Gonioscopia

1040-5488/11/8801-0029/0 VOL. 88, NO. 1, PP. 29–35 OPTOMETRY AND VISION SCIENCE Copyright © 2011 American Academy of Optometry

REVIEW

A History of Gonioscopy
Wallace L. M. Alward*

ABSTRACT The first view of the iridocorneal angle in a living human occurred accidentally in the late 1800s. Lenses were first used to see the angle in 1914, but practical gonioscopy would not come intoexistence for many years as the slitlamp and lenses that could be used at the slitlamp were developed. This article reviews the history of gonioscopy. (Optom Vis Sci 2011;88:29–35) Key Words: gonioscopy, history, direct gonioscopy, indirect gonioscopy, Salzmann, Trantas, Barkan, Allen

linical gonioscopy is just over 100 years old. During those 100 years, some remarkable scientists and astuteclinicians have played roles in the development of this important examination technique. This review will summarize the development of gonioscopy. The illustrations, rather than being of the people who advanced the field, will concentrate on the angle images that they produced. Gonioscopy is considered to have two “fathers,” and the primacy of the two innovators is dependent on the views of the authors.Dellaporta1 wrote a delightful and detailed history of gonioscopy that included many charming personal anecdotes. Dellaporta focused on the contributions of Trantas, with whom he shares a Greek heritage. Other accounts focus on Salzmann, who was the first to study the optics behind gonioscopy and the first to use a lens to view the angle. In their textbook, Gorin and Posner2 say that Salzmann “willalways be revered by ophthalmologists as the father of gonioscopy.” This review will consider both “fathers” chronologically. Gonioscopy is required to view the iridocorneal angle, because light from the angle reflects back into the anterior chamber at the tear-air interface (Fig. 1). This is because of the total internal reflection—just as in a fiberoptic cable. The only circumstances in whichthe angle can be seen without special manipulation are in cases of keratoglobus where the light from the angle strikes the cornea at an angle perpendicular enough to escape. This is very rare.

C

Direct Gonioscopy
To view the iridocorneal angle, one needs to overcome total internal reflection in some way. We do this today with a variety of
*MD Department of Ophthalmology, University of IowaCarver College of Medicine, Iowa City, Iowa.

lenses, but the first gonioscopy was performed with an ophthalmoscope and indentation. The first person to examine the iridocorneal angle in a living human was the Greek ophthalmologist Alexios Trantas3 in 1898. Trantas was in private practice. He was an outstanding observer—for example, he first identified the conjunctival infiltrates in vernalconjunctivitis that bear his name (Trantas dots). Trantas was able to see the angle using a direct ophthalmoscope while indenting the sclera with his finger (Fig. 2).3 He was actually more interested in viewing the ciliary body, ora serrata, and anterior retina. His view of the iridocorneal angle was a fortunate accident. In 1900, he described the appearance of a cyclodialysis cleft in a patient withan iridodialysis (his view was made easier by the iridodialysis, because the iris was not in the way).1 He later presented remarkably detailed drawings of the angle (Fig. 3).4 His descriptions of the angle were an afterthought, included in an appendix of an article describing the retrociliary region.4 It was Trantas who coined the term “gonioscopy,” meaning “observation of the angle,” in hisnative Greek.1 Maximilian Salzmann was a brilliant ophthalmologist who, upon graduating from college at age 15, went on to contribute in all aspects of eye research. He was also skilled in languages, mathematics, geology, and botany. Salzmann was a gifted painter whose paintings were used in many textbooks of his time.5 His own textbook, The Anatomy and Histology of the Human Eyeball in the Normal...