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Show 'OJ J'J86 Raven Press, New York The Paredrine Test In Normal Eyes A Controlled Study Kurt Heitman, M.D., and Donald D. Bode, M.D., PhD. Paredrine has been used as an adjund to the cocaine test fL1r Horner's syndrome; however, there ilre no controlled studies measuring pupillary responses in normal eyes. Twenty-five volunteers with normal eye examinations received 1(Ir Paredrine in one eye, fl'l1owed bv serial photography to document the ex'tent of pupillar~' dilation. Pupillary measurements were taken from the photographs to prevent identification of the pati~nt, control or treated eye, or the time after instillation ot the eye drops. Lighter irides dilated more rapidly, and some patients with dark irides showed little response. The control eye showed progressive pupillary constriction as its fellow eve became more dilated. Key Words: Horner's syndrome-Paredrine-Postganglionic neuron. From the University of Tl'xas Health Science C.'nter <It S.1n Antonio, San Antonio, Texas. This work was prl'sl'nted <lS a pl)skr at the 90th <lnnual meeting of the American Acadl'my of Ophthalmology, San Francisco, California, Septembl'r 29 to October J, 1985. Address correspondence and reprint requ"sls 10 Kurl Heitman, M.D., Department of Ophthalmology, The UniVt'rsity of Texas f~l'alth Scil'ncl' C.'nll'r at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX 7K2!:l4, U.S.A. . Oculosympathetic paresis is one of a triad of findings described by Horner over 100 years ago (1). Although cocaine has been used for many years to confirm the diagnosis of Horner's syndrome, Paredrine has been shown to be the most useful agent in distinguishing preganglionic from postganglionic lesions (2-4). This study objectively demonstrates the effect of Paredrine on nor~al eyes with either dark or light irides and determines the amount of time necessary to achieve an appreciable response. MATERIALS AND METHODS Twenty-five ocularly normal subjects, ages 24-63, participated. Eighteen had dark irides, and seven had lighter pigmented irides (green or blue). Each participant unden\'ent a complete eye examination prior to entering the study, and only those with normal examinations were included. Applanation tonometry was not performed within 24 h prior to the study, and contact lens wearers discontinued using their lenses as well for at least 1 day prior to the stud~·. Baseline photographs were taken and informed consent obtained. Two drops of Paredrine 1% were instilled in either eye over a I-min interval. The fellow eye served as a control and received no dwps. In 18 people, the left eve was the control; in seven, the right was the control. Serial photographs were taken every 10 min for up to 40 min using standard light and f-stop settings for each patient. Random three-digit numbers were imprinted on the photographs for identification. This technique was used to eliminate bias by the observer. The final pupillary measurements of both eyes were taken directly from the photographs by comparing the diameter of the pupil to a millimeter rule held underneath the eye and included in the photograph. After all measurements were 228 THE PAREDRINE TEST IN NOR.MAL EYES 229 TABLE 1. Change in pupillary size (in mm) after Paredrine-dark irides 10 min 20 min 30 min 40 min Patient CE. SE CE SE CE SE. CE SE. 1 - 0.75 025 025 125 0.5 175 0.5 2.25 2 - 0.5 025 025 20 0.25 275 0.5 3.5 3 0 0 0 025 0.5 0.75 0.5 1.0 4 0 0 025 0 0.5 0.5 - 0.75 20 5 0 0 025 025 0.75 0 0.5 1.0 6 025 0 0 125 025 1.5 0.5 2.75 7 -025 0 0.5 10 0.75 1.5 - 0.75 1.25 8 0.5 0.75 0 0.5 0 25 0 2.5 9 -025 0 0.25 0 0.75 175 -1.25 175 10 - 0.5 0.25 0.5 025 1.0 175 -10 2.5 11 025 0.5 0 0.75 0.25 15 -10 20 12 0 0 0 0.75 0.25 225 -025 275 13 - 05 - 0.5 0 025 -0.5 0.5 -025 1.5 14 -025 0 - 0.5 0 -0.5 0.25 -0.5 1.0 15 0 0 - 025 0 - 0.5 0.75 -0.5 0.5 16 0 0 -025 0.75 -0.75 125 -1.0 20 17 -0.25 -025 -025 1.0 -0.25 125 -025 1.5 18 0 0 -025 0.5 -0.25 0.75 -0.25 1.0 AbbrevIations used: C.E. = control eye; S.E. = study eye. TABLE 2. Change in pupillary size (in mm) after Paredrine-light irides 10 min 20 min 30 min 40 min Patient CE SE CE S.E. C.E S.E. C.E SE 1 -0.5 -0.75 -0.5 0.25 -0.75 2.25 -15 2.5 2 0 -0.25 0 -0.25 -0.25 0 -0.25 1.0 3 -025 0 -0.75 - 0.25 -0.75 175 -0.5 3.25 4 0.25 0.5 -0.25 2.5 -0.5 3.75 -0.75 4.5 5 025 025 -0.75 0.75 -2.25 1.25 -0.75 2.0 6 0 0.25 -0.25 0.5 -0.5 2.0 -0.75 2.75 7 -0.25 -0.25 -10 0.75 -1.5 1.5 -1.5 3.0 Abbreviations used: C.E. = control eye; S.E. = study eye. Light Irides +30 Dark Irides +2.0 +2.0 Study Eyes '"' 0-1-_==:==,.-'--------- +10 -10 Change in Pupil Size (mm) Study Eyes ~ 0t--====-====----- +10 Change in Pupil Size (mm) FIG. 2. Mean change in pupillary diameter (study and control eyes). Light irides group. -10 0 10 20 30 40 Time (minutes) FIG. 1. Mean change in pupillary diameter (study and control eyes). Dark irides group. o 10 20 30 Time (minutes) 40 , Clill Nellro-ophthalmol, Vol. 6, No.4, 1986 230 K. HEiTMAN AND D. D. BODE made, the random numbers were used to identify the patient, and tl1l:' data were recorded. In this way, the observer did not know which eye was the control, or whl,ther the photograph was pretreatment or .1 giwl1 time after drop instillation. RESULTS The subjects were divided into two groups consisting of those with durk irides and those with light irides (Tables I and 2). The data are presented as the change in pupillary size in millimeters from the baseline measurement over time, and compare the control and the study eyes for each participant. A minus sign indicates pupillary constriction. The mean change in pupillary diameter of the study and control eyes at each lO-min interval for the dark and light irides groups appears in Figs. 1 and 2, respectively. Those subjects with blue or green eyes dilated more rapidly in response to Paredrine than subjects with brown eyes, although there was no statistically significant difference by the Student t test between the two groups in the average amount of dilation achieved at 40 min. Thus, the mean dilation was 1.92 mOl for the dark irides group and 2.7 mOl for the light irides group. The control eyes for both groups showed progressive pupillary constriction with time that was statistically significant (p < 0.01) at 40 min when compared with baseline values. Thus, for dark FIG. 3. Photographs taken of patient with light irides (right eye = study eye). (a) Baseline; (b) 40 min after in-stillation of Paredrine. (b). THE PAREDRINL TLST IN NORMAL EYES 231 irides the mt:'an constriction was (l.St mm, and for light irides it was 0.8b mm. DISCUSSION Paredrine dilatl's the normal pupil by stimulating release of norepinephrine from ,111 int.Kt postganglionic s~'mpatht:'lic neuron. This nwch,lnism of action fl)rms tilt' basis for distinguishing between pre- and pl)stganglionic Hllrlwr's syndrome, since usualh' lllllv lesions l)l.yurring central to the superior cl'rvic,ll g,1I1glion vield llCldosympathetic paresis with an iris that is responsive to Paredrine (2-5). Our findings deml)nstrate objectively that, in the normal patient, 2.7 mm and 1.9 mm of pupillary dilation for light and darker irides, respectively, occur within -10 min after the addition of Paredrine. Thus, patients with lightly pigmented irides tended to respond more rapidly. On the other hand, patients with dark irides did achieve significant dilation in most cases. Interestingly, we found objectively that the con-tml eye constricted as pupillary dilation occurred in response to Paredrine in the contralateral eye (Fig. 3). This suggests that excess ambient light is dl'tected at the Edinger-Westphal nucleus, with a resulting dferent impulse for pupillary constriction. Only the control eye constricts, since the other has been treated with Paredrine. Acknowledgment: This work was supported in part by ,m unrl.'strictcd research grant from Research to Prevent Blindness, Inc. REFERENCES I. Friedman JR. Whiting OW. Kosmorsky CS, BurdI.' RM. The cocaine test in normal patients. Am I Opl1tl1almol 1984;98: 808-10. 2. Skarf B. Czarnecki JSC Distinguishing postganglionic from preganglionic lesions. Arch Ophthalmo/1982;100:1319-22. 3. Thompson HS. Mensher JH. Adrenergic mydriasis in Horner's syndrome. Am I OphthalnIO/1971;72:472-80. 4. Crimson BS, Thompson HS. Drug testing in Horner's syndrome. In: Claser JS, Smith JL, eds. Nellro-ophthalmology. 1'01.8.51. Louis: CV Mosby, 1975:265-70. 5. Maloney WF, Young BR: Moyer NJ. Evaluation of the causes and accuracy of pharmacologic localization in Horner's syndrome. Am I Ophthalmo/1980;90:394-402. JClill Nellro-ophthalmol. Vol. 6. No. ~, 1986 |
