Gonioscopy is a technique used to examine structures in the anterior chamber angle (the fluid filled space inside the eye between the iris and the innermost layer of the cornea, the endothelium). It is an essential tool in ophthalmic practice, particularly in the diagnosis of glaucoma. In 1899, the Greek ophthalmologist Alexios Trantas was the first to visualise the angle in vivo and coined the term ‘gonioscopy’. He made a number of other important contributions to ophthalmology.
