Purpose of this study is to exam the hypotensive effectiveness of I-stent implantation depended on number of antiglaucoma eye drops at baseline.

The scientific aim of the project is to estimate the average reduction of intraocular pressure (IOP) in relation to the initial number of antiglaucoma drops at the end of 12 months observation period. The subject must suffer from glaucoma and cataract at the same time, and qualify for a cataract surgery. The group will be composed of 40 patients of the Ophthalmology Clinic of the Medical University of Białystok qualified for planned cataract removal surgery. They will be surgically implanted an I-stent by-pass during phacoemulsification.

Inclusion Criteria:

• co-existing glaucoma and cataract (NC1, NC2) classified by means of the LOCS III scale (Lens Opacity Classification System III)
• patients with primary open-angle glaucoma (POAG), pseudoexfoliative glaucoma (PGX) and normal tension glaucoma (NTG), with topical hypotensive treatment
• written consent to involvement and participation in the study for a period of at least 12 months was obtained from all patients after they had first been informed of the nature of the procedure and other surgical alternatives

Exclusion Criteria:

• no consent to participation in the study
• prior surgical and laser procedures in the area of the eye
• narrow- or closed-angle glaucoma
• post-inflammatory or post-traumatic secondary glaucoma
• chronic illness of the cornea or optic nerve
• advanced macular degeneration
• active inflammatory process
• pregnancy
• systemic steroid therapy

De-identified individual participant data for all primary and secondary outcome measures will be made available

Data will be available within 6 months of study completion

Data access requests will be reviewed by the Chair Person. Requestors will be required to sign a Data Access Agreement