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by Dr. Nilo Vincent Florcruz II

Although it is recognized that not all glaucoma patients demonstrate elevated intraocular pressure and not all glaucomatous optic nerve damage is attributable to pressure damage per se, current standard glaucoma care is devoted almost exclusively to reduction of intraocular pressure. Bringing pressure down into the normal or low normal range (17 mm Hg or less) can be expected to arrest progression or dramatically slow its course in the vast majority of cases. At the same time, it must be recognized that some unfortunate individuals, diagnosed late with end-stage nerve damage, with an unusually sensitive optic nerve, or who are primarily sensitive to non-pressure factors, will continue to show unabated visual field loss despite maximal pressure lowering. These are the individuals to whom future research regarding other non-pressure causative factors and their treatment must be directed. Three methods for glaucoma pressure-lowering treatment are available: medical (usually eyedrops), laser, and surgical. Since the threshold of pressure damage varies among patients, the only reliable indicators of glaucoma stabilization are stability of the visual field and prevention of optic nerve damage. In the usual glaucoma therapy, intraocular pressure may be lowered by any or all of the three methods (drops, laser and surgery). In a normal, non-glaucomatous population, intraocular pressure averages approximately 16 mmHg and most (95%) will fall between 10 mmHg and 24 mmHg. In the glaucomatous population, the mean intraocular pressure is somewhat higher and the range much broader, even as high as 70 mmHg where arterial circulation to the eye begins to be compromised. Typically, however, the early untreated open angle glaucoma patient will manifest an eye pressure in the mid-20s. Measurement of intraocular pressure at different times of the day establishes the degree of pressure variability before glaucoma therapy is started. The experienced ophthalmologist typically will determine a "target pressure" as a goal to achieve with pressure-lowering therapy, recognizing that the goal may have to be revised based on future assessment of the visual field.