Pen Touch Test for Detecting Exophthalmos

Abstract

Graves’ ophthalmopathy (GO) is an autoimmune disease of the retroocular tissue occurring in patients with Grave’s disease leading to exophthalmos. Exophthalmos is usually detected by inspection using Nafziger’s method and objectively measured with Hertel’s exophthalmometry. Here we have described a novel technique “Pen touch test” to clinically diagnose exophthalmos. This cross-sectional study was conducted on patients with suspicious hyperthyroid ophthalmopathy/Grave’s ophthalmopathy (GO) who underwent eye examination by Nafziger’s method and our proposed new method “Pen Touch Test (PTT)”. In this test, a clean ruler or pen is held straight over the middle of orbital ridge touching the superior orbital margin and ipsilateral malar eminence. In normal persons, the ruler or pen touches both the superior orbital margin and ipsilateral malar eminence with or without touching eyelids. In patients with GO, there is true bulging forward of the eyeball. Hence, the ruler or pen cannot be made to touch both upper orbital margin and malar eminence simultanously. The presence and degree of exophthalmos was measured objectively on Hertel’s exophthalmometry, which was considered the “gold standard”. Pen touch test was found to have 100% sensitivity, 100% specificity and 100% Positive Predictive value. Whereas Nafziger’s method had a sensitivity of only 75% compared to Hertel’s exophthalmometry as gold standard test. “Pen touch test” is simple and sensitive method that can be used to screen for exophthalmos in suspected cases of Grave’s ophthalmopathy.