Cutting Edge Glaucoma - Issue 2

TWO-YEAR RESULTS OF A MULTICENTER STUDY OF THE AB INTERNO GELATIN IMPLANT IN MEDICALLY... • 29  The average or median IOP was used for analysis, depending on whether two or three meas- urements were taken, respectively. Use of topical IOP-lowering medications was assessed at baseline and all postoperative visits. Safety assessments included intraoperative complications (day 0 only), monocular best-cor- rected visual acuity—measured in Snellen (at all postoperative visits except day 1) and converted into logMAR for analysis, slit-lamp biomicroscopy, and postoperative AEs (at each postopera- tive visit). AEs of interest, such as shallow anterior chamber with iridocorneal touch, choroidal effusion, macular edema, macular folds, corneal erosion, and corneal edema, were specifically assessed and documented. Ophthalmoscopy (cup/disc ratio), pachymetry (central corneal thick- ness), and visual field (mean deviation) were assessed at baseline, month 12, and month 24. Outcomes and Analyses All effectiveness analyses were performed using the modified intent-to-treat (mITT) population (i.e., all enrolled eyes [with verified informed consent documentation] that received an implant and met the IOP and IOP-lowering medication count inclusion criteria). The primary effective- ness outcomes were the changes in mean IOP and mean number of topical IOP-lowering medica- tions in the study eyes from baseline to month 12; these parameters were also assessed at all other postoperative visits up to 24 months (secondary effectiveness outcomes). Clinical success was defined as achieving ≥ 20% IOP reduction on the same or fewer IOP- lowering medications at month 12 (or 24), compared with baseline, without glaucoma-related SSI (which did not include needling) or intention to be converted to another procedure during the study. Other effectiveness outcomes included the mean IOP and mean IOP-lowering medication count (topical) at each study visit, as well as the proportion of eyes achieving specific target IOPs, proportion of topical medication-free eyes and their mean IOP, proportion of eyes requiring nee- dling, along with the mean number of needling procedures per eye, number of eyes with 1, 2, 3, or > 3 needling procedures, overall needling rate, needling rate by site, and clinical success rate in needled eyes, at 12 and 24 months. The median needling rate was also calculated based on the month-24 needling rate for each site. AEs were summarized by counts and percentages, using the safety population (i.e., all eyes enrolled in the study that received the gelatin implant). Descriptive statistics were used to summarize all endpoints in the overall population, based on observed data (i.e., without imputation for missing data). Statistical testing was also performed to compare the changes from baseline in mean IOP and mean IOP-lowering medication count at months 12 and 24 between treatment groups. Because 19 patients had both eyes treated, a random effect model [21] was used to adjust for correlation between those eyes. Analysis was also performed using only one eye per patient (i.e., the first treated eye). In addition, the differences in needling procedures per eye between groups were analyzed using the modified Wilcoxon rank-sum test (adjusting for correlation [22]). All analyses were generated using the SAS® software version 9.3 (SAS Institute Inc., Cary, NC, U.S.A.). Enrollment of up to 200 eyes was planned; due to unknown variability of the procedure’s effect on IOP, a formal calculation of sample size was not performed. The study was remotely