GLAUCOMA 28 EWAP JUNE 2022 Dr. Van Tassel also said that good visualization of the angle is paramount. She said to stop immediately if the wrong anatomy becomes engaged or if the patient experiences discomfort. “Angle surgery should be painless,” she said. If the trabecular meshwork is pale, Dr. Lee advised staining the target tissue with trypan blue or inducing blood into -chlemm½s canal. e said trypan blue is preferable because it is more reliable and avoids the potential for excess bleeding, which could further complicate the view and procedure. A general pearl for surgical gonioscopy that Dr. Lee provided is to have a gentle touch with the gonioscopy prism to avoid corneal striae that could obscure the view. “I tell residents and fellows to allow gravity to do most of the work. The fingers only guide the positioning of the lens. Using a hands-free gonioprism has come in handy for novice surgeons [in that it] allows the fellow hand to stabilize the device and minimize tremor,” he said. Management of cyclodialysis cleft While Dr. Lee said there are reports of patients recovering vision years after developing a cleft, there is risk for permanent damage without timely intervention. If the cleft is small (less than 1 clock hour), Dr. Lee said it’s likely to close without surgery. Dr. Van Tassel said clefts require management when they cause symptomatic hypotony. “If diagnosed early in the postoperative period, I tend to reduce steroid use and be fairly permissive with inyammation in order to aid in healing, and I’ll use atropine to help appose the ciliary muscle to the eye wall/ scleral spur,” she said. Dr. Lee follows a similar regimen for smaller clefts, explaining that a topical cycloplegic encourages apposition between the uveal tissue and the internal scleral wall. If the cleft doesn’t close within 4–6 weeks, Dr. Lee said overlapping rows of argon laser along the affected area could help. is laser settings are 700–900 mW, 200 micron spot size, and 500 ms. This intervention, Dr. Lee noted, can be painful and may need to be repeated. As such, he finds surgical intervention more reliable and patient friendly. Dr. Lee tends to identify and close larger clefts (1–3 clock hours) surgically. “The majority of patients undergoing MIGS procedures are pseudophakic, which fortunately is a prerequisite for an ab interno approach to cleft closure. Many fascinating and creative techniques have been described,” he said, noting that the simplest technique, in his opinion, is the “bucket handle” technique, which uses a 9-0 Prolene on a double-armed long needle. “Following a conjunctival peritomy overlying the cleft, a 27-gauge needle can be passed just posterior to the iris approximately 2 mm from the limbus. The suture needle is then docked and externalized. This is repeated for the other side of the cleft. The suture is tied off and buried in the sclera or can be placed in a pre-formed partial thickness scleral groove.” Clefts larger than 3 clock hours may require multiple sutures, Dr. Lee added. Another technique is the “sewing machine” maneuver. “Following a conjunctival peritomy, a partial thickness scleral groove should be made approximately 2 mm from the limbus, parallel to the cleft. Prolene suture is loaded into a 27-gauge needle, and the needle is passed underneath the iris from the inside out. The loaded Prolene is pulled and externalized through the scleral groove while the needle is retracted back into the eye. The needle is then passed approximately 1 mm adjacent to the original pass and the suture and the still-loaded suture is externalized,” Dr. Lee explained. “This maneuver is repeated for the entire extent of the cleft. The result should be the free ends of the suture at each end with loops in between. The loops are cut and adjacent sutures are tied together.” For larger clefts, Dr. Lee said cyclophotocoagulation over the affected area as an adjunct to suture closure is an option to encourage adhesion. If the patient is phakic, Dr. Lee said an ab externo technique with a full thickness scleral yap with direct suturing of the uveal tissue to the underlying scleral surface is usually needed. Dr. Van Tassel ended by saying that it’s important to follow cleft patients more closely in the postop period because the “IOP can swing exquisitely high when the cleft closes.” EWAP References 1. Duong A, et al. Adverse events associated with microinvasive glaucoma surgery reported to the Food and Drug Administration. Ophthalmol Glaucoma. 2021;4:433–435. 2. Meislik , erschler . ypotony due to inadvertent cyclodialysis after intraocular lens implantation. Arch Ophthalmol. 1979;97:1297–1299. Editors’ note: Dr. Lee is Director, Glaucoma Research Center, Wills Eye Hospital, Philadelphia, Pennsylvania, and has interests with Allergan, Glaukos, and New World Medical. Dr. Van Tassel is Assistant Professor of Ophthalmology, Weill Cornell Medicine, New York, New York, and has interests with AbbVie and New World Medical.
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