ABSTRACT
As discussed in Chapter 1, the term ‘glaucoma’ encompasses a wide variety of diseases and conditions. In order to arrive at a working diagnosis and institute appropriate therapy, the patient’s history must be obtained and an examination performed. Classification of diseases such as glaucoma into various categories, each distinguished from the other by some essential characteristic or set of characteristics, allows us to deal with a patient’s disease appropriately. For example, the initial treatment of a patient with a pressure of 48 mmHg due to angleclosure glaucoma is very different from that of a patient with the same pressure presenting for the first time with open-angle glaucoma. Similarly, the therapeutic goal set for a patient with extensive visual field loss and optic nerve cupping may be very different if the presenting intraocular pressure was 40 as opposed to 21. Thus, the approach to diagnosis often looks along some sort of classification scheme in which the subcategories have common diagnostic or therapeutic characteristics. Various classification schemes exist, and almost all glaucomatous disease falls somewhere in all of them. Most of the entities will be discussed in other chapters of this atlas.
