Endocycloplasty often effective for angle-closure glaucoma due to plateau iris

In patients with closed-angle glaucoma due to plateau iris, endocycloplasty (ECPL) can often open the angle and lower intraocular pressure (IOP) when peripheral iridotomy (PI) and goniosynechialysis after cataract surgery are not enough, Ramesh Ayyala MD, FRCS told Glaucoma Day at the 2016 ASCRS•ASOA Symposium & Congress in New Orleans, USA. In his clinic at Tulane School of Medicine in New Orleans, Dr Ayyala sees a lot of plateau iris in the local Cajun population, and prefers ECPL before filtration surgery. “Alone it may not succeed in every single patient – some of them may need a glaucoma procedure later. But ECPL is a great procedure and I would never do a trabeculectomy on a patient like this as a first operation,” he said. SHRINKING CILIARY PROCESSES ECPL is derived from endocyclophotocoagulation (ECP), which reduces IOP by destroying the ciliary processes with laser energy, suppressing aqueous production. But while ECPL uses the same E2 diode laser endoscope system (Endo Optiks), the mechanism of action and technique differ from ECP, Dr Ayyala noted. Angle closure in plateau iris syndrome is most often caused by anteriorly positioned ciliary processes pushing the iris so far forward that it crowds the angle and impedes aqueous outflow. The goal of ECPL is to shrink the ciliary processes posteriorly, allowing the iris to pull away from the angle, he explained. This is done by aiming the laser at the posterior or middle of the processes rather than starting with the anterior portion as in ECP. Dr Ayyala recommends a spray-painting technique with the laser on a continuous setting of 0.3W, treating as much of the processes as possible. INDICATIONS Diagnosis of plateau iris syndrome should be made on gonioscopy or ultrasound, Dr Ayyala said. Since pupillary block is often present, PI should be done. Miotics such as pilocarpine may also help open the angle, as may peripheral laser iridoplasty. Removing the crystalline lens may also help open the angle. Dr Ayyala also uses goniosynechialysis if needed to separate the iris and manually open the angle after phacoemulsification. This may result in some bleeding, but it is not usually serious. However, if anteriorly placed ciliary processes are the problem, this may not be enough. Dr Ayyla recommends checking for angle closure with gonioscopy after the lens is removed and the intraocular lens (IOL) inserted. If the iris is still pushed forward, closing the angle, ECPL should be considered to shrink the ciliary processes. After washing out viscoelastic from the cataract surgery from the capsular bag, Dr Ayyala injects viscoelastic in the anterior chamber to maintain depth, and in the ciliary sulcus to open up space for the endoscope. He inserts the endoscope through the main cataract incision and treats as many degrees of processes as can be reached, and then washes the visco out of the anterior chamber. He then injects diluted triamcinolone acetonide (Kenalog) into the ciliary sulcus to prevent inflammation, which can be severe, especially in patients of African descent. Dr Ayyala presented a case in which he treated a monocular patient with pre-op IOP of 35mmHg on three eye drops for closed-angle glaucoma due to plateau iris. He performed phaco and implanted an IOL and performed goniosynechialysis to open the angle, but it remained closed due to an anteriorly displaced iris. ECPL was then used to shrink the ciliary processes, opening the angle. Four years after surgery, the patient’s IOP was 15mmHg with a combined dorzolamide hydrochloride-timolol maleate eye drop, Dr Ayyala reported. In his experience ECPL often does away with the need for a filtration procedure and associated complications. “Always take the cataract, decompress the chamber, do the goniosynechialysis, the ECPL. If necessary do the glaucoma procedure later,” Dr Ayyala concluded. Ramash Ayyala: rayyala@tulane.edu

Tags: closed-angle glaucoma, intraocular pressure, plateau iris