Cutting Edge Glaucoma - Issue 2

CATARACT SURGERY IN PATIENTS WITH GLAUCOMA DRAINAGE IMPLANTS: THE HOOKED TUBE TECHNIQUE • 3  Fig. 1: Glaucoma drainage implant tube ( A ) is occluded with a flexible iris retractor hook ( B ) during phacoemulsification cataract surgery. control group and treatment group at each time point were analyzed using the unpaired t test. Statistical analyses were performed using SSPS version 21.0 for Windows (IBM, U.S.A.). The Hooked Tube Technique After administration of multiple drops of tetracaine 0.5%, the eye is prepared and draped in the usual sterile fashion. A lid speculum is used to retract the eyelids. Before beginning the phaco- emulsification cataract surgery, the location of the GDI tube is determined. The first step in the procedure involves a 1-mm limbal paracentesis placed about 30 degrees laterally to the anterior chamber part of the tube. The paracentesis incision can be made with any 1 mm wide metal or diamond knife. An iris retractor hook (Flexible Iris Retractor for ophthalmic surgery, Alcon Grieshaber AG, Schaffhausen, Switzerland) is then inserted through the paracentesis. Holding the outside part of the hook with forceps, the surgeon moves the inside part of the hook through the orifice/mouth of the GDI tube. Once the hook is inside the tube lumen, the surgeon bends the tube with gentle traction toward the anterior chamber angle, avoiding touch- ing the corneal endothelium (Video 1). The tube is bent by gently pulling the retractor hook with forceps and locked into the bent position by sliding a silicone donut down the shaft and against the cornea (Fig. 1). Once the tube has been occluded by the hook, intracameral lidocaine is injected followed by the OVD. Clear corneal phacoemulsification is performed in the usual manner with an intraocular lens insertion into the capsular bag. Following cataract surgery, the OVD is eventually aspirated using an irrigation/aspiration instrument. The tube is then released by sliding the silicone donut away from the cornea, thus unhooking the tube. After carefully pulling the retractor hook out of the eye to GDI obstruction and a y increase in IOP during fol- ients with the GDI are quite ve IOP spikes. In such cases, tuation could adversely aff ct function. A novel technique is the GDI tube temporarily with ook during cataract surgery to perative IOP spikes. 2 patients with GDI who had a aract surgery between January ith a minimum 1-year follow- operated at the Pa¨ija¨t-Ha¨me tal of 15 patients underwent aract surgery without an intra- the GDI tube between January 010 (control group). Between l 2016, 17 patients u derwent rgery using a n vel techniq e n of the GDI tube—i.e., the (treatment group). The same urgery in the both groups. The act surgery and a visc surgical , Alcon, Fort Worth, TX, USA) ups apart from the temporary be. However, the size of a clear sed from 2.75 to 2.4 mm since s, number of antiglaucoma acuities were collected before ostoperatively at 1 day, then months. Outcome measures uity, number of antiglaucoma cal complications. The study e local ethical review board of arch was performed according elsinki. Data within the group e paired t test between the eyes t surgery. Data between control The hooked tube technique After administration of multiple drops of tetracaine 0.5%, the eye is prepared and draped in the usual sterile fashion. A lid speculum is used to retract the eyelids. Before beginning the phaco mulsification cataract surgery, the location of the GDI tube is determined. The first step in the procedure involves a 1-mm limbal paracentesis placed about 30 degrees laterally to the anterior chamber part of the tube. The paracentesis incision can be made with any 1 mm wide metal or diamond knife. An iris retractor hook (Flexibl Iris Retractor for ophthalmic surgery, Alcon Grieshaber AG, S haffhaus n, Switzerland) is then inserted through the par centesis. Holding the outside part of the hook with forceps, the surgeon moves the inside part of the hook through the orifice/mouth of the GDI tube. Once the hook is inside the tube lumen, the surgeon bends the tube with gentle traction toward the anterior chamber angle, avoiding touching the corneal endotheliu (Video 1). The tube is bent by gently pulling the retractor hook wi h forceps and locked into the be t position by sliding a silicone donut down the shaft and ag inst the cornea (Fig. 1 ) . Once the tube has been occluded by Fig. 1 Glaucoma drainage implant tube ( a ) is occluded with a flexible iris retractor hook ( b ) during phacoemulsification cataract surgery