Prospective Multicenter Randomized Comparison of Phaco + Schlemm Canal Microstent Versus Phaco Alone for Lowering IOP at 24 Months
Purpose
Compare the reduction of washed out diurnal IOP and hypotensive medication due to a Schlemm’s canal microstent in patients with open-angle glaucoma undergoing concurrent phacoemulsification to phacoemulsification alone for 2 years after surgery.
Methods
Prospective, controlled, randomized clinical study in subjects with OAG and cataract at 7 clinical centers. Qualified subjects were washed out of hypotensive medications prior to surgery. Preoperative washed out diurnal IOP was measured using Goldmann tonometry. After cataract surgery, subjects were randomly assigned to receive the Hydrus microstent (Ivantis, Inc) or no treatment. Follow up was conducted at 1 day, 7 days, and 1, 3, 6, 12, 18, and 24 months. Examinations included IOP, medication use, and changes in visual status and ocular health. Wash out and diurnal Goldmann tonometry was repeated at the 12 and 24 months.
Results
One-hundred eyes from 100 subjects were randomized in the study. There were no significant differences between groups in age, sex, ethnicity distribution or baseline visual acuity or glaucoma severity. Screening IOP was 18.8 ± 3.6 mmHg on 2.0 ± 1.0 glaucoma medications. Preoperative washed-out IOP was 26.3±4.4 in the Hydrus group and 26.6±4.2 mmHg in the phaco group. At 2 years, medication use was 50% lower in the Hydrus group and the proportion of patients with a 20% drop in washed out IOP was 80% in the Hydrus group compared to 46% in the phaco group (p=0.0004).
Conclusion
Phaco with a Schlemm’s canal microstent significantly lowered IOP and medication usage compared to phaco alone through 24 months in patients with OAG and cataract.