Glaucoma remains the leading cause of irreversible blindness worldwide. Glaucoma represents a group of diseases that lead to optic nerve damage and corresponding deterioration of the visual field.

Elevated intraocular pressure remains the most important risk factor. Interestingly, glaucomatous damage sometimes occurs despite seemingly normal intraocular pressure.

Recent studies suggest pressure peaks, which are missed under the current practice of spot intraocular measurements during office hours. In order to detect pressure peaks diurnal measurements are mandatory. Costly in-hospital diurnal measurements are the current standard.

The primary study objective is to verify that self-tonometry at home can provide valuable information when looking for pressure peaks in patients with glaucoma.

Inclusion Criteria:

• Informed consent
• Subjects aged 18 and older
• Glaucoma patients and healthy controls
• Best corrected visual acuity >0.1
• Astigmatism ≤ 3dpt.
• Good compliance
• Central corneal thickness (400-650μm)
• Passed certification procedure (detailed description under: Measurements and procedures)
• Therapeutic regimen unchanged throughout the past 30 days

Exclusion Criteria:

• History of ocular trauma
• Corneal condition interfering with tonometry (keratoconus, corneal scaring) Visual acuity <0.1
• Physical or mental disability interfering with self-tonometry (e.g. arthritis, Parkinson's disease)
• Dry eye disease
• Known or suspected non-compliance, drug or alcohol abuse
• Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant
• Pregnancy
• Breastfeeding