Surgical Outcomes of Phacoemulsification Followed by iStent Implantation Versus Goniotomy With the Kahook Dual Blade in Patients With Mild Primary Open-angle Glaucoma With a Minimum of 12-Month Follow-up.

Purpose: To study surgical outcomes after combined phacoemulsification with either iStent implantation or goniotomy using the Kahook Dual Blade (KDB) with a minimum of 12 months of follow-up. Patients and

Methods: Patients with mild primary open-angle glaucoma who underwent phacoemulsification in combination with either iStent implantation or goniotomy using the KDB from 2011 to 2017 were included.

Results: In total, 48 eyes in the iStent group and 29 eyes in the KDB group were included with at least 12 months of follow-up. There was no difference in patient age, sex, previous surgery, preoperative or postoperative visual acuity or intraocular pressure (IOP) between the 2 groups. Mean preoperative IOP in the iStent group decreased from 17.6±4.8 to 15.9±2.9 mm Hg (P=0.01); mean preoperative IOP in the KDB group decreased from 17.4± 4.3 to 15.0±4.0 mm Hg (P=0.01). The overall percentage of IOP reduction was 14.3% in the iStent group and 12.6% in the KDB group at 12 months of follow-up. Mean topical glaucoma medication use decreased from 2.0±0.9 to 0.7±1.1 in the iStent group and from 2.2±1.0 to 1.6±1.3 in the KDB group. Multivariable linear regression accounting for age, sex, race, baseline IOP, and number of eyes treated as covariates indicated a significant reduction in IOP from baseline with both iStent (Wald χ=3.97, P=0.046) and KDB (Wald χ=4.65, P=0.031). Multivariable logistic regression accounting for age, sex, race, baseline IOP, and number of eyes treated as covariates indicated no significant difference in overall success between iStent and KDB (Z-test=0.92, P=0.359).

Conclusions: Phacoemulsification in combination with either iStent implantation or goniotomy using the KDB both achieved statistical significant reduction in IOP and number of glaucoma medications at 12 months of follow-up in patients with mild primary open-angle glaucoma with no complications.