Angle Recession, Traumatic

Definition: Angle recession is considered a sequel of blunt eye trauma in which the ciliary muscle is torn between the longitudinal and circular layers. An obtuse anterior chamber angle results from tearing of the ciliary muscle as there is posterior displacement of the iris root. The longitudinal or meridional ciliary muscle remains attached. (Click here for a review of ciliary muscle anatomy). This distinguishes recession from cyclodialysis, where the entire ciliary body including the longitudinal muscle is detached.
Incidence/ Prevalence: A gonioscopic survey in a South African town, revealed recession in about 15% of people. (Ref. 1) The majority showed bilateral angle recession. Recession was more common in men. 5.5% of patients with angle recession had glaucoma. In patients with 360 degrees of angle recession, 8.0% had glaucoma. Excessive alcohol consumption was significantly related to the presence of angle recession in women. The prevalence of monocular blindness due to trauma was 2.5%.
Etiology: Angle recession is caused by significant blunt trauma. In our experience it is common in boxers. The initial injury is often accompanied by hyphema, so that patient who present with hyphema must be followed for later development of angle recession and glaucoma.
Clinical Findings: On gonioscopy, the ciliary body band is increased in size and irregularly widened. OCT has been recommended to give a 3D image of the recessed angle and more accurately determine the extent without putting pressure on the anterior segment.(Ref. 2).
Gross pathology: The diagnosis of angle recession can be subtle because of anatomic variations of the angle. Yanoff suggests a diagnostic method in sections of the eye that involves drawing a line through the optic axis (pink arrowed line in diagram) and then drawing a second line (yellow arrowed lines in picture) parallel to the first but which includes the scleral spur. If the angle recess is located posterior and lateral to the line (as the white arrow indicates) then there is angle recession. In the normal angle the yellow line would pass at the iris root.
Under gross dissection the normal wedge of the ciliary body is effaced as the ciliary body is stripped from the sclera and moves interiorly. While an unaffected angle has a wedge with the presenting base of the ciliary body anteriorly, the concussive angle deformity shows a fusiform shape of the ciliary body anteriorly. There is a greater area of the ciliary body that is exposed anteriorly. The iris root and pars plicata are displaced posteriorly. There may be fibrous tissue in ciliary body.
Histopathology: The same principles seen in the gross examination apply to histologic sections for diagnosis. The relationship of the sclera spur (arrow #1) reveals the posterior displacement of the iris-ciliary body complex. Residual meridional ciliary muscle strands are seen attached to the sclera (arrow #2). The effaced ciliary muscle shows pigment as it is reflected posteriorly (arrow #3). Angle injury to the outflow tract is indicated by pigment laden macrophages and fibrosis over the trabecular meshwork (arrow 4). The remaining attached longitudinal ciliary muscle is evident at arrow # 5. Circular muscle fibers are seen at arrow #6. Radial ciliary muscle fibers are evident at arrow #7. Secondary complications of angle recession include obstruction of the trabecular meshwork by synechiae or endothelialization over the trabecular meshwork. The synechiae are sequelae of inflammation and hemorrhage. Endothelialization may reflect injury to the cornea. The final result is glaucoma, which if untreated may result in glaucomatous atrophy (see image below).


Treatment: The glaucoma is treated as open angle glaucoma. Some have indicated that trabeculectomy with antimetabolite therapy is more effective than other surgical treatment in these patients. (Ref. 3)
Prognosis: About 6% of patients develop glaucoma after angle recession from the mechanisms of trabecular meshwork obstruction described above. Additional mechanisms include damage and scarring to the outflow apparatus, cataract and phacolytic glaucoma.

References:
1. Salmond JF et al. The detection of post-traumatic angle recession by gonioscopy in a population-base glaucoma survey. Ophthalmology 1994.
2. Keisuke Kawana, Yoshiaki Yasuno, Toyohiko Yatagai, Tetsuro Oshika (2007) High-speed, swept-source optical coherence tomography: a 3-dimensional view of anterior chamber angle recession Acta Ophthalmologica Scandinavica 85 (6) , 684–685
3. Mermoud et al. Ophthalmology 1993.