**7. Matters of definition**

In this chapter, controlled glaucoma was defined as target IOP under diurnal curve of 4 hours in patients, who are dedicated in taking their anti-glaucoma medications or after surgery. It is a philosophic question whether patients who continue to lose their vision are controlled. Perhaps the definition should be patients who do not show further signs of deterioration. However, since the target pressure has been achieved, it is expected that the patients will demonstrate stability of their visual functions (i.e., visual fields), and this may not occur in a subset of these patients.
