How is the target IOP by mmHg range determined?

• A. Patient age
• B. Disease severity
• C. Time of day
• D. Baseline refractive error

Answer: (B)

The target IOP range is set primarily by how much glaucomatous damage there is and how likely it is to progress. When glaucoma is mild, the aim is a modest reduction in pressure, accepting a higher absolute IOP. As damage becomes more advanced or progression risk is higher, a lower target is chosen to better protect remaining vision. In practice, clinicians think in terms of reducing the baseline IOP by a certain percentage or aiming for the lowest safe pressure that still maintains quality of life, and they adjust that target based on how severe the optic nerve damage and visual field loss are, along with patient factors like life expectancy and other risks.

Time of day affects the measured IOP due to natural diurnal variation, but it doesn’t dictate the target range itself. Baseline refractive error is related to optical factors, not the risk of progression or the needed pressure to protect the optic nerve, so it doesn’t drive target IOP decisions.

So the key idea is that more severe disease requires a lower IOP target, while milder disease allows a higher target; the target is then monitored and adjusted as the disease status evolves.