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Show Journal of Clinical Neuro- ophthalmology 11( 3); 186- 189, 1991. The Clinical Significance of Tournay's Pupillary Phenomenon Terry A. Cox, M. D. and Francis C. H. Law, M. D. © 1991 Raven Press, Ltd., New York The act of lateral gaze in some normal individuals causes the pupil of the adducting eye to be smaller than that of the abducting eye. This phenomenon was described by Tournay more than 70 years ago, but it has generally been considered to have no clinical significance. We discuss two situations, episodic anisocoria and aberrant regeneration of the third nerve, in which Tournay's phenomenon should be considered by the clinician. We also describe familial occurrence of this interesting pupillary variant. Key Words: Pupil- Anisocoria- Aberrant regeneration- Oculomotor nerve. From the Departments of Ophthalmology, University of British Columbia, and Vancouver General Hospital, Vancouver, British Columbia. Presented at the 16th Annual North American NeuroOphthalmology Society Meeting, February 4- 8, 1990. Address correspondence and reprint requests to Dr. Cox, at Department of Ophthalmology, University of Utah Health Sciences Center, 50 North Medical Drive, Salt Lake City, UT 84132, US. A. 186 The phenomenon of anisocoria induced by lateral gaze was brought to the attention of the medical community by the French neurologist, Auguste Tournay, in 1917 ( 1). Tournay later acknowledged the priority of Gianelli ( 2), but the term " Tournay's phenomenon" has persisted in the literature. A number of articles were written about this finding during the first few years after its original description, but the study by Loewenfeld et al. ( 3) was the first to provide reliable data. They concluded that anisocoria induced by lateral gaze might be clinically detectable in about 10% of subjects, and that the phenomenon had no clinical significance. This latter opinion is reflected in major neuro- ophthalmic texts. We report two conditions in which the diagnosis of Tournay's phenomenon should be considered. Our first two cases presented with a complaint of episodic anisocoria, and our third case previously had a third nerve palsy. Our fourth case suggests that Tournay's phenomenon is inherited as an autosomal dominant characteristic. CASE REPORTS Case 1 A 21- year- old female student nurse was referred for evaluation of episodic anisocoria. She complained of intermittent dilatation of her right pupil during the three years prior to assessment. Periods of dilatation were variable, lasting hours to days. She had recently developed episodic right hemicranial headaches, but past medical history was otherwise unremarkable. Visual acuity was R E 20/ 15 and L E 20/ 20+ using no correction. The rest of the eye examination was entirely normal, with the exception of the pupils. There was anisocoria in the primary position in both room light and dim illumination. The anisocoria increased on gaze right and diminished on TOURNAY'S PUPILLARY PHENOMENON 187 gaze left ( Fig. 1). The pupils reacted briskly to light and near stimuli, and there were no segmental pareses of the sphincter on slit lamp examination. Case 2 A 7- year- old boy was referred for assessment of anisocoria. During the previous 6 months, his mother had noticed that the right pupil was occasionally much smaller than the left. He had asthma requiring periodic medical treatment, but use of medications did not correspond to periods of anisocoria. Visual acuity with a - 0.50 sphere was 20/ 20 in each eye. The rest of the eye examination was entirely normal, with the exception of the pupilS. There was mild anisocoria in the primary position in both room light and dim illumination. The anisocoria increased on gaze left to become much more noticeable, and diminished on gaze right ( Fig. 2). The pupils reacted briskly to light and near stimuli, and there were no segmental pareses of the sphincter on slit lamp examination. Review of old photographs taken during various positions of gaze showed that the anisocoria had been present since infancy. Case 3 A 17- year- old male sustained a closed head injury in a motor vehicle accident. When he regained consciousness he noticed oblique diplopia, particularly on gaze left. Examination at that time revealed a partial third nerve palsy on the left, affecting the inferior division. There was mild limitation of adduction and moderate limitation of depression of that eye, but no ptosis or problems with ocular elevation. In the primary position of gaze he had a 16- diopter left hypertropia and a 12- diopter exotropia. The left pupil was larger than the right- more so in bright light. When he returned 3 months later, he had only occasional diplopia. Examination revealed minimal left inferior rectus weakness. He was noted to have AG. 1. Case 1: Primary position ( top), right gaze ( middle), and lett gaze ( bottom). Pupil measurements were R E 5.4 mm, l E 4.8 mm ( top); R E 5.9 mm, l E 4.2 mm ( middle); and R E 5.2 mm, l E 5.5 mm ( bottom). All photos in this and subsequent cases were taken in room light. 1Clin Neuro- ophthalmol, Vol. 11, No. 3, 1991 188 T. A. COX AND F. C. H. LAW FIG. 2. Case 2: Primary position ( top) and left gaze ( bottom). Pupil measurements were R E 4.7 mm, L E 5.1 mm ( top); and R E 4.7 mm, L E 5.6 mm ( bottom). anisocoria on right gaze, with the left pupil being smaller than the right, and we considered the diagnosis of aberrant regeneration of the third nerve. However, the pupil reacted normally to light with no segmental paresis, and there was no segmental constriction during eye movements. Furthermore, the anisocoria reversed on gaze left ( Fig. 3). We discussed these findings with the patient's mother, and she stated that her pupils behaved similarly; she became Case 4. Case 4 This 37- year- old woman ( the mother of patient 3) had noted anisocoria on lateral gaze for many years. The eye examination was unremarkable with the exception of the pupillary responses. She had anisocoria in the primary position, increasing on gaze right and decreasing on gaze left ( Fig. 4). There was no induced myopia in the adducted left eye, suggesting that ciliary muscle was not involved in the phenomenon. DISCUSSION In his descriptions of anisocoria associated with lateral gaze, Tournay stated that the phenomenon was universally present. ( 1) Chenet and Noyer ( 4) came to the same conclusion after making clinical observations and performing a photographic study that consisted of photographing the two pupils independently in primary, right, and left gaze. In a more careful photographic analysis, Loewenfeld et al. ( 3) found that the Tournay phenomenon occured in a minority of normal subjects; they estimated that it would be apparent during clinical examination in a maximum of 10% of individuals, and they concluded that it is " a rare anomaly." The study by Sharpe and Glaser ( 5) supports this last assertion; using pupillography, they failed to detect Tournay's phenomenon in 25 normal subjects. We believe that the disagreement between the early clinical observations and the later photographic and pupillographic studies reflects earlier observer error rather than a result of differences in populations studied. The reader is invited to speculate on the mechanism of the Tournay phenomenon at leisure. We suspect that neuroanatomical studies will eventually demonstrate a projection from the medial rectus subnucleus to pupilloconstrictor neurons in the Edinger- Westphal and anteromedian nuclei of the midbrain. We agree with Loewenfeld et ai. ( 3) that other proposed mechanisms are unlikely. Episodic anisocoria is not a common complaint. Various etiologies have been established, including migraine, variations in simple anisocoria, intermittent Horner's syndrome, and others. In our first two cases the simple anisocoria in the primary position was not enough to attract attention; it was TOURNAY'S PUPILLARY PHENOMENON 189 ~- .. REFERENCES 1. Tournay A. Les lois de l'isocorie et de l'anisocorie normales. Corollaire et variations pathologiques. Bull Acad Natimzal Med 1917; 77: 680-- 1. 2. Giannelli A. Sulle modificazioni del diametro pupillare nei movimenti di lateralita dei bulbi oculari. Richerche Psichiat Neural Antrapal Filosa! IV 1907; 58: 433- 40. 3. Loewenfeld IE, Friedlaender RP, McKinnon PFM. Pupillary inequality associated with lateral gaze ( Tournay's phenomenon). Alii I OphtizalllloI1974; 78: 449--- 69. 4. Chenet L, Noyer A. Etude sur la reaction de Tournay. Arch OphtaI1921; 38: 336--- 65. 5. Sharpe jA, Glaser jS. Tournay's phenomenon- a reappraisal of anisocoria in lateral gaze. Alii I Ophthalmol 1974; 77: 250-- 5. 6. Schatz NJ, Savino Pj, Corbett JJ. Primary aberrant oculomotor regeneration. A sign of intracavernous meningioma. Arch Neural 1977; 34: 29- 32. 7. Cox TA, Wurster jB, Godfrey WA. Primary aberrant oculomotor regeneration due to intracranial aneurysm. Arch Neurol 1979; 36: 570-- 1. 8. Czarnecki jSC, Thompson HS. The iris sphincter in aberrant regeneration of the third nerve. Arch Ophtha/ mal 1978; 96: 1606- 10. phenomenon in mother and son suggests to us that this may be a dominantly inherited trait. We hope to gather more data to test this idea. Acknowledgment: Jean E. Cox translated the French articles. FIG. 4. Case 4: Primary position ( top), right gaze ( middle), and left gaze ( bottom). Pupil measurements were R E 6.4 mm, L E 6.1 mm ( top); R E 6.8 mm, L E 6.0 mm ( middle); and R E 6.1 mm, L E 6.0 mm ( bottom). FIG. 3. Case 3: Primary position ( top), right gaze ( middle), and left gaze ( bottom). Pupil measurements were R E 5.1 mm, L E 5.5 mm ( top); R E 5.4 mm, L E 4.6 mm ( middle); and R E 4.3 mm, L E 5.3 mm ( bottom). only during and immediately after eccentric gaze that the difference in pupillary size was noted. We suggest that Tournay's phenomenon should be sought in any patient with a similar presentation. Aberrant regeneration of the third nerve can be an important diagnosis to make. For example, the finding of aberrant regeneration after a presumed ischemic (" diabetic") third nerve palsy may mean that the initial diagnosis was wrong and an aneurysm was missed. In cases of aberrant regeneration with no preceding acute third nerve palsy ( primary aberrant oculomotor regeneration), a mass in the cavernous sinus is likely. ( 6,7) One of the signs of aberrant regeneration of the third nerve is pupillary constriction with eye movements, particularly with adduction. In cases where the only sign of aberrant regeneration is pupil involvement, Tournay's phenomenon should be considered. Generally the pupil in aberrant regeneration will show segmental reactivity during eye movements ( 8), and usually the response to light will be diminished. The finding of a clinically obvious Tournay's I Clin Neuro- ophthalmol, Vol. 11, No. 3. 1991 |
