Fifty glaucoma patients (POAG and PEX) planned for trabeculectomy will be recruited.
At baseline, patients will be trained to use the iCare Home tonometer (RTHome), a handheld device based on rebound tonometry and designed for patients to use at home. After the training session and when patients feel confident, a measurement will be recorded. At the same visit, a new measurement will be obtained by the study staff, an optometrist or a nurse, using the same device. No IOP values will be visible for the examiner at that point. A single IOP measurement will be obtained by the same study staff using Goldmann applanation tonometry (GAT). Patients will come for a second visit where new measurements will be made in the same way as at baseline.
In between visits, patients will borrow the iCare Home tonometer to measure their IOP at 06 and 10 am, and at 2, 6 and 10 pm during three consecutive days to obtain an IOP curve.
Two-three months after trabeculectomy, a new IOP curve will be obtained following the same procedure as pre-operatively. There will be no restrictions in patients' daily activities regarding diet, physical activity or slee. If patients use any eyedrops, they will continue to use them as prescribed.
