Purpose of review: This review summarizes the relationship of 24 h intraocular pressure (IOP) on the management of glaucoma.
Recent findings: The 24 h IOP pattern demonstrates nocturnal elevation in the majority of individuals. Prostaglandin analogs and carbonic anhydrase inhibitors lower both diurnal and nocturnal IOPs. Timolol monotherapy and timolol add-on treatment to a prostaglandin analog does not lower IOP during the nocturnal period. Laser trabeculoplasty can reduce nocturnal IOP elevation in medically treated glaucoma patients, even in those without significant reduction of diurnal IOP. Though both IOP and central corneal thickness display a 24 h rhythm with peaks during the nocturnal period, there is no correlation between central corneal thickness and 24 h IOP variation in normals and glaucoma patients. Corneal biomechanical properties (corneal hysteresis and corneal resistance factor) remain relatively stable during the 24 h period and are not associated with 24 h IOP fluctuation.
Summary: Antiglaucoma therapies differ in their ability to lower IOP throughout the 24 h day. The 24 h IOP pattern is independent of central corneal thickness, corneal hysteresis and corneal resistance factor.