Assessment of IOP
IOP is measured by a non-contact tonometry (NT-510, Nidek, Japan). If the participants cannot be coordinated with NCT, an iCare HOME tonometer (TA022, Icare Oy, Finland) is available. If the level of IOP is higher than normal, a Goldmann applanation tonometry (AT900, Haag Streit, Switzerland) will be used for further confirmation.