Eyeworld Weekly Update

RESEARCH BRIEFS

There is a possibility of bacterial biofilm formation on the optic surface of IOLs in normal eyes after long-term uncomplicated cataract surgery even in the absence of clinical or subclinical symptoms, according to Paloma Mazoteras and colleagues. In an experimental lab investigation, the researchers evaluated 69 eyes donated for transplantation that had previously undergone cataract surgery with posterior chamber IOL implantation and that had no recorded clinical history of postoperative inflammation. Isolated or aggregated cocci were probable in 18.8% of IOL optic surfaces (n=13) studied by scanning electron microscopy, suggesting the presence of bacterial biofilm. In three intraocular fluid samples for IOLs with biofilm, they identified 16S rDNA by polymerase chain reaction and sequencing. No microbial contamination was found in intraocular fluids by conventional microbiological methods. The study is published in the American Journal of Ophthalmology. The addition of bromfenac to topical steroids after cataract surgery in eyes with pseudoexfoliation syndrome (PXF) was associated with greater reductions in inflammation than steroids alone, according to Marco Coassin, MD, and colleagues. They randomized 62 patients with cataract and clinical signs of PXF to either dexamethasone 0.1% and tobramycin 0.3% ophthalmic solution (Group 1) or with the adjunct of bromfenac ophthalmic solution 0.09% (Group 2). All patients were examined on the day of surgery (baseline) and postoperatively at 1, 3, 7, and 30 days. Postoperatively, the mean flare was 31% lower in Group 2 than in Group 1 at 3 days (11.92 ±8.14 ph/msec vs. 17.13±9.03 ph/msec; P=.025) and 43% lower at 7 days (10.77±6.17 ph/msec vs. 18.72±12.37 ph/msec; P=.003). There were no significant differences in postoperative visual acuity, symptoms, or ocular pain between groups. The incidence of intraretinal cysts was higher in Group 1 (n=4) than in Group 2 (n=0). The study is published in the Journal of Cataract & Refractive Surgery. Implantation of the Stegmann Canal Expander (Ophthalmos, Schaffhausen, Switzerland) in circumferential viscocanalostomy (canaloplasty) lowered intraocular pressure (IOP) significantly in primary open-angle glaucoma (POAG) without complications related to the device in this 1-year observation period, according to a study in the Journal of Glaucoma. M.C. Grieshaber and colleagues prospectively evaluated 22 eyes (22 patients) who underwent primary viscocanalostomy and implantation of the Stegmann Canal Expander (a flexible, fenestrated hollow implant of 9 mm in length) into Schlemm's canal and who then had a follow-up time of at least 1 year. Schlemm's canal was unroofed ab externo, and dilated with viscoelastic material and microcatheter. One expander was implanted into either side of the surgically created ostium to keep Schlemm's canal permanently open. Laser goniopuncture of the trabeculo-Descemet membrane window was performed if postoperative IOP exceeded 16 mm Hg. The mean IOP dropped from 27.1±5.3 mm Hg preoperatively to 13.6±1.6 mm Hg at 6 months, 13.0±1.5 mm Hg at 9 months, and 13.1±2.2 mm Hg at 12 months (P<0.001). The complete success rates for an IOP ≤21, ≤18, and ≤16 mm Hg combined with a 30% IOP reduction were 91% each at 6 months, and 86%, 82%, and 82% at 12 months, respectively. The success rate of an IOP ≤16 mm Hg without medications did not depend on age, preoperative IOP, and mean visual defect. Laser goniopuncture was performed on two eyes (9%) 4.1 months postoperatively; the mean IOP was 19.5 mm Hg before and 13.6 mm Hg after goniopuncture. The number of medications dropped from 2.9±0.6 before surgery to 0.05±0.2 after surgery (P<0.001). The postoperative best corrected visual acuity at last visit was comparable to preoperative values.