Tip of the Month
Publishing date: December 2006
Tip Editors: Ann Hoste, John Salmon and John Thygesen
Tip reviewer: Roger Hitchings
The Science behind the Tip
Target pressure is an estimate of the mean intraocular pressure (IOP) obtained with therapy that is expected to prevent further glaucoma damage. The level is chosen from clinical experience and uses the outcomes of clinical trials for guidance(1). In order to obtain a satisfactory therapeutic benefit in glaucoma, it is not adequate to simply approach the upper normal limit of the treated factor (i.e. IOP).
There is no ideal target pressure for all patients. Consider factors such as starting IOP (i.e. the IOP at which the damage occurred), degree of pre-existing glaucoma damage, life expectancy and other risk factors when setting the target pressure level(2) (see Figure, © EGS).
Verify target pressure regularly during follow-up with fields/disc assessment, and adjust when necessary.
Remember that not all patients need a very low IOP. Indeed, reducing IOP to very low levels may increase morbidity. Moreover, an IOP of 12-14 mm Hg is no guarantee that no further damage will occur.
Contributor: Clive Migdal, London
Co-editors: John Thygesen and Ann Hoste
Peer reviewers: Roger Hitchings and Anders Heijl
1. Migdal C. The concept of target intraocular pressure at various stages of glaucoma. In: Glaucoma. 2004. Eds Grehn F, Stamper R. Springer-Verlag, Berlin.
2. European Glaucoma Society. Terminology and Guidelines for Glaucoma, 2nd edition. 2003. Dogma, Savona, Italy.