To explore the demographic and clinical variables associated with intraocular pressure lowering after cataract extraction alone (CE) or in combination with iStent placement (CE-IS).
Retrospective data extraction and survival analysis of consecutive patients identified over a 2-year period.
Patients with mild to moderate glaucoma who underwent CE (48 eyes from 32 patients) or CE-IS (61 eyes from 37 patients) were analyzed.
Inability to reduce the number of medications or the IOP by at least 20% compared to baseline on 2 consecutive visits was considered surgical failure. Using Cox proportional hazards models, survival analysis was performed, and demographic and clinical variables were evaluated as risk factors.
Time to failure after surgical procedure.
CE-IS had lower odds of failure than CE (HR=2.01, p=0.047). In Caucasian subjects, CE-IS had greater odds of success as compared to CE alone (HR=2.86, p=0.007). For non-Caucasian subjects there was no difference in the outcomes for the 2 procedures (HR 0.59, p=0.48). In the multivariate analysis, non-Caucasian race (HR=8.75, p=0.0002) and longer axial length (HR=1.61, p=0.03) were associated with greater hazard of failure after CE-IS. In the CE group, greater odds of failure were associated with steeper corneal curvature (HR=1.74, p=0.008), shallower anterior chamber (HR=0.22, p=0.008), and longer axial length (HR=1.58, p=0.01).
Addition of iStent to CE improved the survival of IOP lowering success in Caucasians but not in non-Caucasians. Associations between IOP lowering after CE and biometric parameters may allow for leveraging these clinical parameters for better case selection for these procedures.

Copyright © 2020. Published by Elsevier Inc.