Purpose
To evaluate and compare the efficacy and safety of combined phacoemulsification and endocyclophotocoagulation with and without ab interno trabeculotomy in patients with uncontrolled open angle glaucoma.

Methods
This comparative non-randomized retrospective study evaluated the 12-month outcomes of patients with uncontrolled open angle glaucoma who underwent combined phacoemulsification with endocyclophotocoagulation (ECP) and ab interno trabeculotomy (group I) vs phacoemulsification with endocyclophotocoagulation (group II). The primary outcome was mean preoperative and postoperative intraocular pressure; the secondary outcomes included the reduction in number of glaucoma medications, visual acuity, reported complete, qualified success or failure, and complications.

Results
Forty-six eyes of 36 patients were included; intraocular pressure was 16.96±3.66 mmHg and 15.64±4.88 mmHg for group I and group II (p=0.122) respectively at baseline, and 11.44±2.15 mmHg and 12.45±1.90 mmHg, respectively (p=0.031) at the 12-month follow-up. The complete success rate was 56% in group I and 55% in group II; the qualified success was 93% (p=0.011) and 91% (p=0.011), respectively. Medications decreased from 2.0±1.4 to 0.8±1.0 (p<0.001) in group I and 1.5±1.3 to 1.0±1.5 in group II (p=0.032). There was similar improvement in visual acuity in both groups. Complications were mild and resolved without intervention.

Conclusion
Both procedures achieved efficient and safe reduction in IOP as observed in patients with uncontrolled open angle glaucoma at 12-month follow-up. When ab interno trabeculotomy is added to phacoemulsification and ECP, the mean intraocular pressure is more greatly reduced, and this difference between the interventions is clinically significant.