Cyclodialysis is an ocular injury characterized by the detachment of the ciliary body’s meridional fibers from their anchor point, the scleral spur. This separation creates an abnormal, direct channel between the anterior chamber, where aqueous humor is produced, and the suprachoroidal space. This anatomical defect causes rapid and uncontrolled drainage of fluid from the eye. This excessive outflow leads to a significant reduction in the eye’s internal pressure, known as ocular hypotony, which requires medical attention.
What Causes Cyclodialysis
The most frequent cause of cyclodialysis is blunt force injury to the eye. A sudden, forceful impact creates a mechanical shearing stress that stretches the ocular tissues and forcibly tears the ciliary body away from the scleral spur. The extent of this detachment can vary significantly, from a small, localized tear to a large, circumferential separation.
Cyclodialysis can also occur as an unintended complication of various surgical procedures, termed iatrogenic cyclodialysis. This is relevant in anterior segment surgeries, such as those performed for cataracts or glaucoma. Procedures like phacoemulsification, micro-invasive glaucoma surgeries (MIGS), goniotomy, or trabeculotomy carry a risk if instruments inadvertently damage the structures near the ciliary body and the angle. Spontaneous cyclodialysis, occurring without a history of trauma or surgery, is extremely rare.
How Doctors Diagnose Cyclodialysis
The initial suspicion for cyclodialysis arises from unexplained, abnormally low intraocular pressure (IOP) following trauma or recent eye surgery. Patients may report blurred vision or discomfort linked to the secondary effects of hypotony, such as the formation of folds in the retina and choroid, known as hypotony maculopathy. Diagnosis is confirmed by measuring the IOP; a reading of 5 millimeters of mercury (mm Hg) or lower is generally considered ocular hypotony.
The primary diagnostic procedure is gonioscopy, which uses a specialized lens to directly view the angle where the iris meets the cornea. The doctor attempts to visualize the cleft, which appears as a deep, dark space between the ciliary body and the scleral spur. Direct visualization can be challenging if the eye is very soft or if there is blood or cloudiness in the anterior segment.
When direct visualization is limited, doctors rely on advanced imaging modalities. Ultrasound Biomicroscopy (UBM) is a high-frequency ultrasound that provides detailed, cross-sectional images of the anterior segment structures. UBM is useful for visualizing the ciliary body’s relationship to the sclera and confirming the location and size of the cleft, even when the internal media are opaque.
Anterior Segment Optical Coherence Tomography (AS-OCT) offers a non-contact method to obtain high-resolution images of the front of the eye. AS-OCT is a valuable tool for accurately measuring the separation and aiding in surgical planning. The combination of clinical signs, IOP measurement, and imaging allows for a precise diagnosis and localization of the abnormal drainage pathway.
Modern Treatments for Cyclodialysis Clefts
The treatment strategy is determined by the size of the detachment and the severity of the associated hypotony. For small clefts, the initial approach involves conservative management using topical medications. Cycloplegic agents, such as atropine eye drops, are administered to paralyze and relax the ciliary muscle. This relaxation causes the ciliary body to move posteriorly, pulling the detached tissue closer to the scleral spur to promote spontaneous reattachment.
If conservative measures fail, the next step may involve a minimally invasive procedure utilizing laser energy. Argon laser photocoagulation is applied directly to the edges of the cleft, usually through a gonioscopy lens, to induce a controlled inflammatory response. The heat from the laser creates scarring and adhesions, which effectively seal the abnormal connection.
For larger detachments that do not respond to medication or laser, surgical intervention is necessary. This procedure is direct cyclopexy, which involves an external approach to the eye. A surgeon creates a partial-thickness scleral flap to access the underlying tissue where the detachment occurred.
Using fine surgical sutures, the detached ciliary body is meticulously reattached and secured back to the scleral spur, restoring the normal anatomy. This direct suturing technique mechanically closes the abnormal pathway and prevents further fluid leakage. Surgical repair may be augmented by an anterior chamber tamponade technique, involving the injection of a viscoelastic substance or a gas bubble into the eye. The internal pressure exerted by the bubble pushes the detached ciliary body against the sclera, providing an internal splint during healing.
Following successful closure, the primary goal of post-treatment management is to restore and maintain normal intraocular pressure. A common occurrence after the pathway is sealed is a transient spike in IOP, as the eye’s fluid drainage system suddenly encounters resistance. This temporary pressure increase is managed with topical and sometimes oral medications until the eye stabilizes.