The study is designed to assess the safety of Hyaluronan Thiomer i.o. implant in patients with primary open angle glaucoma undergoing a combined phacoemulsification - non penetrating deep sclerectomy procedure.

In this study, Hyaluronan Thiomer i.o. will be implanted during a combined surgery of cataract and non - penetrating deep sclerectomy in a group of 16 patients with primary open angle glaucoma and clinically significant cataract. Given that a considerable number of glaucoma patients also suffer from cataract, it is reasonable to test Hyaluronan Thiomer i.o. during a combined procedure of phacoemulsification and deep sclerectomy. This is also of importance because a combined procedure avoids the need of a second operation in this group of patients. Finally, it has been shown that combined phacoemulsification - deep sclerectomy does not induce a further risk compared to deep sclerectomy alone(open phase I study).

Safety will be assessed based on the occurrence of adverse events.

Efficacy assessments will be performed at every visit and efficacy analysis will include:

• Proportion of subjects at each study time point which will need additional IOP lowering drug therapy to achieve an IOP reduction to values < 21 mmHg. If a subject needs more than one drug to achieve target IOP, the number of drugs needed to achieve adequate IOP reduction will be recorded.
• Proportion of subjects at each time point which will need Neodymium:YAG goniopuncture to achieve an IOP reduction to values < 21 mmHg.

Inclusion Criteria:

• Men and women aged over 18 years
• Primary open angle glaucoma with uncontrolled IOP (IOP > 21 mmHg or more) despite maximally tolerated topical medication
• Clinically significant cataract as judged by the investigator
• Scheduled for combined cataract/glaucoma surgery

Exclusion Criteria:

Any of the following will exclude a subject from the study:

• Participation in a clinical trial in the 3 weeks preceding the study
• Presence or history of a severe medical condition as judged by the clinical investigator
• Wearing of contact lenses
• Loss of mean deviation of visual field testing of 15 dB or more
• Diabetic retinopathy
• Dysgenetic glaucoma, secondary glaucoma or any type of angle closure glaucoma
• Previous argon laser trabeculoplasty
• Severe dry eye syndrome as judged by the investigator
• Ocular infection or clinically significant inflammation as judged by the investigator
• Ocular surgery in the 12 months preceding the study
• History of glaucoma surgery in the study eye
• Neovascular form of age related macular degeneration
• The following lenses will not be implanted during cataract surgery Multifocal lenses Toric lenses PMMA lenses
• Ametropy >/= 6 Dpt
• Patients in which the surgical procedure cannot be performed or completed according to the protocol for any reason will be excluded and replaced.
• Pregnancy, planned pregnancy or lactating