Low tension glaucoma--its place in modern glaucoma practice.

MINI REVIEWLow tension glaucoma -its place in modern glaucoma practice One of the commonest referrals to a glaucoma unit for advice on further management is the patient with 'progressing low tension glaucoma'.'There is often considerable disquiet not only about the correctness of the diagnosis but also about what, if any, treatment is appropriate.In this review current ideas on the diagnosis, prevalence, and characteristics of low tension glaucoma are set out,. and some of the many limitations to our knowledge noted, along with possible treatments. DefinitionLow tension glaucoma may be defined as a variety of primary open angle glaucoma, having characteristic glaucomatous cupping and field loss, an open angle, and an intraocular pressure (IOP) within the normal range, with no other cause for these changes.Strictly speaking'as the IOP is 'normal' rather than 'low' it should be called normal tension glaucoma.Common usage will ensure that the older title will continue for a while yet.When diagnosing low tension glaucoma it is necessary to remember how difficult it is to define 'normal' pressure.Mean IOP has been derived from studies of large or 'total' Caucasian adult populations.Two standard deviations above this mean would include 96% of the population and include most of the normals.For the populations studied this 'upper limit of normal' lies near 21 mm Hg.Glaucomatous disease developing in an eye with IOP at or below this level can be said to have 'normal tension glaucoma'.The arbitrariness of this definition will be seen when it is remembered that the IOP in Caucasians rises with age in line with the systolic on July 19, 2023 by guest.