supports the diagnosis.

• A localized deepening of the anterior chamber is frequent

A number of anterior segment abnormalities often accompany angle recession, as follows:

• Cyclodialysis• Iridodialysis• Iridoschisis• Anterior synechia• Iris sphincter tears• Mydriasis• Iris atrophy• Transillumination defects• Iritis• Zonular breaks• Phacodonesis• Subluxated lens• Cataract

RETINAL DIALYSIS

• Posterior segment abnormalities, which may signify prior episodes of trauma, include the following:

• Vitreous opacities• Chorioretinal scars• Macular hole• Retinal breaks• Retinal detachment• Optic atrophy

MANAGEMENT

• Response to treatment of recession-angle glaucoma varies widely and is related chiefly to the nature and extent of the changes in the angle.

• The more extensively the angle is damaged, the less responsive the glaucoma tends to be to treatment

• After the diagnosis of angle recession is established, its management is similar to that of POAG, with a few special considerations.

• Use of topical aqueous suppressants in the initial medical treatment is preferred; these include beta-antagonists, alpha-agonists, and carbonic anhydrase inhibitors.

• Prostaglandin analogs, which increase uveoscleral outflow, have a theoretical benefit in angle recession because the trabecular meshwork is thought to be dysfunctional in such cases.

• Use caution in administering miotic agents because pilocarpine has been reported to cause a paradoxical elevation of IOP in angle recession, presumably due to a reduction of uveoscleral outflow.

• Atropine has been reported to reduce IOP in angle-recession glaucoma; therefore, cycloplegic agents may have a role in treatment.

• A trial of a cycloplegic agent should be reserved either for cases involving failure of conventional glaucoma therapy or for cases with other indications for cycloplegia (eg, inflammation).

• Argon laser trabeculoplasty has yielded rather unsatisfactory results and fails to lower the IOP long term in this group of patient

• Selective laser trabeculoplasty has not been formally studied but is likely to also be ineffective.

• An alternative laser procedure, Nd:YAG laser trabeculopuncture, in which an energy of 1.0 to 2.5 mJ is applied to the meshwork in a manner similar to argon laser trabeculoplasty, has been reported to offer significant advantages over trabeculoplasty in the treatment of angle- recession glaucoma

• When maximally tolerated medical therapy fails to control the IOP adequately, filtering surgery may be indicated.

• Mermoud et al compared standard trabeculectomy, trabeculectomy with antimetabolites, and the implantation of a Molteno device (IOP Ophthalmics) in the eyes of patients with uncontrolled ARG

• Trabeculectomy with antimetabolites was the most effective at controlling the IOP with the fewest postoperative antiglaucoma medications, but the rate of bleb-related infection was also highest in this study group Mermoud A, Salmon JF, Barron A, et al. Surgical management of post-traumatic angle recession glaucoma.Ophthalmology. 1993;100:634-642.

TAKE HOME MESSAGE• Glaucomatous optic neuropathy can be a devastating

consequence of angle-recession blunt injury. • Early diagnosis and aggressive intervention to lower

the IOP are of the utmost importance. • Physicians must educate patients on their injury so

that they understand their lifetime risk of developing glaucoma.

• Careful lifelong monitoring of their IOP and examinations of their optic nerves is recommended for patients who experience angle recession, because glaucoma is usually an asymptomatic disease