ORIGINAL STUDY Efficacy, Safety, and Survival Rates of IOP-lowering Effect of Phacoemulsification Alone or Combined With Canaloplasty in Glaucoma Patients Stella N. Arthur, MD, MSPH,*w Louis B. Cantor, MD,* Darrell WuDunn, MD, PhD,* Guruprasad R. Pattar, MD,* Yara Catoira-Boyle, MD,* Linda S. Morgan, CCRC, COA,* and Joni S. Hoop, CCRC, COA* Conclusions: A combination of canaloplasty with phaco results in a Purpose: To evaluate efficacy and survival rates of intraocular decreased number of glaucoma medications and increased survival pressure (IOP)-lowering effect obtained with phacoemulsification rate of IOP-lowering effect compared with phaco alone. (phaco) alone or in combination with canaloplasty (PCP) in patients with open-angle glaucoma (OAG). Key Words: phacoemulsification, canaloplasty, glaucoma Methods: Retrospective chart review of consecutive cases at the (J Glaucoma 2013;00:000–000) Department of Ophthalmology, Indiana University. Visual acuity (VA), IOP, number of medications (Meds), failures, and survival rates of IOP-lowering effect were analyzed. Inclusion criteria were: patients older than 18 years with OAG and cataract. Exclusion umerous studies demonstrate that phacoemulsification criteria were: no light perception vision, prior glaucoma surgery, N(phaco) may produce long-term reduction of intra- 1,2 chronic uveitis, angle-closure glaucoma, and advanced-stage or ocular pressure (IOP) in subjects without glaucoma, end-stage OAG. Failure criteria were: IOP > 21 mm Hg or <20% patients with pseudoexfoliation syndrome,3,4 or glaucoma reduction, IOP < 6 mm Hg, further glaucoma surgeries, and loss of patients.5–8 The effect is thought to be mediated by 3 major light perception vision. mechanisms: hyposecretion of aqueous humor due to Results: Thirty-seven patients underwent phaco and 32 patients had production of free radicals or partial ciliary body detach- PCP. Follow-up was 21.8 ± 10.1 versus 18.8 ± 9.6 months for ment and irritation; improved uveo-scleral outflow due to phaco and PCP, respectively (P = 0.21). Age (y) (74.7 ± 9.8 vs. increased synthesis of endogenous prostaglandins; and 76.1 ± 8.3, P = 0.54), sex (P = 81), and laser status (P = 0.75) improved trabecular outflow due to increased space in the were similar between the groups. Preoperatively, mean ± SD anterior chamber resulting in increased posterior traction logMAR VA (0.5 ± 0.7 vs. 0.5 ± 0.5, P = 0.77), IOP (16.2 ± 4.6 vs. on the scleral spur and expansion of the trabecular mesh- 18.2 ± 5.1, P = 0.13), and Meds (1.4 ± 1.1 vs. 1.3 ± 0.7, P = 0.75) work and Schlemm canal (SC), and washing out effect on were similar for phaco and PCP, respectively. At 24-month phaco trabecular meshwork.8–10 (n = 17) and PCP (n = 11), respectively, mean ± SD were: logMAR Canaloplasty is a new surgical technique that provides VA 0.2 ± 0.2 versus 0.4 ± 0.7, P = 0.29; IOP 14.1 ± 4.0 versus 11 12.9 ± 3.8, P = 0.43; and Meds 1.5 ± 1.2 versus 0.3 ± 0.5, an alternative to trabeculectomy. The procedure com- P = 0.005. Rates of successful IOP lowering without medications bines nonpenetrating deep sclerotomy with a modified vis- for phaco versus PCP at 12 months were 34% versus 75%, cocanalostomy utilizing a microcatheter (iTrack & iLumen; respectively (P = 0.003). iScience International, Menlo Park, CA). Transtrabecular flow is also thought to be enhanced by distending SC 360 degrees with a 10-0 or 9-0 prolene suture. The procedure greatly reduces the likelihood of bleb formation; therefore, the number of postoperative visits may be reduced. Fur- Received for publication March 3, 2012; accepted September 11, 2012. thermore, there is less long-term risk of bleb-related From the *Department of Ophthalmology, Glaucoma Service, Eugene endophthalmitis associated with canaloplasty. and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN; and wDepartment of Ophthalmology, Although there is a body of literature addressing the Washington University, St Louis, MO. efficacy and safety of canaloplasty,11–16 the data on canal- Design of the study: L.B.C., D.W., Y.C-B.; conduct of the study: oplasty in combination with phacoemulsification are lim- S.N.A., L.B.C., D.W., G.R.P., Y.C-B., L.S.M., J.S.H.; data col- ited.15,17 The goal of this study was to evaluate efficacy, lection: S.N.A., G.R.P., L.S.M., J.S.H.; statistical analysis: D.W.; critical review of the manuscript: S.N.A., L.B.C., D.W., G.R.P., safety, and success rates of the IOP-lowering effect obtained Y.C-B.; administrative support: L.S.M., J.S.H. with phaco alone or in combination with canaloplasty Supported, in part, by an unrestricted grant from Eugene and Marilyn (PCP) in patients with open-angle glaucoma (OAG). Glick Eye Research Endowment for eye and vision research at the Indiana University Foundation. Disclosure: L.B.C.: Allergan (consultant, research support); Alcon METHODS (research support); Pfizer (research support). D.W.: Prizer (con- sultant); Alcon (consultant). Y.C.-B.: Alcon (consultant). The We performed a retrospective chart review of consec- remaining authors declare no conflict of interest. utive phacoemulsification procedures from April 30, 2007 Reprints: Louis B. Cantor, MD, Department of Ophthalmology, to April 15, 2010 performed by 3 surgeons (D.W., L.B.C., Glaucoma Service, Indiana University School of Medicine, Eugene and Y.B.C.) and PCP from May 14, 2007 to July 19, 2010 and Marilyn Glick Eye Institute, 1160 West Michigan Street, Indianapolis, IN 46202 (e-mail: [email protected]). performed by 1 surgeon (L.B.C.) in OAG patients. The Copyright r 2013 by Lippincott Williams & Wilkins study protocol was approved by the Institutional Review DOI: 10.1097/IJG.0b013e3182741ca9 Board. Inclusion criteria were patients older than 18 years J Glaucoma Volume 00, Number 00, ’’ 2013 www.glaucomajournal.com | 1 Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. Arthur et al J Glaucoma Volume 00, Number 00, ’’ 2013 with OAG controlled with medical therapy and presence of visually significant cataract. Laser procedures performed TABLE 1. Demographic Data of the Phaco and Phaco-Canalo- >3 months prior were allowed. Exclusion criteria were no plasty (PCP) Patients light perception vision, prior glaucoma surgery, chronic Parameters Phaco (N = 37) PCP (N = 32) P uveitis, angle-closure glaucoma, and advanced-stage or Age (y), mean ± SD 74.7 ± 9.8 76.1 ± 8.3 0.54 end-stage glaucoma. Follow-up (mo), 21.8 ± 10.1 18.8 ± 9.6 0.21 Visual acuity (VA), IOP, number of medications, mean ± SD success and survival rate of IOP-lowering effect, incidence CCT, mean ± SD 550.6 ± 38.7 549.6 ± 30.0 0.93 of complications, and further surgical interventions were MD, mean ± SD À7.4 ± 6.1 À6.2 ± 7.8 0.54 analyzed. We used the Tube Versus Trabeculectomy study PSD, mean ± SD 5.5 ± 4.0 4.7 ± 3.5 0.45 failure criteria18: IOP >21mm Hg or <20% reduction Female, N 18 14 0.81 below baseline on 2 consecutive follow-up visits after 3 Whites, N 26 31 0.004 Right eye, N 20 20 0.63 months, IOP <6mm Hg on 2 consecutive follow-up visits ALT, N 2 2 1.00 after 3 months, further glaucoma surgery, or loss of light SLT, N 8 6 0.75 perception vision. Eyes that did not fail and did not require DM, N 5 1 0.21 supplemental glaucoma medications were classified as HTN, N 7 5 0.76 complete successes. Eyes that did not fail but required POAG, N 33 27 0.69 supplemental glaucoma medications were classified as NTG, N 4 2 0.69 qualified successes. PG, N 0 3 0.09 ALT indicates argon laser trabeculoplasty; CCT, central corneal thick- Surgical Procedures ness; DM, diabetes mellitus; HTN, hypertension; POAG, primary open- Phaco with temporal clear corneal incision and pos- angle glaucoma; MD, mean deviation; NTG, normal-tension glaucoma; PG, pigmentary glaucoma; PSD, pattern standard deviation; SLT, selective laser terior chamber intraocular lens implant were performed on trabeculoplasty. all patients. The canaloplasty technique was described previously.13 In the PCP procedure, initially a conjunctival peritomy was performed 10 mm superior to the limbus and conjunctiva, and Tenon capsule were dissected toward the status, central corneal thickness, mean deviation, and pat- limbus. Superficial and deep scleral flaps were dissected as tern standard deviation were similar in both groups. Majority of patients were whites and had primary OAG previously described. The phaco procedure was performed through clear cornea. The deep scleral flap was then ele- (Table 1). There were no statistically significant differences vated to unroof SC and expose a trabeculo-Descemet in preoperative VA (Table 2), IOP (Table 3), or number of membrane. A flexible microcatheter (iTrack-250A; iScience glaucoma medications (Table 4). Interventional, Menlo Park, CA) was advanced into the SC When analyzing each study group separately, we 360 degrees. A red-blinking light at the distal tip of the found that postoperative VA (Table 2) and IOP (Table 3) catheter helped ensure the proper location of the catheter. were statistically different than preoperative VA and IOP P After complete catheterization of the SC, a 10-0 or 9-0 (all = 0.001). In the phaco group, the postoperative polypropylene suture was tied to the exposed distal tip of number of glaucoma medications was statistically lower the catheter at the surgical cut-down and looped through than the preoperative number of glaucoma medications at 3 P P the SC. At the same time, Healon GV (AMO, Abbott Park, months ( = 0.001) and at 6 months ( = 0.001), but not at 12 months (P = 0.52), at 18 months (P = 0.48), or at 24 IL) was injected to dilate the SC while the catheter was P withdrawn.