Which instrument is traditionally used for measuring intraocular pressure?

The Goldmann tonometer is recognized as the standard instrument for measuring intraocular pressure (IOP), which is crucial for diagnosing and managing glaucoma. It works on the principle of applanation, where the instrument flattens a specific area of the cornea. The amount of force required to achieve this flattening correlates with the intraocular pressure, allowing for accurate measurement.

In contrast, the other instruments mentioned have different primary purposes. A retinoscope is used to assess refractive errors and determine the prescription for glasses, not for measuring IOP. A pachymeter measures corneal thickness, which is important in glaucoma assessment but does not directly measure IOP. An ophthalmoscope is primarily used for examining the interior structures of the eye, such as the retina, but it does not provide any information about intraocular pressure. Thus, the importance and function of the Goldmann tonometer specifically align with the requirement to measure intraocular pressure accurately.