OC-OPDSG-3 Posner Gonioprism w/Ergonomic Handle
■ The Posner Diagnostic and Surgical Gonioprism is a four mirror gonio lens for static and dynamic gonioscopy which requires no gonioscopic solution for optical interface.
■ The lens consists of a highly polished truncated pyramid with a plano anterior viewing surface over four mirrors inclined at 64°.
■ The mirrored surfaces are silvered and double coated with a proprietary coating to prevent peeling and damage under normal daily use.
■ The posterior surface of the lens has a base curve of 41.5D and a diameter of 9mm.
■ The lens is easily positioned and maneuvered by an aluminum handle set at 17°.
■ Lenses also available in select colors. Contact Ocular Instruments for further information.
■ Gonioscopy can be accomplished using one of two methods.
· Method 1: Place the gonioscope on the eye with mirrors arranged perpendicular and planar to horizon.
o Observation is begun in the inferior angle using the superior mirror.
o Next, lower the slit lamp beam to the inferior mirror to check the superior angle.
o Finally, with the beam horizontal and tilted, observe the angle near the 180° meridian.
· Method 2: Place the gonioscope on the eye with the mirrors arranged obliquely (diamond position). In this orientation, nearly all of the angle can be observed.
o With the slit lamp beam vertical, simply move the slit lamp from right to left across the two superior mirrors.
o Next, lower the beam and move the slit beam from left to right across the two inferior mirrors. Complete observation of the angle can be quickly achieved with minimal rotation of the lens (11° in either direction) is needed to view the small sections of angle, which were missed during the initial sweep.
■ Because of the light weight and small size of this gonio lens, it is easily applied to the eyes of small children and individuals with narrow palpebral fissures.
■ Deliberate compression with the gonioscope (dynamic gonioscopy) gives the observer a certain amount of control over the iris configuration.
■ In an eye with a relatively narrow angle, deeper structures can be visualized by flattening the periphery of the iris gonioscopically.
■ It is also used to distinguish between true peripheral anterior synechiae and simple apposition of the iris to the cornea.
■ The center axis may be used to view the posterior pole and disc.
■ Evaluation of the anterior chamber angle may be made prior to and immediately following surgery for narrow angle glaucoma.
■ The gonio lens must be sterilized for surgical use.
■ The gonio lens is applied to the cornea with balanced salt solution or a visco-elastic solution as an optical interface.
■ The slit beam of the microscope is used for illumination and the angle is observed.