Abstract
Purpose:
To evaluate the safety profile of a new Schlemm’s canal expander device in non-penetrating glaucoma surgery.
Methods:
We invited all patients with uncontrolled open-angle glaucoma (OAG) on maximally tolerated medication between September 2013 and March 2014 to participate in a prospective, non-comparative, interventional study. We included patients with primary or pseudoexfoliative OAG. All cases were operated under local anesthesia by the same surgeon (GSM) using a standardized canaloplasty procedure with 360-degrees dilatation of Schlemm's canal using a flexible ophthalmic microcannula (iScience Surgical Corporation, Menlo Park, CA) followed by the insertion of the new 9mm long and 240μm wide polyimide stent (Ophthalmos GmbH, Switzerland) into both surgically created Schlemm’s ostia. Primary outcomes: percentage of eyes without intra- or post-operative complications; percentage of eyes losing > 3 lines of best-corrected visual acuity (BCVA) at 6 months. Secondary outcomes: mean change of intraocular pressure (IOP) following surgery; percentage of eyes with successful insertion of the device in Schlemm's canal.
Results:
20 of 20 patients were recruited. All were Caucasians of whom 13 (65%) were female. Mean age (±SD) at the time of surgery was 74.5 ± 5.78 years. Mean follow-up was 10.2 ± 2 months (range: 6-12). 9 eyes (45%) were pseudophakic. Mean BCVA (logMAR) before surgery was 0.11 ± 0.1 whereas, no eye lost > 3 lines 6 months after surgery. 10 eyes (50%) had no surgery-related complication. 7 eyes (35%) had a spontaneously resolved micro-hyphema; 2 eyes (10%) had a localized Descemet's membrane detachment; 3 eyes (15%) had hypotony that resolved spontaneously within 3 months. One eye (5%) developed anterior uveitis, which responded to steroid drops. 2 eyes (10%) had YAG laser goniopuncture for iris incarceration into the Descemet's window. Mean IOP decreased from 23.12 ± 7.0 mmHg before surgery to 5.82 ± 3.0, 10.9 ± 4.06, 10.5 ± 5.08, 11.1 ± 3.39, 12.1 ± 2.5, 13 ± 6.26 at week-1, month-1, -3, -6, -9, -12 respectively. Insertion of the canal expander was successful in 17 eyes (85%) whereas, the stent had to be trimmed in 3 cases (15%) due to some resistance during insertion.
Conclusions:
Insertion of the new canal expander device in combination with canaloplasty for OAG did not cause sight-threatening surgical complications. Short-term data showed promising IOP lowering results.