Background: The Cypass Microstent (Transcend Medical, Menlo Park, CA, USA) is a biocompatible polyamide implant that is implanted in the suprachoroidal space and improves the flow of the aqueous humour via the uveoscleral pathway.
Material and methods: In a retrospective clinical study 162 patients (220 eyes) with an average age of 71.8 (±14.2) years with a mild to moderate glaucoma were treated with a Cypass implant. In the study three groups of patients (group 1, group 2 and group 3) were formed. Group 1 included patients with pseudophakia who received a Cypass implant, group 2 consisted of patients with a Cypass implant combined with phacoemulsification and implantation of an intraocular lens (Phako/HKL) and group 3 included patients who had had multiple eye surgeries before the Cypass implantation. The follow-up period of the study was 1 year.
Results: The mean preoperative intraocular pressure (IOP) in group 1 was 20.0 (±8.4) mm Hg and in group 2 was 20.8 (±8.7) mm Hg. The mean IOP fell to 17.7 (±7.1) mm Hg in group 1 (pressure reduction: 11.7%, p < 0.05) and in group 2 to 18.0 (±7.0) mm Hg (pressure reduction: 13.4%, p > 0.05) 12 months postoperatively. The decrease of IOP in group 3 after 1 year was 11.2%. In 20.5% of the cases (45 eyes), additional operative pressure reducing interventions was performed because the target pressure was not achieved.
Conclusion: After 1 year patients in group 2 showed a significantly similar reduction in pressure as group 1. Additionally, both groups showed a reduction in the number of locally applied antiglaucoma agents. The reduction of the IOP in group 3 was not significant after 12 months, in contrast to the other two groups.
Keywords: Cataract surgery; Cypass implant; Intraocular pressure; Primary open-angle glaucoma; Suprachoroidal space.