iStent inject in phakic open angle glaucoma

Abstract

Background: The effectiveness and complication profile of the iStent inject implantation among different open angle glaucoma subgroups were analyzed.

Methods: In this retrospective cohort outcome study, 35 consecutive patients suffering from glaucoma (primary open angle glaucoma (POAG) N = 17, pseudoexfoliation glaucoma (PEX) N = 15, and pigmentary glaucoma (PG) N = 3) were treated with the iStent inject. The intraocular pressure (IOP) and the number of antiglaucoma medications before and after surgery were evaluated.

Results: In POAG, the mean IOP at 6 months measured 14.19 ± 1.38 mmHg with an average decrease of 33 % from preoperative IOP (p < 0.001), and 15.33 ± 1.07 mmHg with an average decrease of 35 % in PEX (p < 0.001), respectively. The number of antiglaucoma medications significantly decreased from 2.19 ± 0.91 to 0.88 ± 0.62 in POAG (p < 0.001) and from 2.33 ± 1.23 to 1.04 ± 0.30 in PEX (p < 0.001) after 6 months. In PG, IOP before surgery was 28.31 ± 3.21 mmHg and the number of antiglaucoma medications was 3.66 ± 0.57. One day after surgery, IOP decreased significantly to 12.33 mmHg ± 4.93 (p < 0.001). Within four weeks after surgery, IOP was raised above 30 mmHg in every patient. To exclude a steroid response, topical steroids were stopped, but IOP did not decrease. To exclude blockage, Nd:YAG - laser treatment of the visible opening of the iStents was performed. Since the IOP stayed high and escalation of antiglaucoma medication was insufficient to control IOP, trabeculectomy was performed.

Conclusions: In conclusion, implantation of the iStent inject has the ability to lower the postoperative IOP significantly in POAG and PEX after a short follow-up of 6 months with a favorable risk profile. However, limitation of this surgical procedure in phakic PG may exist and need to be investigated in further studies.