An interventional, open, prospective, multi-center pre-market clinical investigation according to §§20-23a Medizinproduktegesetz (MPG, medical devices act), in which a total of 40 eyes of 40 consecutive patients at up to five (5) clinical sites will be enrolled, treated with the VISULAS green with option CSLT, and followed for a three months period.

The primary objective of this clinical investigation is to evaluate safety and effectiveness of SLT with the VISULAS green laser with option CSLT.

Inclusion Criteria:

• Males and females at least 22 years of age or older, primary open-angle glaucoma (HPG + NPG), who did not reach target pressure .
• IOP with or without medications ≥17 mmHg in the study eye
• Chamber angle Shaffer 3 and 4
• Patients must be legally competent and able to give consent and must have read, understood and signed patient information leaflet and consent to undergo SLT in one eye
• Patients are willing and able to return for follow-up examinations
• In the opinion of the investigator, the patient will be compliant and have a high probability of completing the clinical investigation and all required procedures

Exclusion Criteria:

• Corneal disease or pathology in a way that distortion of laser light in the study eye can be expected or that precludes stabilization of the cornea by the contact glass, visibility of the trabecular meshwork or transmission of laser wavelength
• Strong clouding of the anterior ocular media (e.g. the lens due to dense cataract) and the vitreous body (e.g. due to strong vitreous hemorrhage) in either eye
• Deep orbits and/or narrow palpebral fissures
• Corneal or conjunctival abnormality precluding contact lens adaptation in either eye
• History of Amblyopia in either eye
• Any contraindications to SLT in study eye.
• Any kind of planned ocular surgeries during the next 3 months (for example, cataract surgery) in either eye
• Previous intraocular or corneal surgery of any kind (except cataract surgery longer than three months prior to the clinical investigation), including surgical glaucoma intervention in study eye before the clinical investigation.
• Signs of Fuchs' Dystrophy (e.g. corneal endothelial guttata) in either eye
• Active or history of Uveitis in either eye
• Congenital glaucoma in either eye
• Diabetic retinopathy or branch retinal vein occlusion with the risk to develop neovascularizations in either eye
• Heavily pigmented trabecular meshwork due to pseudoexfoliation syndrome or pigment dispersion glaucoma in either eye
• Degenerative disorders of the central nervous system if it prevents proper compliance or the ability to undergo the tests in the clinical investigation (e.g. Parkinson Disease, Alzheimer Disease, or other forms of dementia)
• History of or has a current, clinically significant major psychiatric disorder (e.g., major depressive disorder, psychosis, schizophrenia)
• Patients who are pregnant, lactating, or of child-bearing potential and not practicing a medically approved method of birth control.
• Enrollment in another drug or device study within the prior 3 months