gonioskopian

Gonioskopian, commonly referred to as the gonioscope, is an ophthalmic instrument used to perform gonioscopy, the examination of the iridocorneal angle. The angle is the junction between the iris and cornea through which aqueous humor drains, and its assessment helps classify angle openness and detect abnormalities relevant to glaucoma risk and management.

Gonioscopes are typically contact lenses with reflective surfaces or mirrors. The most widely used designs are three-mirror and four-mirror lenses, which allow visualization of angle structures when viewed through a slit lamp. A coupling medium, such as saline or methylcellulose, and topical anesthesia are usually employed to minimize contact friction and discomfort.

Technique and findings: After anesthesia and sterile preparation, the lens is gently placed on the cornea while the patient looks in different directions. The clinician uses the mirrors to inspect angle components such as Schwalbe’s line, the trabecular meshwork, and the scleral spur, determining whether the angle is open, narrow, or closed. The examination also looks for signs of peripheral anterior synechiae, iris pigment changes, neovascularization, or angle recession.

Indications and utility: Gonioscopy is essential in glaucoma evaluation, differentiation between open- and narrow-angle configurations, assessment before laser or surgical interventions, and monitoring post-traumatic or inflammatory conditions. Limitations include the need for patient cooperation and clinician skill, potential corneal injury, and visibility affected by edema or scarring. Non-contact imaging options such as AS-OCT or ultrasound biomicroscopy may serve as adjuncts or alternatives in certain cases.