Clinical exophthalmometry: a comparative study of the Luedde and Hertel exophthalmometers

Exophthalmometry, the quantitative assessment of the position of the globe in the orbit, is a clinically useful measurement. The purpose of this study was to examine the performance of a simple exophthalmometer that would lend itself to accurate and convenient use in clinical practice. In this study, two observers independently performed exophthalmometry on 100 eyes using the Hertel and Luedde instruments. The results were compared between instruments and between observers. There was no statistically or clinically significant difference between measurements taken with the Luedde as compared with the Hertel instrument. The Luedde exophthalmometer has a number of advantages over the Hertel exophthalmometer, and represents a simple, inexpensive and equally reliable means of evaluating clinically the anteroposterior position of the eye in the orbit.