Angle recession is a condition in which a tear occurs between the circular (Müller’s) and longitudinal (Brücke’s) muscles of the ciliary body, causing the ciliary body to move posteriorly along with the iris. It is also called angle dissociation.
Angle recession occurs as a complication of blunt ocular trauma. Many patients with blunt trauma accompanied by hyphema have angle recession, and the incidence increases with the severity of trauma. Rather than causing immediate problems, it is often recognized only years later when glaucoma develops.
Angle recession
Site of tear: Between the circular (Müller’s) and longitudinal (Brücke’s) muscles of the ciliary body
Features: The ciliary body moves posteriorly, making the angle appear widened.
Complications: Late-onset intraocular pressure elevation due to trabecular meshwork dysfunction (angle-recession glaucoma).
Cyclodialysis
Site of tear: Attachment between the ciliary body and sclera
Features: The ciliary body detaches from the sclera, creating a communication between the angle and the suprachoroidal space.
Complications: Marked hypotony, hypotony maculopathy. Causes more severe hypotony than angle recession.
No specific treatment is needed for angle recession itself. However, treatment for associated hyphema and hypotony, as well as long-term follow-up to monitor for future glaucoma development, is necessary. It is important to explain the possibility of increased intraocular pressure to the patient and ensure regular follow-up visits.
Angle recession itself does not cause any subjective symptoms. Symptoms vary depending on the type and severity of associated injuries.
Gonioscopic findings are the most important.
Other findings:
The basic approach is to maintain rest and sleep with the head elevated. Because of the risk of rebleeding, gonioscopy should be avoided while hyphema is present. Also avoid medications that promote bleeding, such as aspirin. If intraocular pressure is high, manage with eye drops.
Angle recession is caused by a sudden increase in anterior chamber pressure due to blunt trauma. When external force is applied to the eye, the intraocular pressure rises momentarily, causing a tear between the ciliary muscle layers at the angle, which is under the greatest stress.
Gonioscopy is essential for the definitive diagnosis of angle recession. When hyphema is present after ocular trauma, the possibility of angle recession should always be considered.
Characteristic findings include an increased distance from the iris root to the scleral spur and a wide gray band of the ciliary body. Comparison with the fellow eye (uninjured eye) is important for accurately assessing the extent and severity of angle recession.
Gonioscopy should be avoided while hyphema is present due to the risk of rebleeding.
| Examination | Purpose | Remarks |
|---|---|---|
| Gonioscopy | Assessment of extent and severity of angle recession (comparison with fellow eye) | Contraindicated during hyphema |
| Ultrasound biomicroscopy (UBM) | Detailed evaluation of ciliary body and iris root | Can be performed even with hyphema |
| Anterior segment OCT | Non-contact evaluation of angle structures | Simpler than UBM |
| Intraocular pressure measurement | Detection of acute high IOP and chronic glaucoma | Long-term regular measurement is important |
| Fundus examination | Confirmation of retinal and vitreous damage | Angle recession and retinal damage often coexist |
No specific treatment is required for angle recession itself. Treatment targets the associated hyphema, hypotony, and angle-recession glaucoma.
For hypotony, conservative medical therapy is attempted first; if it persists, surgical treatment is performed.
Medical treatment (prescription example):
The combination of the above two drugs is the basic treatment.
Surgical treatment (if ocular hypotension persists with medication):
Angle recession glaucoma that develops years to decades after injury is treated similarly to open-angle glaucoma.
| Treatment Stage | Options | Notes |
|---|---|---|
| First-line | Prostaglandin (PG) analogs and beta-blockers | Suppress aqueous production or enhance outflow |
| Second-line | Carbonic anhydrase inhibitor (CAI) eye drops / α2 agonists | Combination of multiple drugs |
| Laser therapy | SLT (Selective Laser Trabeculoplasty) | Effectiveness is considered limited due to trabecular meshwork damage |
| Surgical treatment | Trabeculectomy / Tube shunt surgery | Cases resistant to drug therapy |
It can develop several years to decades after injury. The risk is higher with a wider extent of angle recession (especially ≥180°). After the initial post-injury hypotony resolves, elevated intraocular pressure may occur years later. Regular measurement of intraocular pressure, visual field testing, and fundus examination are important for early detection.
When blunt external force is applied to the eye, intraocular pressure rises rapidly. This pressure causes the corneal limbus to stretch, and the aqueous humor moves posteriorly and into the angle, stretching the iris. This series of physical changes causes damage to the iris root.
The ciliary muscle consists of three layers: the circular muscle (Müller’s muscle), the longitudinal muscle (Brücke’s muscle), and the radial muscle. The rapid pressure change from blunt force causes a tear between the anatomically vulnerable circular and longitudinal muscles. This tear is the essence of angle recession.
At the moment of trauma, the trabecular meshwork sustains physical damage. This damage impairs aqueous humor outflow, leading to elevated intraocular pressure. It often does not manifest immediately after injury, but develops after a latent period of several years to decades as the functional reserve of the trabecular meshwork declines.
The following specific mechanisms are considered:
When cyclodialysis is present, the pathophysiology differs. If the ciliary body detaches from the sclera, the angle communicates with the suprachoroidal space, and aqueous humor flows massively into the suprachoroidal space. This results in marked hypotony and hypotony maculopathy. If the cyclodialysis closes spontaneously or with treatment, a sudden rise in intraocular pressure may occur.
Angle recession is a tear between the circular and longitudinal muscles of the ciliary body, resulting only in a change in the position of the ciliary body. Cyclodialysis is a detachment of the ciliary body from the sclera, creating a communication between the angle and the suprachoroidal space. Cyclodialysis causes more pronounced hypotony and greater impact on vision. In cases of severe trauma, both conditions may coexist.
Quantitative evaluation methods for angle recession using anterior segment OCT and UBM are advancing. Research is underway to objectively quantify the extent and depth of angle recession and use them as predictive factors for glaucoma development risk. 2)
Studies tracking the long-term incidence of glaucoma in cases with angle recession of 180° or more have shown that the risk of developing glaucoma 5 to 10 years after injury is significantly higher compared to normal eyes. The extent of angle recession and the degree of trabecular meshwork damage are being investigated as potential independent predictors of glaucoma development. 1)
The application of minimally invasive glaucoma surgery (MIGS) to angle recession glaucoma is being studied. In angle recession glaucoma where the trabecular meshwork is damaged, the effectiveness of MIGS targeting the trabecular meshwork may be limited, and approaches that create bypass pathways to the suprachoroidal space or subconjunctival space are being evaluated.
