Surgical Repair of Cyclodialysis Cleft

Abstract

Cyclodialysis cleft is separation of meridonal ciliary muscle fibers from the scleral spur, thereby creating an additional drainage pathway of aqueous humor into the suprachoroidal space.1-4 This new drainage pathway leads to increase in uveoscleral outflow and may result in chronic ocular hypotony.5 The hypotony may also be due to decreased aqueous production.6 In past, creating an iatrogenic cyclodialysis cleft was used as one of the surgical option for the management of aphakic glaucoma. Cyclodialysis mostly occurs inadvertently during anterior segment surgery or due to blunt ocular trauma.2,7 The magnitude of the hypotony due to cyclodialysis cleft may not be proportional to the size of the cleft.5 As a result of ocular hypotony, patient may develop choroidal effusion, cystoid macular edema, optic nerve edema, engorgement and stasis of retinal veins, retinal folds, shallow anterior chamber, and cataract. Cystoid macular edema is one of the major contributing factor for visual loss due to hypotony caused by cyclodialysis cleft. If hypotony remains undetected and untreated for long time, visual loss may become permanent. Ocular hypotony itself is the most frequent cause of ciliochoroidal detachment following cataract extraction. Therefore, prior to considering cyclodialysis cleft as a cause of hypotony, other causes like wound leak, retinal detachment, chronic inflammation, and anterior segment ischemia should be ruled out. A careful gonioscopic examination of the anterior chamber angle is the key to the diagnosis of iatrogenic or traumatic cyclodialysis cleft. Sometimes it is difficult to see the cleft itself, as it is often small and obscured by a narrowed anterior chamber angle. A shallow chamber generally is caused by diffuse choroidal effusion due to hypotony that leads to forward displacement of the lens iris diaphragm. It has been suggested that anterior chamber deepening by the injection of a viscoelastic agent into the anterior chamber may facilitate visualization of the cleft.8 High-resolution ultrasound biomicroscopy (UBM) is a good tool to diagnose and provide detailed information about the extent and location of a cyclodialysis cleft.9-11 UBM allows imaging of a cyclodialysis cleft along its entire longitudinal and circumferential extent, with an accurate assessment of its location and size, regardless of gonioscopic visibility or patent cleft aperture.10,11 While gonioscopy allows evaluation only from the anterior face of the ciliary cleft, UBM provides cross sectional information of the iridocorneal angle. Once the diagnosis of cyclodialysis is made, medical treatment consisting of topical 1% atropine, 2 to 3 times daily should be attempted at-least for 6-8 weeks. Miotics and corticosteroids should be avoided. If the cleft is small in size (< 1⁄2 clock hour) or no significant structural or functional abnormalities secondary to hypotony is seen, then, wait and watch along with medical treatment may be the best mode of action. In small clefts, Argon laser therapy for repair of cyclodialysis can be tried. Various treatment options to close the cleft with laser has been described.3,12-17 It is assumed that, following laser treatment, edema of the choroid closes the cleft and blocks aqueous flow into the suprachoroidal space or perhaps the inflammation produced by laser treatment plays a role in altering the aqueous humor composition, thereby obstructing the drainage.13 Other surgical options includes external transconjunctival cryotherapy at the presumed location of a cyclodialysis cleft, direct cyclopexy, ciliochoroidal diathermy, anterior scleral buckling, or vitreoretinal procedures.18-24 We usually reserve surgical intervention for those cases that do not respond to medical treatment. We prefer direct surgical cyclopexy (Cleft closure) to other surgical options.