Ahmed ClearPath 250 implantation: hypertensive phase and ripcord management patterns in a retrospective cohort

Postoperative pressure behavior after ligated Ahmed ClearPath 250 implantation is incompletely characterized. We examined hypertensive-phase occurrence and early and later intraocular pressure changes following intraluminal ripcord removal. This retrospective cohort included 112 eyes of 112 adults assessed through 24 months. Hypertensive phase was defined as intraocular pressure (IOP) ≥ 21 mmHg on postoperative days 43–132 after presumed tube opening. Ripcord outcomes included pre-removal, early post-removal (typically within 7 days), and month-6 IOP. Standardized success required IOP > 5 and ≤ 21 mmHg with ≥ 20% reduction and no specified failure events, including additional glaucoma surgery/revision, persistent hypotony, or loss of light perception. Analyses used Wilcoxon signed-rank tests with Bonferroni adjustment, group comparisons, and separate logistic regression models. Hypertensive phase occurred in 30 eyes (26.8%; 95% confidence interval, 19.5%–35.7%), first documented at month 3 with IOP of 24.3 ± 2.4 mmHg on 3.37 ± 0.89 medications. All 30 underwent ripcord removal. Their early IOP was 20.9 ± 3.0 mmHg; 17/30 (56.7%) were below 21 mmHg. At month 6, IOP was 18.2 ± 3.8 mmHg on 2.63 ± 1.65 medications, with 23/30 (76.7%) below 21 mmHg. Overall, 35 eyes (31.2%) underwent removal. Mean IOP was 23.7 ± 2.7 mmHg before removal, 20.1 ± 3.8 mmHg at early review, and 17.6 ± 3.9 mmHg at month 6. Paired reductions were 3.5 ± 3.8 and 6.1 ± 2.5 mmHg, respectively (both adjusted p < 0.001). In separate models, adjusted odds ratios per 5-mmHg increase were 3.89 for baseline IOP and 3.46 for month-1 IOP. Overall 24-month success was 83.9%; success was 60.0% with versus 92.7% without hypertensive phase (Fisher exact p < 0.001). Hypertensive phase affected approximately one-quarter of eyes. Ripcord removal was followed by lower IOP at early review and month 6. These observational findings distinguish early from later pressure changes but do not establish an isolated treatment effect or optimal removal timing.