The Importance of Gonioscopy and Angle Assessment in Ocular Hypertension

Ocular hypertension (OHT) is characterized by elevated intraocular pressure (IOP), without any visible optic nerve damage or visual field loss. The mean normal intraocular pressure is 15 mm Hg, and the mean intraocular pressure in patients with untreated glaucoma is 18 mm Hg. However, simply having ocular hypertension does not necessarily lead to the development of glaucoma, instead, it is deemed a considerable risk factor. An example is a person with thick corneas who may have no glaucomatous damage with an IOP of 24 mm Hg. Thus, early detection and management of OHT and corneal pachymetry are imperative to help detect higher risk patients with thinner corneas with ocular hypertension or glaucoma early. The Laroche Glaucoma calculator is an effective inexpensive method to detect patients with glaucoma, glaucoma suspects, and ocular hypertensive with a higher risk of thinner corneas and older age. With respect to the physiology of ocular hypertension, the anterior chamber angle anatomy serves a crucial role in the regulation of IOP. Gonioscopy is an important technique for examining the angle structures, which provides essential information regarding the status of the trabecular meshwork and how this can affect aqueous outflow. This chapter will further explore the anatomy and physiology of the anterior chamber angle, specific principles, techniques, and interpretation of gonioscopy, the significance of early detection as well as the management of OHT.