Wang SY, et al. - Experts ascertained if implantation of the iStent concurrent with cataract surgery was linked to reduced use of ocular antihypertensive medications in a US healthcare claims database. Findings suggested an association of the implantation of the iStent trabecular micro-bypass stent concurrent with cataract surgery with moderate reduction in the use of topical ocular antihypertensive medication. Adverse effects seen with medication may be reduced, and better adherence promoted with the reduction in the use of glaucoma medications.

Methods

• Researchers conducted a retrospective, observational longitudinal cohort study of individuals enrolled in a US managed care network who underwent iStent implantation with cataract surgery (iStent/CEIOL) from 2012 to 2016 (n=1,509 bilateral and n=1,462 unilateral surgery).
• They matched a control group of individuals who underwent bilateral cataract surgery only (CEIOL) 1:1 to patients undergoing bilateral iStent/CEIOL on baseline demographic and clinical factors.
• They analyzed the data between November 1, 2017 and January 31, 2018.
• Main outcomes and measures included the number of topical ocular antihypertensive agents used postoperatively by patients undergoing iStent/CEIOL vs baseline and matched CEIOL control individuals, and hazard ratios with 95% confidence intervals for sustained reduced use of at least 1 topical ocular antihypertensive agent postoperatively.

Results

• Findings suggested that out of the 2,971 eligible enrollees, mean age at first surgery was 74.3 years, and 1,659 (55.8%) were women.
• Diagnoses that included primary open-angle glaucoma (n=2,329; 78.4%), narrow angles (n=381; 12.8%), and secondary glaucomas (n=261; 8.8%) were included in the patients undergoing iStent/CEIOL.
• At baseline, no topical glaucoma agents were received by 1,223 (41.2%); 876 (29.5%), 437 (14.7%), and 435 (14.6%) were receiving 1, 2, or at least 3 agents, respectively.
• The proportion of patients receiving no drops increased postoperatively, although, only 678 persons (22.8%) completed at least 2 years of postoperative follow-up (64.7%, 20-24 months, P < .001, Χ²).
• Mean reduction of 1.01 and 0.61 medications used at 20 to 24 months with bilateral or unilateral surgery, respectively (both P < .001, paired t) was seen in the patients receiving at least 1 topical agent at baseline.
• Results demonstrated greater likelihood of sustained reduction in glaucoma medication use in patients receiving at least 3 vs 1 medication at baseline (hazard ratio, 1.68; 95% CI, 1.36-2.09).
• A greater mean reduction in drops used (0.99 vs 0.49; postoperative month 20-24; P < .001; paired t) and a higher proportion receiving no drops postoperatively (73.5% vs 55.3%, postoperative month 20-24; P < .001; Χ²) was seen in patients undergoing bilateral iStent/CEIOL vs matched control individuals undergoing CEIOL.