Cutting Edge Glaucoma - Issue 2

2 • CUTTING EDGE - GLAUCOMA Conclusions: The hooked tube technique seems to provide an effective way to reduce the risk of the IOP spikes after cataract surgery in eyes with GDI. Keywords Cataract surgery, Glaucoma drainage implant, Iris retractor hook, Postoperative IOP spikes Introduction Glaucoma drainage implant (GDI) surgery has become a standard procedure in various forms of uncontrolled glaucomas [1]. The development of visually significant cataract is common after GDI surgery and many patients need cataract surgery afterward. Cataract surgery can affect IOP control in eyes with the tube [2–4]. Some GDI patients have even exhibited IOP spikes (≥ 10 mmHg increase) postoperatively [2, 4]. One reason might be the flow of lens debris through the GDI tube into the bleb cavity during cataract surgery. Also, intraoperative use of viscoelas- tic material may lead to GDI obstruction and a clinically unsatisfactory increase in IOP during follow-up [5]. Many glaucoma patients with the GDI are quite sensitive to postoperative IOP spikes. In such cases, postoperative IOP fluctuation could adversely affect visual field and visual function. A novel technique is presented for occluding the GDI tube temporarily with a flexible iris retractor hook during cataract surgery to reduce the risk of postoperative IOP spikes. Methods This study includes all 32 patients with GDI who had a phacoemulsification cataract surgery between January 2005 and April 2016 with a minimum 1-year follow-up. All patients were oper- ated at the Päijät-Hämeen Central Hospital. A total of 15 patients underwent phacoemulsification cataract surgery without an intraoperative occlusion of the GDI tube between January 2005 and December 2010 (control group). Between January 2011 and April 2016, 17 patients underwent phacoemulsification surgery using a novel technique for temporary occlusion of the GDI tube— i.e., the hooked tube technique (treatment group). The same surgeon performed the surgery in the both groups. The technique used for cataract surgery and a viscosurgical device (OVD) (Viscoat, Alcon, Fort Worth, TX, U.S.A.) were same in both groups apart from the temporary occlusion of the GDI tube. However, the size of a clear corneal incisions decreased from 2.75 to 2.4 mm since January 2015. Data such as IOPs, number of antiglaucoma medications and visual acuities were collected before cataract surgery, and postoperatively at 1 day, then after 1, 3, 6, and 12 months. Outcome measures included IOP, visual acuity, number of antiglaucoma medications, any surgical com- plications. The study met the criteria set by the local ethical review board of the institution. The research was performed according to the Declaration of Helsinki. Data within the group were compared using the paired t test between the eyes before and after cataract surgery. Data between